Research On Improving Steam Thermal Efficiency

Based on the facts from investigation of various petroleum literatures, in site and production tests, several key issues on heat loss of surface pipeline and production string in injection steam of heavy oil fields have been carefully researched by using hydrodynamics, heat transfer, numerical method, production engineering and modern completion method. The model of heat loss of surface pipeline and production string in steam injection has been built, through checkout in site, the model is in good agreement with the data of site test. Heat lose of four type production string can be calculated by the model, namely tubing, tubing and packer, heat insulated string, heat insulated string and packer. The follow factors were considered in heat lose calculation of surface pipeline, namely various valves, elbows, compensator, tube diameter and the bracket of surface pipeline. It has been used for design of the injection strings in Baizhong 7 oilfield and Keqian 10 oilfield by theoretical analysis, numerical simulation, and site test.The key problem of heat loss of surface pipeline in the oil fields is found that the brackets of surface pipeline have no heat insulation. The achievements gained in the study have been applied to the development for Baizhong 7 oilfield and Keqian 10 oilfield, obviously the study will have a wider application in heavy oil fields in the future.