Fracturing technology with enhanced fracture network and reinforced support for deep shale gas under high closure pressure
In Block D,the reservoir stimulation results in deep shale gas wells are suboptimal,mainly reflected in simplistic fracture geometries due to high horizontal stress difference and underdeveloped natural fractures,high fracture pressure and operational pressure due to high vertical stress,and unsatisfactory fracture supporting effect because of high closure pressure.To address these challenges,a series of hydraulic fracturing experiments were conducted using a true triaxial simulation system to investigate fracture propagation under high-stress difference conditions.Furthermore,the impact of narrow cluster spacing on fracture propagation was analyzed by using the facies field fracture propagation software.Field trials were conducted on four wells,implementing a dense multi-cluster perforation design(8-11 clusters per stage),high displacement rates(17-18 m3/min),a fracture initiation pattern with pressure-limited but non-restricted injection rates,and a real-time temporary plugging and diversion strategy for comprehensive real-time judgment and control of fracturing to increase fracture complexity.The use of pre-acid treatment,sandblasting,and optimizing perforation numbers(44-50 holes per stage)effectively reduced fracture pressure and operational pressure.Additionally,high-intensity proppant injection design(3.6-4.0 t/m)and combined proppant types ensured sufficient fracture conductivity.Following the application of these technologies,all four wells in block D exhibited average gas production rates exceeding 200 000 m3/d,demonstrating successful reservoir stimulation.These technical measures provide valuable insights and field experience for reservoir stimulation in deep shale gas wells under high closure pressure conditions and offer significant potential for broader application.
万方数据
维普
