Hard and brittle mud shale fracturing pressure predicting method

Abstract

The invention discloses a hard and brittle mud shale fracturing pressure predicting method. The hard and brittle mud shale fracturing pressure predicting method comprises the steps that firstly, rockparameters of hard and brittle mud shale are obtained through an indoor hydration triaxial experiment, ground stress testing data of a mud shale stratum are obtained through a site stratum fracturingtest, then other required general data are collected and calculated, and based on the elastic-plastic mechanics theory and the rock mechanics theory, stress distribution, considering speeage, of surrounding stratums of the well wall of a vertical well is calculated; then, effective tangential stress under the effect of considering hydration is calculated; and finally, according to the maximum tensile stress criterion, a fracturing pressure model of the hard and brittle mud shale stratum is obtained. The fracturing pressure of the mud shale stratum is predicted more effectively and more accurately, and accordingly the high-precision basic data are provided for the fracturing construction design.

Description

technical field [0001] The invention relates to the technical field of fracture pressure prediction technology for oil exploration formations, in particular to a method for predicting fracture pressure of hard and brittle mud shale. Background technique [0002] In the production operation of oil and gas wells, it is very important to predict formation fracture pressure. In the prior art, models include Eaton model, Anderson model, exlog model, Huang's model, etc. Among them, the Eaton model considers the relationship between Poisson's ratio and depth; The stress-strain relationship of elastic porous media; the exlog model considers the problem of tectonic stress, and makes the assumption of uniform horizontal tectonic stress; Huang's model is mainly proposed for general reservoirs, and it generally considers various factors Not only the overlying stress of the rock formation is a function of depth, the influence of the stress concentration on the wellbore wall, but also th...

AI Technical Summary

Problems solved by technology

[0004] In summary, there is currently no more effective and accurate method for predicting the fracture pressure of hard and brittle shale formations considering multiple factors.

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