断层垂向封闭所需断层面压力下限的确定方法  

A method to determine the lower pressure limit on fault surface required by vertical seal of fault and its application

作　　者：王秋菊[1] 

机构地区：[1]大庆油田有限责任公司勘探开发研究院,黑龙江大庆163712

出　　处：《大庆石油地质与开发》2008年第4期30-34,共5页Petroleum Geology & Oilfield Development in Daqing

基　　金：国家"973"重点基础研究项目(2001CB209104)资助

摘　　要：利用前人泥岩塑性变形实验数据,通过建立泥岩塑性变形极限与埋深之间关系,建立了断层垂向封闭所需断层面压力下限随埋深变化的研究方法。将此方法应用于松辽盆地汪家屯气田W1、W2、W3、W4断层及三站气田S1、S2、S3、S4断层在青一段盖层内的垂向封闭性定量评价中,结果表明,汪家屯气田W1、W2、W3、W4断层在青一段内均具垂向封闭性,与目前青一段泥岩存在异常孔隙流体压力和气藏能保存至今的事实相符;三站气田S1、S2、S3、S4断层在青一段内也具垂向封闭性,但封闭程度不如汪家屯气田,也与目前三站气田天然气不如汪家屯气田的事实相符。这说明采用该方法确定的评价标准用于定量研究断层垂向封闭性是可行的。Based on the analysis of mechanism of vertical seal of faults and the influencing factors, and according to the theory of mudstone deformation, it is proposed that the plastic deformation limit of mudstone should be the lower limit on fault surface required by vertical seal of faults. Based on predecessors experimental data about mudstone plastic deformation, a method, with the application of the relationship between the plastic deformation ultimate of mudstone and the buried depth, to research on the changes of the lower limit of pressure on fault surface needed by the vertical seal of faults with the buried depth is established. The method is used to the quantitative evaluation of the vertical closure property of faults in Kq1 caprock, and the faults include Fault W1 , W2, W3 and W4 in Wangjiatun gas field and Fault S1 , S2, S3 and S4 in Sanzhan gas field in Songliao basin. The result shows that Fault W1 , W2, W3 and W4 in Kql have vertical closure property, which accords with the fact of the existence of abnormal pore fluid pressure in Kq1 and the preservation of gas field at present ; Fault S1, S2 , S3 and S4 of Sanzhang gas field has also vertical closure property in Kq1, but the closure degree is lower than that in Wangjiatun gas field, and it accords with the fact that reserves in Sanzhan gas field are less than those in Wangjiatun gas field. It is indicated that it is feasible to apply the evaluation standard based on the method mentioned to the quantitative study on vertical closure property of faults.

关 键 词：断层 垂向封闭性 评价标准 泥岩变形 塑性极限 汪家屯气田 

分 类 号：TE122.34[石油与天然气工程—油气勘探]