Adaptability Of Fracturing Stimulation For Low Permeability Reservoir In Block 44 Of Raoyang Sag

For the problem that yield is low and inefficient after several times of fracture in Lu 44block,Shasan reservoir,Liuxi oilfield,on the basis of analyzing the geologic features of target block,a method for evaluating the production of fracturing effect is made.Then,single factor analysis method,Pearson correlation analysis method and grey relational analysis method is used to analyze the geologic and technological factors affecting the fracturing effect.Meanwhile,the research of well and layer fracturing selection method and adaptability of fracturing process analysis is done and software of Fracpro PT is used to fit the fracturing curve of the low production well.At last,the fracturing parameters of production well and water injection well is optimized and whole fracturing scheme of low yield well is put forward.The analysis results show that Lu 44 fault block is the reservoir with low porosity and low permeability and shows the characteristics of moderately weak water sensitivity,acid sensitivity and no speed sensitivity.Meanwhile,results evaluated by the fracturing wells production evaluated method established show that there are 4 wells with high yield,6 wells with middle yield and 2 wells with low yield.Besides,the order of geologic and technological factors affecting the fracturing effect from string to weak is:thickness,oil saturation,porosity,permeability and average sand ratio,displacement,sand-adding strength,sand quantity and total squeeze amount.Fracturing fluid has the characteristics of good viscosity stability,sand-carrying property,breaking gum property and low damage rate.The ideal fracturing well parameters of reservoir thickness,porosity,permeability and oil saturation is 6m-25m,12%-16%,6×10^-3?m²-30×10^-3?m²and 40%-70%obtained by fuzzy recognition method.At the same time,the coincidence with actual production using support vector machine method to predict the daily oil increase of 18 fractured wells is better.The optimization results of fracture length and flow conductivity of production well and water injection well show that the best fracture length and its conductivity is 60m-80m and 20?m²·cm-30?m²·cm respectively and water injection well is designed without fracturing.Meanwhile,the optimal scheme is fracture seam length of 80m and fracture conductivity of 30?m²·cm and water injection well without fracturing.The results of field application show that the fracturing of some middle and low-yielding wells is good by using the whole fracturing scheme.