Providing Lost Circulation Material to Cure Fluid Losses in a Well

This application is a divisional of and claims priority to U.S. patent application Ser. No. 18/455,348, filed on Aug. 24, 2023, the entire contents of which are incorporated by reference herein.

This disclosure relates to systems and methods for providing a lost circulation material (LCM) to a reservoir.

During drilling operations, a drilling fluid may be “lost” to the formation due to instability or other issues with the formation that surrounds the wellbore. In some cases, a lost circulation material (LCM) is added to the drilling fluid to help stop the loss of drilling fluid to the formation. Reducing or stopping fluid losses during the drilling operations can enhance drilling practices and minimize any risk associated to well control or hole instability and also reduce any additional cost spent while controlling the fluid losses.

In an example implementation, a method includes drilling at least a portion of a wellbore from a terranean surface toward a subterranean formation by rotating a drill bit on a drill string; while drilling the portion of the wellbore, circulating a drilling fluid downhole through the drill string, to and through the drill bit, into the wellbore, and uphole toward the terranean surface; determining that at least a portion of the drilling fluid circulated into the wellbore is lost to the subterranean formation and does not circulate uphole toward the terranean surface; based on the determination, circulating a plurality of lost circulation material (LCM) pills in an inactive state through the drill string and the drill bit and into the wellbore, each of the LCM pills set to adjust from the inactive state to an active state based on at least one wellbore criteria; emplacing the plurality of LCM pills at a location in which the portion of the drilling fluid circulated into the wellbore is lost to the subterranean formation; adjusting the plurality of LCM pills from the inactive state to the active state based on the at least one wellbore criteria; and reducing the portion of the drilling fluid circulated into the wellbore that is lost to the subterranean formation with the plurality of LCM pills in the active state.

In an aspect combinable with the example implementation, adjusting the plurality of LCM pills from the inactive state to the active state includes expanding each LCM pill from a contracted state to an expanded state to expose a lost circulation material mesh of the LCM pill from a housing of the LCM pill.

In another aspect combinable with any of the previous aspects, expanding each LCM pill from the contracted state to the expanded state to expose the lost circulation material mesh of the LCM pill from the housing of the LCM pill includes expanding a framework from within the housing to expose the lost circulation material mesh from the housing.

In another aspect combinable with any of the previous aspects, the lost circulation material mesh includes an acid-dissolvable fiber material.

In another aspect combinable with any of the previous aspects, the acid-dissolvable fiber material is configured to dissolve in the wellbore based on exposure to hydrochloric acid.

In another aspect combinable with any of the previous aspects, the at least one wellbore criteria includes a wellbore temperature at the location in which the portion of the drilling fluid circulated into the wellbore is lost to the subterranean formation.

Another aspect combinable with any of the previous aspects further includes adjusting the plurality of LCM pills from the inactive state to the active state based on a temperature sensor of each of the plurality of LCM pills sensing a temperature of at least the wellbore temperature at the location.

In another aspect combinable with any of the previous aspects, the at least one wellbore criteria includes a wellbore depth at the location in which the portion of the drilling fluid circulated into the wellbore is lost to the subterranean formation.

Another aspect combinable with any of the previous aspects further includes adjusting the plurality of LCM pills from the inactive state to the active state based on a depth sensor of each of LCM pills sensing a depth of at least the wellbore depth at the location.

Another aspect combinable with any of the previous aspects further includes setting a controller of each of the LCM pills with the at least one wellbore criteria at the terranean surface.

In another aspect combinable with any of the previous aspects, the at least one wellbore criteria includes a signal.

Another aspect combinable with any of the previous aspects further includes subsequent to emplacing the plurality of LCM pills at the location, circulating a signal generator through the drill string and the drill bit and into the wellbore with the drilling fluid; based on the signal generator reaching the location, activating the signal with the signal generator; and based on activation of the signal, adjusting the plurality of LCM pills from the inactive state to the active state.

In another aspect combinable with any of the previous aspects, the at least one wellbore criteria includes a time duration.

Another aspect combinable with any of the previous aspects further includes adjusting the plurality of LCM pills from the inactive state to the active state based on a timer of each of LCM pills reaching the time duration.

