Downhole environment evaluation based on monitoring degradable devices

Abstract

A wellbore apparatus includes a carrier apparatus to deploy downhole in a wellbore. The carrier apparatus includes multiple coupons of different degradable materials housed in the carrier. The multiple coupons degrade at different rates based on the difference in materials. The difference in degradation rates indicates specific performance of the material composition in the wellbore environment.

Description

PRIORITY

[0001] This application is a continuation-in-part of, and claims the benefit of priority of, U.S. patent application Ser. No. 19 / 283,217, filed Jul. 28, 2025, which in turn is based on, and claims the benefit of priority of, U.S. Provisional Application No. 63 / 676,005, filed Jul. 26, 2024.TECHNICAL FIELD

[0002] Descriptions are generally related to oil and gas well completions, and more particular descriptions are related to deployment and monitoring with degradable devices.BACKGROUND OF THE INVENTION

[0003] Current unconventional completion operations in the oil and gas industry have seen a growing utilization of degradable equipment, primarily in the form of degradable frac plugs, for specialized applications that have historically posed operational risks for traditional completion equipment. Examples of specialized applications include difficult millout operations as a result of casing damage or relatively low bottom hole pressure. While degradable equipment significantly reduces the risk of coil tubing and milling issues over a conventional frac plug in such applications, the use of degradable material is not without its own risks. Degradable equipment is made of material that is highly reliant on chemistry of the wellbore fluid.

[0004] In standard oil and gas operations, wellbore fluid is analyzed in advance of the completion, typically in an offsite facility, to determine the best material selection with respect to degradation targets determined by the application. As such, the material selection alone must be tailored to the specific well. Without performing the analysis, there is a potential for highly volatile degradation rates, or lack of complete degradation of the selected material. The risk of improper material degradation is further compounded with the fact that wellbore fluid chemistry may not be consistent over the duration of the completion operation. Rather, considerable changes in chemistry can occur that would drastically alter the dissolution reaction of the selected degradable material. Failure to match the material selection to the wellbore chemistry can result in a failed stage and cost the customer down time and lost production revenue.BRIEF DESCRIPTION OF THE DRAWINGS

[0005] The following description includes discussion of figures having illustrations given by way of example of an implementation. The drawings should be understood by way of example, and not by way of limitation. As used herein, references to one or more examples are to be understood as describing a particular feature, structure, or characteristic included in at least one implementation of the invention. Phrases such as “in one example” or “in an alternative example” appearing herein provide examples of implementations of the invention, and do not necessarily all refer to the same implementation. However, they are also not necessarily mutually exclusive.

[0006] FIG. 1 is an example of a wellbore with a downhole carrier apparatus.

[0007] FIG. 2A is an example of a downhole carrier apparatus with a single cavity having multiple degradable coupons.

[0008] FIG. 2B is an example of a downhole carrier apparatus subassembly, with the single cavity carrier.

[0009] FIG. 3A is an example of a downhole carrier apparatus with multiple cavities.

[0010] FIG. 3B is an example of a downhole carrier apparatus subassembly, with the multiple cavity carrier.

[0011] FIG. 4 is an example of a downhole carrier apparatus subassembly having multiple degradable coupons held externally.

[0012] FIG. 5 is an example of a downhole carrier apparatus subassembly having concentric ring degradable coupons.

[0013] FIG. 6 is an example of a downhole carrier apparatus subassembly with degradable coupons anchored to the exterior of the carrier.

[0014] FIG. 7 is an example of a downhole carrier apparatus subassembly with degradable coupons housed in pockets in the sidewall of the carrier.

[0015] FIG. 8 is a flow diagram of an example of monitoring a wellbore.

[0016] FIG. 9A-9B is an example of a downhole carrier apparatus subassembly with degradable coupons anchored in exterior mounts on the carrier.

[0017] FIG. 9C-9D are examples of coupon mount attachments.

[0018] FIG. 10A-10B is an example of a downhole carrier apparatus subassembly with degradable coupons anchored in exterior mounts on the carrier.

[0019] FIG. 11 is an example of a wellbore with a downhole carrier apparatus having sensors to communicate with the surface.

[0020] FIG. 12A is an example of a downhole carrier apparatus subassembly having downhole monitoring.

[0021] FIG. 12B-12C are examples of coupon degradation sensing.

[0022] FIG. 13 is a flow diagram of an example of downhole coupon monitoring.

[0023] Descriptions of certain details and implementations follow, including non-limiting descriptions of the figures, which may depict some or all examples, and well as other potential implementations.DETAILED DESCRIPTION OF THE INVENTION

[0024] As described herein, a wellbore apparatus includes a carrier apparatus to deploy downhole in a wellbore. The carrier apparatus includes multiple coupons of different degradable materials housed in the carrier. The multiple coupons degrade at different rates based on the difference in materials. The difference in degradation rates indicates specific performance of the material composition in the wellbore environment. In one example, the system monitors the material degradation while downhole, through the use of sensors. The downhole monitoring information can be communicated via uphole communication lines to the surface, allowing realtime evaluation of the wellbore environment.

[0025] FIG. 1 is an example of a wellbore with a downhole carrier apparatus. System 100 illustrates a downhole carrier coupled to a setting tool and a fracturing plug, such as a fracturing plug assembly. System 100 illustrates wellbore 150, which includes the vertical portion vertical 152, the curved portion curve 154, and the horizontal portion horizontal 156. While a wellbore with a horizontal portion is specifically illustrated, it will be understood that any type of wellbore can deploy the degradable test coupons described to test the wellbore environment.

[0026] The well can be drilled vertically to a known depth, resulting in vertical 152, then curved and drilled to a known horizontal position, resulting in curve 154. Once at the horizontal depth, the drilling can continue, resulting in horizontal 156. Equipment 140 represents the surface equipment used to deploy and control the wellbore equipment. Lines 142 represent the lines used to set and manage the downhole equipment. For example, lines 142 can be or include wireline conveyance equipment to deploy the carrier downhole.

