System for Control and Treatment in a Well

This application claims priority to and the benefit of co-pending U.S. Provisional Application Ser. No. 63/653,536, filed May 30, 2024, the full disclosure of which is incorporated by reference herein in its entirety and for all purposes.

The present disclosure relates to wellbore operations, and more specifically to a system that controls devices in a well and provides treatment of the well.

Wells for extracting hydrocarbons from subterranean formations commonly include a string of production tubing deployed in the well for directing fluid to surface that is extracted from the formation. These wells are usually lined with casing, which is perforated at depths where the hydrocarbons are trapped within the formation. Packers are generally placed in an annulus between the tubing and casing proximate these depths to prevent the produced fluid from flowing uphole in the annulus. The fluid enters the production tubing through various types of valves, that include inflow control devices and inflow control valves. Gas lift valves are another type of valve that allow communication through the walls of the production tubing and between the annulus and production tubing bore. Gas lift valves are part of a gas lift system used for assisting with the production of liquid from inside a well having insufficient pressure to drive the liquid to surface. Gas lift systems inject lift into the annulus, and selectively inject the lift gas into a column of liquid in the tubing to reduce static head pressure in the column, so that the formation pressure is sufficient to push the liquid and other fluids inside the production tubing to surface.

Many oil and gas wells have production that can be aided with the addition of chemicals. Typical chemicals include foaming agents, corrosion inhibitors, viscosity reducers, and chemicals for generally improving production. Often these chemicals are added into the wells through a small diameter capillary tube that extends from the surface down to the injection point. When designing a chemical injection system, it is advisable that chemical level never drops below the surface into the capillary tube so that a void or vacuum to liquid interface does not form in the capillary tube. If there for any amount of time, many chemicals will evaporate and leave particulates. This in turn clogs the capillary tube and the system will no longer function. Check valves on a capillary tube exit are not fully effective since check valves cannot maintain a fluid column in the capillary tube when annulus pressure drops below hydrostatic pressure in the capillary tube, while relief valves increase injection pump head requirements and can leak over time. Maintaining a chemical level in the capillary tube is also important so that flowrates of chemical additive can be accurately monitored. Because chemical additives are usually costly, amounts of chemical additive injected is generally low; and if not accurately monitored well performance can be reduced.

Disclosed is an example of a well system for producing fluids from a wellbore that includes a tubular installed in the wellbore, a fluid line having an operating fluid, and a control system selectively changeable to a position in which operating fluid is routed to an injection port in the tubular and is selectively changeable to another position in which operating fluid is routed to a valve that is moveable in response to the operating fluid. The valve is optionally an inflow control valve (“ICV”). Embodiments of the tubular include a production string and wellbore casing. In examples the control system includes a directional valve having a body with multiple passages, in examples of which, moving the body into a first position directs operating fluid from the fluid line to move the ICV into an open configuration so that fluid in an annulus surrounding the production string flows into a bore in the production string. Optionally, the control system includes a surface controlled actuator connected to the directional valve and in an alternative, the ICV includes a sleeve that is slideable within the production string, and has an opening that selectively registers with an opening in the production tubing when in the open configuration. In embodiments, the body is selectively positioned so that operating fluid is directed to the injection port, in an alternative, the body is selectively positioned so that operating fluid in the fluid line is isolated from the injection port, and in another alternative, the body is selectively positioned so that operating fluid from the fluid line to move the valve into a closed configuration so that fluid in an annulus surrounding the production string is isolated from a bore in the production string. In one embodiment, a seal is in the directional valve that is energized by a compressive force exerted by the body. The well system optionally includes a pressure sensor in communication with the fluid line for use in one of diagnostic, verification, or positioning requirements.

Also disclosed is a method of operating a well that includes receiving an operating fluid in the well, treating the well by injecting the operating fluid into the well, and using the operating fluid for actuating a valve in the well. Examples of the operating fluid include a foaming agent, an anti-foaming agent, a biocide, a corrosion inhibitor, a scale inhibitor, an asphaltene inhibitor, an agent to prevent hydrate formation, an adsorbent, an emulsifier, an emulsion breaker, a viscosity reducer, any currently known or later developed agent injected into a well, and combinations. The valve optionally is an inflow control valve that is selectively changed into open and closed configurations by rerouting the operating fluid. The method further includes optionally operating a directional valve to reroute the operating fluid. In examples, the directional valve includes a spool with multiple passages formed within that move in and out of alignment with the fluid line by operating an actuator coupled with the spool. In an alternative, the method further includes automatically calibrating operation of the inflow control valve based on sensing conditions in the well. The method optionally further comprising using multiple stages each with a directional valve and flow control valve or a packer. The method alternatively further includes using multiple stages each with a directional valve and flow control valve or packer, and directing fluid into a single return line.

