断层泥比率法在储气库断层侧向封闭性定量评价中的应用——以中原文23储气库为例

Application of shale gouge ratio method in quantitative evaluation of lateral fault sealing of gas storage: A case study of Zhongyuan Wen23 gas storage

主块内部断层封闭性的确定对于储气库二期工程井位部署和后续注采方案制定至关重要,为了提高断层泥比率法在文23储气库断层封闭性评价中的符合率,找出存在问题并制定了改进措施。在垂直断距计算中需综合考虑地层产状和断层产状;泥岩层厚度计算是在断距窗口范围内求取,断距窗口内的逐点计算地层数等于断距窗口厚度除以0.125 m。采用改进后的断层泥比率法对已知封闭性的7条断层开展二次评价,其符合率达到100%。将改进后方法应用于主块内部全部断层封闭性评价,结果表明主块内部整体连通,但存在3个相对封闭空间,在后期库容落实和注采方案制定中,需考虑相对封闭空间的影响。

The determination of fault sealing in the main faulted block is very important for geometric arrangement of well and subsequent injection-production strategy of the second phase of the gas storage project.In order to improve the coincidence rate of shale gouge ratio method in fault sealing evaluation of Wen23 gas storage,the existing problems were found out and the improvement measures were made.The attitude of strata and fault should be considered comprehensively in the calculation of normal shift.The thickness of mudstone strata is calculated within the range of fault throw window.The number of strata calculated point by point in the fault window is equal to the thickness of the fault throw window divided by 0.125 m.The improved shale gouge ratio method was used to conduct the secondary evaluation of 7 faults with known sealing,and the coincidence rate is 100%.The improved method is applied to evaluate the sealing property of all faults in the main faulted block.The results show that the interior of the main faulted block is in whole communication,but there are three relative closed spaces,and the effects of the relative closed space are to be taken into account in the implementation of storage capacity and making injection-production strategy in the later stage.