[0027] In one example, system 100 includes tool 122, which represents a setting or retrieving tool deployed downhole. System 100 also illustrates plug 124, which represents a component or equipment that is set downhole in wellbore 150. Wellbore 150, at the target depth where plug 124 will be set, has a specific chemistry due to the liquid, gases, dissolvables, and other materials at the depth.

[0028] In one example, system 100 includes carrier 110 coupled to tool 122 and to plug 124. Carrier 110 represents a carrier apparatus that can carry multiple degradable coupons downhole when tool 122 is deployed downhole. In one example, carrier 110 is an attachment to the downhole assembly. In one example, carrier is integrated into or onto the body of a piece of downhole assembly equipment. Thus, for example, the downhole setting equipment can perform setting while also gathering information about the downhole environment.

[0029] Carrier 110 has body 112, where the details of the body are not illustrated or specified in system 100. In general, there are no restrictions on the composition and form of body 112, as long as it accommodates multiple degradable coupons in accordance with any example described below. Body 112 can be made from metal, composite, ceramic, elastomer, wood, plastic, glass, or other material, or a combination of any of these materials. Body 112 can have multiple component parts, which can be made of any one or more of these materials.

[0030] Body 112 has uphole end 114, referring to a portion of carrier 110 that is closest to the surface when the carrier is deployed in the wellbore. Body 112 also has downhole end 116, referring to a portion of carrier 110 that is furthest from the surface when the carrier is deployed in the wellbore. The uphole and downhole ends can be configured differently for different coupling equipment to connect to other components of an assembly.

[0031] Carrier 110 houses N coupons, coupon 132-1, coupon 132-2, . . . , coupon 132-N, where N is an integer greater than 1. The N coupons can collectively be referred to as coupons 132. Coupon 132-1 has a different composition from coupon 132-2, which in turn has a different composition from another coupon, and so forth until coupon 132-N. The differences in coupon composition cause the coupons to degrade at different rates in the wellbore environment of wellbore 150.

[0032] While system 100 illustrates N coupons each having a different composition, there is no restriction on deploying multiple coupons having the same composition, for example, deploying two or more coupons of the same composition with one or more coupons of different composition. However, it will be understood that generally the system will gather more information about the wellbore environment when each coupon has a different composition. Descriptions of gathering information about the wellbore environment may be more specifically stated to say they are gathering information about how different compositions react to a given wellbore environment.

[0033] Rather than sampling the wellbore once prior to deployment, and then lacking additional feedback about the wellbore environment, including changes in the environment, carrier 110 can be deployed with every downhole deployment. When setting equipment is returned to the surface, analysis of the degradation of the various coupons provides useful information about rates of degradation of various compositions, enabling more accurate matching of materials for dissolvable plugs or other dissolvable equipment.

[0034] System 100 does not specifically illustrate environment communication, which refers to an opening or port that exposes coupons 132 to the materials in the wellbore, but subjecting coupons 132 to the wellbore environment with environment communication subjects the coupons to dissolution / degradation of their degradable material. Loss of volume of affected degradable test coupons resulting from exposure to the wellbore environment can be determined at the surface after removing coupons 132 from the carrier apparatus. Events such as full dissolution, or volume change to the point that the remaining portion of the affected degradable test coupon is about to fall out of an access port, serve as significant dissolution indicators even though test coupons that do not return to surface cannot be analyzed.

[0035] As indicated above, coupons 132 can be made of different materials. Reference to being made of different materials can refer to the use of entirely different materials, as well as referring to different compositions of a material. In one example, one or more of coupons 132 is made from a magnesium alloy. In one example, one or more of coupons 132 is made from a composition of polyglycolic acid (PGA). In one example, one or more of coupons 132 is made from a composition of polylactic acid (PLA). In one example, coupons 132 are made from different compositions of magnesium alloy. In one example, coupons 132 are made from different compositions of PGA. In one example, coupons 132 are made from different compositions of PLA. In one example, coupons 132 include composite materials made from at least one of the above with one or more other materials (which could be another material indicated above).

[0036] FIG. 2A is an example of a downhole carrier apparatus with a single cavity having multiple degradable coupons. System 202 represents components of a downhole assembly in accordance with an example of system 100. System 202 specifically illustrates a single cavity carrier apparatus, carrier 220. Carrier 220 can convey degradable test coupons into and out of a wellbore environment.

[0037] Carrier 220 is specifically illustrated as housing four degradable coupons, coupon 242-1, coupon 242-2, coupon 242-3, and coupon 242-4, collectively, coupons 242. Carrier 220 represents a single cavity carrier apparatus having top sub 222 and bottom sub 224, which connect at a thread connection, represented by thread 226, to form an enclosed carrier volume. The enclosed volume is represented by cavity 230, which is a common cavity or open internal space for all of coupons 242.

[0038] In one example, the body of bottom sub 224 has multiple access ports, represented by ports 232. It will be understood that system 202 includes more ports than are pointed to by the arrows. Ports 232 allow environmental communication (communication 234) between the enclosed carrier volume and the wellbore environment. The wellbore environment is able to communicate both in to and out of the enclosed carrier volume formed by top sub 222 and bottom sub 224.

[0039] In one example, top sub 222 is connected to tool 212, which represents a component of an assembly (also used synonymously with subassembly) to which carrier 220 can be connected to be deployed downhole and retrieved from the downhole position. Carrier 220 houses coupons 242, enabling the gathering of information about the downhole wellbore environment.

[0040] In one example, cavity 230 represents a single cavity having multiple coupons that have different materials or different compositions, or both different materials and different compositions in a single chamber. It will be understood that cavity 230 is a single chamber internal to carrier 220.

