Multi-Stage Horizontal Well Fracturing Technology in Deep Shale Gas Well DY2HF

Well DY2HF is a key exploration well in Dingshan Longmaxi marine shale gas reservoir featuring in high temperature and ultra high stress.In order to overcome the challenge of high injection pressure and difficult proppant injection,multi-stage fracturing technology of horizontal well in the deep shale gas reservoir has been developed.According to the characteristics of Dingshan shale,wellhead injection pressure and pumping rate were optimized,mutiple fracture coverage ratio model for horizontal section was established,and fracturing stages and clusters were optimized on the basis of induced stress analysis result.According to the demands of shale gas network fracturing technology and specific characteristics of this well,high friction reduction and low damage hybrid fluid of slick water and low surfactant tension gel was used as fracturing fluid,together with low-density and high-strength coated ceramic proppant in combined meshes.Fracturing parameters were also optimized through numerical simulation.DY2HF deep shale gas horizontal well fracturing was successfully performed under the limited wellhead pressure,95 MPa,with a cumulative fracturing fluid volume of 29,516 m3,cumulative proppant volume of 319 m3,maximum pumping rate of 13.6 m3/min,friction reduction rate of slick water of up to 78%,and complete hydration of post-frac gel.Industrial gas production was reached,which marked a breakthrough in multi-stage horizontal well fracturing of deep shale gas reservoirs.The treatment result indicates that deep shale gas reservoirs like Dingshan are capable of being effectively developed under the present fracturing technology and equipment.