Method and device for protecting optical cable outside oil well casing

Abstract

The invention provides a method and a device for protecting an optical cable outside an oil well casing. The protection method comprises the following steps: selecting a steel wire rope with the diameter being greater than that of the optical cable, and fixing the steel wire rope on one side or two sides of the optical cable to protect the optical cable outside the oil well casing. The invention further provides a protection device for realizing the protection method. The protection device comprises two steel wire ropes which are arranged in parallel, wherein when the protection device is in ause state, the optical cable and the steel wire ropes are arranged on the outer side of the sleeve in parallel, and the optical cable is located between the steel wire ropes. According to the methodand device for protecting the optical cable outside the oil well casing pipe, the overall outer diameter of the casing pipe is not increased, protection of the optical cable at the casing pipe coupling position can be guaranteed, the protection cost is reduced, and the optical cable laying efficiency and speed are improved.

Description

technical field [0001] The invention relates to a method for running an optical cable outside a casing in the field of geophysics in a distributed optical fiber sensing well, in particular to a method and a device for protecting an optical cable outside the casing of an oil well. Background technique [0002] Distributed optical fiber sensing in-well geophysics technology is a new technology in well-bore geophysics emerging in recent years. With the continuous progress of Distributed Optical Fiber Acoustic Sensing (DAS for short), DAS has achieved certain results in the fields of border security, oil and gas pipeline monitoring, geological disaster prediction, and engineering tunnel bridge monitoring. The application of sensing well seismic, hydraulic fracturing microseismic monitoring, long-term monitoring of oilfield temperature, pressure, stress and strain, and oilfield dynamic monitoring has gradually matured. Optical fiber geophysical technology in wells is the applica...

AI Technical Summary

Problems solved by technology

[0004] The position of the casing collar The optical cable protection device is generally fixed at the position of the casing collar, that is, the right-angle position between the casing and the casing collar, and protects the contact part between the optical cable and the casing collar reducing position to avoid rocks on the well wall. The collision between the optical cable and the collar position of the casing achieves the purpose of protecting the optical cable at the collar position of the casing, but it does not achieve any protection for the optical cable in the outer casing except for the collar

At the same time, this device belongs to the external custom-made processing components of the casing, the processing technology is complex, the production cost is high, the construction difficulty is relatively large, the layout efficiency is low, the downhole operation time is long, and there is a risk of falling into the well

[0005] The design of the protection device needs to meet the standards for downhole follow-up operations, that is, it must protect the optical cable, and the size must be suitable to ensure the smooth running of the casing without affecting the return of the cement. The position of the collar is the position with the largest diameter of the casing. The installation of protective devices will inevitably increase the outer diameter of the casing as a whole. Considering the margin of the drill bit size, the drill bit diameter will be increased and the drilling efficiency will be reduced.

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