The Deliverability Analysis And Exploitation Strategy Of Shanxi-2 Formation In Yu30 Area Of Zizhou Gas Filed

The low-permeability and the ultra-low permeability reserves have become the significant factor which influences the stable development of China's onshore oil and gas industry and still will play a very important role in the future sustainable development of the petroleum industry. In general, the low-permeability and the ultra-low permeability reservoirs have characteristics of large reserves, low abundance, poor physical property and hard exploiting, etc. In this study, Shanxi-2 formation in Yu30 area of Zizhou gas field has the characteristics of large changes of physical properties and more sand reservoir lithology, etc. , which is a typical low-porosity and low-permeability gas reservoir controlled by structure and lithology.Productivity evaluation is quite crucial to the low-permeability wells, which will directly influence the working system of gas well. This thesis takes Yu30 area of Zizhou gas field as research object. Based on the deliverability analysis of gas well and considering the dynamic and the static parameter, this thesis proposes the correspondent exploitation strategy of the different reservoir by adopting well test analysis, cluster analysis, multi-discriminant analysis, gas reservoir engineering, numerical simulation and so on.Using various deliverability analysis methods, this thesis first calculates the deliverability of the gas wells in Zizhou gas field, and then compares the computational solutions, finally comes to the result that the AOF calculated by production data is better than that worked by the single point test. So this method can be utilized to compute the deliverability. The comprehensive analysis shows that the deliverability in Zizhou gas filed is affected by many factors, such as flow capacity, formation heterogeneity, storage coefficient and reservoir pressure depletion, etc., and meanwhile points out that the main controlling factor is storage coefficient.Making use of the basic data of Zizhou gas filed, the author established the three-dimensional geological model of Yu30 area. Seen from the porosity and the permeability property models, we know that the physical property in this work area is determined by the facies and in the main stream channel the sand body develops well and has better physical properties. In order to develop the gas field targetedly, this thesis conducts the cluster analysis and the multiple discriminant analysis on the effective reservoir of Shanxi-2 Formation in Zizhou gas filed based on the related parameters of permeability reservoir, such as the energy storage coefficient, the AOF and the gas test data, etc., and works out that the multiple discriminant standard of the three kinds of effective reservoir in Shanxi-2 Formation. For the sake of better integrating the three kinds of effective reservoir and the deliverability analysis, and then conducting correspondent calculation, this thesis innovatively proposes the concept of"reservoir classification index". Combining the AOF of deliverability calculation and the computational solutions of"reservoir classification index", the horizontal distribution of the three kinds of reservoir is confirmed by the correspondent classifying standard of the static and the dynamic reservoir. This three-type reservoir classification obtained by this method will provide foundation for the future exploitation technology strategy.According to the reservoir classification standard, many methods can be utilized to work out the correspondent exploitation strategy of the three kinds of reservoirs. This thesis mainly adopts the methods of the economic limit evaluation and the numerical simulation to determine the reasonable production and the reasonable pattern well spacing of the three kinds of reservoirs. For a few water production wells, the method proposed by Turner is used to calculate the minimal gas production rate for carrying water. Referring to the reasonable production and the interface gas production rate for carrying water, gas recovery rate can be calculated by the method of analogy and gas reservoir engineering. Finally, the empirical formula and the turbulent flow potential equation are utilized to calculate the abandonment pressure of the formation.Through the geologic research and the dynamic property analysis on the Yu30 area of Zizhou gas field, the author has obtained a clear understanding about the gas well deliverability, the classification and the exploitation strategy of the three reservoirs in this area. This research provides reliable foundation for the future exploitation and program regulation of the gas reservoir, and meanwhile provides the research idea for the same type of gas reservoir's exploitation.