Feasibility Study On Reconstruction Of Underground Gas Storage In Wanxingyuan Carboniferous Gas Reservoir

With the rapid development of China’s economy, the demand of our country for clean energy—natural gas is increasing. The21st century is the era of natural gas. In recent years, the phenomenon of "gas shortage" has occurred frequently in our country. The construction of underground gas storage is one of the important ways to ease the contradiction between supply and demand of natural gas and to solve the phenomenon of "gas shortage". So, it is vitally necessary to carry out the study of converting depleted oil and gas reservoir to underground gas storage.On the basis of consulting a large number of domestic and foreign literatures, this paper has developed the feasibility study of Wanshun gas field in Carboniferous gas reservoir converted to underground gas storage through the application of theoretical knowledge and methods of geological engineering, gas reservoir engineering, gas engineering, petroleum engineering and rock mechanics, computer science and other multi-disciplinary system. The main contributions of this paper are as follows:1. The potential of converting target reservoir area Wanshun field Carboniferous gas reservoir to underground gas storage has been analyzed by start from the target reservoir area gas reservoir construction and exploration and development, as well as a gas well status and pipe network facilities.2. The comprehensive geological of the target gas reservoir has been evaluated. The result shows that the target reservoir area has certain structural trap area, good reservoir physical properties, cap rock and fault sealing.3. The characteristics of target gas reservoir have been analyzed. It turns out that the characteristics of the dry gas, H2S content is low, and formation temperature is78℃, which is micro-super-pressure gas reservoir.4. The characteristics of gas reservoir development have been overall evaluated. The Study Reveals that single well productivity is high, production pressure difference is small and connectivity is good. Also, gas reservoirs are mainly gas drive, water drive supplemented composite drive type. Edge water is partially active and the formation pressure is close to the abandonment pressure.5. The target reservoir gas reserves have been calculated and comprehensive evaluated by volumetric and cumulative production methods and shut-in pressure drop methods. Finally, it determines76x108m3as the reserves.6. The parameters of the reconstruction of target gas underground gas storage have been demonstrated. It confirms the operation cycle of the gas storage reservoir and the gas storage reservoir injection-production formations, which are defined as C2M2. The effective maximum storage capacity is Estimated, it is58.68x108m3. Gas storage working pressure range is15-38MPa. This paper analyses reasonable production pressure of the injection or production well, which is3MPa. 7. The constraints of converting exhausted gas reservoir to underground gas storage injection-production have been analyzed in theory. It programs the related computational process by Visual Basic6.0. by taking the target area Wanshun gas reservoir as an example and inputting gas reservoir related data into program.8. The injection-production ability of target area---Wanshun gas reservoir rebuilding underground gas storage well has been forecasted on the basis of production experience formula and node analysis. By using Visual Basic6.0program to calculate some parameters, at the same time, writing a program by myself to do note analysis compared to PIPESIM program forecast the under biggest Injection-production capacity injection-production limit condition.Through the above researches, this paper gets the advantages and disadvantages of the target area Wanshun carboniferous gas reservoir rebuilding underground gas storage, and gives the next work implementation suggestion. It will provide theoretical significance for exhausted gas reservoir rebuilding underground gas storage. At the same time, it will offer realistic significance to the target area Wanshun carboniferous gas reservoir rebuilding underground gas storage.