Optimization Design Research Of The Regulating Separate Water Injection String At The High Water-cut Stage

Most of the oil fields in our country have input water flooding development at present. And most of them is multi-zone production. The heterogeneity between the layers is serious. Because the technology of zonal injection was not perfected,some separate water injection well in program had to adapt commingled water injection. The layer with high and low permeability can't get effective water injection. The sweep efficiency and the water flood recovery efficiency can't get effective improve. So the development result of the oil field is influenced. The paper research the water injection technology at home and abroad. According to analyzing the character of the existent technology and the characteristic of related reservoir, it studied the conventional string in the technology. It also studied the force changing regulator in the various working situation of the water injection process string and the liquid flow state when working status transfer each other. And it also studied the zonal water injection string's force change when the injection rate and the injection pressure and the temperature change with the rate and pressure is changed. It provided the theoretical proof for the string design. The paper optimization design the structure of the zonal water injection process string of sanding reservoir and not sanding reservoir in high water-cut stage. It designed and get the accuracy locating zonal injection string and the integrated string with selective sand control and zonal injection. And it also studied the reliability technology of iMProve the sealing separate zone and the setting safe reliability of the packer and the string. It designed and got the device of checking the leakproofness about the string and the packer on-line. On the basic of the success of the intermediate experiment of the string and tools, it carried out the field trial study through attaching to the field at last. The whole program took the route of research and design and demonstration and implementation and test and modification and intermediate experiment and field experiment. The zonal water injection theoretical level is raised effectively after completing the program. And the interval qualification rate and the development effectiveness of zonal water injection is also improved. So it has important effect to improve the water flooding recovery efficiency of the multi-zone reservoir.