Experimental Study On Separation And Treatment Of Water In Situ In High Water Cut Oilfield

Some oil fields have entered a high water cut period due to the increase of the exploring years.Oilfields with high water cut period are faced with problems such as unbalanced injection and production in blocks,overload operation of pipelines and processing equipment,large energy consumption for transportation of waste water,corrosion and even leakage of pipelines.In order to solve the problems caused by high water cut in oil fields,a pre-water separation process was proposed.In this study,we conducted separation process experiments in a oil field which is the representative of the high water-cut oilfields.And a novel and highly effective process has been proposed including wellhead dosing demulsifier+three-phase separator water splitting+dosing flocculant+T-tube secondary purification.Through the water separation test of produced liquid,pipephase is employed to calculate the balance of injection and recognize the quality and location of the separation water.Through the optimization of demulsifier,the adding mode and optimum conditions of demulsifier were determined.The residence time of the three-phase separator was determined through field water separation test,and the water quality analysis was completed.It was concluded that physical and chemical methods were needed for sewage purification.Through the first-class sewage purification test,the types and dosages of inorganic flocculants and organic flocculants were screened respectively.Orthogonal experiment of L16(2~2×4~2)was designed.The compounding of flocculant was completed,and the optimum compounding method was obtained and verified.Through the secondary sewage purification test,the multiphase flow in T junctions are simulated using high-quality structured mesh.The L9(3~4)orthogonal experimental design was employed to consider the effects of multiple factors and determine the best structure.The operating parameters are further compared in the structre.Finally,the experimental data in the A oil field shows that this process can be successfully used in the oil field.And this process can be further employed in the successfully used in the oil field.And this process can be further employed in the other oilfields with high water-cut.