Study On The Development Mode Of Reasonable Gas Injection In The Heavy Oil Reservoir Of Condensate Gas In

With the increasing difficulty of exploration and development of oil reserves, the proportion of difficult mining reserves is more and more big. Part of our country’s heavy oil reservoirs are deeply buried, and it is difficult to achieve steam injection as high steam injection pressure, and the heat loss is serious, so the thermal recovery can not adapt to this kind of reservoir exploitation. Gas injection is an important method of the tertiary recovery, one hand the injected gas can be fully contacted with the heavy oil under pressure, have good viscosity reduction; on the other hand for the heavy oil reservoir with buried depth, thin reservoir,low permeability, gas injection is more effective for thermal recovery. Therefore, research on gas injection for enhancing recovery for heavy oil reservoir has very important economic significance and the practical significance.In this paper, on the JⅢ with condensate gas cap heavy oil development evaluation shows that the reservoir’s physical property is poor, the viscosity of heavy oil is big, gas cap shrink too fast, single well production decline rapidly, resulting in the oil and gas channeling, the paoduction well’s water ratio is well above the high water cut,the reservoir is low recovery degree. Based on the research of gas injection development at home and abroad, analyzes the oil displacement mechanism of different injected gas medium, and a detailed analysis of the changes of fluid properties of oil and gas in the process of contact. By the method of numerical simulation, established the JⅢ reservoir eight component well group model, were studied in different media (CO2, N2, hydrocarbon gas) and injection process parameters (injection gas layer, injection rate, injection and production well spacing) effect on development of the gas injection, and based on oil production, using the orthogonal design method to orthogonal optimize injection amount, injection position, injection rate, injection and production well spacing and other parameters which are designed for heavy oil reservoir, designed gas injection development plan, combined with the economic evaluation of the selection of the scheme.