Degradable Delivery Devices to Facilitate Dissolution of Degradable Downhole Tools

This application is a divisional of U.S. Non-Provisional application Ser. No. 18/760,437, filed Jul. 1, 2024, titled “DEGRADABLE DELIVERY DEVICES TO FACILITATE DISSOLUTION OF DEGRADABLE DOWNHOLE TOOLS,” now U.S. Pat. No. 12,258,830, issued Mar. 25, 2025, which claims priority to, and the benefit of U.S. Provisional Application No. 63/655,012, filed Jun. 2, 2024, titled “DEGRADABLE DELIVERY DEVICES TO FACILITATE DISSOLUTION OF DEGRADABLE DOWNHOLE TOOLS,” the disclosures of which are incorporated herein by reference in their entirety.

The present disclosure generally relates to degradable downhole tools and degradable delivery devices, as well as their methods of use in oil and gas operations. More specifically, the present disclosure relates to systems and methods for delivering chemical additives and/or flowable sensors into a wellbore to facilitate and/or monitor downhole tool dissolution treatment of degradable downhole tools, such as degradable frac plugs.

Modern oil and gas operations utilize a variety of downhole tools for drilling and completion of oil and gas wells, such as valves, liners, sleeves, nozzles, and plugs. For example, in a hydraulic fracturing (also known as “fracking”) operation, one or more hydraulic fracturing plugs (also known as “frac plugs”) may be used to fluidly isolate a section of a wellbore. Once isolated, the section of the wellbore may then be perforated, and hydraulic fluid and proppant pumped down the wellbore and into these perforations. Thereafter, the frac plug is removed from the wellbore to enable production of hydrocarbon. Traditionally, frac plugs are removed by a milling operation after fracking operations are complete. However, such milling operations require the use of additional downhole equipment and can result in the delay of hydrocarbon production, both of which undesirably increase the cost and complexity of well completion. Additionally, in certain cases, a frac plug may be disposed too far downhole to allow for milling equipment to be used to remove the frac plug.

One approach to resolving these issues involves the use of frac plugs that partially dissolve over time while in contact with wellbore fluids. However, because the chemical composition, temperature, and pressure of wellbore fluids can vary in different wells, it is difficult to accurately determine when such a frac plug will dissolve. For example, if a frac plug dissolves too soon, this can result in an undesirable loss of fluid isolation within the section of the wellbore being fracked, which may lead to unexpected delays and/or damage to the equipment and/or well. If a frac plug dissolves too late, then there can be undesirable delays in hydrocarbon production. Additionally, partial dissolution of such frac plugs results in undissolved fragments of the frac plug remaining within the wellbore fluid (also referred to as “mucking”), which can interfere with the normal operation of wellbore equipment (e.g., pumps, valves, etc.) and result in undesired stoppages and downtime, undesirably increasing cost and completion time.

To address the aforementioned problems, embodiments disclosed herein relate to degradable downhole tools, such as degradable frac plugs, that are used in combination with degradable delivery devices. Certain embodiments of the degradable delivery devices contain one or more chemical additives that, when released into the wellbore fluid, enhance or promote the dissolution of the degradable downhole tool. Certain embodiments of the degradable delivery devices additionally or alternatively contain one or more flowable sensors that, as is or upon release from the degradable delivery device, measure operational conditions of the treated reservoir section (e.g., pressure, temperature, pH, etc.) within the wellbore to monitor a downhole tool dissolution treatment. In some embodiments, one or more of the degradable delivery devices may be inserted into cavities of the degradable downhole tool prior to the tool being deployed in the wellbore and/or may be flowed into position near the deployed degradable downhole tool. Each degradable delivery device is designed to dissolve in the wellbore fluid to release the chemical additives and/or flowable sensors contained therein to promote the complete dissolution of the degradable downhole tool and/or monitor the downhole tool dissolution treatment process. Moreover, in some embodiments, the degradable delivery devices are designed to predictably dissolve within a predetermined time window to release the chemical additives and/or flowable sensors, and the degradable downhole tool is designed to predictably dissolve within a predetermined time window upon being exposed to the chemical additives. As such, the disclosed embodiments enable the complete dissolution of the degradable downhole tool in a predicable time window, obviating the need for complex and expensive milling operations and undesirable delays during oil and gas well completion.

One such embodiment of a system or apparatus is a degradable frac plug including a first cavity configured to receive a first degradable delivery device without mechanical or adhesive attachment to the degradable frac plug, the first degradable delivery device configured to dissolve in a wellbore fluid to release a first amount of a first one or more chemical additives that promote dissolution of the degradable frac plug. The degradable frac plug includes a second cavity configured to receive a second degradable delivery device without mechanical or adhesive attachment to the degradable frac plug, the second degradable delivery device configured to dissolve in the wellbore fluid to release a second amount of a second one or more chemical additives that further promote the dissolution of the degradable frac plug. In some embodiments, the first cavity is disposed above a sealing section of the degradable frac plug and the second cavity is disposed below the sealing section of the degradable frac plug when the degradable frac plug is deployed in a wellbore. In some embodiments, the first degradable delivery device is spherical and the second degradable delivery device is cylindrical. In some embodiments, the first degradable delivery device is disposed within the first cavity in a cone section of the degradable frac plug and the second degradable delivery device is disposed within the second cavity in a shoe extension of the degradable frac plug. In some embodiments, the degradable frac plug includes a degradable cover configured to mechanically couple to the shoe extension to cover the second cavity and maintain the second degradable delivery device within the second cavity after loading, the degradable cover configured to dissolve in the wellbore fluid such that the wellbore fluid reaches and dissolves the second degradable delivery device to release the second one or more chemical additives. In some embodiments, the degradable frac plug includes a metallic shoe connected to a metallic slip and a metallic cone, and the metallic slip and the metallic shoe contain a plurality of buttons, the plurality of buttons formed from a degradable metal, a degradable ceramic material, or a degradable polymeric material. In some embodiments, the first degradable delivery device, the second degradable delivery device, or both, contain one or more flowable sensors configured to detect temperature or pressure of the wellbore fluid.

