Study on the hydraulic fracture extension pattern of Gulong Shale Oil Reservoir in Songliao Basin

Abstract

This study aimed to investigate the fracture extension pattern of the Gulong shale oil reservoir through rock mechanical tests, fracturing physical simulation experiments, and on-site tracer fracture monitoring to enhance fracturing stimulation effectiveness. The results of the rock mechanical tests revealed the anisotropic mechanical properties of the rocks attributed to the lamellation structure. Fracturing physical simulation experiments were conducted to determine the fracture extension pattern in the laboratory, indicating that increasing the fracturing fluid viscosity and injection rate could help overcome the vertical extension limitations caused by the lamellation structure. For the first time, on-site tracer fracture monitoring was implemented to study the hydraulic fracture extension pattern of the Gulong shale oil reservoir. The findings suggested that utilizing stages with three or four perforation clusters, a 50% slick water ratio, and temporary plugging could enhance fracture initiation efficiency and promote uniform extension. After modifying the parameters based on the research results, the on-site fracturing wells exhibited excellent fracturing stimulation effects. This study is significant for understanding the unique fracture extension pattern of the Gulong shale oil reservoir both in laboratory settings and on-site, providing technical recommendations for improving fracturing stimulation in other reservoirs with similar characteristics.