Patent Application
20160356095
None.
Methods and apparatus are presented for connecting downhole connectors in a wellbore environment. More particularly, methods and apparatus are presented for protecting a Point of Interest prior to and during connection to another Point of Interest, for example, when making a downhole fiber optic connection.
Without limiting the scope of the present invention, its background is described with reference to using optical fibers for communication in a subterranean wellbore environment, as an example. It is well known in the subterranean well completion and production arts that downhole sensors can be used to monitor a variety of parameters in the wellbore environment. For example, during a treatment operation, it may be desirable to monitor a variety of properties of the treatment fluid such as viscosity, temperature, pressure, velocity, specific gravity, conductivity, fluid composition and the like. Transmission of this information to the surface in real-time or near real-time allows the operators to modify or optimize such treatment operations to improve the completion process. One way to transmit this information to the surface is through the use of communication lines, such as one or more optical fibers, copper or metallic cables, or hydraulic or pressure lines. In addition, optical fibers may serve as sensors, where the optical fiber obtains distributed measurements related to a parameter along the length of the fiber.
In a typical wellbore treating or stimulation operation, a lower portion of completion string including various tools such as sand control screens, fluid flow control devices, wellbore isolation devices and the like is permanently installed in the wellbore. The lower portion of the completion string may include various sensors, particularly, a lower portion of optical fiber. After the stimulation process, an upper portion of the work string including an upper portion of optical fiber is separated from the lower completion string and retrieved to the surface. This operation cuts-off communication between the lower string, which remains in place, and the surface. Accordingly, if information from the production zones is to be transmitted to the surface during later production operations, a connection to the lower optical fiber must be reestablished when the production tubing string is installed.
It has been found, however, that wet-mating optical fibers in a downhole environment is very difficult. Difficulties due to lack of precision in the axial movement of the production string relative to the previously installed completion string are addressed, for example, in U.S. Pat. No. 8,122,967, to Richards, entitled Apparatus and Method for Controlling the Connection and Disconnection Speed of Downhole Connectors, which is hereby incorporated by reference for all purposes. Further disclosure regarding downhole connections can be found in U.S. Patent Application Publication 2012/0181045, to Thomas, entitled Apparatus and Method for Controlling the Connection and Disconnection Speed of Downhole Connectors, which is hereby incorporated by reference for all purposes.
Additionally, wet-mate connections or wet-connects have become prevalent, especially in off-shore deep wells where it is difficult to provide for a dry-connection. A downhole communication line and a connector are often left in place, such as at the upper end of a completion string or production string. A second tool string is later lowered into the wellbore, also having a communication line and connector. The communication connectors are mated to provide an operable communication link between the tools. While it is possible to lower tool strings with all of the communication lines and corresponding conduits in place, there is increasing interest in wet-connect or wet-mate capabilities, that is, connections made in a wet environment. Further, it is often necessary or desirable to disconnect the tools and repeat the process, as later tools are inserted into the well, to speed and simplify equipment changes, replacement, or employ different tool configurations over time.
Typically wet-connects are hydraulic or electric in nature, where a pressure-competent connection or an electrically isolated connection, respectively, must be created. These require a reasonably high degree of cleanliness and several methods are known to make these connections with varying success. With the increase in usage of fiber optic communication lines in particular, it has become critical to provide an especially “clean” connection between mating connectors. Fiber optic connections generally require relatively greater positional registration and cleanliness.
Therefore, a need has arisen for apparatus and methods for wet-connecting optical fibers and other communication lines in a subterranean wellbore environment.
