Dynamic permeability testing device and method in oil-gas well cement paste solidification process

Abstract

The invention discloses a dynamic permeability testing device and method in the solidification process of oil and gas well cement slurry. The device comprises a sealing slurry cup, an upper end pressure control system, a lower end micro-flow control system, a temperature control system, an annular injection and drainage system and a computer control acquisition system. Wherein the sealing slurry cup is used for containing cement slurry to be detected; the upper end pressure control system is used for applying pressure to the upper end of the cement paste to be detected; the lower-end micro-flow control system is used for controlling micro-seepage of the test medium in the to-be-tested cement paste; the temperature control system is used for heating and measuring the temperature of to-be-measured cement And the annular injection and drainage system is used for injecting and draining a heating medium into the sealed slurry cup. The permeability development process in the cement paste solidification process is monitored in a micro-seepage mode, a test medium seeps through the cement paste at a weak flow, and formation of a cement paste hydration and gelling structure is not affected; the slurry preparation water is used as a test medium, cement slurry hydration is not affected, and hydration and solidification of cement slurry in a shaft under temperature and pressure can be simulated.

Description

technical field [0001] The invention relates to a dynamic permeability testing device, in particular to a dynamic permeability testing device and method during the solidification process of oil and gas well cement slurry. Background technique [0002] During the cementing construction process, the cement slurry is filled in the annular space between the casing and the formation rock, and after solidification, a cement sheath is formed. The main function is to isolate layers, protect the casing, and prolong the service life of the wellbore. After the cement slurry is injected into the annulus, it undergoes a hydration and condensation process from a liquid state, a liquid-plastic state to a solid state. During this period, the cement slurry must stabilize the formation to prevent formation gas and liquid from entering. Due to the "weightlessness" of the cement slurry, the cement slurry is required to The cementitious structure of the slurry develops rapidly. When the pressure...

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Problems solved by technology

[0004] The purpose of the present invention is to provide a dynamic permeability testing device and method during the solidification of oil and gas well cement slurry, which solves the problem of dynamic permeability testing during the solidification of oil and gas well cement slurry, and can simulate the temperature and pressure of the cement slurry in the wellbore The setting process of cement slurry can effectively test the change of permeability during the setting process of cement slurry

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