Another such embodiment is a system having a wireline assembly including a wireline, one or more perforation guns, and a setting tool, the wireline assembly communicatively connected to a controller. The system includes a degradable frac plug removably connected to the setting tool of the wireline assembly. The degradable frac plug includes a first degradable delivery device disposed within a first cavity of the degradable frac plug without mechanical or adhesive attachment to the degradable frac plug, the first degradable delivery device configured to dissolve in a wellbore fluid to release a first amount of a first one or more chemical additives that promote dissolution of the degradable frac plug. The degradable frac plug includes a second degradable delivery device disposed within a second cavity of the degradable frac plug without mechanical or adhesive attachment to the degradable frac plug, the second degradable delivery device configured to dissolve in the wellbore fluid to release a second amount of a second one or more chemical additives that further promote the dissolution of the degradable frac plug, and the first degradable delivery device, the second degradable delivery device, or both, being configured to release one or more flowable sensors configured to measure a temperature, a pressure, or both, within a treated reservoir section during a treatment operation. The system also includes the controller having a processor configured to receive the measured temperature, the measured pressure, or both, determined by the one or more flowable sensors while monitoring operational conditions within the treated reservoir section during the treatment operation. In some embodiments, each flowable sensor of the one or more flowable sensors includes: a battery to power the flowable sensor; at least one sensing element configured to measure the temperature, the pressure, or both, within the treated reservoir section during the treatment operation; a memory configured to store the measured temperature, the measured pressure, or both; and an input/output (I/O) interface configured to provide the measured temperature, the measured pressure, or both, to the controller after the flowable sensor has been extracted from the treated reservoir section. In some embodiments, the controller is configured to adjust an operational parameter of a well associated with the treated reservoir section based at least in part on the measured temperature, the measured pressure, or both, determined by one or more flowable sensors.

Another such embodiment of a system or apparatus is a downhole tool dissolution treatment kit having a package containing a set of degradable delivery devices formed from one or more degradable materials that are configured to dissolve in a wellbore fluid, each degradable delivery device containing different types or different amounts of one or more chemical additives configured to promote dissolution of a degradable downhole tool, one or more flowable sensors configured to measure an operational condition within a wellbore, or a combination thereof. In some embodiments, the set of degradable delivery devices comprises a plurality of spherical degradable delivery devices, a plurality of cylindrical degradable delivery devices, or a combination thereof, each having a respective diameter ranging from about 5 centimeters (cm) to about 8 cm. In some embodiments, each degradable delivery device of the set of degradable delivery devices is formed from one or more degradable materials, the one or more degradable materials including magnesium alloys, zinc alloys, aluminum alloys, polylactic acid (PLA), or poly (glycolic acid) (PGA). In some embodiments, the one or more chemical additives comprise ammonium chloride (NHCl), sodium nitrite (NaNO), citric acid, acetic acid, sodium chloride (NaCl), calcium chloride (CaCl)), magnesium chloride (MgCl), potassium chloride (KCl), one or more oxidizers, one or more acids, one or more bases, or any combination thereof. In some embodiments, the operational condition comprises a temperature, a pressure, or a combination of temperature and pressure, within the wellbore. In some embodiments, the downhole tool dissolution treatment kit includes a set of instructions indicating which of the set of degradable delivery devices should be selected for a treatment operation based on a chemical composition of the degradable downhole tool, a chemical composition of the wellbore fluid, a target dissolution time to dissolve the degradable downhole tool, operational conditions within the wellbore to be measured during the treatment operation, or any combination thereof. In some embodiments, the downhole tool dissolution treatment kit includes a set of computer-implemented instructions configured to be executed by a processor of a local or remote computing system, wherein, when executing the set of computer-implemented instructions, the processor is configured to: receive input from an operator indicating an identity of the downhole tool dissolution treatment kit, a chemical composition of the degradable downhole tool, a chemical composition of the wellbore fluid, a target dissolution time to dissolve the degradable downhole tool, operational conditions within the wellbore to be measured during a treatment operation, or any combination thereof; determine, based on the received input, which of the set of degradable delivery devices of the downhole tool dissolution treatment kit should be selected for the treatment operation; and provide output to the operator indicating which of the set of degradable delivery devices should be selected from the downhole tool dissolution treatment kit for the treatment operation.

One such embodiment is a method that includes the steps of: determining a chemical composition of a degradable downhole tool; determining, based at least on the chemical composition of the degradable downhole tool, respective amounts of one or more chemical additives to effectively dissolve the degradable downhole tool within a wellbore; and preparing one or more degradable delivery devices containing the one or more chemical additives for use in dissolving the degradable downhole tool within the wellbore. In some embodiments, the method includes determining a chemical composition of a wellbore fluid, the respective amounts of the one or more chemical additives being determined based at least on the chemical composition of the degradable downhole tool and the chemical composition of the wellbore fluid. In some embodiments, the one or more chemical additives comprise ammonium chloride (NHCl), sodium nitrite (NaNO), citric acid, acetic acid, sodium chloride (NaCl), calcium chloride (CaCl)), magnesium chloride (MgCl), potassium chloride (KCl), one or more oxidizers, one or more acids, one or more bases, or any combination thereof. In some embodiments, the degradable downhole tool comprises a degradable frac plug, a degradable valve, a degradable liner, a degradable sleeve, a degradable nozzle. In some embodiments, the method includes determining a desired dissolution time to dissolve the degradable downhole tool, wherein the respective amounts of the one or more chemical additives are determined based at least on the chemical composition of the degradable downhole tool and the desired dissolution time. In some embodiments, preparing the one or more degradable delivery devices comprises: forming the one or more degradable delivery devices from one or more degradable materials configured to dissolve in a wellbore fluid; loading the one or more degradable delivery devices with the respective amounts of the one or more chemical additives; and scaling the one or more degradable delivery devices with the respective amounts of the one or more chemical additives loaded therein. In some embodiments, preparing the one or more degradable delivery devices comprises: loading one or more flowable sensors into the one or more degradable delivery devices prior to scaling the one or more degradable delivery devices, the one or more flowable sensors being configured to measure a temperature, a pressure, or a combination of temperature and pressure, within the wellbore. In some embodiments, preparing the one or more degradable delivery devices comprises selecting one or more pre-made degradable delivery devices from a downhole tool dissolution treatment kit, the one or more pre-made degradable delivery devices each containing the respective amounts of the one or more chemical additives. In some embodiments, the method includes disposing the one or more degradable delivery devices into one or more cavities of the degradable downhole tool before disposing the degradable downhole tool within the wellbore, the one or more degradable delivery devices being configured to dissolve in a wellbore fluid to release the one or more chemical additives to promote dissolution of the degradable downhole tool. In some embodiments, at least one of the one or more degradable delivery devices is not mechanically or adhesively attached to the degradable downhole tool. In some embodiments, the method includes flowing the one or more degradable delivery devices down the wellbore to reach the degradable downhole tool within the wellbore, wherein the one or more degradable delivery devices are configured to dissolve in a wellbore fluid to release the one or more chemical additives to promote dissolution of the degradable downhole tool. In some embodiments, the one or more degradable delivery devices comprise at least two degradable delivery devices each containing a different respective amount of the same chemical additive. In some embodiments, the one or more degradable delivery devices comprise at a first degradable delivery device containing a first chemical additive and a second degradable delivery device containing a second chemical additive.

