薄层SAGD循环预热管柱结构优化研究

Study on SAGD Circulating Preheating String Structure Optimization in Thin Super Heavy Oil Reservoir

SAGD试验区循环预热管柱二次换热严重、注汽效率低,为提高薄层SAGD油藏注汽效率,通过井筒数值模拟等方法,研究了注汽井长管开孔、短管管鞋位置对注汽效率的影响,并得出了超稠油油藏隔热油管应用的临界井深。研究表明:长管不开孔,水平段干度损失小于5%、温度损失小于5℃;注汽井短管管鞋位于水平段1/3处,汽窜风险低;斜直井段超过350 m的水平井采用光油管跟端干度低于70%。研究成果为薄层SAGD循环预热管柱的优化设计提供了依据。

The heat exchange between the columns of SAGD well group in pilot test area is serious,and the efficiency of steam injection is low in circulation and preheat stage.In order to improve the thin SAGD reservoir steam injection efficiency,Wellbore numerical simulation method is applied.The effectof position on the steam injection efficiency,Punched in the long pipe of the steam injection and short tube shoes,is studied.The critical well depth for the application of insulation oil pipe in super heavy oil reservoir is determined.Research results show that Long tube without holes,the horizontal section of the dry degree of loss is less than5,the temperature loss is less than5%;Short steam injection wells shoe is located at1/3level,the risk of steam channeling is lower;If the horizontal well with inclined straight well is more than350m,the end of the horizontal well’s dry degree is less than70%.The research results provide a basis for the optimization design of the thin layer SAGD circulation and preheat pipe column.