[0041] FIG. 2B is an example of a downhole carrier apparatus subassembly, with the single cavity carrier of system 202. More specifically, system 204 represents components of a downhole subassembly including carrier 220.

[0042] In one example, system 204 represents a wireline adapter kit subassembly, represented by assembly 214, utilized in coupling a downhole fracturing plug, represented by plug 216, and downhole setting tool, represented by tool 212. In one example, carrier 220 connects to a tension mandrel, represented by mandrel 272, by thread 264 on the downhole end (e.g., at downhole 284). In one example, carrier 220 connects to tool 212 by thread 262 on the uphole end (e.g., at uphole 282).

[0043] In one example, carrier 220 and mandrel 272 form a subassembly concentrically enclosed by a setting sleeve, represented by sleeve 274. In one example, sleeve 274 includes multiple ports, represented by port 252, located around the setting sleeve, forming a second environment communication, represented by communication 254, that allows access to access ports 232 and communication 234 within the carrier volume.

[0044] Cavity 230, which represents the internal carrier volume, houses coupons 242. In one example, the wireline adapter kit subassembly (e.g., assembly 214) can convey carrier 220 downhole to a setting depth for plug 216. Once the fracturing (frac) plug is set and released from assembly 214, carrier 220 and the rest of the bottom hole assembly is conveyed uphole and removed from the wellbore. Someone can analyze the degradation of coupons 242 at the surface and determine a specific composition to use for degradable equipment to be used downhole.

[0045] FIG. 3A is an example of a downhole carrier apparatus with multiple cavities. System 302 represents components of a downhole assembly in accordance with an example of system 100. System 302 specifically illustrates a multiple cavity carrier apparatus, carrier 320. Carrier 320 can convey degradable test coupons into and out of a wellbore environment.

[0046] Carrier 320 is specifically illustrated as housing four degradable coupons, coupon 340-1, coupon 340-2, coupon 340-3, and coupon 340-4, collectively, coupons 340, in separate isolated chambers. Segment 330-1, segment 330-2, segment 330-3, and segment 330-4, collectively, segments 330, correspond respectively to coupon 340-1, coupon 340-2, coupon 340-3, and coupon 340-4.

[0047] Each segment has a separate isolated internal chamber for a separate coupon. The isolated internal chamber is formed by the separate isolated subs (iso subs) of each individual segment, with iso sub 332-1, iso sub 332-2, iso sub 332-3, and iso sub 332-4, collectively iso subs 332, corresponding to segment 330-1, segment 330-2, segment 330-3, and segment 330-4, respectively.

[0048] Carrier 320 represents a multiple cavity carrier apparatus having top sub 322, bottom sub 324, and iso subs 332. Each segment connects to the next downhole segment with a thread connection. As illustrated, thread 334-1 connects iso sub 332-1 to top sub 322, thread 334-2 connects iso sub 332-2 to iso sub-332-1, thread334-3 connects iso sub 332-3 to iso sub 332-2, and thread 334-4 connects iso sub 332-4 to iso sub 332-3. In one example, bottom sub 324 is connected to or part of iso sub 332-4. Each connection forms a separate enclosed volume, represented by cavity 338-1 for coupon 340-1, cavity 338-2 for coupon 340-2, cavity 338-3 for coupon 340-3, and cavity 338-4 for coupon 340-4. The cavities can be referred to collectively as cavities 338, with each cavity being an isolated cavity or isolated open internal space for separate coupons 340.

[0049] In one example, the body of each separate segment has multiple access ports, represented by port 336-1 for iso sub 332-1, port 336-2 for iso sub 332-2, port 336-3 for iso sub 332-3, and port 336-4 for iso sub 332-4. The ports can be referred to collectively as ports 336. It will be understood that system 302 includes more ports than are pointed to by the arrows. Ports 336 allow environmental communication between the enclosed carrier volumes and the wellbore environment. The wellbore environment is able to communicate both in to and out of the enclosed carrier volumes. The environmental communication is illustrated for each segment as comm (communication) 342-1 for coupon 340-1, comm 342-2 for coupon 340-2, comm 342-3 for coupon 340-3, and comm 342-4 for coupon 340-4.

[0050] In one example, top sub 322 is connected to tool 312, which represents a component of an assembly (also used synonymously with subassembly) to which carrier 320 can be connected to be deployed downhole and retrieved from the downhole position. Carrier 320 houses coupons 340, enabling the gathering of information about the downhole wellbore environment.

[0051] In one example, each of the multiple cavities, cavities 338, represents a single cavity having a single coupon, allowing carrier 320 to house degradable test coupons without the comingling of degradable coupons. Carrier 320 can provide a multiple carrier structure to house coupons 340 that have different materials or different compositions, or both different materials and different compositions in a single chamber. Each separate chamber can house a coupon of different degradable material or composition.

[0052] FIG. 3B is an example of a downhole carrier apparatus subassembly, with the multiple cavity carrier of system 302. More specifically, system 304 represents components of a downhole subassembly including carrier 320.

[0053] In one example, system 304 represents a wireline adapter kit subassembly, represented by assembly 314, utilized in coupling a downhole fracturing plug, represented by plug 316, and downhole setting tool, represented by tool 312. In one example, carrier 320 connects to a tension mandrel, represented by mandrel 372, by thread 364 on the downhole end (e.g., at downhole 384). In one example, carrier 320 connects to tool 312 by thread 362 on the uphole end (e.g., at uphole 382).

[0054] In one example, carrier 320 and mandrel 372 form a subassembly concentrically enclosed by a setting sleeve, represented by sleeve 374. In one example, sleeve 374 includes multiple ports, represented by port 352, located around the setting sleeve, forming a second environment communication, represented by communication 354, that allows access to access ports 336 and comm 342 within the carrier volume.