Another such embodiment is a method that includes the steps of: loading a plurality of degradable delivery devices into a plurality of cavities of a degradable frac plug, each of the plurality of cavities configured to receive a respective degradable delivery device without mechanical or adhesive attachment to the respective degradable delivery device; setting the degradable frac plug within a wellbore; activating the degradable frac plug to isolate a section of the wellbore; forming perforations and hydraulically fracturing the isolated section of the wellbore; and allowing the plurality of degradable delivery devices to dissolve in a wellbore fluid to release one or more chemical additives contained therein to promote dissolution of the degradable frac plug in a predetermined amount of time and to release one or more flowable sensors configured to measure an operational parameter within the wellbore. In some embodiments, disposing the degradable frac plug within a wellbore comprises: connecting the degradable frac plug to a setting tool of a wireline assembly; lowering the degradable frac plug and the setting tool into the wellbore; and sending control signals to the setting tool via the wireline assembly to set the degradable frac plug within the wellbore. In some embodiments, the operational parameter comprises temperature, pressure, or a combination thereof. In some embodiments, the predetermined amount of time is less than 30 minutes. In some embodiments, activating the degradable frac plug comprises flowing a frac ball down the wellbore to reach the degradable frac plug within the wellbore and isolate the section of the wellbore. In some embodiments, the frac ball is an additional degradable delivery device that is configured to dissolve in the wellbore fluid to release an additional one or more chemical additives to promote the dissolution of the degradable frac plug, to release an additional one or more flowable sensors configured to measure the operational parameter within the wellbore, or a combination thereof. In some embodiments, a first degradable delivery device of the plurality of degradable delivery devices contains a first chemical additive configured to promote the dissolution of the degradable frac plug, a second degradable delivery device of the plurality of degradable delivery devices contains a flowable sensor configured to measure the operational parameter within the wellbore, and the frac ball contains a second chemical additive configured to further promote the dissolution of the degradable frac plug. In some embodiments, a first degradable delivery device of the plurality of degradable delivery devices contains a first chemical additive configured to promote the dissolution of the degradable frac plug, a second degradable delivery device of the plurality of degradable delivery devices contains a second chemical configured to further promote the dissolution of the degradable frac plug, and the frac ball contains a flowable sensor configured to measure the operational parameter within the wellbore. In some embodiments, activating the degradable frac plug comprises activating a ball-in-place feature of the degradable frac plug within the wellbore to isolate the section of the wellbore. In some embodiments, a first degradable delivery device of the plurality of degradable delivery devices contains a first chemical additive configured to promote the dissolution of the degradable frac plug, a second degradable delivery device of the plurality of degradable delivery devices contains a flowable sensor configured to measure the operational parameter within the wellbore. In some embodiments, a first degradable delivery device of the plurality of degradable delivery devices contains a first chemical additive configured to promote the dissolution of the degradable frac plug, a second degradable delivery device of the plurality of degradable delivery devices contains a second chemical additive configured to promote the dissolution of the degradable frac plug.

Aspects and advantages of these exemplary embodiments and other embodiments, are discussed in detail herein. Moreover, it is to be understood that both the foregoing information and the following detailed description provide merely illustrative examples of various aspects and embodiments, and are intended to provide an overview or framework for understanding the nature and character of the claimed aspects and embodiments. Accordingly, these and other objects, along with advantages and features of the present disclosure, will become apparent through reference to the following description and the accompanying drawings. Furthermore, it is to be understood that the features of the various embodiments described herein are not mutually exclusive and may exist in various combinations and permutations.

The present disclosure describes various embodiments related to systems and methods for facilitating completion of oil and gas wells. The description may use the phrases “in certain embodiments,” “in various embodiments,” “in an embodiment,” or “in embodiments,” which may each refer to one or more of the same or different embodiments. Furthermore, the terms “comprising,” “including,” “having,” and the like, as used with respect to embodiments of the present disclosure, are synonymous. The term “plurality” as used herein refers to two or more items or components. The terms “about” or “approximately” are defined as being close to as understood by one of ordinary skill in the art. In one non-limiting embodiment, these terms are defined to be within 10%, preferably within 5%, more preferably within 1%, and most preferably within 0.5%.

The terms “removing,” “removed,” “reducing,” “reduced,” or any variation thereof, when used in the claims and/or the specification includes any measurable decrease of one or more components in a mixture to achieve a desired result. The use of the words “a” or “an” when used in conjunction with any of the terms “comprising,” “including,” “containing,” or “having,” in the claims or the specification may mean “one,” but it is also consistent with the meaning of “one or more,” “at least one,” and “one or more than one.” The terms “wt. %”, “vol. %”, or “mol. %” refers to a weight, volume, or molar percentage of a component, respectively, based on the total weight, the total volume of material, or total moles, which includes the component. In a non-limiting example, 10 grams of component in 100 grams of the material is 10 wt. % of component.

are diagrammatic representations of an embodiment of an oil and gas wellat different stages of a hydraulic fracturing operation involving a degradable frac plug. The illustrated oil and gas wellincludes a wellborehaving a casingdisposed therein and coupled to a wellhead. While the illustrated wellboreincludes a substantially vertical section and a substantially horizontal section, for clarity, the term “above” is used to describe the relative position of a first component in the wellborethat is disposed closer to the wellheadthan a second component, while the term “below” is used to describe the relative position of a first component that is disposed in the wellborefarther from the wellheadand closer to a terminus or tocof the wellborethan a second component.

For the embodiment illustrated in, a wireline systemis being used to lower a wireline assemblyinto the wellbore. The wireline systemincludes a wireline anchorthat spools a wirelineto lower the wireline assemblyinto the wellbore. A controller(e.g., a controller of the wireline systemor another controller associated with the oil and gas well) is communicatively connected to the wirelineand the wireline anchorreceive operational data regarding the position and status of the wireline assembly, to provide suitable control signals to the wireline anchorto lower the wireline assemblyinto the wellbore, and to provide suitable control signals to operate the wireline assemblywithin the wellbore, as discussed below. While not illustrated infor simplicity, in some embodiments, the controllermay provide suitable control signals to other equipment (e.g., pumps, valves, other controllers) to cause hydraulic fluids to be pumped down the wellborealong with the wireline assemblyin order to flow the wireline assemblyinto a desired position in the wellbore.

For the embodiment illustrated in, the wireline assemblyincludes one or more perforation gunspositioned above a setting tool, which is in turn positioned above a degradable frac plug, when disposed within the wellbore. As such, the degradable frac plugis removably connected at the distal end of the wireline assembly. The setting toolis communicatively coupled to the controller via the wirelineto receive suitable control signals to explosively deploy the degradable frac plugonce the wireline assemblyis in the desired position, as discussed below. Additionally, the perforation gunsare communicatively connected to the controller via the wirelineto receive suitable control signals to explosively perforate portions of the casingafter the degradable frac plughas been deployed, as discussed below. For the illustrated embodiment, the degradable frac plugincludes two cavities, each loaded with a respective degradable delivery device, as discussed in greater detail below.

