The present disclosure relates generally to wellbore operations and, more particularly (although not necessarily exclusively), to performing fiber optic cable splicing operations on fiber optic cables within the wellbore.
Fiber optic cables may be installed within a wellbore for performing various sensing operations within the wellbore. To communicatively couple the fiber optic cable to devices at a surface of the wellbore, the fiber optic cable installed within the wellbore may be spliced to a section of fiber optic cable extending from the surface. One or more of the spliced fiber optic cables may have an extra length to ensure that a sufficient amount of fiber optic cable is present for the splicing operation. Techniques for managing extra length may include wrapping the extra length around the production tubing, but wrapping the extra length of fiber optic cable may put the fiber optic cable at greater risk of failure. Additionally, without the extra length of fiber optic cable, the fiber optic cables may not be sufficiently long for performance of a second splice if a first attempt fails.
Certain aspects and examples of the present disclosure relate to splicing an uphole fiber optic cable with a downhole fiber optic cable downhole in a wellbore. In an example, the two cables may be spliced by extending the uphole fiber optic cable in a downhole direction through a splice housing protector, bending the uphole fiber optic cable in an uphole direction to form a U-shape, and mating the uphole fiber optic cable and the downhole fiber optic cable with a splice housing. A splice housing is a device that may enable fiber optic communication between fiber optic cables, such as between the uphole fiber optic cable and the downhole fiber optic cable. A splice housing protector may be positioned around the splice housing and may include mating channels through which the fiber optic cables can extend and mate with the splice housing. The splice housing and splice housing protector may be positioned along a portion of a tubing string. Extending the uphole fiber optic cable through the splice housing protector and bending the uphole fiber optic cable in the uphole direction may provide a controlled mechanism for providing additional lengths of fiber optic cable that may extend in a downhole direction from the splice housing protector. The tail ends of the downhole fiber optic cable and the uphole fiber optic cable may each enter the splice housing through the splice housing protector and mate with ports in the splice housing to create a splice.
Bending the uphole fiber optic cable in the U-shape may allow for the tail ends of the uphole fiber optic cable and downhole fiber optic cable to be parallel with each other as the fiber optic cables enter the splice housing protector to mate with the splice housing. Bending the uphole fiber optic cable into the U-shape may also allow for the tail ends to be cut to appropriate lengths for performing the splice. In the event of an insufficient splice, a damaged portion of the uphole fiber optic cable or downhole fiber optic cable may be removed. The intact fiber optic cable may also be cut back so that its tail end position matches that of the shortened fiber optic cable. The splice housing may be translated in an uphole or downhole direction along the tubing string to allow the extra length of the uphole fiber optic cable to be fed into the splice housing for re-splicing.
In one example, the uphole fiber optic cable may descend from a tubing hanger positioned at a surface of the wellbore. The uphole fiber optic cable may be annealed, thus allowing for the uphole fiber optic cable to easily bend. In some examples, the downhole fiber optic cable may not be annealed and may not easily bend. The downhole fiber optic cable may mate with a first port of the splice housing after extending through the splice housing protector. The first port of the splice housing may be positioned at a downhole end of the splice housing protector. A second port of the splice housing may also be positioned at a downhole end of the splice housing protector. The uphole fiber optic cable may extend through the splice housing protector by entering a throughport at an uphole end of the splice housing protector and exiting the throughport at a downhole end of the splice housing protector. After extending through the splice housing protector, the uphole fiber optic cable may bend into a U-shape. The bend may enable an end of the uphole fiber optic cable to mate with the second port of the splice housing after entering the splice housing protector at the downhole end of the splice housing protector.
Illustrative examples are given to introduce the reader to the general subject matter discussed herein and are not intended to limit the scope of the disclosed concepts. The following sections describe various additional features and examples with reference to the drawings in which like numerals indicate like elements, and directional descriptions are used to describe the illustrative aspects, but, like the illustrative aspects, should not be used to limit the present disclosure.
