Proppant embedding-based optimal design method for fracturing coalbed methane wells in Qingshui basin

Area of Science:

• Petroleum Engineering
• Geomechanics
• Coalbed Methane Extraction

Background:

• Proppant embedding in coal fractures reduces well productivity.
• Accurate fracturing design for coalbed methane (CBM) wells requires understanding proppant embedment effects.

Purpose of the Study:

• To develop and validate an optimal fracturing design method for CBM wells that incorporates proppant embedding.
• To analyze the influence of proppant embedding on coal fracture conductivity and optimize design parameters.

Main Methods:

• Conducted coal fracture conductivity experiments to study proppant embedding.
• Developed a coal fracture conductivity model accounting for proppant embedding.
• Implemented a proppant index method for dynamic conductivity analysis.
• Applied the optimized design method to CBM wells in the Qinshui Basin.

Main Results:

• Fracture conductivity decreases with increasing closure pressure and increases with proppant size, placement layers, and formation Young's modulus.
• Proppant embedding reduces fracture width and conductivity.
• Optimized fracture length decreased by 10.6%, while fracture width increased by 11.5% when considering proppant embedment.

Conclusions:

• Proppant embedment significantly affects fracture geometry and conductivity in CBM wells.
• The developed method provides a practical approach for optimizing fracturing designs, leading to improved well production.
• Accounting for proppant embedment is crucial for effective fracturing design in coalbed methane extraction.