For the embodiment illustrated in, the wireline assemblyhas been lowered into the desired position within the wellboreto deploy the degradable frac plug. As such, the controllerprovides a suitable control signal to activate an explosive charge of the setting tool, which expands sections of the degradable frac plugto seal against the interior surfaces of the casing. After setting the degradable frac plug, it is separated from the remainder of the wireline assembly, such that the wireline assemblycan be raised out of the wellbore. While the wireline assemblyis positioned at various predetermined locations within the wellbore, the controllerprovides suitable control signals to activate explosive charges of the perforation gunsto perforate portions of the casingof the wellbore.

For the embodiment illustrated in, after the wireline assemblyhas been removed from the wellbore, the deployed degradable frac plugis activated by flowing a frac balldown the wellboreto reach a corresponding opening in the degradable frac plug, which fluidly isolates the section of the wellboreabove the degradable frac plugfrom other sections of the wellborepositioned below the degradable frac plug. In some embodiments, the deployed degradable frac plugmay be activated by a ball-in-place feature upon being deployed, which may obviate the need for the separate frac ball. In some embodiments, the frac ballis a degradable delivery device, as discussed in greater detail below. Once the section of the wellborehas been fluidly isolated, the controllermay provide suitable control signals to cause a hydraulic injection systemto activate suitable pumps, valves, and so forth, to inject hydraulic fluids and proppantinto the isolated section of the wellbore. The injected hydraulic fluids and proppant traverses the perforationsin the casingto hydraulically fracture the surrounding geological structures.

For the embodiment illustrated in, the degradable frac plugincludes two cavities, each loaded with a respective degradable delivery device. Additionally, as noted, in some embodiments, the frac ballmay also be a degradable delivery device. At least a portion of these degradable delivery devices are designed to deliver one or more chemical additives near the degradable frac plugto promote the dissolution of the degradable frac plug. In some embodiments, one or more of the degradable delivery devices additionally or alternatively are designed to deliver flowable sensors into the wellbore fluid that collect measurements (e.g., pressure, temperature, pH, among others) within the wellbore to monitor the dissolution of the degradable frac plug.

For the embodiment illustrated in, promoted by the one or more chemical additives delivered by one or more of the degradable delivery devices, the degradable frac plug has completely dissolved within the wellbore, removing the fluid isolation within the wellbore. The wellbore fluid is pumped to the wellhead, or is pressurized by the produced hydrocarbons, to the reach the wellhead. For the illustrated embodiment, flowable sensorsthat were released by at least one of the degradable delivery devices reach the surface, where they are collected by a flowable sensor analyzerthat is communicatively connected to the controller. The flowable sensor analyzerextracts the flowable sensorsfrom the wellbore fluid, and then extracts and provides to the controllerthe measurements collected by the flowable sensorsduring the dissolution of the degradable frac plug. Based on these measurements, the controllermay determine whether or not the degradable frac plugcompletely dissolved. If the controllerdetermines that the degradable frac plughas not completely dissolved, the controllermay provide recommendations of additional actions to be performed to further promote the dissolution of the degradable frac plug, as discussed in greater detail below.

is a diagrammatic representation of an embodiment of a methodof using a degradable frac plug during a hydraulic fracturing operation. The illustrated methodis provided as an example, and in other embodiments, the methodmay include repeated steps, omitted steps, or steps performed in other orders. In some embodiments, at least a portion of the methodmay be stored as computer-implemented instructions stored in a memory and executed by a processor of one or more controllers to facilitate or implement the hydraulic fracturing operation.

For the embodiment illustrated in, the methodbegins with the stepof loading one or more degradable delivery devices into one or more cavities of a degradable frac plug. For example, the one or more degradable delivery devices may be inserted into respective cavities of the degradable frac plug before or after the degradable frac plug has been attached to the setting tool of the wireline assembly, as discussed above, and before the wireline assembly is introduced into the wellbore. In some embodiments, the one or more degradable delivery devices may be preloaded into the degradable frac plug after manufacturing and before the degradable frac plug is delivered to the worksite. The degradable delivery devices are not directly mechanically or adhesively attached to the degradable frac plug, which may simplify and speed the loading of the one or more degradable delivery devices into the degradable frac plug. In some embodiments, at least two degradable delivery devices are loaded into at least two respective cavities of the degradable frac plug. Additionally, in certain embodiments, the cavities of the degradable frac plug are arranged such that at least one cavity is disposed above a sealing section and at least one cavity is disposed below the sealing section of the degradable frac plug. For such embodiments, this arrangement enables degradable delivery devices inserted into these cavities to advantageously deliver the one or more chemical additives on both sides of the sealing section of the degradable frac plug after deployment.

For the embodiment illustrated in, the methodcontinues with the stepof connecting the degradable frac plug to a setting tool of a wireline assembly. Once the wireline assembly has been lowered into and suitable positioned within the wellbore, the method continues with the stepof setting the degradable frac plug within the wellbore. For example, as discussed above, the controller provides suitable control signals to the setting tool of the wireline assembly via the wireline to deploy the degradable frac plug within the wellbore and to form perforations in the casing of the wellbore using the perforation guns of the wireline assembly.

For the embodiment illustrated in, after the degradable frac plug has been deployed within the wellbore and the perforations formed, the methodcontinues with the stepof activating the degradable frac plug to fluidly isolate a section of the wellbore. For example, as noted above, in some embodiments, a frac ball is flowed into position to seal against the deployed degradable frac plug and fluidly isolate the section of the wellbore above the degradable frac plug from the section(s) of the wellbore below the degradable frac plug. As noted, in some embodiments, the frac ball may also be a degradable delivery device, in addition to the one or more degradable delivery devices loaded into cavities of the degradable frac plug, and may contain one or more chemical additives to promote dissolution of the degradable frac plug, one or more flowable sensors to measure operational conditions in the wellbore while the degradable frac plug is being dissolved, or both. In some embodiments, instead of using a separate frac ball to activate the degradable frac plug, a ball-in-place feature of the frac plug may be used, which involves a degradable delivery device that is loaded into the degradable frac plug moving into position after the degradable frac plug has been deployed to fluidly isolate the section of the wellbore. The methodcontinues with the stepof pumping hydraulic fluid and proppant into the wellbore to hydraulically fracture the isolated section of the wellbore.

