Research On Multilayer Segmentation Injection String And Supporting Technology

In order to meet the development requirements of different stage of water driving in daqing oil field,the multilayer water injection technology with characteristics of Daqing oil field has been set up by generations.However,facing the situation that Daqing oilfield has entered the multilayer production in extremely high water-cut stage,the technology of refined division of the injection layer and effective sealing string were needed to reduce the contradiction between layers(or inside of layer),to trap the potential of each layer's reserves,and to improve the effect of water-driving.Therefore,research on multilayer segmentation injection string and supporting technology were need,in which we need to design the process string and related method for measuring and adjusting,understand the stress and strain distribution on the process string.The technology would provide technical support for oilfield development that high qualified,efficiency and sustainable.According to the requirements of oil field,first,this paper researched on theprincipal of multilayer subdivision water injection string,determined the structure of pipe string,designed supporting and measuring tools.Second,set up the pipe string mechanical models,carried outthe force analysis of water injection pipe string,and obtained the boundary conditions.According tothe real conditions,determined the calculation process and methods of treatments of the boundary conditions.Based on the basis theory of string mechanics to programmed the layered water injection string mechanics analysis software,which was used for mechanics simulation analysis of layered water injection string,guiding the layered water injection process of construction,and ensuring the safe construction of water injection string.Through the research above,a set of fine subdivision multilayer water-cut process string and test method which were suitable for daqing oil field in extremely high water-cut stage were finally formed.A set of layered water injection string simulation system was developed,and realized the process of stressanalysis for tubing string,these could providereference and guidance for zonal injection construction design,and has the function of further expansion.And analysis of the effect of multilayer segmentation injection and evaluation was developed,significant development effect was obtained,and won the acceptance of application unit and the relevant departments,it proved that the research was very necessary.