In another example implementation, a system includes a drilling sub-system configured to form at least a portion of a wellbore from a terranean surface toward a subterranean formation by rotating a drill bit on a drill string; a drilling fluid circulation sub-system configured to circulate a drilling fluid downhole through the drill string, to and through the drill bit, into the wellbore, and uphole toward the terranean surface while the drilling sub-system drills the portion of the wellbore; and a lost circulation sub-system including a plurality of lost circulation material (LCM) pills configured to circulate, with the drilling fluid, through the drill string and the drill bit and into the wellbore in an inactive state. Each of the LCM pills is set to adjust from the inactive state to an active state based on at least one wellbore criteria at a location of the wellbore in which a portion of the drilling fluid circulated into the wellbore is lost to the subterranean formation to reduce the portion of the drilling fluid circulated into the wellbore that is lost to the subterranean formation.

In an aspect combinable with the example implementation, each of the plurality of LCM pills is configured to adjust from the inactive state to the active state by expanding from a contracted state to an expanded state to expose a lost circulation material mesh of the LCM pill from a housing of the LCM pill.

In another aspect combinable with any of the previous aspects, each of the plurality of LCM pills is configured to expand from the contracted state to the expanded state to expose the lost circulation material mesh of the LCM pill from the housing of the LCM pill by expanding a framework from within the housing to expose the lost circulation material mesh from the housing.

In another aspect combinable with any of the previous aspects, the lost circulation material mesh includes an acid-dissolvable fiber material.

In another aspect combinable with any of the previous aspects, the acid-dissolvable fiber material is configured to dissolve in the wellbore based on exposure to hydrochloric acid.

In another aspect combinable with any of the previous aspects, the at least one wellbore criteria includes a wellbore temperature at the location in which the portion of the drilling fluid circulated into the wellbore is lost to the subterranean formation.

In another aspect combinable with any of the previous aspects, each of the plurality of LCM pills is configured to adjust from the inactive state to the active state based on a temperature sensor of each of the plurality of LCM pills sensing a temperature of at least the wellbore temperature at the location.

In another aspect combinable with any of the previous aspects, the at least one wellbore criteria includes a wellbore depth at the location in which the portion of the drilling fluid circulated into the wellbore is lost to the subterranean formation.

In another aspect combinable with any of the previous aspects, each of the plurality of LCM pills is configured to adjust from the inactive state to the active state based on a depth sensor of each of LCM pills sensing a depth of at least the wellbore depth at the location.

In another aspect combinable with any of the previous aspects, each of the LCM pills includes a controller configured to be set with the at least one wellbore criteria at the terranean surface.

In another aspect combinable with any of the previous aspects, the at least one wellbore criteria includes a signal.

In another aspect combinable with any of the previous aspects, the lost circulation sub-system includes a signal generator configured to circulate through the drill string and the drill bit and to the location in the wellbore with the drilling fluid and activate the signal to adjust the plurality of LCM pills from the inactive state to the active state.

In another aspect combinable with any of the previous aspects, the at least one wellbore criteria includes a time duration, and each of the plurality of LCM pills is configured to adjust from the inactive state to the active state based on a timer of each of LCM pills reaching the time duration.

In another example implementation, a lost circulation material (LCM) pill includes a housing; a framework coupled to the housing and configured to adjust from a retracted state enclosed within the housing to an expanded state outside of the housing; and a fiber material that forms a mesh across and coupled to the framework, the mesh exposed from the housing when the framework in the expanded state.

In an aspect combinable with the example implementation, the housing is spherical.

In another aspect combinable with any of the previous aspects, the fiber material includes an acid-dissolvable material.

Another aspect combinable with any of the previous aspects further includes a controller coupled to at least one of the housing or the framework.

In another aspect combinable with any of the previous aspects, the controller includes a programmable radio frequency identification (RFID) tag configured to adjust the framework from the retracted state to the expanded state upon receipt of a signal.

In another aspect combinable with any of the previous aspects, the controller includes at least one sensor configured to sense a value of a wellbore parameter, the controller configured to adjust the framework from the retracted state to the expanded state based on the sensor sensing the value of the wellbore parameter.

