Method for establishing fine anisotropic shale rock physical model

Abstract

The invention discloses a method for establishing a fine anisotropic shale rock physical model. The method comprises the following steps: establishing a rock physical model capable of predicting the shale stiffness tensor through logging, mud logging, indoor testing, anisotropic SCA and DEM models, isotropic SCA and DEM models and a Brown-Korringa model. According to the method, the influence of inorganic matter pores and organic matter pores on a modeling result is considered respectively; the contents of organic matter pores and inorganic matter pores are respectively calculated by utilizingthe contents of adsorbed gas and free gas and and combining the total porosity; the method comprehensively considers the cause of shale anisotropy, is more consistent with the actual physical property characteristics of the shale stratum, has higher modeling precision than other methods, and can provide basic data for subsequent wave velocity prediction, anisotropy evaluation, rock elasticity parameter evaluation, crustal stress evaluation and the like.

Description

technical field [0001] The invention relates to a method for establishing a fine anisotropic shale rock physics model, and belongs to the technical field of rock physics. Background technique [0002] The microscopic properties of shale will have an important impact on the macroscopic properties. For example, the directional arrangement and layering of organic minerals and the existence of flat pores (micro-cracks developed in the lateral direction) in the rock are the main factors that cause the shale to exhibit transverse isotropy. reason. There are large differences in the elastic properties of shale rocks in the direction parallel to the bedding and perpendicular to the bedding, the most obvious being the difference in Young's modulus and Poisson's ratio in the two directions. Conventional oil and gas reservoirs (such as sandstone oil and gas reservoirs and carbonate rock oil and gas reservoirs) often exhibit isotropic properties, and their elastic parameters can be cha...

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Problems solved by technology

Considering the fluid connection problem, Hu used the clay and fluid mixture simulated by anisotropic SCA and DEM as the background medium, and used the V-R-H limit to simulate the equivalent elastic modulus of the mixture of kerogen, quartz, calcite and other minerals, and finally used Anisotropic DEM adds the mixture to the background medium. Due to the large difference in the elastic modulus of minerals such as kerogen and quartz, the model also has a large error; Liu Zichun regards kerogen as the In the background medium, the pores are added to the kerogen with the SCA+DEM model to ensure the interconnection of the pores and the kerogen, and the equivalent elastic modulus of the minerals other than the kerogen is calculated using the H-S limit and used as inclusions, and then added to the In the background medium, the saturated shale petrophysical model is finally obtained by fluid replacement. This model takes into account the interconnection of kerogen and pores, but does not consider the influence of different pores on the modeling results

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