[0055] Cavities 338, which represent the internal carrier volumes, house coupons 340. In one example, the wireline adapter kit subassembly (e.g., assembly 314) can convey carrier 320 downhole to a setting depth for plug 316. Once the fracturing (frac) plug is set and released from assembly 314, carrier 320 and the rest of the bottom hole assembly is conveyed uphole and removed from the wellbore. Someone can analyze the degradation of coupons 340 at the surface and determine a specific composition to use for degradable equipment to be used downhole.

[0056] FIG. 4 is an example of a downhole carrier apparatus subassembly having multiple degradable coupons held externally. System 402 represents a carrier apparatus in accordance with an example of system 100. More specifically, system 402 illustrates a carrier apparatus with external grooves to convey degradable test coupons.

[0057] System 402 includes grooved sub 420, which represents the body of a carrier apparatus. Grooved sub 420 includes grooves 424 around an outside of sub wall 422. With separate grooves 424, system 402 can convey degradable coupons in separate grooves in to and out of wellbore environments. Grooved sub 420 can be connected to tool 412 for sending downhole in a wellbore and for retrieving it from the wellbore.

[0058] The grooved carrier apparatus includes top sub 440, which can be a top sub of another component of a downhole assembly, and grooved sub 420. Grooved sub 420 can have carrier grooves, represented by grooves 424, sub wall 422, which represents the wall of the grooved sub, and retainer 430. In one example, top sub 440 is connected to grooved sub 420 by a thread connection, represented by thread 442. Retainer 430 is positioned concentrically about grooved sub 420 and holds the degradable test coupons within the carrier grooves while the external groove carrier apparatus is conveyed throughout a wellbore environment.

[0059] In the view of system 402, coupon 450-1 is visible within groove 424 and held by retainer 430. Groove 424 represents external grooves in the exterior of the carrier apparatus. Grooves 424 represent an example of separate chambers in exterior cavities of the carrier.

[0060] View 404 represents a cross-section looking back at arrows B, which does not show retainer 430. In view 404, coupon 450-1, coupon 450-2, coupon 450-3, and coupon 450-4, collectively coupons 450, are visible arranged concentrically around the carrier apparatus, disposed in carrier grooves 424 in sub wall 422. Coupons 450 are exposed to wellbore environment when housed in grooves 424, which are open to the wellbore environment.

[0061] FIG. 5 is an example of a downhole carrier apparatus subassembly having concentric ring degradable coupons. System 500 represents a carrier apparatus in accordance with an example of system 100. More specifically, system 500 illustrates a carrier apparatus with external grooves for concentric rings to convey degradable test coupons.

[0062] System 500 includes carrier sub 520, which represents the body of a carrier apparatus. Carrier sub 520 includes grooves or location for concentric rings around an outside of the sub wall. With separate grooves 524, system 500 can convey degradable coupons in separate grooves in to and out of wellbore environments. Carrier sub 520 can be connected to tool 512 for sending downhole in a wellbore and for retrieving it from the wellbore.

[0063] The concentric ring carrier apparatus includes top sub 540, which can be a top sub of another component of a downhole assembly, and carrier sub 520. The body of carrier sub 520 is identified as mandrel 522. The carrier apparatus includes concentric rings around concentric carrier sub 520. In one example, top sub 540 is connected to carrier sub 520 by a thread connection, represented by thread 542.

[0064] In one example, system 500 includes four degradable test coupon rings, represented by coupon 550-1, coupon 550-2, coupon 550-3, and coupon 550-4, collectively coupons 550. In one example, top sub 540 holds degradable test coupon rings axially in place when top sub 540 is connected to carrier sub 520. Such rings can be referred to as external rings disposed in external, concentric cavities. In one example, the carrier sub also houses separator rings, represented by separator 530, between each test coupon ring. Separator 530 represents the separation of the different coupons. Coupons 550 are exposed to the wellbore environment when housed concentrically about carrier sub 520, because they are on the outside of the carrier body and exposed to the environment the carrier is placed in.

[0065] FIG. 6 is an example of a downhole carrier apparatus subassembly with degradable coupons anchored to the exterior of the carrier. System 602 represents a carrier apparatus in accordance with an example of system 100. More specifically, system 602 illustrates a carrier apparatus with external cavities or chambers to anchor degradable test coupons to convey into and out of a wellbore environment.

[0066] System 602 includes carrier 610, having carrier sub 612, which represents the body of a carrier apparatus. Carrier sub 612 includes chambers around an outside of the sub wall, represented by chamber 614, chamber 616, and chamber 618. It will be understood that more or fewer chambers can be used, for example, there can be more chambers to convey more degradable coupons. With separate chambers, system 602 can convey degradable coupons in separate cavities in to and out of wellbore environments. Each chamber can provide a location to anchor a test coupon that will be exposed to the wellbore environment.

[0067] View 604 represents a cross-section looking back in the direction of the arrows. In view 604, coupon 620-1, coupon 620-2, coupon 620-3, and coupon 620-4, collectively coupons 620, are visible arranged concentrically around the carrier apparatus, disposed in separate chambers in the sub wall, represented by wall 622. In one example, coupons 620 are anchored to wall 622 in individual chambers through the use of threaded connections, represented by thread 624. Thus, each coupon can be individually threaded into an external cavity to be secured to carrier 610. Coupons 620 are exposed to wellbore environment when anchored to carrier 610, seeing that the chambers are open to the wellbore environment.

[0068] In one example, the coupons are threaded into openings or chambers in carrier sub 612. In one example, the openings represent mounts in carrier sub 612, and the coupons are secured in a removable container or a removable cartridge. A container or a cartridge refers to a device that has a structure that holds one or more coupons. Thus, a removable container can have a chamber, and the container and coupon inside the container can then be mounted in carrier sub 612. A removable container can be mounted and allow the removal of the entire chamber instead of just the coupon or remains of the coupon.

