Optimization Of Well Completion Of SAGD Horizontal Wells With Heavy Oil

With short development cycle, high thermal energy’s utilization rate, high oil recovery factor and low steam oil ratio, SAGD horizontal well technology has been the main technique to develop heavy oil. In recent years, researchers have optimized the completion of SAGD horizontal well to improve the efficiency of recovering heavy oil, and conducted tests on long-horizontal-section of SAGD horizontal well and the completion of uniform steam injection, the productivity has been improved. Therefore, learning from foreign technical progress, focusing on the interior completion of SAGD horizontal well, and the article studied the optimized completion practice. To further improve productivity is very important of heavy oil.In this paper, X oil field in west China utilized the technology of SAGD is main study object, the article studied the optimized SAGD horizontal well completion practice. According to the characteristics of heavy oil reservoir, the model of3D geological and wellbore has been established in a numerical simulation manner, so as to simulate the production process of SAGD horizontal well and the pressure in wellbore. Simulated the pressure of wellbore, cumulative water, cumulative oil, cumulative steam-oil-ratio and steam chamber. The simulative result show that the optimal completion length of177.8mm liner is600m, if the length of well is more than1000m, conventional well completion methods cannot meet the needs of the production. Hence, conducted the optimized evaluation of long horizontal section of SAGD completion string, the analysis of the effect of length and size of completion string on the productivity of SAGD horizontal well, and have got completion strings of different sizes. The study shows that the completion adaption horizontal section length of177.8mm screen pipe is less than800m; and219.1mm in is from800m to1000m; while244.5mm in is longer than1000m. To further improve productivity of SAGD, predicted the recovery of SAGD horizontal well with the uniform steam injection liner in different length and size of completion string. The result show that the oil recovery factor of completion with uniform steam injection liner increased by40%than conventional completion, and reduced the size of completion string from244.5mm to177.8mm in long-horizontal-section.Though studied in this paper, article presented an optimized program of SAGD completion in X oil field, utilized the completion string of long-horizontal-section and large size and completion of uniform steam injection liner, these methods can improve the productivity of SAGD in X oil field. The method of SAGD optimization completion provides a theoretical basis for development of domestic heavy oil reservoir.