Implementations of a systems and methods for providing LCM to a reservoir according to the present disclosure may include one or more of the following features. For example, implementations according to the present disclosure can cure or control drilling fluid losses while drilling an oil, gas and water well. Also, implementations according to the present disclosure can overcome drilling fluid losses by the use of mechanical LCM system allowing the continuous operations of drilling a well. Further, implementations according to the present disclosure can avoid reservoir damages by using acid soluble LCM material components to complete a well. As a further example, implementations according to the present disclosure can use LCM material applicable n any type of environment and independent of fracture size or losses rate. Also, implementations according to the present disclosure can minimize extensive lost time due to drilling fluid losses while also controlling such losses. Further, implementations according to the present disclosure can avoid risks associated to drilling fluid losses in an oil, gas or water well related to well control, while curing or controlling the fluid losses in the well.

The details of one or more implementations of the subject matter described in this disclosure are set forth in the accompanying drawings and the description below. Other features, aspects, and advantages of the subject matter will become apparent from the description, the drawings, and the claims.

The present disclosure describes implementations of a lost circulation material (LCM) as well as methods and systems for delivering the LCM to a downhole reservoir (for example, during a drilling operation) to reduce or cease a loss of drilling fluid. Reducing lost drilling fluid can be an important consideration during drilling operations. For example, some of the purposes of the drilling fluid are to: provide support of the wellbore (in other words, the rock formation) while drilling the wellbore, act a lubricant to a drill string that it is used to drill the wellbore, and provide hydraulic forces to move drilling tools and prevent well control events when the drilling fluid weight is higher than a reservoir formation pressure. Thus, maintaining drilling fluid in the wellbore at all time can be important and, when severe to total losses of drilling fluid are encountered, the whole drilling operation is disrupted while trying to control such losses.

is a schematic diagram of an example wellbore systemthat operates to deliver LCM pills to a location in a wellboreaccording to the present disclosure. Implementations according to the present disclosure describe an LCM pill that, in some aspects, is spherically or pill shaped in an inactive (or contracted) state. Thus, although the term “pill” refers to a shape that can be generally spherical or capsule shaped, the present disclosure does not exclude LCM pills of different three-dimensional shapes when in an inactive state.

Multiple (for example, tens, hundreds, thousands) of LCM pills can be circulated into the wellborethrough the drilling string. The LCM pills can be circulated in a drilling or other wellbore fluid through downhole tools, such as conventional rotary assemblies without any special tool on it or through open ended drill pipe. Circulation techniques of the LCM pills can depend, for example, on wellbore diameter, the size of the tools used in the drill string, a severity of the drilling fluid losses experienced during a drilling process, and/or other factors. Thus, implementations of the LCM pills according to the present disclosure can have different external dimensions (lengths, circumferences, or otherwise) in order to have different alternative for uses.

Once undesired drilling fluid losses occur, LCM pills can be inserted into the drilling equipment (for example, into a drill pipe or string) and circulated downhole, where they are positioned at or near a bottom of the wellboreor wherever drilling fluid losses are occurring. In some aspects, once the LCM pills are emplaced, the drill stringcan be pulled out of the wellbore. Further in some aspects, in order to ensure or help ensure that the LCM pills move into the fracture or loss zone (in other words, the location in the reservoir where drilling fluid losses are occurring), a squeeze operation can be performed by applying pressure in the wellborein an annular space (or annulus)in order to further push or urge (or circulate) the LCM pills into the loss zone.

After the LCM pills are emplaced into the reservoir, the LCM pills adjust from the inactive state to an active or expanded state to expose a larger cross-section of LCM. For example, in some examples and as described herein, in an active state, the LCM pills can take the shape of a spiderweb or other shape that is more planar than a sphere or pill. This expanded shape can more efficiently (as compared to a sphere or pill shape), cover zones of drilling fluid loss in the reservoir. In some aspects, as multiple LCM pills are circulated into the loss zone, the activated LCM pills form a larger mesh structure with overlapping or adjacent spiderweb structures to block or act as a bridging mechanism to seal the loss zone in which drilling fluid is lost into the reservoir.