For the embodiment illustrated in, after the fluidly isolated section of the wellbore has been hydraulically fractured, the methodincludes the stepof allowing the degradable delivery devices to dissolve releasing one or more chemical additives to promote dissolution of the degradable frac plug, releasing one or more flowable sensors to measure one or more operational conditions within the treated reservoir section of the wellbore, or a combination thereof. As noted, the degradable delivery devices may include one or more degradable delivery devices loaded into cavities of the degradable frac plug, a frac ball degradable delivery device, or any combination thereof. As discussed in greater detail below, the degradable delivery devices include a container formed from a material that dissolves in the wellbore fluid to release the one or more chemical additives, the one or more flowable sensors, or a combination of chemical additives and flowable sensors. Moreover, the respective containers of the degradable delivery devices are designed to predicably dissolve in the wellbore fluid to release their respective contents in a first predetermined amount of time after being exposed to the wellbore fluid. The chemical additive(s) released into the wellbore fluid by one or more of the degradable delivery devices promotes (e.g., accelerates, enhances) the dissolution of the degradable frac plug in a second predetermined amount of time. The first predetermined amount of time can be tuned, for example, based on the material used to construct the container of each of the degradable delivery devices, the shape and dimensions of each of the degradable delivery devices, and the chemical composition of the wellbore fluid. The second predetermined amount of time can be tuned, for example, based on the one or more chemical additives delivered by the degradable delivery devices, the chemical composition of the degradable frac plug, and the chemical composition of the wellbore fluid. As such, based on the first and second predetermined amounts of time, the controller or an operator can predictably determine the total time window needed for the degradable frac plug to completely dissolve.

For the embodiment illustrated in, the methodincludes the stepof monitoring the operational conditions within the wellbore (e.g., within the treated reservoir section) and/or controlling operational parameters of the well based on the one or more operational conditions measured by the one or more flowable sensors. For example, as noted, in some embodiments, at least one of the degradable delivery devices includes one or more flowable sensors that, upon being released from the container of the degradable delivery device, collect measurements of operational conditions (e.g., pressure, temperature, pH, etc.) within the wellbore as the degradable frac plug is being dissolved. Once these flowable sensors are retrieved from the wellbore fluid at the surface, these measurements are collected and analyzed to determine whether the degradable frac plug was successfully dissolved. In some embodiments, these measurements are provided to the controller for analysis to determine if the complete dissolution of the degradable frac plug was successful within the predetermined time window. Responsive to the controller determining that the dissolution of the degradable frac plug was unsuccessful, the controller may modify operation of equipment associated with the well in response, in certain embodiments. In other embodiments, the controller may instead output recommendations to the operator regarding additional degradable delivery devices that can be flowed into position near the degradable frac plug to accelerate or complete the dissolution process. In some embodiments, the controller may collect the measurements from the flowable sensors, in addition to other parameters related to the dissolution treatment of the degradable frac plug, and use this data to update recommendations of degradable delivery devices, degradable frac plugs, and chemical additives to be used in future hydraulic fracturing operations.

are diagrammatic representations of an embodiment of a degradable frac plugfor use in combination with a frac ball. The illustrated degradable frac plugincludes a cone section, a scaling section, a slip section, and a shoe section. The cone sectionof the degradable frac plugis designed to connect to the wireline assembly during deployment. As such, once deployed, the cone sectionis disposed above the other sections of the degradable frac plug, and the shoe sectionis disposed below the other sections of the degradable frac plug, within the wellbore. During deployment, the setting tool of the wireline assembly receives a suitable control signal from the controller via the wireline to trigger an explosive charge that expands the slip section, such that a plurality of buttonsof the slip sectioncontact and engage the inner surface of the casing of the wellbore, and such that the sealing sectioncontacts and seals against the inner surface of the casing to restrict or prevent the flow of wellbore fluids in either direction. The degradable frac plugis manufactured from degradable materials that predictably dissolve in a predetermined time window once exposed to the one or more chemical additives contained by the degradable delivery devices. The degradable materials may include dissolvable metals (e.g., magnesium alloys, zinc alloys, aluminum alloys) and dissolvable polymers (e.g., polylactic acid (PLA), poly (glycolic acid) (PGA)). For example, in an embodiment, the degradable frac plugis predominantly formed from one or more dissolvable metals, while the buttonsand/or the scaling sectionof the degradable frac plugare formed from a dissolvable polymer. In various embodiments, the buttonsmay be formed from a degradable metal, a degradable ceramic material, or a degradable polymer. It is noted that, for various fracking operations, it may be desirable for the degradable frac plugto remain intact and maintain fluid isolation for minutes (e.g., 30 minutes), hours, days, or even weeks after deployment. For example, in some embodiments, it may be desirable for the degradable frac plugto remain intact and maintain fluid isolation for between 30 minutes and 30 days, while in other embodiments, it may be desirable for the degradable frac plugto remain intact and maintain fluid isolation for between 3 and 24 hours.

As illustrated in, the illustrated embodiment of the degradable frac plugis activated by a frac ballthat is suitably sized to become lodged or sealed in the cone sectionof the degradable frac plugto block or prevent the flow of wellbore fluids through the interior of the degradable frac plug. As noted, in some embodiments, the frac ballmay be a degradable delivery device containing one or more chemical additives to promote the dissolution of the degradable frac plugand/or one or more flowable sensors to measure operational conditions within the wellbore during the dissolution of the degradable frac plug. As discussed below, in some embodiments, such a frac ball degradable delivery device can be used in combination with other degradable delivery devices disposed within cavities of the degradable frac plug.

is a diagrammatic representation of another embodiment of a degradable frac plug. The illustrated degradable frac plugincludes a cone section, a sealing section, a slip section, and a shoe section, as discussed above. Unlike the embodiment of the degradable frac plugillustrated in, the embodiment of the degradable frac plugillustrated inincludes a ball-in-place feature that blocks or prevents the flow of wellbore fluids through the interior of the degradable frac plugonce deployed. For the embodiment illustrated in, the setting mandrelis still coupled to the degradable frac plugto facilitate its deployment within the wellbore. Once the setting mandrelhas expanded the degradable frac plugand is removed from the deployed frac plug, a degradable delivery devicethat is loaded into an interior cavitydefined within the cone sectionof the degradable frac plugis designed act as the ball-in-place feature, which flows into position against an opening of the internal passage of the degradable frac plugto block or prevent the flow of wellbore fluids through the interior of the frac plug. The internal cavityand the degradable delivery deviceare positioned above the sealing sectionof the degradable frac plugwhen the frac plug is deployed within the wellbore. As such, the ball-in-place feature of the degradable frac plugillustrated inobviates the need for the separate frac ballused by the degradable frac plugofto block or prevent the flow of wellbore fluids through the interior of the frac plug.