In a preferred embodiment, an apparatus for excluding debris during a downhole wet-mate connection is presented. The apparatus includes a first downhole assembly having a housing, a first connector attached to the housing, a first communication line attached to the first connector, and a reciprocating cover member mounted for sliding engagement with the first housing. A second downhole assembly is provided, having a housing, a connector attached to the housing, a communication line having a free end attached to the connector, and a bladder cover member attached to the housing. The reciprocating cover member is moveable between a closed position, wherein the free end of the communication line is substantially enclosed, and an open position in which the free end of the communication line is exposed. The reciprocating cover member is moved in response to contact with the second downhole assembly. The bladder cover member is movable between a closed position, in which the bladder cover member substantially closes an otherwise open end of a housing chamber defined in the second downhole assembly, and an open position, wherein the bladder cover member is moved to open the open end of the housing chamber. The bladder cover member is moved to the open position by contact with the reciprocating cover member of the first downhole assembly. The reciprocating cover member can be biased towards the closed position by a spring element. The reciprocating cover member is preferably slidably mounted on the housing, such as slidably mounted on a cylindrical extension of the housing. The reciprocating cover member is preferably operable to move the bladder cover member to the open position. The reciprocating cover member is preferably operable to, prior to moving to an open position, move into the housing chamber. The housing chamber and the reciprocating cover member are preferably filled with a clean fluid, such as a dielectric fluid. The reciprocating cover member is preferably operable to move in response to relative movement of the first and second downhole assemblies. The housing of the second downhole assembly can define a surface for contacting and moving the reciprocating cover member axially. In a preferred embodiment, the connector of the first assembly is operable, in response to movement of the reciprocating cover member, to force open the reciprocating cover member. The bladder cover member can have pre-formed cuts, be made of elastomeric material, be spring biased toward the closed position, etc. The reciprocating cover member is preferably made of metal or other material stronger than the bladder cover. The reciprocating cover member is preferably biased towards a closed position. Additionally, the apparatus can include clean fluid reservoirs for re-filling the housing chamber and/or reciprocating cover member upon disconnection of the communication lines. The apparatus can provide clean fluid to the housing chamber or reciprocating cover member in response, for example, to suction pressure created during disconnection of the assemblies.
For a more complete understanding of the features and advantages of the present invention, reference is now made to the detailed description of the invention along with the accompanying figures in which corresponding numerals in the different figures refer to corresponding parts and in which:
It should be understood by those skilled in the art that the use of directional terms such as above, below, upper, lower, upward, downward and the like are used in relation to the illustrative embodiments as they are depicted in the figures, the upward direction being toward the top of the corresponding figure and the downward direction being toward the bottom of the corresponding figure. Where this is not the case and a term is being used to indicate a required orientation, the Specification will state or make such clear.
While the making and using of various embodiments of the present invention are discussed in detail below, a practitioner of the art will appreciate that the present invention provides applicable inventive concepts which can be embodied in a variety of specific contexts. The specific embodiments discussed herein are illustrative of specific ways to make and use the invention and do not limit the scope of the present invention. The description is provided with reference to a vertical wellbore; however, the inventions disclosed herein can be used in horizontal, vertical or deviated wellbores. 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. It should be understood that, as used herein, “first,” “second,” “third,” etc., are arbitrarily assigned, merely differentiate between two or more items, and do not indicate sequence. Furthermore, the use of the term “first” does not require a “second,” etc. The terms “uphole,” “downhole,” and the like, refer to movement or direction closer and farther, respectively, from the wellhead, irrespective of whether used in reference to a vertical, horizontal or deviated borehole. The terms “upstream” and “downstream” refer to the relative position or direction in relation to fluid flow, again irrespective of the borehole orientation. Although the description may focus on a particular means for positioning tools in the wellbore, such as a tubing string, coiled tubing, or wireline, those of skill in the art will recognize where alternate means can be utilized. As used herein, “upward” and “downward” and the like are used to indicate relative position of parts, or relative direction or movement, typically in regard to the orientation of the Figures, and does not exclude similar relative position, direction or movement where the orientation in-use differs from the orientation in the Figures.
