Patent Application
20170247966
Repair devices can be used to repair damaged and/or leaking tubing strings in a variety of oil and/or gas wellbores. A tubing string can be damaged by installing well tools downhole in the tubing string, conveying the well tools through the tubing string, failure to properly secure threaded connections of the tubing string, or failures in the manufacturing process. A repair device can be run into the tubing string while the tubing string remains in a wellbore, thereby repairing the damaged portion of the tubing string without requiring removal of the tubing string from the wellbore.
The features and advantages of certain embodiments will be more readily appreciated when considered in conjunction with the accompanying figures. The figures are not to be construed as limiting any of the preferred embodiments.
Oil and gas hydrocarbons are naturally occurring in some subterranean formations. In the oil and gas industry, a subterranean formation containing oil or gas is referred to as a reservoir. A reservoir can be located under land or off shore. Reservoirs are typically located in the range of a few hundred feet (shallow reservoirs) to a few tens of thousands of feet (ultra-deep reservoirs). In order to produce oil or gas, a wellbore is drilled into a reservoir or adjacent to a reservoir. The oil, gas, or water produced from a reservoir is called a reservoir fluid. As used herein, a “fluid” is a substance having a continuous phase that tends to flow and to conform to the outline of its container when the substance is tested at a temperature of 71° F. (22° C.) and a pressure of one atmosphere “atm” (0.1 megapascals “MPa”). A fluid can be a liquid or gas.
A well can include, without limitation, an oil, gas, or water production well, or an injection well. As used herein, a “well” includes at least one wellbore. A wellbore can include vertical, inclined, and horizontal portions, and it can be straight, curved, or branched. As used herein, the term “wellbore” includes any cased, and any uncased, open-hole portion of the wellbore. A near-wellbore region is the subterranean material and rock of the subterranean formation surrounding the wellbore. As used herein, a “well” also includes the near-wellbore region. The near-wellbore region is generally considered to be the region within approximately 100 feet radially of the wellbore. As used herein, “into a well” means and includes into any portion of the well, including into the wellbore or into the near-wellbore region via the wellbore.
A portion of a wellbore can be an open hole or cased hole. In an open-hole wellbore portion, a tubing string can be placed into the wellbore. The tubing string allows fluids to be introduced into or flowed from a remote portion of the wellbore. In a cased-hole wellbore portion, a casing is placed into the wellbore that can also contain a tubing string. A wellbore can contain an annulus. Examples of an annulus include, but are not limited to: the space between the wellbore and the outside of a tubing string in an open-hole wellbore; the space between the wellbore and the outside of a casing in a cased-hole wellbore; the space between the inside of a casing and the outside of a tubing string in a cased-hole wellbore; and the space between the outside of a well tool and the inside of a casing or tubing string.
Completion of the wellbore can initially require installation of a tubing string into the wellbore. Then various well tools and/or other tubing strings can be run in the wellbore to perform various wellbore operations, such as cementing, perforating, etc. Installation of the well tools and/or other tubing strings can cause damage to the tubing string initially installed in the wellbore.
The tubing string can become damaged during 1) installation of well tools downhole in the tubing string, 2) conveying the well tools through the tubing string, 3) a failure to properly secure threaded connections of the tubing string, or 4) failures in the manufacturing process. The damage can cause an inner wall of the tubing string to lose its sealing capability and/or cause leakage through the wall of the tubing string. The inability to form a seal with a well tool can cause the well tool to fail when it is landed at the location of the damage in the tubing string. Leakage through the tubing wall can also cause loss of a fluid from the tubing string and an inability to maintain pressure in the tubing string.
Tools have been developed to repair this type of damage without having to remove the tubing string from the wellbore. One such tool includes a polishing wheel that is positioned at the location of the damage to the tubing string. A repair material is supplied to an exterior of the polishing wheel while the wheel is rotating within the tubing string. Rotation of the wheel forces the repair material into the recesses caused by the damage and polishes the inner wall of the tubing string, thereby forcing the repair material into the recesses. However, this type of tool requires a motor which can increase the complexity and expense of the tool. The polishing of the inner wall can actually increase a diameter of the inner wall of the tubing string. Additionally, the tool does not prevent excess repair material from being released into a remainder of the tubing string during the polishing operation.
Thus, there is a need for improved repair devices that can repair damaged tubing strings. It has been discovered that a repair device can be used that has a reduced complexity when compared to other repair tools. Additionally, the device can repair the damaged tubing without changing the inner diameter of the tubing string, and prevent release of repair material into the remainder of the tubing string when the recesses are being filled with repair material. Furthermore, the repair device can repair the damage to the tubing string without having to remove the tubing string from the well.
According to certain embodiments, a repair device can include a chamber, a piston positioned within the chamber, and a filler material contained within the chamber. The filler material can be expelled from the chamber and forced to fill a recess in a damaged portion of a tubing string (e.g., a seal bore, a threaded connection, etc.). When the repair device is moved upward, a seal, such as a chevron-type seal with V-shaped seal elements, can wipe away any excess filler material that is not contained within the recess, and cause the damaged portion of the tubing string to be repaired. An actuator can be used to apply a force to the piston, thereby expelling the filler material from the chamber. The force can also be applied to the piston by a means other than an actuator. For example, hydraulic pressure from an internal flow passage of the tubing string or coiled tubing can act on the piston to move it within the chamber, thereby expelling some of the filler material from the chamber.