While subject matter is described in connection with embodiments disclosed herein, it will be understood that the scope of the present disclosure is not limited to any particular embodiment. On the contrary, it is intended to cover all alternatives, modifications, and equivalents thereof.

The method and system of the present disclosure will now be described more fully hereinafter with reference to the accompanying drawings in which embodiments are shown. The method and system of the present disclosure may be in many different forms and should not be construed as limited to the illustrated embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey its scope to those skilled in the art. Like numbers refer to like elements throughout. In an embodiment, usage of the term “about” includes +/−5% of a cited magnitude. In an embodiment, the term “substantially” includes +/−5% of a cited magnitude, comparison, or description. In an embodiment, usage of the term “generally” includes +/−10% of a cited magnitude.

It is to be further understood that the scope of the present disclosure is not limited to the exact details of construction, operation, exact materials, or embodiments shown and described, as modifications and equivalents will be apparent to one skilled in the art. In the drawings and specification, there have been disclosed illustrative embodiments and, although specific terms are employed, they are used in a generic and descriptive sense only and not for the purpose of limitation.

Shown in a side sectional view inis an example of a well system, which includes a production stringinstalled within a wellborethat intersects a subterranean formation. The wellboreis lined with casingthat has perforationsshown projecting radially outward from the wellboreinto the surrounding formation. In this example, the perforationsprovide a pathway for fluid F to flow into the wellborefrom the formation. In the example shown the fluid F is made up primarily of liquid with some small bubbles of gas G mixed within. A packercircumscribes a downhole end of stringto block the fluid F from flowing into an annulusbetween the stringand casing, and instead directs the fluid F to a borein the production tubing.

The well systemincludes a lift gas systemfor assisting the flow of the fluid F uphole within the boreof production tubing. An example of a lift gas sourceis shown on the surface, embodiments of which include an adjacent well, a pipeline, or a vessel. Lift gas sourceprovides lift gas, which is shown being injected into the wellborethrough an injection line. Lift gasinside injection lineis at a designated pressure so that the lift gasis forced downhole within annulusto a surface controlled flow control valve (“SCFCV”)shown mounted on an outer surface of the production tubing. SCFCVis intermittently opened to allow the lift gasinto the boreof production tubing, once in the bore, bubblesof lift gasare formed inside the fluid F. The lower density bubblesreduce the density of the fluid F to assist the flow of fluid F uphole inside boreand to a wellhead assemblyshown mounted over the wellboreand connected to an end of production tubing. Inside wellhead assembly, the fluid F is directed to a production lineshown attached to a lateral side of wellhead assembly. Inside production line, fluid F is carried to a location that is offsite for transportation or to a processing facility (not shown). In the example of, a controlleris schematically illustrated outside of wellboreand in signal communication with the SCFCVvia communication means. Examples of communication meansinclude electrically conducting wire, fiber optics, and wireless, such as telemetry. Further optionally included are sensorsthat are in temperature and pressure communication with annulusand/or bore, and which transmit downhole conditions to controllervia communication means. A specific example of SCFCVis what is commonly referred to as a gas lift valve, one example of which unit is described in Wygnanski, U.S. Pat. No. 8,925,638, and which is incorporated by reference herein its entirety and for all purposes.

Another example of a surface controlled flow control valveis shown in a side sectional view in. In this example, the valveis in a deviated or horizontal section of wellboreand mounted in a sidewall of the production string, and in a section of the stringhaving an eccentric portion. In an example shown, the valveoperates in response to command signals received that have been transmitted from surface via communication means. In response to the command signals, the SCFCVis moved into an opened and/or closed configuration to allow or block fluid communication between the annulusand bore. Specific examples of SCFCVinclude an interval control valve and/or a circulation valve.

