Device and method for evaluating water invasion resistance of oil well cement slurry in setting waiting process

Abstract

The invention discloses a device and a method for evaluating the water invasion resistance of an oil well cement slurry in the setting waiting process. The device mainly comprises a magnetic stirrer 1, an electric conductivity tester 2 and a kettle body 3, the kettle body is arranged on the magnetic stirrer, a cement mortar 7, an iron filter screen 4 and a simulated stratum water 8 are arranged in the kettle body from outside to inside, the iron filter screen is connected and fixed to the kettle body through a buckle 10, 3-8 nylon filter screens 5 wind around the outer wall of the iron filter screen, the bottom of the iron filter screen is seamlessly pasted to the bottom of the kettle body, the simulated stratum water 8 is arranged in the iron filter screen, the bottom of the simulated stratum water 8 is provided with a magneton 9 matching with the magnetic stirrer, and the probe 11 of the electric conductivity tester 2 is placed in the simulated stratum water 8. The method is characterized in that the critical water speed of the stratum water interfering and destroying the cement mortar on the simulated cement-formation interface is measured to characterize the water invasion resistance of the oil well cement slurry in the setting waiting process. The device and the method have the advantages of reliable principle, simplicity in operation, and provision of reference and basis for the optimization and adjustment of the formula of the oil well cement slurry and the improvement of the water invasion resistance of the cement slurry.

Description

technical field [0001] The invention relates to a device and a method for evaluating the water-invasion resistance of cement slurry in the cementing process of oil and gas wells, in particular to an evaluation device and method for the water-invasion resistance of cement slurry in the setting process. Background technique [0002] In recent years, with the development of domestic exploration and development, most oil fields have entered the middle and late stages of development. In order to improve the development effect and ultimate recovery, adjustment wells (such as water injection wells, infill wells, renewal wells and oil displacement profile adjustments) must be drilled in old areas. well). Some old oilfields have formed a multi-pressure system in which high-pressure layers, normal-pressure layers, and low-pressure layers coexist after long-term layered well layout, three-time infill drilling, high-pressure water injection, and large-displacement forced pumping. The pr...

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Problems solved by technology

However, none of the above methods can start with the ability of the structural strength of the cement slurry to resist formation water interference during the setting process, and combine the physical process of the cement slurry being seeped by the formation water to form the ability of the cement slurry to resist the formation water seepage interference during the waiting setting process. evaluation methods and evaluation indicators

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