The influence of high-rank coal reservoir stress characteristics on coalbed methane development

The distribution patterns of stress field hold significant importance in determining well deployment and the scale of fracturing treatments. To elucidate the stress distribution patterns in the Zhengzhuang block of the Qinshui Basin and reveal the influence of stress on coalbed methane development, rock mechanics parameters and stress were obtained through experimental testing and logging calculations. A three-dimensional geological-mechanical model of the coal reservoirs in the Zhengzhuang block was established using Ansys software, and numerical simulations of the stress field were conducted using finite element method to finely describe stress characteristics and further explore their impacts on coalbed methane development, providing rational suggestions for subsequent development. The research findings indicate that the stress magnitude in the Zhengzhuang block follows the pattern σ_H>σ_v>σ_h, indicating a strike-slip fault stress state. The maximum horizontal principal stress ranges from 15.6 MPa to 28.2 MPa, primarily oriented in the northeast-southwest direction. Stress is generally lower in areas of anticline development and higher in syncline development, while stress is typically lower in fault development areas. This research aims to provide theoretical guidance for well deployment, well trajectory optimization, and fracturing design during coalbed methane development.