Research And Experiment Of Bridge Concentric Layered Water Injection In Ultra-deep And Double-step Horizontal Well

Double step horizontal wells are adopted to develop the Hade oilfield in tarim basin.However,the reservoir physical property vary greatly,as a result,oil-water distribution and the movement of water in the reservoir become fairly complicated during the waterflooding.Separate layer water injection has being used to ensure stable and high yield of oilfield by its ability to adjust the vertical profile of the reservoir and alleviate interlayer contradiction.In such condition,the technology of concentric separate layer water injection has been developed to gurantee the demand of the reservoir tapping.Specifically,the technology uses packer to realize interlayer separation.The pressure and flow rate of each layer can be tested simultaneously to eliminate the interlayer interference and in result the efficiency of the injection test modification has been remarkably improved than traditional eccentric separate injection.The geological department dynamic can monitor of the reservoir and adjust the situation to decrease the ineffective water injection cycle according to the driving conditions.So it has great significance for the development of the oilfield efficiently.So,taking ultra-deep double step horizontal well for research objects,based on the investigation of water injection technology at home and abroad and characteristics of existing technology,and combing with features of reservoir,a novelty named integrated concentric layered waterflooding has been proposed and accompanying tools have been manufactured.The force variation of the pipe is also studied to provide a theoretical basis for the design of the pipe string.Mechanical analysis is performed by WELLCAT software to optimize the string structure.In addition,how to improve the reliability of the seal delamination and the safety of the seal have been studied,finally,the packer and tubing sealing technique has been successfully developed;Based on the analysis of the tools and structure and flow field characteristics of nozzle via numerical simulation,a plate is presented to decide nozzle size.Based on the theoretical research of the tools and string,experiments have been carried out on Hade oilfield successfully.The whole research was carried out according to the route of investigation,design,demonstration,implementation and field experiment.Through the research process,the theoretical level of layered water injection technology has been effectively enhanced.The technique can improve the qualified rate of water injection and the effect of water injection development to a certain extent,and play an important role in improving the water drive recovery rate of multi-layer reservoirs.