According to certain other embodiments, a repair device can include multiple chambers, one or more pistons, and multiple filler materials contained within the chambers. The filler materials can be expelled from the chambers by moving the piston(s) and forcing the filler material out of the chambers to fill a recess in a damaged portion of a tubing string. The multiple filler materials can mix sufficiently within the repair device and/or in an annulus between the repair device and the tubing string to create a filler material that will remain within the recesses. For example, if a two-part epoxy were used as a filler material, one chamber can contain an epoxy part A material and another chamber can contain an epoxy part B material. When the piston is moved by application of a force, portions of the epoxy part A material and epoxy part B materials can be expelled from the chambers and sufficiently mixed in the repair device and/or the annulus. After mixing, the final viscosity of the mixture can increase, compared to the initial viscosity of each separate component, thereby filling the recess and repairing the damaged portion of the tubing string.
Turning to the Figures,
As seen in
Referring again to
The repair device 20 can include a body 21, engagement members 90, a chamber 51, a piston 52, and first and second annular seals 81, 82. The engagement members 90 can be extended and retracted in a variety of ways.
Referring again to
The first and second annular seals 81, 82 seal off an annulus 34 formed between the outside of the repair device 20 and the inner wall of the seal bore 32. An annular recess 66 can be provided in the body 21 to provide more volume in the annulus 34, but it is not necessary to have a recess 66 in the body 21. The annular space provided by the first and second annular seals 81, 82 can be sufficient to support the repair operation.
The first and second annular seals 81, 82 can form a seal against the seal bore 32 to prevent the expelled filler material 50 from escaping the annulus 34 (except through bleeder flow passages and possibly a longitudinal recess 30). The first annular seal 81 is shown as an 0-ring type seal in
The second annular seal 82 is shown in
The male and female end rings 84, 86 are preferably non-resilient, with the semi-resilient seal elements 88 providing a controlled interference fit in the seal bore 32. The seal elements 88 can be made out of a semi-resilient seal material, such as 3×moly-filled TEFLON® material, that provides a proper amount of interference fit with the seal bore 32 to form a seal without substantially extruding into the recess 30 when it wipes the excess material 50 from the seal bore 32. However, other seal assemblies and seal materials can be used as long as they do not substantially extrude into the recess 30 when the second annular seal 82 wipes the excess filler material 50 from the seal bore 32.
The chamber 51 of the repair device 20 can provide a storage area for a filler material 50. The chamber can be a bladder (or multiple bladders) located within the body. When the repair device 20 is positioned at the predetermined location in the tubing string 22, then the filler material 50 can be expelled from the chamber into the annulus 34, where at least a portion of the expelled filler material 50 fills each recess 30.
The chamber 51 can include a piston 52, which is configured to move up and down within the chamber 51. The piston can include a seal 53 that prevents fluid flow past the piston 52. The piston 52 can include a latch mechanism 60, which can be a one-time set/unset mechanism, such as shear pins shown in
Referring to
Bleeder flow passages (not shown) can provide an exit path for the trapped fluid being displaced from the annulus 34. These bleeder flow passages can include a one-way check valve to permit the trapped fluid to exit the annulus 34 while preventing any well fluids from entering the annulus 34. However, the bleeder flow passages can also be open flow passages without including a valve.
The bleeder flow passages can provide an indication to an operator that the filler material 50 has filled the annulus 34. The filler material 50 will generally be a higher viscosity fluid than the fluid that is trapped in the annulus 34. Therefore, when the trapped fluid exits the annulus through the bleeder flow passages and the higher viscosity filler material 50 begins to flow through the bleeder flow passages, the pressure differential across the filler material 50 can increase. This pressure increase can be detected by the operator at the rig 48 or remote location. Upon the detection, the operator can deactivate the actuator 54, and/or remove pressure applied to the piston 52, to prevent expelling any more filler material 50 from the chamber 51. This increased pressure can indicate that the annulus 34 and any recesses in the annulus are filled with the filler material 50.
However, the pressure indication is not required for the repair operation. The amount of filler material 50 to be expelled into the annulus 34 can be determined beforehand. The expelled volume of filler material 50 can be controlled by adjusting the amount of travel of the piston 52, the size of the piston 52, the amount of time the actuator 54 is actuated, etc. The radially reduced annular ring 62 can be used as a stop for the piston 52. Therefore, when the latch mechanism 60 releases the piston 52, the actuator can move the piston 52 until it engages the stop 62. Since the volume of the filler material 50 displaced by the piston 52 is known, then no remote detection is required to complete the process of filling the annulus 34.
