A New Technology of Combined Network Fracturing for Shale Oil Reservoir in Jiyang Depression

Abstract The resources of Paleogene shale oil reservoirs in Jiyang depression of Bohai Bay are very rich. However, compared with other shale oil reservoirs, Jiyang Depression has a deeper burial depth, complex structure, stronger heterogeneity, more developed bedding fractures, and poor crude oil mobility. Conventional fracturing technology generally has low fracturing efficiency, leading to low production and fast attenuation after fracturing. In general, there are the following scientific problems: 1) it is difficult to evaluate the fracturing sweet spot of reservoirs with high stress, high plasticity, and strong heterogeneity reservoirs, and it is difficult to effectively guide the well and fracturing section selection; 2) it is difficult for hydraulic fractures to cross through multiple shale layers in reservoirs with developed bedding fractures; 3) It is difficult for conventional continuous sanding fracturing to meet the special demand of high viscous crude oil for high conductivity of fracture network. To solve the problems, a new technology of combined network fracturing is proposed. The technology has been applied to shale oil reservoirs in Jiyang Depression, and has continuously broken the record for the highest daily production of shale oil in China, which supports the construction of the "Jiyang Depression Shale Oil National Demonstration Zone".