In some embodiments, the degradable frac plug may additionally or alternatively include one or more cavities disposed in one or more shoe extensions disposed below the sealing section of the degradable frac plug when the degradable frac plug is deployed within the wellbore.are diagrammatic representations of an embodiment of a shoe extensionof a degradable frac plug. As discussed below, one or more shoe extensionscan be mechanically attached to the shoe section,of the degradable frac plug. The illustrated shoe extensionsdefine a cylindrical internal cavitythat is loaded with a cylindrical degradable delivery device. While the cylindrical degradable delivery deviceis not directly mechanically or adhesively attached to the shoe extension, a coveris disposed over the opening of the cylindrical internal cavityafter the cylindrical degradable delivery devicehas been loaded, and a plurality of screwsare used to mechanically attach the coverto the shoe extensionto maintain the cylindrical degradable delivery devicewithin the internal cavityprior to and during deployment of the degradable frac plug. In some embodiments, the cover, the screws, or both, are formed from a degradable material having a composition and/or dimensions that are more readily dissolved in the wellbore fluid, which enables the wellbore fluid to readily dissolve the cover, the screws, or both, to reach and dissolve the cylindrical degradable delivery device. As discussed below, any number of shoe extensionscan be connected to the distal end of the degradable frac plug, each delivering a respective degradable delivery devicebelow the sealing section,of the degradable frac plug,.

As illustrated in, in some embodiments, multiple degradable delivery devices can be used to deliver one or more chemical additives to facilitate dissolution of the degradable frac plug and/or to deliver one or more flowable sensors to measure operational conditions in the wellbore during dissolution of the degradable frac plug. In particular,is a diagrammatic representation of an embodiment of a degradable frac plugfor use in combination with a frac ballthat is a first degradable delivery device positioned above the sealing sectionof the degradable frac plugwithin the wellbore. In addition, the degradable frac plugillustrated inalso includes a second degradable delivery devicepositioned in the internal cavityof the shoe extensionbelow the sealing sectionof the degradable frac plug.

is a diagrammatic representation of an embodiment of a degradable frac plugfor use in combination with a frac ballthat is a first degradable delivery device positioned above the sealing sectionof the degradable frac plugwithin the wellbore. In addition, the degradable frac plugillustrated inalso includes a second degradable delivery deviceA positioned in an internal cavityA of a first shoe extensionA, as well as a third degradable delivery deviceB positioned in an internal cavityB of a second shoe extensionB, such that the second degradable delivery deviceA and the third degradable delivery deviceB are positioned below the sealing sectionof the degradable frac plug.

is a diagrammatic representation of an embodiment of a degradable frac plughaving a ball-in-place feature, as discussed above. The illustrated degradable frac plugincludes a first degradable delivery device(e.g., the ball-in-place) positioned in an internal cavitywithin the cone sectionof the degradable frac plugabove the sealing sectionof the degradable frac plugwhen deployed within the wellbore. Additionally, the illustrated degradable frac plugincludes a second degradable delivery deviceA positioned in an internal cavityA of a first shoe extensionA, and a third degradable delivery deviceB positioned in an internal cavityB of a second shoe extensionB, according to an embodiment, such that the second degradable delivery deviceA and the third degradable delivery deviceB are positioned below the sealing sectionof the degradable frac plug.

As mentioned, embodiments of the degradable frac plug that include at least one degradable delivery device on each side of (i.e., above and below) the scaling section,of the deployed frac plug within the wellbore enhance the effectiveness and flexibility of the disclosed approach. As noted, once the degradable frac plug is deployed and activated, the scaling section,(in addition to the frac ball or ball-in-place feature) of the degradable frac plug blocks or prevents the exchange of fluids above and below the scaling section. As such, when a degradable delivery device is only disposed above or below the sealing section,, the one or more chemical additives released from the degradable delivery device must degrade the sealing section first before they are able to contact and promote dissolution of the opposite end of the degradable frac plug. In contrast, embodiments that include at least one degradable delivery device on each side of the scaling section,are able to release the one or more chemical additives and immediately contact and begin promoting dissolution of both ends of the degradable frac plug, decreasing the time window required for the degradable frac plug to completely dissolve.

For embodiments in which one or more of the degradable delivery devices include flowable sensors, it may also be advantageous to have degradable delivery devices disposed on one or both sides of the scaling section,. For example, flowable sensors may be released by one or more degradable delivery devices positioned above the sealing section of the degradable frac plug, and because the released flowable sensors have a clear flow path to reach the surface even before the degradable frac plug has dissolved, detection of these flowable sensor may provide an indication that the dissolution of the degradable frac plug has commenced. For embodiments in which flowable sensors are released by one or more degradable delivery devices positioned below the scaling section of the degradable frac plug, the flowable sensors are unable to traverse the portion of the wellbore occupied by the degradable frac plug until after the sealing section has been sufficiently dissolved to disrupt the fluid isolation. As such, detection of these flowable sensor may provide an indication that the dissolution of the degradable frac plug is complete or has at least progressed to the point that fluid isolation has been disrupted.

are cross-sectional diagrammatic representations of an embodiment of a degradable delivery device. More specifically,respectively depict a first segmentand a second segmentof a containerof the degradable delivery device, whiledepicts the assembled containerof the degradable delivery device. In some embodiments, the first segmentand the second segmentcan be coupled together using any suitable connection mechanism. For example, in some embodiments, the first segmentand the second segmentmay each include respective threads or another suitable connection mechanism, and the segments may be connected to one another by screwing the treads or mating another suitable connection mechanism to form a complete seal. The first segmentand a second segmentof the containerare generally hemispherical in shape and each define a hemispherical cavity. When combined, the first segmentand a second segmentof the containerform generally spherical degradable delivery devicehaving a spherical cavitydefined therein. It may be appreciated that the spherical degradable delivery deviceis merely illustrated as an example, and in other embodiments, the degradable delivery devicemay have other shapes, such as a disk shape, a cylindrical shape, an oblong shape, among others. In some embodiments, the degradable delivery devicehas a diameter from about 2 inches (in) or about 5.1 centimeters (cm) to about 3 inches or about 7.6 cm; however, other sizes may be used in other embodiments. The containerof the degradable delivery deviceis made of one or more degradable materials. The degradable materials may include dissolvable metals (e.g., magnesium alloys, zinc alloys, aluminum alloys) and dissolvable polymers (e.g., polylactic acid (PLA), poly (glycolic acid) (PGA)).

For the embodiment illustrated in, the first segmentand a second segmentof the containereach include corresponding connection featuresdesigned to connect in a mating correspondence (e.g., screwing together corresponding threads or any other suitable mechanism to form a seal) to form the degradable delivery device. More specifically, as illustrated in, an exterior surfaceof the first segmentof the containerdefines a first annular groovethat is radially disposed about the axis. The first annular grooveof the first segmentof the containerdefines a region of minimal thickness of the first segmentof the container. Additionally, the exterior surfaceof the first segmentof the containerdefines a first shoulder regionradially disposed about the axisand adjacent to the annular groove. The thickness of the first segmentof the containerin the shoulder regionincreases slightly compared to its thickness within the annular groove. As illustrated in, the interior surfaceof the second segmentof the containerdefines a second annular groovethat is radially disposed about the axis. The second annular grooveof the second segmentof the containerdefines a region of minimal thickness of the second segmentof the container. Additionally, the interior surfaceof the second segmentof the containerdefines a second shoulder regionradially disposed about the axisand adjacent to the second annular groove.

