Non-destructive experimental evaluation method for damage degree of heterogeneous compact rock

Abstract

The invention discloses a non-destructive experimental evaluation method for the damage degree of heterogeneous compact rocks, which comprises: (1) testing the initial acoustic wave velocity of a rocksample and converting it into an initial dynamic Young's modulus and an initial dynamic Poisson's ratio; (2) testing the porosity, pore size distribution and stratified moisture content of the rock sample; (3) performing high temperature and high pressure working fluid damage treatment on the rock sample; (4) testing the acoustic wave velocity of a damaged rock sample and converting it into a dynamic Young's modulus and a dynamic Poisson's ratio; (5) testing the porosity, pore size distribution and stratified moisture content of the damaged rock sample, and analyzing the physical properties,pore structure changes, and the depth of working fluid intrusion of the rock sample; (6) calculating a damage variable of the rock sample; (7) Fitting the relational formula between the damage variable of the rock sample and the dynamic Young's modulus and the dynamic Poisson's ratio, and evaluating and predicting the mechanical damage of the working fluid. According to the non-destructive experimental evaluation method for the damage degree of heterogeneous compact rocks, the problem of damage evaluation of heterogeneous dense rock is solved thereby providing technical guidance and theoretical basis for the optimization design of drilling and completion.

Description

technical field [0001] The invention relates to the field of oil and gas field development, in particular to a non-destructive experimental evaluation method for the damage of working fluid to rock during the drilling and completion process of heterogeneous reservoirs. Background technique [0002] Rock is a heterogeneous body composed of different mineral particle aggregates and cementing materials. The mineral composition and content in rock are the main factors that determine the physical and mechanical properties of rock (Tao Zhenyu, Pan Bietong. Principles and methods of rock mechanics [M]. Wuhan : China University of Geosciences Press, 1991). A large number of rock mechanics test results show that the heterogeneity of rock itself is an important factor affecting the large dispersion of physical and mechanical property parameters of rock. Therefore, for rocks with complex mineral compositions, such as igneous rocks and lithic sandstones, the compositional heterogeneity...

AI Technical Summary

Problems solved by technology

However, for rock samples with strong heterogeneity such as igneous rocks, the physical and mechanical properties of the rock samples are quite different, and the reliability of the parallel sample comparison analysis method is poor, and it is impossible to accurately characterize the effect of the working fluid on the rock mechanical properties. It is also impossible to effectively evaluate the influence of working fluid on rock mechanical parameters.

As a result, the implementation effect of the drilling and completion scheme design for reservoirs with strong heterogeneity is not ideal, so there is an urgent need for a damage evaluation method for heterogeneous rocks

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