A tubing string 120 can be lowered into the wellbore 106 of the oil or gas well as part of a completion operation of the oil or gas well. An uphole fiber optic cable 122 may descend in a downhole direction from the tubing hangar and extend through a splice housing protector 124. The splice housing protector 124 may be positioned around the tubing string 120. Upon exiting a downhole end of the splice housing protector 124, the uphole fiber optic cable 122 may bend in an uphole direction in a U-shape and enter the splice housing protector 124. A downhole fiber optic cable 126 may extend in an uphole direction and enter the splice housing protector 124.
The uphole fiber optic cable 122 may extend through the throughport 205 by entering the uphole opening 204 and exiting the downhole opening 206. After extending through the throughport 205, the uphole fiber optic cable 122 may bend in a U-bend 208 such that a downhole end of the uphole fiber optic cable 122 may enter the downhole mating channel 210. The uphole fiber optic cable 122 and downhole fiber optic cable 126 may be cut to an appropriate length to mate with the ports of the splice housing 202. In some examples, a wellbore operator may perform a fusion splice of the uphole fiber optic cable 122 and the fiber optic coupling loops 219. The fusion splice can include exposing the fibers inside the uphole fiber optic cable and fusing the fibers to the fiber optic coupling loops 219. In this manner, the uphole fiber optic cable 122 may be communicatively coupled with the first downhole port 214. The downhole fiber optic cable 126 may enter the splice housing protector 124 through the downhole mating channel 210. A fusion splice may then be performed between the downhole fiber optic cable 126 and the fiber optic coupling loops 219 in the splice housing 202. In this manner, the downhole fiber optic cable 126 may be communicatively coupled with the second downhole port 216. In an example, an optical integrity test may be used to determine if the uphole fiber optic cable 122 and downhole fiber optic cable 126 have optical integrity with one another. If there is optical integrity, a successful splice has been performed to create a combined fiber optic cable. The splice may be sealed and the combined fiber optic cable may be positioned within the wellbore 106.
In some examples, the splice housing 202 may include a first uphole port and a second uphole port. The first uphole port and second uphole port may align with the uphole mating channel 212. The downhole fiber optic cable 126 may be annealed and the uphole fiber optic cable 122 may not be annealed. The downhole fiber optic cable 126 may extend in an uphole direction through the throughport 205 of the splice housing protector 124 by entering the downhole opening 206 and exiting the uphole opening 204. The downhole fiber optic cable 126 may then bend into a downhole direction in a U-shape and enter the first uphole port of the splice housing 202 through the uphole mating channel 212. The uphole fiber optic cable 122 may descend from the tubing hanger and enter the second uphole port of the splice housing 202 through the uphole mating channel 212. Bending the downhole fiber optic cable 126 rather than the uphole fiber optic cable 122 may allow the tubing hanger, or hardware associated with the tubing hanger such as a cable shield, to protect the U-bend in the downhole fiber optic cable 126. For example, a channel may be machined into the tubing hanger to accommodate the U-bend in the downhole fiber optic cable 126.
In one example, such as the one shown in
As shown in
As shown in
At block 402, the process 400 may include communicatively coupling an uphole fiber optic cable 122 with a first port at a downhole end of a splice housing 202 and a downhole fiber optic cable 126 with a second port of the splice housing 202. For example, the first port at the downhole end may be the first downhole port 214 of
At block 404, the process 400 may include determining whether the uphole fiber optic cable 122 and downhole fiber optic cable 126 have optical integrity with the splice housing 202. For example, an optical integrity test may be used for determining optical integrity. The optical integrity test may determine if the uphole fiber optic cable 122 is sufficiently communicatively coupled with the downhole fiber optic cable 126. If there is optical integrity, a successful splice operation may have been performed and the process 400 may continue to block 406 to end the process 400. If there is not optical integrity, the splice operation may have been unsuccessful and the process may continue to block 408.
At block 408, the process 400 may include decoupling the coupling between the uphole fiber optic cable 122 and the first port. For example, the uphole fiber optic cable 122 may have been damaged during the splice and may need to be decoupled from the first port to perform another splice operation.