[0069] FIG. 7 is an example of a downhole carrier apparatus subassembly with degradable coupons housed in pockets in the sidewall of the carrier. System 702 represents a carrier apparatus in accordance with an example of system 100. More specifically, system 702 illustrates a carrier apparatus with external cavities or chambers to anchor degradable test coupons to convey into and out of a wellbore environment.

[0070] System 702 includes carrier 710, having carrier sub 712, which represents the body of a carrier apparatus. Carrier sub 712 includes chambers around an outside of the sub wall, represented by chamber 714, chamber 716, and chamber 718. It will be understood that more or fewer chambers can be used, for example, there can be more chambers to convey more degradable coupons. With separate chambers, system 702 can convey degradable coupons in separate cavities in to and out of wellbore environments. Each chamber can provide a location to anchor a test coupon that will be exposed to the wellbore environment.

[0071] View 704 represents a cross-section looking back in the direction of the arrows. In view 704, coupon 720-1, coupon 720-2, coupon 720-3, and coupon 720-4, collectively coupons 720, are visible arranged concentrically around the carrier apparatus, disposed in separate chambers in the sub wall, represented by wall 722. In one example, coupons 720 are anchored to wall 722 in individual chambers through the use of caps, represented by cap 732. Thus, each coupon can be individually held in pocket 730, which is an external cavity of carrier 710.

[0072] System 702 illustrates that each chamber has a cap (cap 732) and an opening or gap in the cap. The chambers provide pockets 730 for coupons 720. The cap secures the test coupon in place, while the opening exposes the test coupon to the wellbore environment. Coupons 720 are exposed to wellbore environment when anchored to carrier 710, seeing that the chambers are open to the wellbore environment. Comm (communication) 740 represents the environmental communication of the coupons to the wellbore environment through the opening in caps 732.

[0073] In one example, the coupons are retained in the openings or chambers in carrier sub 712 with caps 732. In one example, the openings represent mounts in carrier sub 712, and the coupons are secured in a removable container. Thus, a removable container can have a chamber, and the container and coupon inside the container can then be mounted in carrier sub 712. A removable container can be mounted and allow the removal of the entire chamber instead of just the coupon or remains of the coupon.

[0074] FIG. 8 is a flow diagram of an example of monitoring a wellbore. Process 800 represents a process for monitoring a wellbore environment. Process 800 can be implemented by a system in accordance with an example of system 100.

[0075] Someone prepares a carrier apparatus in accordance with any example described herein. In one example, an individual can input different degradable coupons into the carrier, block 802. In one example, the different degradable coupons can have different compositions, different materials, or a combination of different materials and different combinations to degrade at different rates. Degradation at different rates refers to the fact that in the same environment, one coupon will degrade at a different rate than a different coupon. Inputting the coupons can be referred to as setting, mounting, securing, or anchoring the coupons to an appropriate location on or in the carrier, in accordance with any example herein.

[0076] In one example, the coupons can be mounted directly in a chamber or opening in the carrier apparatus. In one example, the coupons can be mounted in a removable container, with the removable container then mounted in or on the carrier apparatus.

[0077] A user of the carrier can deploy the carrier downhole, optionally with setting equipment, block 804. Setting equipment can be any equipment used to set a component at a target depth in a wellbore. Alternatively to setting equipment, other equipment can be used to deploy the carrier, such as other completion operations. Completion operations can include deployment of firing guns for a perforator, pumping down a gauge to measure the internal dimension, or other operation that can be performed without setting a component.

[0078] If the carrier is deployed with setting equipment, block 806 YES branch, the assembly can set the equipment downhole at the target depth, block 808. The system can complete the downhole operations, block 810, with the setting or with other operations. If the carrier is deployed without setting equipment, block 806 NO branch, the system can perform other operations to complete the downhole operations, block 810.

[0079] Once downhole operations are complete, the system can retrieve the equipment, block 812. At the surface, someone can analyze the system, including checking the degradable coupons, block 814. The analysis allows someone to observe the different amounts of degradation of the different materials / compositions. The degradable coupon analysis can indicate the wellbore environment at the target depth and indicate a rate degradation of different compositions / materials. Thus, the system can be set up with the proper degradable components for the desired operation in the wellbore, with current information about the environment in which the degradable components will be deployed.

[0080] FIG. 9A-9B is an example of a downhole carrier apparatus subassembly with degradable coupons anchored in exterior mounts on the carrier. In FIG. 9A, system 902 represents a carrier apparatus in accordance with an example of system 100. More specifically, system 902 illustrates a carrier apparatus with external mounts on carrier sub 912 to anchor degradable test coupons to convey into and out of a wellbore environment.

[0081] System 902 includes carrier 910, having carrier sub 912, which represents the body of a carrier apparatus. Carrier sub 912 includes a portion cut out that has mounts to anchor the coupons around a portion of the sub wall. Mount 914, mount 916, and mount 918 represent different mounts spaced radially around the cutout portion of carrier sub 912. It will be understood that more or fewer mounts can be used, for example, there can be more mounts to convey more degradable coupons.

[0082] With separate mounts, system 902 can convey degradable coupons in separate cavities or containers into and out of wellbore environments. Each mount can provide a location to anchor a test coupon that will be exposed to the wellbore environment.

[0083] In FIG. 9B, view 904 represents a cross-section looking back in the direction of the arrows. In view 904, coupon 920-1 is contained in a mount, coupon 920-2 is contained in mount 914, coupon 920-3 is contained in mount 916, and coupon 920-4 is contained in mount 918. The coupons can collectively be referred to as coupons 920, disposed at separate mounts arranged concentrically around the mandrel of carrier sub 912. The mounts respectively expose their coupons to the wellbore environment when anchored to carrier 910, seeing that the mounts provide containers that are open to the wellbore environment.

[0084] FIG. 9C is an example of a coupon mount via side threading. In one example, the coupons are threaded into an opening or chamber in the mounting container. Container 930 represents the mounting container or the mount. Coupon 932 represents any of coupons 920. Threads 934 represent threading on an outer edge of coupon 932 to secure the coupon in container 930. In one example, container 930 can be a removable container that is not permanently secured to carrier 910.