Examples of suitable filler materials 50 include, but are not limited to, a plastic resin, a silicone based fluid with additives, a coating compound, an epoxy, and combinations thereof. The material 50 can be any substance so long as the substance can flow from the chamber 51 and can be retained in the recess 30 once the repair device 20 is retrieved from the tubing string 22. The substance would preferably produce a surface with sufficient rigidity that a seal can be formed in the tubing string at the location of the recess 30, e.g., when a well tool is landed in the seal bore 32.
The expelled filler material 50 should be of sufficient viscosity to remain in each recess 30 when the repair device 20 is removed from the tubing string 22. The viscosity of the expelled filler material 50 can be the same as the initial viscosity of the filler material 50 prior to it being expelled into the annulus 34. However, the expelled filler material 50 can have an increase in viscosity after being expelled. By way of example, the expelled filler material can become at least partially cured in the annulus in order to remain within the recess. As used herein, the term “cure” and all grammatical variations thereof means the process of developing compressive strength and becoming hard or solid through heat or a chemical reaction.
Once each recess 30 is filled with the expelled filler material 50, and the desired viscosity for the expelled filler material 50 is reached, then the repair device 20 can be pulled out of the seal bore 32 and out of the tubing string 22. The desired viscosity is the viscosity required to prevent the expelled filler material 50 from flowing out of the recess 30 when the repair device is pulled out of the seal bore 32. The expelled filler material 50 can continue to harden even after the repair device 20 has been removed from the seal bore 32.
The repair device 20 can be removed from the tubing string 22 after the recess 30 have been filled with the filler material 50. The second annular seal 82 can be used to wipe (or squeegee) any excess expelled filler material 50 from the seal bore “without substantially removing” any of the expelled filler material 50 that was forced into the recess 30. A small amount of the expelled filler material 50 may be removed from the recess 30 producing a dimple in the expelled filler material 50 in the recess. However, it is preferable, in order for a seal to be created, that the dimple does not increase the radius R of the seal bore 32 at the recess 30 by more than 0.001 inches. Therefore, the phrase “without substantially removing” refers to not removing more than a dimple with a depth of 0.001 inches of material 50 from the filled recess 30. Additionally, the resulting surface of the expelled filler material 50 that fills the recess 30 can be at least within radius R+/−0.001 inches from the center axis 80. This resulting surface can provide a circumferentially contiguous sealing surface at the location of the recess 30 in the seal bore 32. This contiguous sealing surface can provide sufficient sealing for seals that are landed in the seal bore 32 and sealingly engage the seal bore 32.
Referring to
By way of example, there can be a 2 part epoxy system comprising two or more ingredients, such as a curable resin and a curing agent, where the curable resin is included in one chamber and the curing agent is included in another chamber. The curable resin and the curing agent can then be expelled into the annulus via the distributed ports to enable adequate mixing of the resin and agent within the annulus to form the filler material. According to certain embodiments, the number of chambers and the number and distribution of the ports are selected such that an adequate amount of mixing occurs to enable the mixed filler material to fill the recesses. The rest of the operation of this embodiment is similar to the operation of the repair device 20 described above and depicted in
Therefore, the present system is well adapted to attain the ends and advantages mentioned as well as those that are inherent therein. The particular embodiments disclosed above are illustrative only, as the present invention can be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is, therefore, evident that the particular illustrative embodiments disclosed above can be altered or modified and all such variations are considered within the scope and spirit of the present invention.
As used herein, the relative terms “up” and “above” and all grammatical variations thereof mean at a location closer to the wellhead of the wellbore. As used herein, the relative terms “down” and “below” and all grammatical variations thereof mean at a location farther away from the wellhead of the wellbore. It is also to be understood that as used herein, the term “metal” is meant to include pure metals and also metal alloys without the need to continually specify that the metal can also be a metal alloy. It should also be understood that, as used herein, “first,” “second,” “third,” etc., are arbitrarily assigned and are merely intended to differentiate between two or more seals, chambers, pistons, etc., as the case can be, and does not indicate any particular orientation or sequence. Furthermore, it is to be understood that the mere use of the term “first” does not require that there be any “second,” and the mere use of the term “second” does not require that there be any “third,” etc.
As used herein, the words “comprise,” “have,” “include,” and all grammatical variations thereof are each intended to have an open, non-limiting meaning that does not exclude additional elements or steps. While compositions and methods are described in terms of “comprising,” “containing,” or “including” various components or steps, the compositions and methods also can “consist essentially of” or “consist of” the various components and steps. Whenever a numerical range with a lower limit and an upper limit is disclosed, any number and any included range falling within the range is specifically disclosed. In particular, every range of values (of the form, “from about a to about b,” or, equivalently, “from approximately a to b”) disclosed herein is to be understood to set forth every number and range encompassed within the broader range of values. Also, the terms in the claims have their plain, ordinary meaning unless otherwise explicitly and clearly defined by the patentee. Moreover, the indefinite articles “a” or “an,” as used in the claims, are defined herein to mean one or more than one of the element that it introduces. If there is any conflict in the usages of a word or term in this specification and one or more patent(s) or other documents that can be incorporated herein by reference, the definitions that are consistent with this specification should be adopted.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2014/067982 | 12/1/2014 | WO | 00 |
