Excess optical fiber deployment control
Various embodiments include methods and apparatus structured to increase efficiencies of a drilling operation. These efficiencies may be realized with a fiber cable located in a wellbore at a well site, where the fiber cable can include an optical fiber disposed as a single handed helix in the fiber cable, where the optical fiber is disposed in the cable without having helix hand reversal. Construction of such fiber cables may include applying a twist to the optical fiber during insertion of the optical fiber into the fiber cable in a tubing process in which control of an amount of the twist to form a portion of the optical fiber can control excess fiber length in the tube. Additional apparatus, systems, and methods can be implemented in a variety of applications.
1. A method comprising:
controlling insertion of an optical fiber into a tube in a tubing process;
applying a twist to the optical fiber during the tubing process;
controlling an amount of the twist to form a portion of the optical fiber as a single handed helix in the tube to control excess fiber length in the tube; and
at least one of forming an optical fiber as a single handed helix coaxial in a retrievable wireline cable, forming the optical fiber as a single handed helix, helically wound with other core elements in a retrievable wireline cable, forming the optical fiber as a single handed helix coaxial in a cable in a permanent installation, forming the optical fiber as a single handed helix helix, helically wound with other core elements in a cable in a permanent installation.
2. The method of claim 1 , wherein applying the twist to the optical fiber includes rotating a fiber spool during the tubing process, the fiber spool containing the optical fiber being inserted into the tube.
3. The method of claim 2 , wherein the insertion of the optical fiber into the tube includes pumping the optical fiber into the tube in the insertion of the optical fiber into the tube.
4. The method of claim 2 , wherein the method includes increasing fiber rotations for a period of time to create a localized high angle helix.
5. The method of claim 1 , wherein controlling then amount of the twist includes mounting a cable spool, containing the optical fiber, sideways with respect to direction of the tube and pulling the optical fiber off the cable spool in the direction of the tube and into the tube.
6. The method of claim 5 , wherein the insertion of the optical fiber into the tube includes pumping the optical fiber into the tube.
7. The method of claim 1 , wherein applying the twist to the optical fiber includes rotating a fiber spool containing the optical fiber, and re-spooling the optical fiber from the fiber spool onto a second fiber spool in the tubing process such that the optical fiber is pre-twisted on the second fiber spool from which the optical fiber is inserted into the tube.
8. The method of claim 7 , wherein, insertion of the optical fiber from the second fiber spool includes pumping the optical fiber into the tube.
9. The method of claim 1 , wherein the method includes inserting one or more additional optical fibers into the tube, each additional optical fiber inserted with a controlled amount of twist.
10. The method of claim 1 , wherein the method includes varying twist imparted on the optical fiber along a length of the tube such that sections of the optical fiber have a higher angle helix than other parts of the optical fiber.
11. The method of claim 1 , wherein the method includes controlling excess fiber length in the tube such that the excess fiber length is matched to an expected tube elongation caused by temperature and mechanical forces in the deployed tube.