Referring now to, shown in a side sectional view is an example of a production stringin the well, which includes a control subequipped with a control system. The production stringfurther includes production tubingconnected to ends of the control sub. In a non-limiting example, the structure and operation of production stringis the same or similar to that of stringof, and has an upper end in communication with wellhead assemblyand a lower end receiving fluid produced from the surrounding formation. A fluid lineis shown extending from surface into the welland with a lower end that connects into the sub. In the example ofan operating fluid is delivered into the wellthrough the fluid line. Embodiments of the operating fluid include a motive fluid for actuating devices downhole and a chemical injection or additive for insertion into the production string. Examples of the chemical injection or additive include a foaming agent (to maintain gas bubble size), an anti-foaming agent, a biocide, a corrosion inhibitor, a scale inhibitor, an asphaltene inhibitor, an agent to prevent hydrate formation, an adsorbent, an emulsifier, an emulsion breaker, a viscosity reducer, any currently known or later developed agent injected into a well, and combinations thereof. In this example, chemical injection or additive is from a chemical additive/injection source (not shown), examples of the chemical additive/injection source include a vessel, a pipeline, a tank, a truck, and the like. In this example, injecting the chemical injection or additive into the wellbore, such as into the annulusor the production string, is for treatment of the wellbore, casing, string, components within the string, and/or fluid within the wellboreor string. An example of chemical injection is found in Shaw, U.S. patent application Ser. No. 17/987,613, which is assigned to the assignee of the present application, and is incorporated by referenced herein in its entirety and for all purposes. Alternative, the operating fluid is a hydraulic fluid or other fluid useful for actuating devices in the well, such as by obtaining a mechanical advantage. Examples exist in which the operating fluid is pressurized, either on surface or by a downhole pump (not shown). Included with the control systemis a directional valveshown disposed in the suband connected to the end of the fluid line. Slidably disposed in subis a sleeve-like inflow control valve (“ICV”), which selectively provides communication between an annulussurrounding stringand boreof string. Directional valveincludes a surface controlled actuatorand spool valveshown coupled with an end of actuator. An injection lineconnects between directional valveand an injection portformed through a sidewall of production tubing. An optional check valveis provided in injection line. Control lines,are shown each having an end connected to the directional valve. Opposite ends of the lines,each connect to an annular cylinderformed in subwhere borehas an increased diameter. The ends of lines,connect to the cylinderat axially spaced apart locations. For the purposes of discussion herein, fluid line, lines,,, and valves,form a flow circuit. A mid-portion of ICVhas an increased diameter to define a pistonthat is slidable within cylinderbetween the locations where lines,connect to cylinder. Openings,are formed radially through ICVand sub, annulusand boreare in communication when the openings,are registered with one another.

Spool valveincludes a cylindrical spool(or spool body) within having a series of flow passages,,,formed at different axial locations in the spool. Spoolis slidable to different positions along an axial direction as depicted by arrow A. Selective positioning of the spool, such as by operating actuatorfrom surface, puts fluid linein communication with injection lineor lines,through passages,,,. In a non-limiting example of operation, the spoolis moved to a first position, which aligns an end of passagewith fluid line, aligns an opposite end of passagewith line, aligns an end of passagewith line, and aligns an opposite end of passagewith line. With spoolin the first position chemical injection fluid inside fluid lineis allowed to flow through passageand through lineinto cylinder. Directing pressurized chemical injection fluid into cylinderfrom lineapplies a force against pistonto urge ICVin a direction away from valveto register openings,and put ICVinto its open configuration. When openings,are in registration, annulusand boreare in communication with one another through the registered openings,so that fluid flows from within annulusinto boreof production string. The fluid is directed to surface once inside bore. With the valve spoolstill in the first position, fluid inside cylinder, such as chemical injection fluid or other fluid, is urged into line, through passage, into line, across injection port, and into bore. Further in this example, the spoolis selectively moved into a second position by operation of actuator. The configuration ofillustrates the valve spoolin the second position. In the second position, one end of passagealigns with fluid lineand an opposite end of passagealigns with line. In this configuration fluid lineand lineare in communication with one another through passage, which provides for direct introduction of chemical injection inside fluid lineinto bore. When the valve spoolis in the second position, lines,are in communication with one another via passage. Urging valve spooltowards actuatorfrom its second position to a third position (not shown) aligns an end of passagewith lineand an opposing end with line, which puts linein communication with linevia passage. When in the third position, opposing ends of passagealign with lineand line, but as a mid portion of passageis blocked, there is no communication between fluid lineand any of lines,,. Putting the valve spoolin the third position isolates lines,and cylinderfrom pressurized fluid in line, and removes pressurized fluid in lineas a source of a motive force to reposition ICV. Moving spoolfurther towards actuator from its third position to a fourth position aligns an end of passagewith fluid lineand an opposing end of passagewith lineand aligns an end of passagewith lineand an opposing end of passagewith line. When the valve spoolis in the fourth position, pressurized chemical injection fluid within fluid lineis flowable through passage, through line, and into cylinderon a side of pistonopposite valve. The pressurized fluid applies a force onto pistonurging ICVtowards valveto move ports,out of registration with one another and change ICVinto the closed configuration shown in. Moving the ICVinto the closed configuration while valve spoolis in the fourth position forces fluid in cylinderbetween pistonand valveinto line, through passage, into line, and then into borethrough injection port. An advantage of the present disclosure includes using a single fluids carrying line for controlling a downhole valve and also for injecting fluid downhole, which reduces the number of lines in a well. A further advantage is that selective repositioning of a single valve spoolcontrols operation of the ICVas well as fluid injection into the production string. In alternatives, fluid inside the flow circuitis a chemical injection fluid, a treatment fluid, a hydraulic fluid, or combinations. Further optionally, fluid inside circuitis replaced by a different fluid by providing the different fluid from surface in lineand at a pressure adequate to urge fluid within circuit through check valveand into bore. Fluid in linesand cylinderis replaced by selectively shifting the valve spoolinto the different positions.