At block 410, the process 400 may include discarding a damaged portion of the uphole fiber optic cable 122 and moving the splice housing 202 to enable re-coupling of the uphole fiber optic cable 122 with the first port. After removing the damaged portion of the uphole fiber optic cable 122, the uphole fiber optic cable 122 may be re-coupled to the first port. The splice housing 202 may be translated in an uphole or downhole direction along the tubing string 120 to allow the uphole fiber optic cable 122 to be re-coupled to the first port. Alternatively, after removing the damaged portion of the uphole fiber optic cable 122, the splice housing 202 may first be translated in an uphole or downhole direction along the tubing string, the uphole fiber optic cable 122 may be re-bent into a U-bend, and the uphole fiber optic cable 122 may then be re-coupled to the first port. In some examples, if a length of the uphole fiber optic cable 122 is discarded such that the uphole fiber optic cable 122 no longer has the U-bend shown in
In some examples, such as the one shown in
In some examples, such as the one shown in
The uphole fiber optic cable 122 may extend in a downhole direction past the splice housing 600, bend into a U-bend 208, and extend in an uphole direction to mate with the first port 606. The downhole fiber optic cable 126 may extend in an uphole direction past the splice housing 600, bend into a U-bend 604, and extend in a downhole direction to mate with the second port 608. In some examples, the downhole fiber optic cable 126 may extend in an uphole direction and mate with the third port 610. Cable clamps 616a and 616b may be used to clamp portions of the fiber optic cables to the tubing string 120. For example, a portion of the downhole fiber optic cable 126 that extends past an uphole end of the splice housing 600 may be clamped with cable clamp 616a to the tubing string 120 for support such that the downhole fiber optic cable 126 can bend into the U-bend 604.
If the splice body 612 performs an insufficient splice operation, the uphole fiber optic cable 122 may be de-coupled from the first port 606 and the downhole fiber optic cable 126 may be de-coupled from the second port 608. Damaged portions of the uphole fiber optic cable 122 or downhole fiber optic cable 126 may be discarded. The uphole fiber optic cable 122 may be re-bent in an uphole direction into the U-bend 208 to feed the uphole fiber optic cable 122 into the first port 606 for a re-mating. The downhole fiber optic cable 126 may be re-bent in a downhole direction into the U-bend 604 to feed the downhole fiber optic cable 126 into the second port 608 for a re-mating. Because the U-bends may be re-bent, the splice housing 600 may remain in place for performing an additional splice operation. After re-mating, the splice body 612 may perform the additional splice operation.
In some aspects, systems, methods, and apparatus for performing downhole splices of fiber optic cables are provided according to one or more of the following examples:
Example #1: A system may include a splice housing positionable along a portion of tubing, a splice housing protector positionable around the splice housing, an uphole fiber optic cable, and a downhole fiber optic cable. The uphole fiber optic cable may be positionable to extend through the splice housing protector and mate with a first port of the splice housing at a downhole end of the splice housing protector. The downhole fiber optic cable may be positionable to mate with a second port of the splice housing in the splice housing protector. The splice housing may be positionable to splice the uphole fiber optic cable and downhole fiber optic cable.
Example #2: The system of Example #1 may feature the uphole fiber optic cable being extendable through the splice housing protector at a length sufficient (i) to discard a portion of the uphole fiber optic cable upon detection of an insufficient splice and (ii) to re-mate the uphole fiber optic cable with the first port of the splice housing.
Example #3: The system of any of Examples #1-2 may feature the uphole fiber optic cable being positionable to bend in an uphole direction in a U-shape after extending through the splice housing protector such that a tail end of the uphole fiber optic cable is parallel with a tail end of the downhole fiber optic cable.
Example #4: The system of any of Examples #1-3 may feature the second port of the splice housing being positionable at a downhole end of the splice housing protector.
Example #5: The system of any of Examples #1-4 may feature the downhole fiber optic cable being positionable to extend in an uphole direction through the splice housing protector and mate with the second port of the splice housing at an uphole end of the splice housing protector.
Example #6: The system of any of Examples #1-5 may feature the downhole fiber optic cable being positionable to bend in a downhole direction in a U-shape after extending in the uphole direction through the splice housing protector.
