Plugging performance testing device for drilling fluid

Abstract

The invention discloses a plugging performance testing device for a drilling fluid. The plugging performance testing device comprises a sample measuring cup and a drilling fluid sample cup, wherein a cavity is arranged inside the sample measuring cup, an elastic tube is arranged inside the cavity, the outer wall of the elastic tube and the inner wall of the cavity form a ring-shaped hydraulic cavity body, the ring-shaped hydraulic cavity body is communicated with an external hydraulic pump, the opening in the upper end of the elastic tube is communicated with the top wall of the sample measuring cup, a rock sample fixing ejector rob with a filter liquor through hole is arranged at the lower end of the elastic tube in an inserting manner, and a core sample is placed in the interior of the elastic tube; the bottom of the drilling fluid sample cup is hermetically connected with the upper end of the sample measuring cup, the inner cavity of the drilling fluid sample cup is communicated with the opening in the upper end of the elastic tube, the drilling fluid sample cup is used for placement of a drilling fluid sample to be tested, and the drilling fluid sample can permeate into the core sample from the opening in the upper end of the elastic tube and is filtered out through the filter liquor through hole. The plugging performance testing device for the drilling fluid can quickly and accurately test the plugging performance of different drilling fluid systems or formulas to different tested samples.

Description

technical field [0001] The invention relates to the field of drilling fluid plugging performance testing, in particular to a drilling fluid plugging performance testing device. Background technique [0002] At present, the industry generally believes that drilling fluid plugging technology is one of the key technologies to effectively prevent wellbore instability in shale formations. The excellent plugging ability of drilling fluid can significantly reduce the amount of drilling fluid filtrate intruding into shale formations. Avoid or weaken the hydration expansion of the drilling fluid filtrate and clay minerals contained in the shale formation, and improve the ability to stabilize the well wall. Therefore, whether it is indoor evaluation or field application, the plugging performance of drilling fluid is regarded as one of the important technical indicators of the stability of the shale well wall, which has extremely important guiding significance for the successful comple...

AI Technical Summary

Problems solved by technology

[0003] However, there is a lack of laboratory tests and instruments for evaluating the plugging performance of drilling fluids. At present, only non-permeable water loss testers, high-temperature and high-humidity water loss testers, and high-temperature and high-pressure sand bed plugging testers are used.

Among them, the non-permeable water loss tester and the high temperature and high pressure sand bed plugging tester evaluate the plugging effect of drilling fluid on different meshes of quartz sand beds (usually in the range of 40-120 meshes), while the high temperature and high pressure water loss tester evaluates It is the plugging effect of the drilling fluid on the filter paper and the permeability of the mud cake itself. It cannot reflect the plugging effect of the drilling fluid on the real formation and can only be used as a reference

The evaluation methods of these evaluation instruments are relatively simple, the use is limited, the test objects are not universal enough, and the test results often have no reference and guiding significance, which is not very helpful for the design of the drilling fluid system and field application

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