Steam Injection Exploitation Of Heavy Oil Reservoir To Improve Development Effect Research

With the rapidly development of world economic and the energy becomes tension, the experts of domestic and overseas pay close attention to the exploration of heavy oil reservoirs. In China, there are plenty of heavy oil reservoirs which distribute to Liaohe oilfield, Sinkiang Karamay oilfield, Henan oilfield and Shengli oilfield.For the viscosity of heavy oil has strong sensitivity to temperature, steam injection which includes steam stimulation and steam driving is one of the most effective methods of exploitation the heavy oil reservoirs.The fundamental principle is injecting steam into the oil layers, increasing the temperature of the oil layers, decreasing the viscosity of the heavy oil, enhancing the sweep efficiency and oil recovery.In China, heavy oil reseavoirs of thermal exploitation are at the multicyclic steam stimulation stage. It takes on characteristics as high water-cut, low production and developed benefit, low degree of reserve recovery. At the mid-late stage of steam stimulation, how to improve the development effect, transform to other exploitations and enhance oil recovery become the urgent affairs.Based on exploitation status of heavy oil reservoirs, affecting factors on development effect at the mid-late stage of multicyclic steam stimulation in heavy oil reservoirs are analyzed by compositive ways, such as modern reservoirs engineering, oil field exploitation performance and monitoring data, and reservoir simulator, etc., in combined with steam stimulation exploitation experience and existing issue in the heavy oil reservoirs of Qigu Formation in block Jiu9of Karamay oilfield, and research on remainder oil distribution characteristics at the mid-late development stage of multicyclic steam stimulation.Using numerical simulation software STARS, we choose four typical well groups which are97720,97705,99441,99702.We design five exploitation methods which contain steam stimulation,one-well injection and multi-well production, steam drive, steam stimulation&steam drive and hot water drive.On the basis of the geological conditions and production performance of four typicl well groups, we carried out numerical simulation on five exploitation methods at the mid-late stage of steam stimulation.By contrast and analyze, the place in the Qigu Formation in biock Jiu9does not have water breakthrough, in which the best way is steam driving. Modern reservoirs engineering combined with numerical simulation prove steam driving is feasibility.With the two methods, we analyze the sensitivity to steam driving. According to the results of numerical simulation, we design three programs. By comparing and analyzing those programs, we will choose the best one.The research on improving development effect at the mid-late stage of steam stimulation, not only can improve the economic benefits of the development of steam injection, but also can enhance oil recovery to a certain degree.The researched results of this paper can be applied and popularized in the development of other heavy oil reservoirs with similar geological conditions of Qigu Formation in block Jiu9, the researching results also have practical guidance significance for the development of similar reservoirs.