[0085] FIG. 9D is an example of a coupon mount via bottom threading. In one example, the coupons are threaded onto threading in the bottom of the mounting container. Container 940 represents the mounting container or the mount. Coupon 942 represents any of coupons 920. Thread 944 represents threading on a post in the bottom of container 940, and coupon 942 has a corresponding opening and threading to secure into container 940. In one example, container 940 can be a removable container that is not permanently secured to carrier 910.

[0086] FIG. 10A-10B is an example of a downhole carrier apparatus subassembly with degradable coupons anchored in exterior mounts on the carrier. In FIG. 10A, system 1002 includes carrier 1010, having carrier sub 1012, which represents the body of a carrier apparatus. Carrier sub 1012 includes a portion cut out that has mounts to anchor the coupons along a portion of the sub wall. Mount 1014, mount 1016, and mount 1018 represent different mounts aligned linearly along the cutout portion of carrier sub 1012. It will be understood that more or fewer mounts can be used, for example, there can be more mounts to convey more degradable coupons.

[0087] In FIG. 10B, view 1004 represents a cross-section looking back in the direction of the arrows. In view 1004, coupon 1020-1 is contained in mount 1022, with the other mounts and coupons not visible as they would be behind mount 1022 from the perspective of view 1004. The mounts are anchored to carrier sub 1012 and respectively expose their coupons to the wellbore environment, seeing that the mounts provide containers that are open to the wellbore environment.

[0088] While system 902 illustrates aligning the mounts around the carrier sub concentrically, and system 1002 illustrates aligning the mounts around the carrier sub linearly, it will be understood that these descriptions are not limiting. For example, the mounts can be aligned in a helix pattern around the sub. As another example, the mounts can be placed randomly or pseudo-randomly, rather than being aligned. In another example, groups of two or more mounts can be aligned in one pattern, and the groups aligned in another pattern (e.g., concentrically-spaced groups of two or more aligned mounts). In general, there is no limitation to the pattern or configuration of the mounts.

[0089] FIG. 11 is an example of a wellbore with a downhole carrier apparatus having sensors to communicate with the surface. System 1100 illustrates a system in accordance with an example of system 100. System 1100 can use any form of chamber or mount or container to deploy degradable coupons in accordance with any example herein.

[0090] System 1100 does not specifically illustrate the equipment coupled to carrier 1110, but it will be understood that carrier 1110 can be deployed downhole by a setting tool or some other equipment that will be deployed downhole and returned to the surface. System 1100 illustrates wellbore 1150, which includes the vertical portion vertical 1152, the curved portion curve 1154, and the horizontal portion horizontal 1156. While a curved wellbore is illustrated, the test coupons can be deployed in any type of wellbore.

[0091] In one example, the well can be drilled vertically to a known depth, resulting in vertical 1152, then curved and drilled to a known horizontal position, resulting in curve 1154. Once at the horizontal depth, the drilling can continue, resulting in horizontal 1156. Wellbore 150, at some target depth where carrier 1110 will be deployed, has a specific chemistry due to the liquid, gases, dissolvables, and other materials at the depth.

[0092] System 1100 specifically illustrates comm (communication) line 1142, which represent one or more lines coupled between carrier 1110 and the surface to enable communication from the carrier to surface equipment. System 1100 illustrates manager 1140 as surface equipment that will receive and process the communication from carrier 1110. More specifically, the communication is monitoring data or sensor data that manager 1140 can evaluate to determine a rate of degradation of one or more test coupons.

[0093] In one example, to the extent wireless communication is possible, communication line 1142 can be replaced with a comparable communication path between the downhole components and the surface equipment. For example, a low-frequency communication signal may be transmitted through the ground or through a medium (such as filling the wellbore with fluid that transmits the signal). In general, the form of communication is not limiting; rather, the communication enables the system to pass information from the carrier deployed in the wellbore to the surface without needing to extract the carrier. Any feasible form of communication can be used. A communication connection refers to any type of wired or wireless communication link between the carrier and the surface.

[0094] Carrier 1110 has body 1112, where the details of the body are not illustrated or specified in system 100. In general, there are no restrictions on the composition and form of body 1112, as long as it accommodates multiple degradable coupons in accordance with any example herein. Body 1112 can be made from metal, composite, ceramic, elastomer, wood, plastic, glass, or other material, or a combination of any of these materials. Body 1112 can have multiple component parts, which can be made of any one or more of these materials.

[0095] Body 1112 has uphole end 1114, referring to a portion of carrier 1110 that is closest to the surface when the carrier is deployed in the wellbore. Body 1112 also has downhole end 1116, referring to a portion of carrier 1110 that is furthest from the surface when the carrier is deployed in the wellbore. The uphole and downhole ends can be configured differently for different coupling equipment to connect to other components of an assembly.

[0096] Carrier 1110 houses N coupons, coupon 1132-1, coupon 1132-2, . . . , coupon 1132-N, where N is an integer greater than 1. The N coupons can collectively be referred to as coupons 1132. In one example, coupon 1132-1 has a different composition from coupon 1132-2, which in turn has a different composition from another coupon, and so forth until coupon 1132-N. The differences in coupon composition cause the coupons to degrade at different rates in the wellbore environment of wellbore 1150.

[0097] System 1100 illustrates N coupons each having different compositions. There is no restriction on deploying multiple coupons having the same composition, for example, deploying two or more coupons of the same composition with one or more coupons of different composition. However, it will be understood that generally the system will gather more information about the wellbore environment when each coupon has a different composition. As indicated above, coupons 1132 can be made of different materials. The descriptions above regarding the coupons and their possible compositions apply equally to coupons 1132.

