Method for plugging leakage of oil-gas well casing by adopting liquid casing

Abstract

The invention discloses a method for plugging leakage of an oil-gas well casing by adopting a liquid casing. The method comprises the following steps that 1, a water outlet layer section is measured; 2, the water outlet layer section is clamped and sealed by adopting double drillable bridge plugs; 3, a blocking agent is extruded into a drillable center pipe in a bypass mode, overflows from a leakage point under the action of pressure and is solidified and cemented outside the leakage point; and 4, after construction, a clamping and sealing tubular column made of the drillable material is drilled and ground off through a grinding tool. The plugging agent used in the method is short in on-site preparation time, and is easy to extrude and low in pumping pressure requirement due to adjustable density and good fluidity; the compressive strength is high and is greater than 150MPa; micro-expansion is achieved during curing, and the cementing strength with the casing pipe is greater than 60MPa; the initial setting time can be randomly adjusted within 20 minutes to 12 hours at the temperature of 20-240 DEG C of the plugging section, the construction risk is low, and the initial setting is controllable; the validity period is long and exceeds 10 years, and the cost is low; and the method can be used for vertical well operation and also can be used for horizontal well operation.

Description

technical field [0001] The invention relates to the technical field of petroleum drilling, in particular to a method for plugging oil and gas well casing leakage by using a liquid casing. Background technique [0002] During the production of oil and gas wells, due to the constraints of reservoir conditions and current technology, shallow casing leakage, casing leakage caused by poor cementing, channeling outside the pipe, intralayer and interlayer water leakage while drilling, and malignant Facing the increasingly complex problems of deep well drilling loss, wellbore integrity and high water cut, there is an urgent need for an oil and gas well loss plugging method with simple construction, good plugging effect, long validity period and reasonable cost. [0003] Therefore, a method for oil and gas well casing leakage plugging by using liquid casing has become an urgent problem to be solved. Contents of the invention [0004] The purpose of the present invention is to use ...

AI Technical Summary

Problems solved by technology

[0002] During the production of oil and gas wells, due to the constraints of reservoir conditions and current technology, shallow casing leakage, casing leakage caused by poor cementing, channeling outside the pipe, intralayer and interlayer water leakage while drilling, and malignant In the face of increasingly complex problems such as deep well drilling loss, wellbore integrity and high water cut, there is an urgent need for an oil and gas well loss plugging method with simple construction, good plugging effect, long validity period and reasonable cost

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