Multifunctional dynamic pollution evaluation device of coalbed drilling fluid

Abstract

The invention relates to a multifunctional dynamic pollution evaluation device of coalbed drilling fluid, belonging to the technical field of damage evaluation of coalbed methane drilling fluid. The multifunctional dynamic pollution evaluation device comprises a gas booster pump, a triaxial stress coal core gripper, a measuring axial-loading pump, a gas mass flow meter, a computer acquisition board, a mud container, an oven, a precise advection pump, and the like; wherein the gas booster pump is arranged at the left side of the oven; a gas storage tank, the precise advection pump, the measuring axial-loading pump and the gas mass flow meter are arranged at the lower part of the oven; and the triaxial stress coal core gripper and the mud container are arranged in a working space of the oven. The evaluation device can not only simulate the invasion, the invasion depth and the invasion degree of the drilling fluid to a coal bed under the condition of coalbed true triaxial stress, but also simulates the dynamic pollution process of mud in positive differential pressure, negative differential pressure and balanced drilling process and ensures that the coalbed pollution process is integrated with the percolation test process. The invention solves the problem that the conventional evaluation device can not load different axial loads on three axial directions and has the advantages ofconvenient operation and standardized experimental data.

Description

Technical field: [0001] The invention relates to a multi-functional coal seam drilling fluid for simulating the invasion of coal seam, the depth and degree of intrusion into coal seam by drilling fluid under the condition of true triaxial stress of coal seam, and the research on the anisotropy characteristics of coal seam under various true triaxial stress conditions A dynamic pollution evaluation device belongs to the technical field of coalbed methane drilling fluid damage evaluation testing instruments. Background technique: [0002] The exploration and development technology of coalbed methane is developed on the basis of the exploration and development technology of conventional oil and gas. brought great economic benefits. [0003] However, coal seams are very different from conventional oil and gas reservoirs. Potential damage factors of coal seams are as follows: 1. Coal seam pores and fractures develop, and solid and liquid phases in drilling fluid enter deep into ...

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Problems solved by technology

[0005] At present, there is only a single oil and gas reservoir protection research in China, which simulates the drilling fluid damage device and the dynamic damage evaluation system for measuring the depth and degree of damage to the core by the well fluid.

However, coal seam protection runs through every production process of coal seam exploration and development. It is a comprehensive supporting technology involving multiple disciplines. The above-mentioned instruments and devices are far from meeting the needs of actual production.

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