Flexible sidetracking stimulation technology of horizontal wells in low-permeability mature oilfields

A flexible sidetracking stimulation technology of horizontal wells is formed to develop the lateral deep remaining oil and gas resources of the low-permeability mature oilfields. This technology first uses the flexible sidetracking tool to achieve low-cost sidetracking in the old wellbore, and then uses the hydraulic jet technology to induce multiple fractures to fracture. Finally, the bullhead fracturing of multi-cluster temporary plugging for the sidetracking hole is carried out by running the tubing string, to realize the efficient development of the remaining reserves among the wells. The flexible sidetracking stimulation technology involves flexible sidetracking horizontal wells drilling and sidetracking horizontal well fracturing. The flexible sidetracking horizontal well drilling includes three aspects: flexible drill pipe structure and material optimization, drilling technology, and sealed coring tool. The sidetracking horizontal well fracturing includes two aspects: fracturing scheme optimization, fracturing tools and implementation process optimization. The technology has been conducted several rounds of field tests in the Ansai Oilfield of Changqing, China. The results show that by changing well type and reducing row spacing of oil and water wells, the pressure displacement system can be well established to achieve effective pressure transmission and to achieve the purpose of increasing liquid production in low-yield and low-efficiency wells. It is verified that the flexible sidetracking stimulation technology can provide favorable support for accurately developing remaining reserves in low-permeability reservoirs.