Inversion analysis of three-dimensional geostress field in northwest Hancheng Block

Abstract

In order to improve the current situation of relying on empirical formulas in the current research on goestress fields, a finite element inversion and regression calculation method of goestresss is proposed based on the geological conditions of Hancheng Block. First, a more accurate three-dimensional geological model is established according to the geological situation of Hancheng Block; the three-dimensional finite element regression analysis method is used to fit the measured data, and finally the distribution law of the goestress field in the study area is obtained. The research results show that the three-dimensional goestress of the coal seam is in descending order: vertical stress, horizontal maximum principal stress, and horizontal minimum principal stress; the overall stress difference of the coal seam is between 2 MPa and 4 MPa, and there is a larger stress in the northwest; the overall stress direction trend of the coal seam is 45 degrees north to east; the error size does not exceed 20%, which meets the actual requirements of the project.

Keywords

• goestress field
• hydraulic fracturing method
• multiple linear regression
• hancheng block
• coalbed methane