Critical physical properties of tight sandstone reservoir of He 8 Member in Sulige Gas Field
With the deepening of exploration,more and more attention has been paid to the reservoir dynamic evaluation system.The determination of the critical physical properties of the reservoir in the accumulation period can provide an important basis for reservoir dynamic evaluation and tight sandstone gas exploitation.A new method for determining critical physical properties of tight sandstone reservoirs in the accumulation period is proposed by using the data of mud-logging,logging,gas testing and physical properties.Combined with the current lower limit of gas-bearing physical properties,the critical physical properties value of the reservoir in the accumulation period are determined by using push-back method of porosity compaction profile and physical simulation of natural gas charging.The results show that,the average porosity variation of He 8 Member reservoir of Sulige Gas Field is 3.3％,and the critical porosity of the reservoir in the accumulation period is 6.1％.The gas charging physical simulation confirms that the breakthrough pressure increases with the increase of burial depth.The larger the burial depth,the more difficult to charge,and the greater the power required for natural gas to be injected into the reservoir,which also indicates that there is a lower limit of physical properties when natural gas is charged in the accumulation period.The experiment verifies that the critical charging pressure of natural gas is mainly controlled by permeability and has poor correlation with porosity.The critical permeability of the reservoir in the accumulation period is about 0.15×10-3 μm2.
万方数据
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