Plugging effect evaluating method by completely dipping rock debris

Abstract

A plugging effect evaluating method by completely dipping rock debris is disclosed. The method includes: preparing rock debris or drill core of a stratum to be evaluated, and dividing the rock debris or the drill core into at least two parts; respectively putting the at least two parts of the rock debris or the drill core into cups of a high-temperature high-pressure filtration instrument and weighing each part; respectively putting the weighed at least two parts of the rock debris or the drill core into slurry cups containing drilling liquids of different formulas; setting the temperature according to the depth of the stratum; setting the pressure according to the pressure of the stratum and the hydrostatic fluid column pressure of the drilling liquids; allowing the mixture to stand for a specified period of time; taking the rock debris out and drying by wiping; rapidly weighing each part again; separately calculating the imbibition mass increase ratio; and comparing the plugging effects of the different drilling liquids for the specific drill core by calculating the mass increase ratios of the rock debris. The method provides a novel route for using of the drilling liquids in a permeable stratum and a micro-fracture stratum, has good reference value for optimization of systems and additives, and enhances judgment for anti-sloughing and leakage-proof capabilities of the drilling liquids.

Description

technical field [0001] The invention relates to a technique for evaluating the plugging effect of a drilling fluid or a plugging agent, in particular to a method for evaluating the plugging effect of cuttings fully immersed. Background technique [0002] Accurately evaluating the plugging effect of drilling fluid or plugging agent is a problem often faced by oil drilling or other exploration drilling industries. At present, the commonly used method is to grind the obtained cuttings or downhole cores into powder and then press them into cores ; Then use a dilatometer to carry out the expansion experiment; because the original state of the pores and fractures of the sample is destroyed, it is impossible to accurately evaluate the plugging effect of the drilling fluid on a specific formation; moreover, the equipment for this experiment is relatively expensive, and it can only be carried out in the laboratory of a research institution , cannot be completed at the construction si...

AI Technical Summary

Problems solved by technology

[0007] Many existing evaluation methods, such as the measurement method of the specific surface area of ​​shale, the measurement method of hydration expansion of shale, and the evaluation method of drilling mud cake compressibility, are all aimed at the study of the collapse of shale formations, and how to stabilize the fracturability There is no method for evaluating the feasibility of strata and fractures

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