Abstract:
In view of the challenges of many lithology interlayers vertically and high clay content in continental shale reservoirs, the vertical penetration of network fracturing technology for horizontal wells is proposed. This technology primarily includes the fracability evaluation of continental shale, optimization of fracture parameters for estimated ultimate recovery (EUR) maximization, optimization of fracturing treatment parameters based on single cluster fracture propagation simulation, optimization of whole-process vertical penetration of fracturing based on improving fracture height far from the borehole, development and evaluation the integrated fracturing fluid system with high imbibition and oil displacement efficiency, and optimization of post-fracturing shut-in period based on imbibition mechanisms, etc. The research results show that the complexity of fractures in continental shale oil and gas fracturing is generally low. To achieve network fracturing, the focus should be on the “dense cluster spacing” fracturing and the vertical penetration fracturing throughout the whole process. The field tests show that the production by vertical penetration of network fracturing can be increased by more than 20%. Therefore, this technology has significant potential for widespread application.