Research On Re-fracture Mode And Key Parameters Optimization Of Horizontal Wells In Tight Reservoirs

Tight reservoirs are the key areas for the future development of China's oil,and are usually mined by volumetric fracturing.However,due to lack of understanding or fracturing process defects,there are partial fracture failure wells;for some effective wells,with the progress of production,some of the initial pressure Fractures are closed and blocked,and the yield increase effect is reduced;for some wells with considerable output,reasonable transformation is made.Higher recovery can be obtained.For the above three cases,it can be modified by repeated fracturing.Repeated fracturing as a method to effectively reform reservoir conditions requires in-depth study,especially the influencing factors of repeated fracturing and optimization of fracturing parameters.Based on the research results of repeated fracturing and fracturing numerical simulation at home and abroad,this paper firstly established two horizontal wells 49 and Qingping 50 in the area using Fractman numerical simulation software Fragman.The numerical model of the discrete fracture of the initial fracturing and the discrete numerical model of the re-fracturing fracture,and using the microseismic data to constrain,obtain the repetitive fracture propagation pattern conforming to the actual situation.According to the discrete Fracture numerical model and the well testing analysis software Topaze,the pressure changes and the seam-controlled reserves before and after repeated fracturing analysis show that repeated fracturing can effectively supplement the formation energy and improve the seam-controlled reserves.Finally,the numerical simulation method is used to study the repeated fracture of oil wells in typical blocks,and the influencing factors of repeated fracturing effects are analyzed.It is proposed that the optimized re-fracturing timing is before the seepage into the boundary control flow;the use of layered mining and zipper is proposed.Fracturing fracturing mode improves the effect of repeated fracturing,which guides the re-fracturing work in the field,improves the effect of repeated fracturing measures,improves the development of tight reservoirs,and provides a technical reference for the rational and effective development of tight reservoirs.