Referring to
A wellbore 38 extends through the various earth strata including formation 14. An upper portion of wellbore 38 includes casing 40 that is cemented within wellbore 38. Disposed in an open hole portion of wellbore 38 is a completion string 42 that includes various tools such as packer 44, a seal bore assembly 46 and sand control screen assemblies 48, 50, 52, 54. In the illustrated embodiment, completion string 42 also includes an orientation and alignment subassembly 56 that houses a downhole wet mate connector. Extending downhole from orientation and alignment subassembly 56 is a conduit 58 that passes through packer 44 and is operably associated with sand control screen assemblies 48, 50, 52, 54. Preferably, conduit 58 is a spoolable metal conduit, such as a stainless steel conduit that may be attached to the exterior of pipe strings as they are deployed in the well. In the illustrated embodiment, conduit 58 is wrapped around sand control screen assemblies 48, 50, 52, 54. One or more communication media such as optical fibers, electrical conducts, hydraulic fluid or the like may be disposed within conduit 58. In certain embodiments, the communication media may operate as energy conductors including power and data transmission between downhole a location or downhole sensors (not pictured) and the surface. In other embodiments, the communication media may operate as downhole sensors.
For example, when optical fibers are used as the communication media, the optical fibers may be used to obtain distributed measurements representing a parameter along the entire length of the fiber such as distributed temperature sensing. In this embodiment, a pulse of laser light from the surface is sent along the fiber and portions of the light are backscattered to the surface due to the optical properties of the fiber. The slightly shifted frequency of the backscattered light provides information that is used to determine the temperature at the point in the fiber where the backscatter originated. In additions as the speed of light is constant, the distance from the surface to the point where the backscatter originated can also be determined. In this manner, continuous monitoring of the backscattered light will provide temperature profile information for the entire length of the fiber.
Disposed in wellbore 38 at the lower end of production tubing string 36 are a variety of tools including seal assembly 60 and anchor assembly 62 including downhole wet mate connector 64. Extending uphole of connector 64 is a conduit 66 that extends to the surface in the annulus between production tubing string 36 and wellbore 38 and is suitable coupled to production tubing string 36 to prevent damage to conduit 66 during installation. Similar to conduit 58, conduit 66 may have one or more communication media, such as optical fibers, electrical conducts, hydraulic fluid or the like disposed therein. Preferable, conduit 58 and conduit 66 will have the same type of communication media disposed therein such that energy may be transmitted therebetween following the connection process. As discussed in greater detail below, prior to producing fluids, such as hydrocarbon fluids, from formation 14, production tubing string 36 and completion string 42 are connected together. When properly connected to each other, a sealed communication path is created between seal assembly 60 and seal bore assembly 46 which establishes a sealed internal flow passage from completion string 42 to production tubing string 36, thereby providing a fluid conduit to the surface for production fluids. In addition, as discussed in greater detail below, the present invention enables the communication media associated with conduit 66 to be operatively connected to the communication media associated with conduit 58, thereby enabling communication therebetween and, in the case of optical fiber communication media, enabling distributed temperature information to be obtained along completion string 42 during the subsequent production operations.
Even though
The tool string shown is schematic only, lacking details such as joints, tubing sections, additional tools, lines, sealing devices, etc., is not to scale, does not attempt to show all of the tools and sections typically used in such a work string, and is exemplary, as the tool string can have fewer or more tools, in various arrangements, as is known in the art. The wellbore can be cased, cemented, and at various stages of preparation, stimulation, production, etc. Further, the wellbore can be vertical, deviated or horizontal.
The tool string 74 is shown lowered into position above a lower tool assembly 90 positioned at a downhole location in the wellbore. The exemplary lower tool assembly 90 includes a scoop head assembly 92, an isolated tubing section 94, a circulating valve 96, screen assembly 98 adjacent perforated region 99, and sensors, gauges, data transmission systems, and other downhole electronic equipment 97. The region 99 is isolated by annular barriers such as sump packer 95 and packer 93. The lower tool assembly is held in position by packers, anchoring devices, or the like. The lower assembly shown is exemplary and schematic only and may include additional or differing tools and configurations as are known in the art. The scoop head assembly 92 is designed to connect to the anchor head of the tool string 74. A lower wet-mate connector assembly 91 with multiple lower wet-mate connectors 89 is positioned at the upper end of the lower tool assembly 90. The lower wet-mate connector can be positioned in or adjacent the scoop head assembly. The lower wet-mate connector maintains the positioning of a free end of lower communication cable or line 87.
