Research On Integration Technology Of Injection And Production For Super Heavy Oil Reservoir In Cheng 91 Block

Heavy oil contains less light fraction,high content of gum and asphalt;and the viscosity of heavy oil changes with temperature,change significantly,such as temperature increases 8~9℃,viscosity can be reduced by half.These characteristics determine the heavy oil of mining,transmission,refining must be around the heavy oil viscosity reduction or coagulation modification or modification treatment carried out.Different oil production processes can be adopted for the characteristics of heavy oil and the structure of each reservoir.The technology of water flooding in heavy oil reservoir mainly includes mechanical viscosity reduction,wellbore heating,dilution and viscosity reduction,chemical viscosity reduction,microbial single well stimulation,and so on.The thermal recovery technology of heavy oil reservoir mainly includes steam soaking,steam flooding,cluster directional well,horizontal well,fire oil layer and other techniques,which are matched with the thermal recovery of heavy oil.Cheng 91 block has strong characters of high oil viscosity,deep buried depth,reservoir sensitivity.The difficulty of the development for deep super heavy oil reservoir is: deep buried depth,high steam injection pressure;well length,heat loss in wellbore;the bottom hole is low,the steam quality is lower,and the steam injection effect is poor;high viscosity of crude oil,high temperature sensitivity,operation and production management process due to the cold damage caused by the oil into the well can greatly affect the production capacity of oil wells,In the process of lifting,the viscosity of crude oil changes greatly,which causes the difficulty in lifting the wellbore,and the production cycle is short,and the ground crude oil gathering and transportation is difficult.According to the above development difficulty,we have carried out the research on the deep ultra heavy oil development supporting technology.The technology of super heavy oil injection production integration has been successfully applied in the Cheng 91 block of 50 wells,and achieved good results.The research showed: over the research on the integrated process of injection and production in this area,the research of wellbore heat loss and the establishment of the stress model of the pipe string can adapt to the need of the injection and production of deep heavy oil reservoirs;in the process of steam injection and oil production,the viscosity of crude oil could be reduced effectively and the oil production of single well could be improved;through the research and optimization of deployment,well,well spacing and length of horizontal well network,we could effectively open the oil flow channel,release the reservoir potential and improve the development effect;during the process,the three factors of steam injection oil soluble viscosity reducer,carbon dioxide and steam injection of super heavy oil reservoir play decisive roles.The injection and production integration pipe string and electric heating sucker rod lifting process have reduced the cold damage of oil well,improved the effectiveness,which has solved the problem of lifting the wellbore to explore a set of economic and feasible way for the future development of deep super-heavy oil reservoir.