Accordingly, for the embodiment illustrated in, the containerof the degradable delivery deviceis formed by connecting the corresponding connection featuresof the first and second segments,. For example, the first shoulder regionof the first segmentmay be inserted into the second annular grooveof the second segment, while the second shoulder regionof the second segmentmay be inserted into the first annular grooveof the first segment, securing the two segments of the containertogether. This embodiment merely provides one example of constructing the degradable delivery device, and in other embodiments, other connection features(e.g., threads, pins, screws, etc.) may be used to connect together container segments. In some embodiments, welding and/or adhesives may be used to connect and secure the container segments,together.

One or more chemical additivesand/or one or more flowable sensorsmay be loaded into the hemispherical cavityof one or both of the first segmentand the second segmentof the containerprior to connecting the two segments together to form the degradable delivery device. In other embodiments, one or both of the segments,of the containermay include a fill portthat enables one or more chemical additives to be flowed into the spherical cavityof the degradable delivery deviceafter connecting the two segments together to form the degradable delivery device. For such embodiments, after the fill porthas been used to deliver one or more chemical additives into the spherical cavityof the degradable delivery device, the fill portmay be sealed mechanically (e.g., using a screw or pin), adhesively (e.g., using a polymer or elastomer), or by applying a weld bead to cover the exterior opening of the fill port. In some embodiments, one or more elastomer or polymer seals may be inserted between the container segments (e.g., within the first annular groove, within the second annular grooves, or both) to retain the contents of the degradable delivery devicewithin the cavityuntil the containerat least partially dissolved in the wellbore fluid.

As discussed below, the one or more chemical additivesmay vary depending on a number of factors, including the chemical composition of the degradable downhole tool and the chemical composition of the wellbore fluid. In general, chemical additivesmay include salts (e.g., chloride salts), oxidizers, acids, and/or bases (e.g., alkali chemicals). A non-limiting list of example chemical additives includes, but is not limited to: ammonium chloride (NHCl), sodium nitrite (NaNO), citric acid, acetic acid, sodium chloride (NaCl), calcium chloride (CaCl)), magnesium chloride (MgCl), potassium chloride (KCl), or any combination thereof. The one or more chemical additivesmay be solid (e.g., powders, crystals), liquid, or a mixture of solids and liquid (e.g., a solution or suspension). It may be appreciated that certain chemical additives may degrade flowable sensors, and as such, the flowable sensorsmay be advantageously delivered using a separate degradable delivery device, in some embodiments.

is a diagrammatic representation of an embodiment of a flowable sensorthat is delivered into the wellbore using a degradable delivery device. While a housingof the illustrated flowable sensoris spherical, in other embodiments, the flowable sensormay have other shapes, such as a disk shape, a cylindrical shape, an oblong shape, among others, that promote low-resistance movement through the wellbore. The housingis formed from a material that is not degradable or dissolvable within the wellbore fluid. In some embodiments, the housingof the flowable sensoris made of a magnetic metal, and a magnetic field may be applied to wellbore fluids that reach the surface to magnetically retrieve the flowable sensorfrom the wellbore fluid. In some embodiments, the flowable sensormay be made of lower density components or may include an internal air pocket that renders the flowable sensorbuoyant within the wellbore fluid, and this buoyancy causes the flowable sensorto rise within a vessel that receives the wellbore fluid to facilitate their recovery (e.g., via a skimming technique).

For the embodiment illustrated in, the flowable sensorincludes a batterythat provides power to operate the flowable sensor. For example, the batterymay have a suitable capacity to remain in a charged state for weeks to months prior to the flowable sensorbeing deployed and have a suitable capacity to operate the flowable sensorfor hours to days once released from the degradable delivery device. In some embodiments, the flowable sensormay support wireless charging of the battery. The flowable sensorincludes at least one processorand at least one memory. The processormay be a low-power or application specific processor that executes instructions stored in the memoryto enable operation of the flowable sensor. In addition to instructions, the memorystores measurements of operational conditions in the wellbore measured by one or more sensing elementsof the flowable sensorduring operation. Furthermore, for embodiments in which multiple degradable delivery devices contain respective flowable sensors, the memorystores an identifier that indicates which degradable delivery device released the flowable sensor. In some embodiments, the one or more sensing elementsmay include a temperature sensor that measures the temperature of the wellbore fluid, a pressure sensor that measures the pressure of the wellbore fluid, and/or a pH sensor that measures the pH of the wellbore fluid, once the flowable sensor is released from the degradable delivery device. The measurements collected by the one or more sensing elementsmay be stored in the memoryalong with timestamps indicating when each measurement was taken. In some embodiments, the sensing elementsmay include an accelerometer that detects acceleration of the flowable sensor, and this data may be stored with the other collected measurements and timestamps to enable the controllerto determine or estimate the movement of the flowable sensorover time and/or the position of the flowable sensor when each of the measurements were collected. In some embodiments, the one or more sensing elements or another component (e.g., an activation element) may delay activation of the flowable sensor until after it contacts the wellbore fluid, indicating it has been released from the degradable delivery device.

For the embodiment illustrated in, the flowable sensoralso includes an input/output (I/O) interfacethat enables the flowable sensorto communicate with an external computing system (e.g., the controller). In some embodiments, the I/O interfaceenables wireless communication via a radio-frequency or optical communication channel. For example, in some embodiments, the I/O interfaceenables measurements to be received from the flowable sensorvia WiFi®, Bluetooth®, or another wireless communication protocol. In some embodiments, the I/O interfaceenables measurements to be received from the flowable sensorvia a wired connection. For example, the flowable sensormay include one or more ports, which may include one or more ports for charging the batteryand/or receiving measurements collected by the flowable sensorduring operation. For embodiments that include the one or more ports, a suitable polymeric or elastomeric cover may be placed over the portsto prevent entry of the wellbore fluids during operation.