As the tool string 74 is lowered into position above the lower tool assembly 90, the anchor head assembly aligns with and contacts the scoop head assembly. Further movement of the tool string downward results in contact and connection of the upper and lower wet-mate connectors, thereby allowing communication between downhole equipment and the surface. The details of the connection are discussed herein in exemplary embodiments including apparatus and methods for executing a clean connection between wet-mate connectors.
The invention described herein is generally discussed in terms of providing for protected connections or connectors of fiber optic cables or lines. Such terms are used to generically refer to communications cables, wires, lines, conduits, etc., including fiber optic, copper or other metal, hydraulic, etc. The term “Point of Interest” is used to refer to the end of the communication line which is to be connected to a corresponding end of another line, or to the line end and connector or connector body holding the line end. In
The anchor head assembly 108 preferably houses the upper components of the reciprocating debris exclusion assembly while the lower cooperating components of the reciprocating debris exclusion assembly are preferably housed in a top sub 124 of the lower tool assembly 120. The upper tool assembly has a mandrel 126 on which is slidably mounted the anchor head assembly 108, including anchor head 128. The anchor head 128 defines longitudinally downwardly extending props 130 which cooperate with the operation locking assembly 110. The operation locking assembly 110 includes an operation locking body 131 with locking keys 132 mounted thereon which cooperate with corresponding key windows 134 in the locking assembly. The locking keys are unsupported during run-in.
The upper tool assembly also includes an alignment subassembly 136 with exterior longitudinally extending alignment lug 138 which interacts with the slot 174 of the scoop head of the lower tool assembly 120 to rotate the upper tool assembly to the preferred alignment during insertion into the lower tool assembly.
The reciprocating debris exclusion assembly 118 includes an upper reciprocating subassembly 140 mounted on the upper tool assembly 100 and a lower reciprocating subassembly 142 mounted on the lower tool assembly 120.
The upper reciprocating subassembly 140 includes a slidably mounted connector block 144 which slides longitudinally within recess 146 defined in anchor head 128. The upper connector block 144 contacts lug 143 which is fixedly attached to, or extends from, the mandrel 126. The upper fiber optic lines are carried in upper connectors 147, one for each fiber optic line. The upper connectors 147 are slidably mounted to the anchor head 128 and extend from the splicer block 150 and through corresponding holes 148 in reciprocating connector block 144. The splicer block 150 is spring biased, such as by biasing elements 113, shown as springs. Protective covers 152 are mounted on the reciprocating block 144 and positioned to cover the free ends of the connectors 147 (and the line ends held thereby) during run-in and prior to connection. The covers 152 are preferably biased by biasing elements towards a closed position, as seen in
The upper reciprocating connector block 144 defines at its lower end a plurality of longitudinally downward extending lugs 153 which cooperate with corresponding guides 168 in the top sub 124 of the lower tool assembly 120. The anchor head 128 has longitudinally extending lugs 129 which extend under the reciprocating block 144 and cooperate, in use, with corresponding channels 141 defined in the interior surface of the top sub 124 of the lower tool assembly, as best seen in
It is understood that one or more communication lines can be used, and that a single line from the surface can be split using conventional splitters into multiple lines at or near the lower end of the work string. For example, the multiple connectors 147 each carry a length of fiber optic line for connection to corresponding lengths of line on the lower tool assembly. However, a single fiber optic line extends from the surface to a splitter positioned within splicer or splitter housing 150 on the upper tool assembly. Similarly, one or more lines can be run on the lower tool assembly, or a single line with splitters near the connection location. Splices can be used to merge lines as well, such as lines from various sensors on the lower tool assembly.
