断陷盆地岩性圈闭成藏特征及地质风险评价研究

中国石化东部的济阳坳陷、东濮凹陷、南泌凹陷、苏北盆地、江汉盆地等，均为中新生界陆相断陷含油气盆地，具备相似的构造沉积特征和岩性油藏地质特征，具有建立统一的岩性圈闭地质风险评价方法和评价标准的地质基础。不同的地质条件在岩性圈闭成藏中所起的作用不同，研究5项评价条件及各项地质要素权系数时，应能充分体现这种差异。圈闭地质要素可以归纳为圈闭成藏要素和圈闭品位要素两大类，可分别采用钻探成功率分级法、累计概率曲线法、地质分析法建立分级评价标准。应用表明，建立的岩性圈闭地质风险评价方法和评价标准，能反映探区地质特点和勘探实际情况。

CHARACTERISTICS OF LITHOLOGIC TRAP AND EVALUATION METHODS OF GEOLOGIC RISK IN FAULTED BASIN

Jiyang depression,Dongpu sag,Nanmi sag,Subei basin,and Jianghan basin in east part of SINOPEC are all oil bearing continental faulted basins formed in Mesozoic to Cenozoic.They possess similar structural and sedimentary features and similar geologic features for lithologic reservoir,and this is the basic factor to establish common method and criteria of analyzing geologic risk for mithologic trap.Different geologic conditions play different roles in reservoir forming in lithologic trap.During analyzing of weight coefficient of five evaluation conditions and different geologic factors,such difference must be considered efficiently.Geologic factors for trap evaluation can be divided into two classes,and they are reservoir forming factors and trap quality factors.There are several methods to establish grading and evaluation criteria for trap evaluation, and they are grading method based on success ratio,grading method based on cumulative probability curve,and grading method geologic analyzing.Application effects showed that,these methods and criteria for geologic risk analysis of lithologic trap can represent geologic feature and exploration practice for a given area.