The Screen And Research Of The Series Plugging Agents In The Carbonate Reservoir Of Tahe Oilfield

In order to solve the problem of water plugging in the oil and gas production process of the carbonate reservoir in Tahe Oilfield,based on the analysis of characteristics,the geological characteristics and water seeing types of the reservoirs,the paper summarizes and analyzes the problems existing in the development of the research blocks.According to the development of fractures and caves in the reservoirs,epoxy-bonded quartz sand,aluminum sheets and tiny aluminum balls were used to make artificial fracture cores and fracture-cavity cores similar to the reservoirs.Forming the method of making fracture cores and fracture-cavity cores and the optimum acid concentration for fracture-cavity and fractures are formed.Four fracture cores and four fracture-cavity cores are selected as the indoor physical model studied in this paper.According to the reservoir conditions with high reservoir temperature and high fluid salinity in the study block,the current well-adjusted plugging and regulating system is screened and analyzed.The multifunctional inorganic composite gel system is preferred.The system is applied in sandstone reservoirs and the effect is good,but it is not used in carbonate fractures and fracture-cavity complex reservoirs.In this paper,the plugging mechanism,advantages and disadvantages of multifunctional inorganic composite gel system and several kinds of plugging agents are compared.The temperature resistance,salt tolerance and shearing property of the multifunctional inorganic composite gel system are studied.The concentration of water-based liquid are screened and optimized.The inject-ability,erosion resistance and plugging rate of multifunctional inorganic composite gel are evaluated in fracture cores and fracture-cavity core.The experimental results show that the multifunctional inorganic composite gel has good temperature,salt and shear resistance,and the water-based liquid has good injection ability in the core.The plugging rate of the gel to various cores exceeds 90%.The ability of plugging and regulating to reservoir could meet the requirements of controlling water and oil in oil field.