[0098] System 1100 does not specifically illustrate environment communication, which refers to an opening or port that exposes coupons 1132 to the materials in the wellbore, but subjecting coupons 1132 to the wellbore environment with environment communication subjects the coupons to dissolution / degradation of their degradable material. System 1100 specifically illustrates sensor 1130, which monitors the degradation of coupons 1132 and communicates the monitoring information via communication line 1142 to manager 1140. Manager 1140 can then analyze the data or present the data to a human operator for analysis.

[0099] Sensor 1130 can represent any type of sensor device or sensor system that enables detection of degradation of coupons 1132. For example, sensor 1130 can monitor gas production of coupons. In another example, sensor 1130 can monitor a change in pH. In one example, sensor 1130 can monitor a change in volume. In one example, sensor 1130 can monitor a change in mass.

[0100] In one example, sensor 1130 represents a single sensor to monitor multiple coupons 1132. In one example, sensor 1130 monitors all coupons 1132. In one example, sensor 1130 represents a group of sensors, where each coupon 1132 is monitored by a separate sensor.

[0101] Whereas the description of system 100 is specifically about analysis of degradation of the various coupons when the carrier is returned to the surface, system 1100 provides the additional ability of monitoring in situ. Thus, sensors or other monitoring equipment in or on carrier 1110 can monitor and provide communication back to manager 1140 while the carrier is still deployed downhole. The communication of sensor data or monitoring data can be continually sent or can be sent at scheduled intervals or can be sent in response to the reaching of various thresholds of sensing. Even if the communication from the sensors is not necessarily sent continuously, the monitoring described can be referred to as done in “real time” (or realtime) because the monitoring is performed while the carrier is deployed rather than waiting for retrieval from the wellbore before there is information available about the wellbore environment.

[0102] Thus, system 1100 provides useful information about rates of degradation of various compositions, enabling more accurate matching of materials for dissolvable plugs or other dissolvable equipment, while the carrier is still downhole. Additionally, leaving carrier 1110 downhole can indicate changes in rates of degradation, indicating rates of change in the downhole environment, if any.

[0103] FIG. 12A is an example of a downhole carrier apparatus subassembly having downhole monitoring. System 1202 includes carrier 1210, having a carrier sub, which represents the body of a carrier apparatus. The carrier sub includes mounts for various coupons, coupon 1220-1, coupon 1220-2, coupon 1220-3, and coupon 1220-4, collectively coupons 1220. The position and layout of the mounts can be in accordance with any example herein. The layout in the drawing is simply to show multiple coupons, rather than to indicate their position within carrier 1210. It will be understood that more or fewer mounts can be used, for example, there can be more mounts to convey more degradable coupons.

[0104] Sensor 1230 represents any type of sensor that can monitor the degradation of coupons 1220. In one example, sensor 1230 includes analog measurement capability. In one example, sensor 1230 includes digital measurement capability. Comm (communication) 1232 represents the communication connection between carrier 1210 and equipment on the surface.

[0105] FIG. 12B-12C are examples of coupon degradation sensing. Both view 1204 and view 1206 illustrate the monitoring of a single coupon. It will be understood that sensor 1230 can monitor a single coupon or can monitor multiple coupons. Thus, the descriptions of these view can be applied to monitor multiple coupons instead of a single coupon.

[0106] FIG. 12B illustrates view 1204, which is a cross-section view of one of coupons 1220. Coupon 1220 is disposed in container 1212, which represents a mount or a chamber to hold a coupon. In one example, container 1212 includes cap 1242 to retain coupon 1220 in container 1212.

[0107] As illustrated, container 1212 includes spring 1244, which represents a spring, a lever, or some other mechanism to monitor a spatial displacement caused by coupon 1220. In one example, spring 1244 represents a mechanism configured to measure displacement in response to a loss of volume of coupon 1220. In one example, coupon 1220 can be cone-shaped at the bottom, as illustrated by cone 1222, to allow spring 1244 to apply pressure to the coupon. Alternatively to a cone shape, coupon 1220 can be cylindrical with a bottom surface that is formed or machined to receive a spring or other mechanism to measure pressure. The cylindrical shape is one example, but any shape can be used, such as a coned 3 dimensional (3D) polygram or 3D polygon. Coupon 1220 can be of any shape that allows interaction with the spring or pressure sensing mechanism. As coupon 1220 degrades, spring 1244 will displace corresponding to the volume loss or the mass loss.

[0108] FIG. 12C illustrates view 1206, which is a cross-section view of one of coupons 1220. Coupon 1220 is disposed in container 1214, which represents a mount or a chamber to hold a coupon. In one example, sensor 1252 is mounted above or around container 1214. Coupon 1220 degrades in response to a chemical reaction. Thus, in one example, degradation 1254 generates a chemical change in the environment around coupon 1220. Degradation 1254 can be the release of a gas or a liquid detected by sensor 1252.

[0109] In one example, sensor 1252 can be or include a chemical sensor that detects a chemical byproduct of degradation 1254. In one example, sensor 1252 can be or include a pH sensor that detects a change in acidity of the wellbore environment around coupon 1220 due to degradation 1254. In one example, sensor 1252 can be or include an optical sensor that detects a change to the size of coupon 1220 due to degradation 1254.

[0110] FIG. 13 is a flow diagram of an example of downhole coupon monitoring. Process 1300 represents a process for monitoring a wellbore environment. Process 1300 can be implemented by a system in accordance with an example of system 1000.

[0111] Someone prepares a carrier apparatus in accordance with any example described herein. In one example, an individual can input different degradable coupons into the carrier, block 1302. In one example, the different degradable coupons can have different compositions, different materials, or a combination of different materials and different combinations to degrade at different rates. Degradation at different rates refers to the fact that in the same environment, one coupon will degrade at a different rate than a different coupon. Inputting the coupons can be referred to as setting, mounting, securing, or anchoring the coupons to an appropriate location on or in the carrier, in accordance with any example herein. A user of the carrier can deploy the carrier downhole, optionally with setting equipment, completion equipment, or any other downhole equipment, block 1304.

