Pressurization Time Prediction And Effectiveness Evaluation In He-3 Gas Reservoir Of Daniudi Gas Field

With the deepening development of the gas reservoir, all kinds of pressure are caused to declinecontinuously, it has brought serious challenges to the stable production of gas well. When gas reservoir engineers is facing challenges, emergent gas reservoir pressurization mining technology has already been widely used in gas reservoir, it has become an important measure in increased yield and stableyield of gas reservoir.As a relatively mature technology, gas reservoir pressure boosting has made considerable progress in some respects, such as the design and research of pressurization scheme, the determination of pressurization reasonable production,the selection and setting of compressor and so on. However, the predictionof pressurizationtime still is a problem needed to be resolved for engineers at present. And it has relatively rare studies in rationality and veracity, therefore, the effective implementation of these techniques has important significance for the reasonable and effective development of gas fieldsNow the study is started from the characteristics of He-3 gas reservoir of Daniudigas field, such as structure, sedimentary, reservoir, physicaland so on. Based on the full study of predecessors' achievements, we have a comprehensive knowledge of geological features of low-porosity, low permeability and low pressure in gas reservoir. Through reviewing exploration and developmentjourney of He-3 gas reservoir, the current situation of the pressurization mining is analyzed. Then, the challenges and problems needed to resolve in reservoir are analyzed deeply.In order to better solve the facedproblems, the relationship between the formation pressure and cumulative production is analyzed. The closed constant-volumeofcharacteristicsgas reservoir is determined inDaniudigas field. Volumetric method is selected in various calculationsto calculatethe single-well geological reserves of 192 gas wells.According to the principle of reserveresidualdegree is greater than 45%, 139 gas wells are considered to meet the reservesrequirements of pressurization mining. Besides, in prediction of plateauduration, based on the traditional pressure decline analysis,fitting of pressure decline analysis is implemented by using oil pressure and casing pressure, respectively. Throughanalyzing the precision of fitting, it is considered that it is appropriate forplateaudurationprediction of gas reservoirand gas well in Daniudi by using the casing pressure fitting effect. Furthermore, by combining the node analysis method andproduction performance, thedifference of oil pressure and casing pressure is determined. It is ensured that the accuracy of gas forecast in further, and the gas wellwhich needs to pressurizationis selectedNumerical simulation model of Daniudigas field is set up, by historical fitting and revising parameters repeatedly, it is ensured that the accuracy of pressurizationtime prediction and predict the pressurizationtime of pressurizationwell. According to the distribution of pressurizationtime and gas well, pressurizationtime predictiondistribution is drawn. Then by fully considering various factors and according to the principle of stage successive pressurization, the corresponding solution is proposed. The pressurization in combined decentralizeand centralize manner is appropriate for implementation of solution. Finally, by comparing and analyzing the natural mining and pressurization mining, average stable productionage limit of pressurization mining wells increase 1.17 year. And the average increment of single well achieved at 105.13×10~4m~3, increment of extraction degree achievedat 1.34%.It illustrates that the effective of pressurization mining is obvious and development potential of He-3 gas reservoir remains great.The researchresults of this paper has great significant on maintaining the effective exploitation in He-3 gas reservoir, realizing continuous stable productionof gasreservoir, improvingdevelopment benefits and technology level of gas reservoir. In addition, it has a certain reference value on effectiveexploitation in low-porosity, low permeability and low pressure of gas reservoir.