A kind of prestressed ground anchor and its method for segmental completion of horizontal well screen pipe

Abstract

The invention relates to the technical fields of oil drilling, well cementing and well completion, in particular to a prestressed ground anchor and a method for segmental completion of horizontal well screen tubes. The housing, piston, connecting ring, anchor body and first limit ring arranged outside the central tube, the housing, connecting ring and anchor body form an annular cavity with the central tube, and the piston is slidably arranged in the annular cavity; the connecting ring One end is fixedly connected with the housing, and the other end is radially slidingly connected with the anchor body; the anchor body is composed of several anchor body units, which are arranged in a circle and combined into a hollow ring through an elastic tightening ring. When moving down, the anchor expands radially. The prestressed ground anchor provided by the present invention and the method for using the prestressed ground anchor to carry out horizontal well screen completion in sections have a wide application range and good anchoring effect, which ensures the casing prestressing effect when the prestressing force is pulled in the well completion. Fully released.

Description

technical field [0001] The invention relates to the technical fields of oil drilling, well cementing and well completion, in particular to a prestressed ground anchor and a method for segmented completion of horizontal well screen pipes. Background technique [0002] Heavy oil (heavy crude oil) refers to degassed crude oil with a viscosity of 100-10000mPas at the original reservoir temperature or a density of 0.9340-1.0000g / cm at 15.6°C and atmospheric pressure 3 , due to the high viscosity of heavy oil, the method of injecting high-temperature steam above 300°C is usually used for thermal recovery, so as to increase the production of heavy oil wells. Due to the influence of high-temperature steam, the casing in the well will be elongated and deformed, and the casing will go out of the wellhead, which will damage the cement sheath between the casing and the well wall, seriously affecting the production life of the oil well. In order to solve the above problems, prestressed ...

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Problems solved by technology

[0005] 1. The screen completion process is mostly used in unconsolidated sandstone reservoirs that require thermal recovery of heavy oil. However, the cat claws of the above-mentioned prestressed ground anchor device have an unsatisfactory anchoring effect on unconsolidated sandstone. The prestressed ground anchor used in the above method The anchoring is carried out by piercing the anchor fluke into the well wall, but due to the poor physical and mechanical properties of loose sandstone, loose structure, low mechanical strength and other geological characteristics, the anchor flukes that play an anchoring role are prone to slippage, resulting in anchorage failure. Failure, in severe cases, may cause the anchoring layer to break, so the effect of lifting and eliminating prestress is not ideal, and the process is not safe and stable enough;

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