The lower reciprocating subassembly 142 includes a slidably mounted connector block 154 which slides longitudinally within a recess or between guides defined in the top sub 124 of the lower tool assembly 120. The lower connector block 154 is spring biased, such as by biasing elements 156, shown as springs, towards a closed position, as seen in
The lower reciprocating assembly also includes an upper profile having a plurality of longitudinally extending guides 168 for contacting lugs 153 of the upper reciprocating block 144. Key holes 166 are defined in the top sub 124 for cooperating with locking keys 132 of the operation locking assembly 110 of the upper tool assembly 100. Channels 141 are defined on the interior surface of the top sub to receive and cooperate with lugs 129 of the anchor head.
As the anchor starts metering, that is, as hydraulic fluid is transferred from the upper chamber 216 to the lower chamber 218, the resetting spring 206 is compressing. Metering is started by setting down weight on the upper tool assembly through the work string. For example, a set-down weight of 10k pounds can be used to start metering the anchor. When crack relief pressure is reached, the anchor begins collapsing and the resetting spring is compressed. The anchor continues metering, which pushes downwards on the external components until the anchor head no-goes against the top sub of the lower tool assembly.
For further disclosure as to the operation of the resetting spring and assembly, see U.S. Patent Application Publication No. 2012/0181045, to Thomas, filed Feb. 25, 2012.
The upper reciprocating connector block 144 defines at its lower end a plurality of longitudinally downward extending lugs 153 which cooperate with corresponding guides 168 in the top sub 124. The anchor head 128 has longitudinally extending lugs 129 which extend under the reciprocating block 144 and cooperate with corresponding channels 141 defined in the interior surface of the top sub 124. The lugs 129 contact corresponding faces 170 defined on the upper end of the lower reciprocating block 154, forcing the lower block to move longitudinally downward. The anchor head has “no-go” or lug faces 145 which cooperate with corresponding no-go faces 172 defined on the upper end of the top sub 124 (not seen here).
The lower reciprocating subassembly 142 includes a slidably mounted connector block 154 which slides longitudinally within a recess or between guides defined in the top sub 124 of the lower tool assembly 120. The lower connector block 154 is spring biased by biasing elements 156 towards a closed position. The lower fiber optic lines are carried in lower connectors 158. The lower connectors 158 are attached to top sub 124 of lower tool assembly 120 and extend through corresponding holes 160 in lower reciprocating connector block 154. Protective covers 162 are mounted on the reciprocating block 154 and positioned to cover the free ends of the connectors 158 (and the line ends held thereby) prior to connection. The covers 162 are biased towards a closed position, as seen in
Anchor head 128 moves downward as upper connector block 144 is held in position by the upper profile of the top sub, causing relative movement between the block 144 and anchor head 128. The holes 148 in reciprocating connector block 144 allow upper connectors 147 to maintain position relative to the reciprocating block, and the connector protective covers 152 are pulled along with upper block 144, forcing the covers 152 to open revealing the free ends 149 of the connectors and fiber optic line ends. The longitudinally extending lug 129 of the anchor head 128 extends into corresponding channel 141 defined in top sub 124. Lug 129 of the anchor head contacts corresponding lower connector block face 170 defined at the upper end of the lower connector block 154. As the anchor head continues its downward stroke, the lug 129 forces the lower reciprocating block 154 to move downward. Movement of the block 154 pulls the attached covers 162 downward, thereby exposing the ends of the lower connectors and free ends 278 of the lower fiber optic lines. Biasing element 156 is compressed by this movement as well. The upper connectors 147 move relative to the mandrel 126 as production spring 234 pushes against sub 238 which itself is connected to the anchor head, as better seen in
It is anticipated that it will be desirable to remove the upper tool assembly at some point during the life of the well, to repair or replace parts, to run different tools or strings, etc. In such a case, it is desirable to protect the Points of Interest from environmental fluids, debris, and contaminants. Consequently, after or during disconnection of the connectors, the connector blocks, both upper and lower, are forced back to their initial positions such the covers are moved toward the connector free ends. In the preferred embodiment, the lower connector block 154 is moved to its initial or closed position by a biasing element such as springs 156. The upper reciprocating block 144 is returned to its initial or closed position mechanically by a lug 143 for that purpose extending radially outward from the exterior surface of the mandrel 126. The covers, also biased to a closed position, close over the free ends of the fiber optic lines, thus protecting them during pull out of hole. The reciprocating debris exclusion assembly can be used repeatedly in well operations.
