Study On Parameter Optimization Of Horizontal Well Reservoir Reconstruction In Penglai Town Of Xinma Structure

Xinma region is a main battlefield of Southwest Sinopec Company for increasing oil reserves and production. As the the main producing formation, Penglaizhen is a compact high-pressure gas reservoir with serious heterogeneity,always developed by horizontal wells. Currently, the horizontal wells drilled in Ⅰ and Ⅱ formations have received good performance while Ⅲ formation don’t. Overall speaking, horizontal wells didn’t get desirable results.In this thesis, based on the research of Penglaizhen Formation’s geological features, with analysis on earlier horizontal wells’performance, we studied the parameters affecting reconstruction effects in Penglaizhen Formation and optimized fracture, construction and flowback parameters. We also took practices in Mapeng-23 horizontal well and Mapeng-75 horizontal well.Main conclusions of this thesis are as followed:(1) Early Statistical analysis of horizontal wells’transformation indicated that reservoir properties s fracture parameters、construction parameters and flowback rate can affect production, among these factors reservoir parameters contributes most.(2) Through building productivity prediction model, we optimized the fracture space、 length and conductivity of Xinma Region, the results indicated that fracture spacing and conductivity of reservoirs which had better porosity should be higher than lower one,while the fracture length is the opposite. The optimized parameters are as following:100-125m fracture spacing,100-120m fracture length,25-30μm2.cm fracture conductivity of Ⅰ formations; 85-100m fracture spacing,120-140m fracture length,15-20μm2.cm fracture conductivity of Ⅱ formations; 70-85m fracture spacing,160-180m fracture length,10μm2.cm fracture conductivity of Ⅲ formations.(3) Based on the optimization of fracture parameters, we got the final parameters of Xinma Region: 25-40m3 single-stage proppants、26-32 percentage pad fluid、26-32 percentage proppant concentration 3.5-4.5m/min of output volume in single-seam and 4.5-5.5 m3/min in parallel-seam.(4) We divided two kind of well conditions according to production and optimized the flowback procedure:For non-production wells, we suggest to take "keep pressure, uniform flowback" mode, adopt 3mm nozzle initially and select a small gradient; For others, adopt 4mm as primary nozzle size and subsequently choose 2mm size after cracks closed.(5) Field application shows the optimized length is consistent with reality, the optimized parameters are good guidance of Penglaizhen Formation.Through the research, We provided technical guidance for the exploration of Penglaizhen formation, and provided references for similar gas reservoirs as well.