As shown, the wellbore systemaccesses a subterranean formation, and provides access to hydrocarbons located in such subterranean formation, also called reservoir. In an example implementation of system, the systemmay be used for a drilling operation as well as to deliver LCM pills (shown in). As illustrated in, an implementation of the wellbore systemincludes a drilling assemblydeployed on a terranean surface. The drilling assemblycan be used to form the wellboreextending from the terranean surfaceand through one or more geological formations in the Earth. One or more subterranean formations, such as subterranean zone, are located under the terranean surface. One or more wellbore casings, such as a surface casingand intermediate casing, may be installed in at least a portion of the wellbore(for example subsequent to completion of the drilling operation or some other time).

In some embodiments, the drilling assemblymay be deployed on a body of water rather than the terranean surface. For instance, in some embodiments, the terranean surfacemay be an ocean, gulf, sea, or any other body of water under which hydrocarbon-bearing formations may be found. In short, reference to the terranean surfaceincludes both land and water surfaces and contemplates forming and developing one or more wellbore systemsfrom either or both locations.

Generally, as a drilling system, the drilling assemblymay be any appropriate assembly or drilling rig used to form wellbores or boreholes in the Earth. The drilling assemblymay use traditional techniques to form such wellbores, such as the wellbore, or may use nontraditional or novel techniques. In some embodiments, the drilling assemblymay use rotary drilling equipment to form such wellbores. Rotary drilling equipment is known and may consist of a drill stringand the drill bit(or bottom hole assemblythat includes a drill bit). In some embodiments, the drilling assemblymay consist of a rotary drilling rig. Rotating equipment on such a rotary drilling rig may consist of components that serve to rotate a drill bit, which in turn forms a wellbore, such as the wellbore, deeper and deeper into the ground. Rotating equipment consists of a number of components (not all shown here), which contribute to transferring power from a prime mover to the drill bit itself. The prime mover supplies power to a rotary table, or top direct drive system, which in turn supplies rotational power to the drill string. The drill stringis typically attached to the drill bit(for example, as a bottom hole assembly). A swivel, which is attached to hoisting equipment, carries much, if not all of, the weight of the drill string, but may allow it to rotate freely.

The drill stringtypically consists of sections of heavy steel pipe, which are threaded so that they can interlock together. Below the drill pipe are one or more drill collars, which are heavier, thicker, and stronger than the drill pipe. The threaded drill collars help to add weight to the drill stringabove the drill bit to ensure that there is enough downward force on the drill bitto allow the bit to drill through the one or more geological formations. The number and nature of the drill collars on any particular rotary rig may be altered depending on the downhole conditions experienced while drilling.

The circulating system of a rotary drilling operation, such as the drilling assembly, may be an additional component of the drilling assembly. Generally, the circulating system may cool and lubricate the drill bit, removing the cuttings from the drill bit and the wellbore(for example, through an annulus), and coat the walls of the wellborewith a mud type cake. The circulating system consists of drilling fluid, which is circulated down through the wellbore throughout the drilling process. Typically, the components of the circulating system include drilling fluid pumps, compressors, related plumbing fixtures, and specialty injectors for the addition of additives to the drilling fluid. In some embodiments, such as, for example, during a horizontal or directional drilling process, downhole motors may be used in conjunction with or in the drill bit. Such a downhole motor may be a mud motor with a turbine arrangement, or a progressive cavity arrangement, such as a Moineau motor. These motors receive the drilling fluidthrough the drill stringand rotate to drive the drill bit or change directions in the drilling operation.

In many rotary drilling operations, the drilling fluidis pumped down the drill stringand out through ports or jets in the drill bit. The fluid then flows up toward the surfacewithin annulusbetween the wellboreand the drill string, carrying cuttings in suspension to the surface. The drilling fluid, much like the drill bit, may be chosen depending on the type of geological conditions found under subterranean surface.

In some embodiments of the wellbore system, the wellboremay be cased with one or more casings. As illustrated, the wellboreincludes a conductor casing, which extends from the terranean surfaceshortly into the Earth. A portion of the wellboreenclosed by the conductor casingmay be a large diameter borehole. Additionally, in some embodiments, the wellboremay be offset from vertical (for example, a slant wellbore). Even further, in some embodiments, the wellboremay be a stepped wellbore, such that a portion is drilled vertically downward and then curved to a substantially horizontal wellbore portion. Additional substantially vertical and horizontal wellbore portions may be added according to, for example, the type of terranean surface, the depth of one or more target subterranean formations, the depth of one or more productive subterranean formations, or other criteria.