The methods and steps for removal of the upper tool assembly are briefly described and will be understood by those of skill in the art. The work string is pulled towards the surface (upwards in a vertical well) from the surface rig with enough force to pull the collet dogs 202 out of profile 200 in the scoop head. The resetting spring 206 is then free to expand as the work string is pulled further upwards. The metering assembly operates similarly to that described above but with the metering fluid and piston moving in the opposite direction. The metering fluid travels from chamber 218 to chamber 214. Keys 240 move radially outward to allow the mandrel 244 to move upward with the work string. Spring 234 expands. Sub 238 contacts mandrel 122. Anchor head 128 is then pulled away from the top sub 124. This releases lower block 154 and allows springs 156 to extend and move block 154 to cover the lower connector ends. The lower protective covers 162, due to the biasing elements therein, are moved to a closed position over the free ends of the lower connectors. As anchor head is moved upward relative to the mandrel 126, lug 143 extending radially outward from the exterior surface of the mandrel 126 contacts and pulls the reciprocating block 144 downward, back to its initial or closed position. The upper connector covers 152 return to a closed position over the free ends of the connector lines due to the biasing force of the biasing elements acting thereon. As anchor head 128 moves upward relative to mandrel 126, prop 130 is pulled from under keys 132, leaving the keys unsupported. The unsupported keys move radially inward, releasing the upper tool assembly and work string from the top sub of the lower tool assembly.
The reciprocating debris exclusion device disclosed herein can be used in combination with other tool assemblies; that is, with work strings made up for a different purpose, on coiled tubing or wireline, and to perform other functions which require the protection from debris of Points of Interest. The invention is limited only by the claims.
The upper connector assembly 402 has a housing 406 with an upper connector 408 attached thereto and extending longitudinally therefrom. The connector is seen connected to the housing, such as at threads 410, and holds the free end 403 of a communication line 412 which runs to the surface, other downhole tools or sensors, etc. In the embodiment shown, the connector 408 remains stationary with respect to the housing, however, alternative arrangements can be used wherein the connector also moves relative to the housing, such as on a sliding block, biased element, etc. An upper connector cover 414 is initially in a closed position and protects the free end of the connector and communication line from debris and damage. The cover 414 has a flange 415 at its base 416 and is supported by a biasing element such as spring 418. The cover base 416 is preferably cylindrical and positioned exterior to a support cylinder 420 extending from the housing. The biasing spring 418 abuts a shoulder 419 defined on the housing at one end and a surface of the flange of the cover at the other end. As the cover reciprocates between a closed and open position, the cover slides with respect to and is supported by the support cylinder 420. In one embodiment, the interior chamber 421 defined by the upper cover is filled with a clean fluid, such as a heavy dielectric fluid.
The lower connector assembly 404 has a housing 422 with a lower connector 424 attached thereto. The connector is seen connected to the housing, such as at threads 426, and holds the free end 427 of a communication line 428 which runs other downhole tools or sensors, etc. In the embodiment shown, the connector 424 remains stationary with respect to the housing, however, alternative arrangements can be used wherein the connector moves relative to the housing. A lower connector cover 430 is initially in a closed position and protects the free end of the lower connector and lower communication line from debris and damage. The cover 430 has a flange 432 at its base, where it is attached to the housing 422. The closed cover 430, housing 422, and connector 424 end define a chamber 434 into which the free end of the communication line 428 extends. The chamber is preferably filled with a heavy dielectric fluid or other clean fluid.
During positioning, the lower cover 430 wipes any contaminates from the exterior of the upper cover 414. Additionally, as the upper cover enters the lower chamber 434, the clean fluid therein is flushed out of the chamber, washing the exterior surfaces of the upper cover.
