Casing pipe device structure used for oil drilling and capable of preventing casing damage due to fault slippage

Abstract

The invention discloses a casing pipe device structure used for oil drilling and capable of preventing casing damage due to fault slippage. The casing pipe device structure is installed in the expanding section of a fault and mainly composed of a movable joint of a four-layer structure. A rigidity followable casing pipe layer of the movable joint is connected with an upstream casing pipe part and a downstream casing pipe part through threaded connecting parts. The four-layer structure of the movable joint is connected into a whole at the two ends of the movable joint. An outer steel wire knitmesh is arranged on the outer side of the rigidity followable casing pipe layer, and an inner steel wire knitmesh and a flexible hose are sequentially and inwards arranged in the rigidity followable casing pipe layer. In the fault zone, displacement caused by fault slippage can be offset by a buffer space between the outer steel wire knitmesh of the movable joint and the stratum, the transverse displacement deformation and confining capacity of the rigidity followable casing pipe layer of the movable joint and a ring-pillar-shaped gap between the inner steel wire knitmesh and the flexible hose in the innermost layer. Meanwhile, mud or sandy soil can be effectively prevented from entering the flexible hose in the innermost layer through the outer steel wire knitmesh and the inner steel wire knitmesh, and the flexible hose can properly deform along with partial displacement deformation of the rigidity followable casing pipe layer, so that the flexible hose does not crack and influence oil recovery operation.

Description

technical field [0001] The invention relates to a casing device structure for oil drilling to prevent casing damage caused by fault slippage, which is characterized in that a movable joint with a four-layer structure is installed in the fault reaming section to prevent casing damage caused by fault slippage , belonging to the field of petroleum engineering technology. Background technique [0002] In an oil well, the casing is a steel pipe used to protect the oil suction pipe on the outer layer of the oil pumping pipe, and the outermost layer of the entire oil pumping system is in direct contact with the oil or the formation. During oil field production, when factors such as engineering, geology, and production dynamics change the load on the casing that exceeds the bearing capacity of the casing, the casing will be deformed, broken, and broken, that is, casing damage, referred to as casing damage. [0003] Casing damage is a common problem in major oil fields at home and ...

AI Technical Summary

Problems solved by technology

[0008] The current preventive measures for casing damage caused by fault slippage are limited to casing material selection, without structural improvement. The present invention provides a casing device structure for oil drilling to prevent casing damage caused by fault slippage , in order to solve the problem that the existing materials have limited effect on the strong shear stress generated by the fault slip of the casing, and reduce the incidence of casing damage caused by fault slip

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