中国石油大学学报（自然科学版）2018，Vol.42Issue(1)：21-31,11.DOI:10.3969/j.issn.1673-5005.2018.01.003
盖层有效厚度计算方法及应用
Calculation method and application of cap rock's effective thickness
摘要
Abstract
A method of computing cap rock's effective thickness is proposed based on that cap rock's heterogeneity may result in different capillary sealing ability within cap rock. Using data of thin section,SEM,breakthrough pressure,porosity,per-meability and other test data of argillaceous cap rock and sandstone reservoir, the boundary between cap rock and reservoir can be defined,which includes breakthrough pressure limit,critical lithology(grain size) and petrophysics limit.Subsequent-lythe evaluation criteria of cap rock's capillary sealing ability is established. With gamma ray curve, interval transit time curve and test data,a logging interpretation model is established to quantitatively recognize cap rock's lithology and to calcu-late porosity,permeability and breakthrough pressure.A comprehensive evaluation on capillary sealing ability of cap rock has been made to first remove the cap rock with no capillary sealing ability and then to obtain the effective thickness. Our results show that between cap rock and reservoir of X gas reservoir, the breakthrough pressure limit is 2 MPa;the critical lithology (grain size) is argillaceous coarse siltstone;the porosity limit is about 6%, and the permeability limit is about 0.02×10-3 μm2. Cap rock's capillary sealing ability has been divided into five grades fromⅠtoⅤ. By removing gradeⅣandⅤwhich correspond to no capillary sealing ability,the effective thickness of single cap rock is obtained between 4 and 10 m. Correla-tion between the height of gas column and the effective thickness suggests the robustness of the method. Based on the effec-tive thickness,a weighted average of breakthrough pressure has been taken to obtain equivalent breakthrough pressure, and the whole capillary sealing ability of cap rock has been evaluated as moderate effectively.关键词
盖层/有效厚度/物性封闭/评价标准/测井解释/计算检验/等效突破压力Key words
cap rock/effective thickness/capillary sealing ability/evaluation criteria/logging interpretation/calculation and examination/equivalent breakthrough pressure分类
能源科技引用本文复制引用
马存飞,董春梅,林承焰,尹鹤,谢晶晶,栾国强,曾芳,孙小龙,沈正春..盖层有效厚度计算方法及应用[J].中国石油大学学报（自然科学版）,2018,42(1):21-31,11.基金项目
国家科技重大专项(2017ZX05009-001) （2017ZX05009-001）
国家留学基金项目(201506450031) （201506450031）