Inis an embodiment of the production stringA in which communication between valveand check valveis via lineand line. An end of lineis in selective communication with passages in spooldepending on its positioning within valve. An opposite end of lineconnects to an end of line, which has an opposite end connecting to check valve. An optional sealis schematically represented at the connection between lines,. In alternatives sealis energized by stroking spoolof spool valveto a particular position or positions. Energizing sealforms a fluid flow barrier to injection fluid in linehaving leaked between spooland valve housing, so that the fluid does not flow into line. Some directional valves rely on a spool valve that uses close tolerance to resist flow rather than thermoplastic or elastomeric materials to provide a positive seal. In such cases, some fluid can leak over time. This does not pose a problem when pistons are actively being shifted. However, in some configurations it could allow fluid to slowly leak from the chemical injection line. In those situations, in which this becomes a problem, a valve with a positive seal can be added in series to the directional valve. This positive seal would block all flow and have a zero leak rate. In one embodiment, the zero leak valve would be placed at the end of the directional valve via a spring. When the end of the stroke is reached and communication is allowed between each side of the ICVand from lineto, further stroking the actuatorcould positively block flow to outlet. In another example, the zero leak valve could be placed between the actuatorand the spool valve. Stroking the directional valve spool and all the way to the right would provide an extra seal meant only to block the chemical flow in line. Depending on the directional valve details and seal designs, the separate zero leak valve may or may not be necessary.

In some cases. ICVhas flow characteristics that are adjustable and based on position. In this example, a pressure compensated constant flow device (not shown), such as the Flosert device that is commercially available from the Lee Company (https://www.theleeco.com/) is added to lineand/or lineto make the ICVmove at a constant rate. Then the change in position can be determined based on the amount of time the directional valveallows flow of the operating fluid. Optional locations for monitoring fluid pressure include when entering or leaving the directional or in the line—which would offer information such as when the valve is opened and when it reaches the end of the stroke. This in turn would provide the time to fully open the valve (essentially can be calibrated in place). To move a portion of that distance, the directional valve could be opened for a proportional amount of time. In alternatives, this analysis is conducted from the surface, which introduces a time delay in pressure changes downhole versus at the surface through long lengths of small diameter tubing. In examples, based on signals received from sensors, controller() calibrates internal commands and/or algorithms so that a shifting behavior of the ICVis adjusted. In examples, the calibration is automatic using one or more of conventional techniques, machine learning, and artificial intelligence.

In a non-limiting example of operation, pressure is monitored in one or more of lines,,, or any other relevant line in the circuit. This monitored pressure(s) is used to determine the length of time required to stroke the ICV, and that information is used for the purpose of positioning ICV. This can optionally be used in conjunction with the above mentioned Flosert pressure compensated constant flow device from the Lee Company. Pressure measurements in the various lines can also be used for diagnostic purposes.

Optionally, the operating fluid is not limited to a chemical injectant, and includes any other operating fluid or fluids. More than one stage can be utilized, for example, the techniques and systems disclosed herein are useful for controlling flow into tubing from one or more zones in a subterranean reservoir. In the example of multiple zones, a packer or other flow barrier is optionally employed between zones. Embodiments of these cases include one or more stages each with a directional valve and flow control valve, and in which flow from each zone is controlled using a single control line with an optional return line. This could also apply to gas or fluid injection into zones. Further optionally, circulation valves (not shown) are included for circulating out fluid after installation of a completion to a fluid of different weight or chemistry. After circulating out the fluid in flow circuit, the ICVcan be closed. Components of the flow circuitallow for a circulating fluid functionality as well as a surface controlled chemical injection. Yet another application of the production stringincludes setting a packer (not shown) using a common line. Hydraulic set packers typically utilize tubing pressure to set the packer, which presents difficulties from both a planning and operational perspective. From a planning perspective, all of the other equipment in the well is subjected to the packer setting and test pressures, and the tubing is plugged below the packer to build up pressure. From an operational perspective, there is little feedback as to whether or not a packer has set. The present disclosure allows a hydraulically set packer to be actuated with pressure from the same hydraulic (or chemical injection) line as the completion components in the well.

The present invention described herein, therefore, is well adapted to carry out the objects and attain the ends and advantages mentioned, as well as others inherent therein. While a presently preferred embodiment of the invention has been given for purposes of disclosure, numerous changes exist in the details of procedures for accomplishing the desired results. For example, the control system is useable on any tubular within a well, such as but not limited to wellbore casing, on valves other than ICV's, and any device in a well responsive to a pressurized fluid. These and other similar modifications will readily suggest themselves to those skilled in the art, and are intended to be encompassed within the spirit of the present invention disclosed herein and the scope of the appended claims.