During disconnection, the upper assembly is pulled away from the lower assembly, the upper and lower lines disconnect, and, as the support cylinder is withdrawn from the lower chamber, the upper cover is forced back to its initial position by spring 418. In an embodiment where the upper cover is biased to a closed position, the upper cover closes over the end of the connector 408. Where the lower cover is resilient or biased towards a closed position, the lower cover returns towards its initial or closed position thereby protecting the lower connector. The embodiment shown is exemplary in nature. In other embodiments, where multiple disconnects and re-connects are anticipated, clean fluid reservoirs (not shown) can supply additional fluid during disconnection. For example, fluid can be pulled from the reservoirs by the suction caused during separation of the assemblies, thereby refilling the fluid chambers. Other arrangements will be apparent to those of skill in the art.
In preferred embodiments, the following methods are disclosed; the steps are not exclusive and can be combined in various orders, with steps omitted, repeated and/or performed in different order. A first downhole assembly, having a first connector with a free end of a first communication line fixed thereto, is positioned at a downhole location in the wellbore. A second downhole assembly, having a second connector with a free end of a second communication line fixed thereto, is moved into the wellbore and relative to the first downhole assembly. A first reciprocating member, mounted for movement on the first downhole assembly, is moved from an initial position to an actuated position, the first reciprocating member moving relative to the first connector. A second reciprocating member, mounted for movement on the second downhole assembly, is moved from an initial position to an actuated position, the second reciprocating member moving relative to the second connector. A first protective cover, attached to the first reciprocating member, is moved from an initial position, wherein the free end of the first communication line is protected from debris, to an open position, wherein the free end of the first communication line exposed. A second protective cover, attached to the second reciprocating member, is moved from an initial position wherein the free end of the second communication line is protected from debris to an open position wherein the free end of the second communication line is exposed. The first and second connectors are connected, establishing communication across the free ends of the first and second communication lines. The preceding steps can be accomplished in various orders, as will be clear upon review of the disclosure herein and as will be clear to persons of skill in the art. After use, the first and second connectors are disconnected. The first reciprocating member is returned to its initial position and the first cover is returned to its initial position wherein the free end of the first connector is protected from debris. Similarly, the second reciprocating member is returned to its initial position and the second cover is returned to its initial position wherein the free end of the second connector is protected from debris.
The steps during connection are in response to moving the second downhole assembly toward the first downhole assembly. The communication lines can be fiber optic, copper, or hydraulic lines. The second downhole assembly can be lowered on a work string, coiled tubing or wireline, for example. The method described, further comprising the step of positioning, in an interior space defined by a first mandrel of the first downhole assembly, a second mandrel of the second downhole assembly. The method described, further comprising the step of rotationally aligning the first and second downhole assemblies relative to one another. The method described, further comprising the step of contacting the first reciprocating member with the second downhole assembly and moving the first reciprocating member relative to the first connector in response to movement of the first downhole assembly. The method described, further comprising the step of contacting and moving the first reciprocating member with a selectively sliding sleeve mounted for longitudinal movement with respect to the second mandrel. The method described, further comprising the step of energizing a biasing element operable to move the first reciprocating member towards its initial position. The method described, further comprising wherein the sliding sleeve is an anchor head mounted slidingly on the second mandrel. The method described, further comprising, wherein the first reciprocating member is mounted for sliding movement on the first mandrel. The method described, further comprising, wherein the first connector is positioned in holes extending through the first reciprocating member. The method described, further comprising the step of contacting the second reciprocating member with the first downhole assembly and moving the second reciprocating member relative to the second connector in response to movement of the first downhole assembly with respect to the first downhole assembly. The method described, further comprising the step of contacting and moving the second reciprocating member with an actuating surface of the first downhole assembly. The method described, further comprising, wherein the actuating surface is a top surface of a bottom sub of the first downhole assembly. The method described, further comprising, wherein the second reciprocating member is mounted for movement on a selectively sliding sleeve of the second downhole assembly, and wherein the selectively sliding sleeve is mounted for movement on the second mandrel. The method described, further comprising, wherein the selectively sliding sleeve is an anchor head and acts to anchor the first and second downhole assemblies to one another. The method described, further comprising, wherein the first and second covers comprise multiple radially movable sections, the sections abutting one another when in an initial position and movable to an open position for exposing the free end of a communication line. The method described, further comprising, wherein the first and second covers are biased towards an initial closed position. The method described, further comprising, wherein the covers are biased by metal beam members attached to a circumferential base. The method described, further comprising, wherein the first and second covers are attached to their respective reciprocating members by a flange, a collet assembly, or a snap ring. The method described, further comprising, wherein the first and second covers each have axial folds defining adjacent cover sections. The method described, further comprising, wherein the first and second covers each have overlapping adjacent cover sections. The method described, further comprising, wherein the first and second connectors are wet-mate connectors. The method described, further comprising, wherein the step of disconnecting further comprises the step of pulling the second downhole assembly uphole. The method described, further comprising the step of returning the first reciprocating member toward its initial position using a biasing element. The method described, further comprising the step of returning the second reciprocating member towards its initial position using a lug extending from the second mandrel. The method described, further comprising the step of pulling the second downhole assembly out of the wellbore.
