Study On The Acid Fracturing And Reforming Technology Of Carbonate Reservoir In Tarim Oilfield

Carbonate reservoirs are widely distributed in the whole Tarim Basin,and their total resources account for 38%of the total amount of the basin,so they have always been the focus and hot spot of oilfield exploration.Due to the development of natural fractures and karst caves in carbonate reservoirs,and the strong heterogeneity,not only in different structures,but also in different wells in the same structure,which makes the reservoir reconstruction work for carbonate rocks blind.According to the acidizing and fracturing technology of carbonate reservoir,there are some problems,such as large acid fluid loss,short artificial fracture extension distance,and difficult to achieve deep reconstruction.Based on the carbonate reservoir situation,this paper analyzes the carbonate reservoir test reservoir reconstruction situation in Ta zhong of Tarim Oilfield,gives the general principles of reservoir reconstruction design in each well area,studies the characteristics of organic acid,evaluates the current commonly used gelling acid system,completes the formula of emulsified acid,studies the performance of emulsified acid,and creatively puts forward the method of reducing resistance by emulsified acid.In addition,the large-scale material model was used for experimental demonstration;the advanced experimental study of new variable viscosity acid was carried out;the influence of different acid concentration on acid corrosion fracture conductivity and acid rock reaction speed was studied;the field application test of cross-linked acid deep acid fracturing technology was carried out.Through experimental research and analysis,the micro emulsion developed is stable in acidity and low in viscosity,which is suitable for matrix acidizing and acid fracturing closed acidizing;acid must have good retarding performance to improve the effective acid etching fracture length;organic acid has good retarding performance,so the amount of acid should be increased to improve the fracture conductivity,and closed acidizing is to improve the fracture conductivity In order to increase the effective fracture length,a small amount of sand is added to the pre fluid stage or initial acid injection to improve the conductivity of the deep fracture.