[0112] One or more sensors on the carrier apparatus can monitor coupon degradation, block 1306. The monitoring can be in accordance with any example herein, monitoring with any different kind of sensor, monitoring individual coupons or a plurality of coupons. The carrier includes a communication mechanism or the sensor itself has a communication mechanism to report monitoring data to the surface equipment, block 1308.

[0113] In one example, the information can be gathered and analyzed to identify trends or have more information to better understand the downhole environment. Analysis of the information can indicate realtime changes in the downhole environment. In one example, the surface equipment or a user on the surface can analyze the coupon degradation to determine if a change downhole would improve some aspect of the downhole operation, block 1310.

[0114] If a user or the system determines a change should not be made, at block 1312 NO branch, the monitoring continues at block 1306. If a user or the system determines that a change should be made, at block 1312 YES branch, the change can be executed in the system, block 1314.

[0115] If the downhole operations are complete, block 1316 YES branch, the process finishes at block 1318. If the downhole operations are not complete, block 1316 NO branch, the system can continue to monitor the sensors. In one example, the changes involve the need for equipment removal, in which case the degradable coupons can be traded out, and the process would continue at block 1302. If the coupons do not need to be replaced, the process can continue at block 1304. If the carrier does not need to be removed for whatever change is made, the process can continue monitoring at block 1306.

[0116] The teachings of the present disclosure may be used in a variety of well operations. These operations may involve using one or more treatment agents to treat a formation, the fluids resident in a formation, a wellbore, and / or equipment in the wellbore, such as production tubing. The treatment agents may be in the form of liquids, gases, solids, semisolids, and mixtures of these. Illustrative treatment agents include, but are not limited to, fracturing fluids, acids, steam, water, brine, anti-corrosion agents, cement, permeability modifiers, drilling muds, emulsifiers, tracers, flow improvers, and so forth. Illustrative well operations include, but are not limited to, hydraulic fracturing, stimulation, tracer injection, cleaning, acidizing, steam injection, water flooding, cementing, and so forth.

[0117] While preferred materials for elements of the invention (e.g., components) have been described, the apparatuses of the present invention are not limited by these materials. Wood, plastics, fiber reinforced phenolics, fiber reinforced resins, elastomers, foam, metal alloys, sintered metals, ceramics, fiber, or fabric reinforce composites, and other materials may comprise some or all elements of the apparatuses in various implementations.

[0118] Besides what is described herein, various modifications can be made to what is disclosed and implementations of the invention without departing from their scope. Therefore, the illustrations and examples herein should be construed in an illustrative, and not a restrictive sense. The scope of the invention should be measured solely by reference to the claims that follow.

Claims

1. A wellbore apparatus, comprising:a carrier having one or more mounts exposed to a wellbore environment when the wellbore apparatus is deployed in a wellbore; andmultiple coupons mounted in the one or more mounts, the multiple coupons made of different degradable materials to degrade at different rates in the wellbore environment, where degradation of the multiple coupons indicates a degradation rate of the different degradable materials in the wellbore environment.

2. The wellbore apparatus of claim 1, wherein the mount comprises a structure on an outside of a body of the carrier.

3. The wellbore apparatus of claim 1, wherein the mount comprises a removable cartridge that holds one or more of the multiple coupons.

4. The wellbore apparatus of claim 1, wherein the one or more mounts comprises a single mount holding multiple coupons.

5. The wellbore apparatus of claim 1, wherein the one or more mounts comprises multiple mounts, wherein each mount holds a single coupon.

6. The wellbore apparatus of claim 1, further comprising:a sensor mounted to monitor degradation of one or more of the multiple coupons.

7. The wellbore apparatus of claim 6, wherein the sensor is to monitor degradation of the multiple coupons.

8. The wellbore apparatus of claim 6, wherein the sensor is to monitor one of the multiple coupons.

9. The wellbore apparatus of claim 6, wherein the sensor comprises an optical sensor that detects a change to a size of one or more of the multiple coupons in response to coupon degradation.

10. The wellbore apparatus of claim 6, wherein the sensor comprises a chemical sensor that detects a chemical change in response to degradation of one or more of the multiple coupons.

11. The wellbore apparatus of claim 10, wherein the chemical sensor is to monitor a pH around one or more of the multiple coupons.

12. The wellbore apparatus of claim 6, wherein the sensor comprises a pressure sensor that detects a change to a mass or volume of one or more of the multiple coupons.

13. The wellbore apparatus of claim 6, further comprising:a communication connection between the sensor and surface equipment, wherein the sensor is to provide monitoring information to the surface equipment.

14. A method for monitoring a wellbore, comprising:deploying a carrier downhole to a target depth in the wellbore, the carrier having one or more mounts with multiple coupons mounted in the one or more mounts, the multiple coupons made of different degradable materials to degrade at different rates in a wellbore environment, where degradation of the multiple coupons indicates a degradation rate of the different degradable materials in a wellbore environment of the wellbore; andmonitoring a degradation of one or more of the multiple coupons with a sensor mounted on the carrier.

15. The method of claim 14, wherein the mount comprises a structure on an outside of a body of the carrier.

16. The method of claim 14, wherein the mount comprises a removable cartridge that holds one or more of the multiple coupons.

17. The method of claim 14, wherein monitoring the degradation with the sensor comprises monitoring a change to a size of one or more of the multiple coupons with an optical sensor.

18. The method of claim 14, wherein monitoring the degradation with the sensor comprises monitoring a chemical change with a chemical sensor or a pH sensor.

19. The method of claim 14, wherein monitoring the degradation with the sensor comprises monitoring a change to a mass or volume with a pressure sensor.

20. The method of claim 14, further comprising:sending monitoring information to surface equipment over a communication connection between the sensor and the surface equipment.

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