In another embodiment, an apparatus for excluding debris during a downhole wet-mate connection is presented. The apparatus includes a first downhole assembly having a housing, a first connector attached to the housing, a first communication line attached to the first connector, and a reciprocating cover member mounted for sliding engagement with the first housing. A second downhole assembly is provided, having a housing, a connector attached to the housing, a communication line having a free end attached to the connector, and a bladder cover member attached to the housing. The reciprocating cover member is moveable between a closed position, wherein the free end of the communication line is substantially enclosed, and an open position in which the free end of the communication line is exposed. The reciprocating cover member is moved in response to contact with the second downhole assembly. The bladder cover member is movable between a closed position, in which the bladder cover member substantially closes an otherwise open end of a housing chamber defined in the second downhole assembly, and an open position, wherein the bladder cover member is moved to open the open end of the housing chamber. The bladder cover member is moved to the open position by contact with the reciprocating cover member of the first downhole assembly. The reciprocating cover member can be biased towards the closed position by a spring element. The reciprocating cover member is preferably slidably mounted on the housing, such as slidably mounted on a cylindrical extension of the housing. The reciprocating cover member is preferably operable to move the bladder cover member to the open position. The reciprocating cover member is preferably operable to, prior to moving to an open position, move into the housing chamber. The housing chamber and the reciprocating cover member are preferably filled with a clean fluid, such as a dielectric fluid. The reciprocating cover member is preferably operable to move in response to relative movement of the first and second downhole assemblies. The housing of the second downhole assembly can define a surface for contacting and moving the reciprocating cover member axially. In a preferred embodiment, the connector of the first assembly is operable, in response to movement of the reciprocating cover member, to force open the reciprocating cover member. The bladder cover member can have pre-formed cuts, be made of elastomeric material, be spring biased toward the closed position, etc. The reciprocating cover member is preferably made of metal or other material stronger than the bladder cover. The reciprocating cover member is preferably biased towards a closed position. Additionally, the apparatus can include clean fluid reservoirs for re-filling the housing chamber and/or reciprocating cover member upon disconnection of the communication lines. The apparatus can provide clean fluid to the housing chamber or reciprocating cover member in response, for example, to suction pressure created during disconnection of the assemblies.
Exemplary methods of use of the invention are described, with the understanding that the invention is determined and limited only by the claims. Those of skill in the art will recognize additional steps, different order of steps, and that not all steps need be performed to practice the inventive methods described.
Persons of skill in the art will recognize various combinations and orders of the above described steps and details of the methods presented herein. While this invention has been described with reference to illustrative embodiments, this description is not intended to be construed in a limiting sense. Various modifications and combinations of the illustrative embodiments as well as other embodiments of the invention, will be apparent to persons skilled in the art upon reference to the description. It is, therefore, intended that the appended claims encompass any such modifications or embodiments.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2013/021080 | 1/10/2013 | WO | 00 |
