| To solve the problem of high cost in the process of popularization and application of injection-production in the same well,the injection-production technology scheme of single pump pressurization in the same well is put forward.To ensure that the water content of the process plan is 93%-99%,and the treatment capacity has the optimal separation efficiency in the range of 1.5m~3/h～5m~3/h,this study adopts factorial screening design and orthogonal test methods to optimize the structural parameters of the coalescer and verifies its feasibility through mechanical analysis and indoor tests.Taking the magnification of the average oil droplet size at the outlet of the coalescer as the evaluation standard of the coalescence efficiency,the particle size of the central oil core of the hydrocyclone is larger after the addition of the optimal structure coalescer,and the separation efficiency is increased from 92.17%to 98.43%compared with the hydrocyclone itself.To ensure the mechanical feasibility of single pump pressurized injection-production technology in the same well,the simulation environment of the pump is obtained through the simulation analysis of the centrifugal pump and the comparison with the experimental data of the pump.On this basis,the stress-strain curve of each acquisition point on the tubing is obtained by using the MpCCI coupling platform.Mechanical analysis shows that the pipe string is always in the stage of elastic strain,and the influence of single pump supercharging process on the parts in the process can be ignored.Since the single pump supercharging process relies on only one pump to complete the lifting and reinjection work,it is necessary to obtain the relationship between the pressure at each port of the hydrocyclone and the split ratio of the hydrocyclone.It is verified by simulation calculation that the separation efficiency of the hydrocyclone is only affected by the pressure difference between the overflow port pressure and the bottom outlet pressure.The pressure of the overflow port is fixed at 0,and three differential pressure conditions of 0.3MPa,0MPa and0.3MPa are selected for simulation analysis.When the pressure of the bottom outlet is 0.3MPa,the light oil phase gathers in the middle and upper part of the hydrocyclone.With the decrease of the pressure of the bottom flow port,the light oil phase accumulates in the middle of the hydrocyclone,so it is not easy to discharge from the overflow port.Therefore,the oil phase separation efficiency decreases,and the oil-water separation efficiency increases with the increase of the pressure of the bottom flow port.Then put the hydrocyclone into the injection-production technology of single pump pressurization in the same well and calculate the boundary conditions of the injection-production technology of single pump pressurization in the same well.the internal hydrocyclone can be the same as the hydrocyclone inlet,bottom outlet and overflow outlet pressure conditions calculated separately,and matched with it,the pressure matching function relationship of each group is obtained.In order to verify the accuracy of the numerical simulation results,according to the effects of different treatment capacity,different shunt ratio and different inlet oil concentration on the separation efficiency,the indoor experimental analysis of the coalescence-cyclone is carried out:the separation efficiency of the coalescence-cyclone increases with the increase of the treatment capacity;the separation efficiency of coalescence-cyclone increases with the increase of overflow shunt ratio.The separation efficiency of coalescence-cyclone increases with the increase of oil concentration.The rationality of the optimized structural parameters is verified by numerical simulation and laboratory experiments,and the numerical simulation results are in good agreement with the experimental results,which proves the accuracy of the numerical simulation. |
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