Example #7: The system of any of Examples #1-6 may feature the splice housing protector further including fiber optic coupling loops for enabling the splice between the uphole fiber optic cable and the downhole fiber optic cable.
Example #8: A method may include communicatively coupling, to a splice housing positionable along a portion of tubing and in a splice housing protector, an uphole fiber optic cable with a first port at a downhole end of the splice housing and a downhole fiber optic cable with a second port of the splice housing. The method may include determining whether the uphole fiber optic cable and the downhole fiber optic cable have optical integrity with the splice housing. The method may include, in response to determining that the uphole fiber optic cable and the downhole fiber optic cable do not have optical integrity, decoupling the coupling between the uphole fiber optic cable and the first port. The method may include discarding a damaged portion of the uphole fiber optic cable to enable re-coupling of the uphole fiber optic cable with the first port. The method may include translating the splice housing protector along the portion of tubing using a slack in the uphole fiber optic cable. The method may include re-coupling the uphole fiber optic cable to the first port.
Example #9: The method of Example #8 may include extending the uphole fiber optic cable through the splice housing protector at a length sufficient to discard the damaged portion of the uphole fiber optic cable prior to re-coupling the uphole fiber optic cable with the first port of the splice housing.
Example #10: The method of any of Examples #8-9 may include bending the uphole fiber optic cable in an uphole direction in a U-shape after extending the uphole fiber optic cable through the splice housing protector such that a tail end of the uphole fiber optic cable is parallel with a tail end of the downhole fiber optic cable.
Example #11: The method of any of Examples #8-10 may feature the second port of the splice housing being positioned at a downhole end of the splice housing protector.
Example #12: The method of any of Examples #8-11 may include extending the downhole fiber optic cable in an uphole direction through the splice housing protector. The method may include mating the downhole fiber optic cable with the second port of the splice housing at an uphole end of the splice housing protector.
Example #13: The method of any of Examples #8-12 may include bending the downhole fiber optic cable in a downhole direction in a U-shape after extending in the uphole direction through the splice housing protector such that a tail end of the downhole fiber optic cable is parallel with a tail end of the uphole fiber optic cable.
Example #14: The method of any of Examples #8-13 may feature the splice housing protector further including fiber optic coupling loops for enabling of the splice between the uphole fiber optic cable and the downhole fiber optic cable.
Example #15: A splice housing protector may include a first throughport with a first opening at an uphole end and a second opening at a downhole end such that an uphole fiber optic cable is positionable to extend through the first throughport along a portion of tubing within the splice housing protector. The splice housing protector may include at least one mating channel positionable at an end of the splice housing protector to receive an end of the uphole fiber optic cable and an end of a downhole fiber optic cable such that the end of the uphole fiber optic cable and the end of the downhole fiber optic cable are positionable within the at least one mating channel to communicatively couple with a splice housing positionable inside the splice housing protector.
Example #16: The splice housing protector of Example #15 may feature a second throughport with a first opening at a downhole end and a second opening at an uphole end such that the downhole fiber optic cable is positionable to extend through the second throughport by entering the first opening at the downhole end and exiting the second opening at the uphole end.
Example #17: The splice housing protector of any of Examples #14-16 may feature a first mating channel of the at least one mating channel being positionable at an uphole end of the splice housing protector.
Example #18: The splice housing protector of any of Examples #14-17 may feature a second mating channel of the at least one mating channel being positionable at a downhole end of the splice housing protector.
Example #19: The splice housing protector of any of Examples #14-18 may feature a clamshell hinge positionable to install the splice housing protector around the tubing.
Example #20: The splice housing protector of any of Examples #14-19 may feature the at least one mating channel including an individual mating channel that is positionable to receive at least a portion of the uphole fiber optic cable and at least a portion of the downhole fiber optic cable such that the uphole fiber optic cable is parallel to the downhole fiber optic cable.
The foregoing description of certain examples, including illustrated examples, has been presented only for the purpose of illustration and description and is not intended to be exhaustive or to limit the disclosure to the precise forms disclosed. Numerous modifications, adaptations, and uses thereof will be apparent to those skilled in the art without departing from the scope of the disclosure.