Quantitative Evaluation Of Reservoir Parameters And Movable Fluid In Tight Gas Sandstone

Tight gas sandstone is an unconventional natural gas reservoir with very big developmentpotential. Compared with conventional sandstone reservoir, the tight sandstone has low porosityand permeability, high shale content, relatively poor reservoir properties, and all of thesecharacteristics will make it difficult for the research of logging evaluation method in tight gassandstone. In recent years, with the needs of production in the gas field and the improvement ofresearch methods, the research of seepage law and liquidity in tight gas sandstone reservoir getmore and more attention of people. Therefore, the study of quantitative evaluation method ofreservoir parameters and movable fluid in tight gas sandstone not only has important theoreticalsignificance, but also can provide supplementary methods for the exploration and developmentof tight gas reservoir.In this paper, the P2h reservoir is the main research object in the region of Sulige, byconsidering the low porosity, low permeability, strong heterogeneity in tight gas reservoir,evaluate the reservoir parameters and flow characteristics in tight gas reservoir. First, analyzethe sedimentary characteristics, macroscopic physical properties, micro pore structurecharacteristics and liquidity using the laboratory core analysis, mercury penetration data, welltest data and rock-mineral analysis, grain size analysis and log data. Then combined withthree-water model, by the research of conductive mechanism of free water, micro capillarywater and clay bound water, evaluate the reservoir parameters quantitatively in tight gasreservoir. In the conductive model, the three water’s conductance is connected in parallel. Afterthat, based on quantitative evaluation of movable fluid, this article analyzes the influence offree water porosity and other reservoir parameters to reservoir liquidity, with the result of which,use mathematical means of support vector machine (SVM) to realize the division of flow unit.At last, through the result of interpretation of flow unit in single well, indicate the differences ofreservoir liquidity in longitudinal. Combined with the distribution characteristics ofprecipitation facie and the result of multi-well interpretation of flow unit in the same sand bodyof P2h reservoir in Sulige gas filed, explain the transverse distribution characteristics of flowunit.In this paper, on the basis of evaluation of reservoir parameters and movable fluid,propose the method of evaluating reservoir liquidity combined with three-water model. It not only analyzes the liquidity difference between reservoirs in vertical, also summarizes thetransverse distribution characteristics of flow unit, further study the liquidity of reservoir. Onmathematical methods, puts forward support vector machine (SVM) to divide flow unitautomatically, which is new in this area. Although the support vector machine (SVM) has beenwidely used in many problems of pattern recognition, for the evaluation of flow unit, it is stillan innovative attempt, and has obtained the very good application in the region of Sulige.