In some situations, it may be desirable to provide a set of degradable delivery devices that can be used in combination with degradable downhole tools (e.g., a degradable frac plug), which enables an operator to select one or more degradable delivery devices for a downhole dissolution treatment of the degradable downhole tool based on different factors. For example,is a diagrammatic representation of an embodiment of a downhole tool dissolution treatment kitthat includes a packagingcontaining a set of degradable delivery devices(e.g., degradable delivery devicesA-L). The packagingdefines a plurality of slots, each containing a respective degradable delivery device. Each of the slotsor each degradable delivery device is labeled, marked, or colored to indicate a respective identity of each degradable delivery device. In some embodiments, the identity of each degradable delivery device corresponds to the dimensions and chemical composition of the container the degradable device, as well as the one or more chemical additives, the one or more flowable sensors, or the combination of one or more chemical additives and one or more flowable sensors contained within each degradable delivery device. In some embodiments, each degradable delivery device of the downhole tool dissolution treatment kitcontains a unique combination of the one or more chemical additives, the one or more flowable sensors, or both. In other embodiments, two or more of the degradable delivery devices contain the same one or more chemical additives loaded in the same or different amounts, the same one or more flowable sensors, or both. As such, the downhole tool dissolution treatment kitenables an operator to select one or more of the degradable delivery devices to be used to promote dissolution of the degradable downhole tool, to monitor operational conditions in the treated reservoir section during the dissolution treatment, or both, based on one or more factors specific to the downhole tool dissolution treatment.

For the embodiment illustrated in, the downhole tool dissolution treatment kitincludes or refers to instructions to guide the operator in selecting suitable degradable delivery devices for a downhole tool dissolution treatment. For example, in some embodiments, these instructions include printed instructionsthat indicate which degradable delivery devices should be selected based on one or more factors specific to the dissolution treatment. Additionally or alternatively, in some embodiments, the downhole tool dissolution treatment kitincludes a website link or a quick response (QR) codethat can be accessed by a suitable computing device. Using either the printed instructionsor the website link/QR code, the operator can use one or more factors specific to the dissolution treatment to identify suitable degradable delivery devices for the downhole tool dissolution treatment. A non-limiting list of example factors specific to the downhole tool dissolution treatment include, but are not limited to: a temperature of the wellbore fluid near the downhole tool, a pressure of the wellbore near the downhole tool, a chemical composition of the downhole tool, a mode of activation (e.g., frac ball or ball-in-place) of the downhole tool, a chemical composition of the wellbore fluid, a desired dissolution time for the downhole tool, and one or more operational conditions within the wellbore to be measured during the treatment operation. In some embodiments, the operator may utilize information related to one or more of these factors to identify one or more suitable degradable delivery devices from the downhole tool dissolution treatment kitusing a lookup table contained within the printed instructions. In some embodiments, the operator may provide information related to one or more of these factors as input to a website accessed via the website link/QR code, and in response, receive recommendations of one or more suitable degradable delivery devices to be used in the downhole tool dissolution treatment.

is a diagrammatic representation of an embodiment of a methodof designing a downhole tool dissolution treatment that utilizes one or more degradable delivery devices. The illustrated methodis provided as an example, and in other embodiments, the methodmay include repeated steps, omitted steps, or steps performed in other orders. In some embodiments, at least a portion of the methodmay be stored as computer-implemented instructions stored in a memory and executed by a processor of one or more controllers to facilitate design and/or implementation of the downhole tool dissolution treatment.

For the embodiment illustrated in, the methodbegins with the stepof determining information about the treatment operation, such as the chemical composition of the degradable downhole tool, the chemical composition of the wellbore fluids, a target dissolution time to dissolve the degradable downhole tool, one or more operational conditions within the wellbore to be measured during the treatment operation, which degradable delivery devices or downhole tool dissolution treatment kits are available for use at the worksite, and/or other relevant treatment information. In certain embodiments, some or all of the information about the treatment operation may be determined or provided by the operator. In other embodiments, at least a portion of the information about the treatment operation may be determined by the controller, based on inputs provided by the operator and/or based on measurements performed by other sensors associated with the well. For example, in some embodiments, certain information about the treatment (e.g., chemical composition of the wellbore fluid, pressure, temperature) may be determined from measurements collected by sensors (e.g., chemical analysis sensors, pressure sensors, temperature sensors) associated with the well.

For the embodiment illustrated in, the methodcontinues with the stepof determining, based on the information about the treatment operation, the respective amounts of one or more chemical additives to effectively dissolve the degradable downhole tool in the wellbore, one or more flowable sensors capable of measuring the one or more operational conditions within the wellbore, or a combination thereof. For example, based on the information about the treatment operation, the operator or controller may determine respective amounts of one or more chemical additives that will effectively dissolve the degradable downhole tool within the chemical and physical conditions present within the wellbore within a predetermined amount of time. Additionally, based on the information about the treatment operation, the operator or controller may determine which flowable sensors are suitable to measure the one or more operational conditions within the wellbore during the downhole tool dissolution treatment.

For the embodiment illustrated in, the methodcontinues with the stepof manufacturing one or more degradable delivery devices, or selecting one or more pre-made degradable delivery device from a downhole tool dissolution treatment kit, containing the respective amounts of the one or more chemical additives, the one or more flowable sensors, or a combination thereof. For example, in some embodiments, the containers of one or more degradable delivery devices may be constructed and loaded, as discussed above, with the respective amounts of the one or more chemical additives and/or the one or more flowable sensors (as determined in step) just prior to deployment. This approach advantageously enables the one or more chemical additives to be stored separately from one another and separate from the container of the degradable delivery devices, until just prior to deployment, which may prevent premature reaction or degradation of the chemical additives and/or the container of the degradable delivery devices prior to deployment. This approach may further enable the one or more flowable sensors, when present, to be accessible for testing and charging until just prior to deployment, ensuring that the flowable sensors have adequate battery power before being deployed. However, in some cases, the worksite may not have the proper equipment or personnel to assemble the degradable delivery devices onsite. For such cases, the operator or controller may instead select one or more pre-made degradable delivery devices from a downhole tool dissolution treatment kit that are pre-loaded with the respective amounts of the one or more chemical additives, the one or more flowable sensors, or both, which desirably reduces the equipment, personnel, and/or time required to prepare the degradable delivery devices for deployment.

For the embodiment illustrated in, the methodconcludes with the stepof using the one or more degradable delivery devices to deliver the one or more chemical additives to the degradable downhole tool within the wellbore to promote dissolution of the degradable downhole tool, to deliver the one or more flowable sensors to measure the one or more operational conditions within the wellbore during the treatment operation, or a combination thereof. For example, deploying the degradable delivery devices may include loading one or more degradable delivery devices into respective cavities of the downhole tool prior to deployment within the wellbore. In some embodiments, deploying the degradable delivery devices may include flowing a frac ball that is a degradable delivery device into position against a deployed degradable frac plug. In certain embodiments, deploying the degradable delivery devices may include loading one or more degradable delivery devices into respective cavities of the downhole tool prior to deployment within the wellbore and also flowing a frac ball that is a degradable delivery device into position against a deployed degradable frac plug. For example, in some embodiments, one or more degradable delivery devices are deployed above at least a portion (e.g., a scaling section) of the degradable downhole tool, and one or more degradable delivery devices are deployed below at least a portion (e.g., a scaling section) of the degradable downhole tool within the wellbore.