Research On Acid Fracturing Experiment And Technology Of Dolomite Reservoir In Shunnan Region

The dolomite reservoirs in Shunnan area of Tahe oilfield are characterized by ultra deep,high temperature,strong heterogeneity and low natural productivity.Because the lithology is mainly dolomite,its diagenetic characteristics and diagenetic variation are different from those of previously developed limestone reservoirs.The traditional limestone reservoir acid fracturing technology has little effect on the yield increase in the area,and the capacity and effective utilization production are relatively low.Aiming at the above difficulties of high temperature and ultra deep dolomite reservoirs in Shunnan area,this paper mainly adopts the combination of experimental research,theoretical analysis and numerical simulation.The mineral composition,poresity,permeability and rock mechanics characteristics were obtained through core experiments.The reaction kinetic parameters,the loss of acid filtrate and optimal acid system of dolomite were obtained through the acid-rock reaction experiment.,The influence factors and regularities of the fracture conductivity are studied through the experimental study of the acid-etched fractures conductivity,and the calculation model of the conductivity of the acid-etched fracture conductivity is established.The action distance of acid solution is calculated through the flow reaction simulation of the acid solution in the dolomite fissure.Through the numerical simulation of acid fracturing,the construction parameters are optimized.Through the theoretical analysis and comparative analysis of process,the technology for the optimization of deep dolomite reservoir in Shunnan high temperature area is optimized(multistage alternating injection+ closed acidizing+temporary plugging to uniform acid fracture),and is applied to process the scene a wells acid fracturing design.The results are evaluated and the results of indoor research are improved.Due to the lack of mature acid fracturing technology in ultra deep and ultra-high temperature dolomite reservoirs,this paper aims to guide and develop a suitable acid fracturing technology.in dolomite reservoir in Shunnan area.