大民屯凹陷构造油气藏有利分布区定量预测

Quantitative prediction of favorable distribution area of structural pools in Damintun Depression

分析大民屯凹陷构造类油气藏地质特征、分布统计规律,发现:区域盖层(C)、沉积相(D)、古隆起(M)和烃源灶(S)是控制大民屯凹陷构造类油气藏形成和分布的4个功能要素。据此,提出了功能要素(T-CDMS)组合控油气分布模式,以及构造类油气藏有利分布区带的预测方法。4个功能要素,纵向上的有序组合控制构造油气藏的成藏层位,平面上的叠加复合决定构造油气藏的分布范围,地史过程中联合决定油气成藏的时间。通过各个功能要素的单因素控油气作用及定量表征方法的分析,得到单因素控藏概率,经加权平均,得到综合控藏概率指数(I),根据该指数的大小可预测构造油气藏分布有利区。应用功能要素组合控油气分布模式,预测了大民屯凹陷古近系Es33,Es34和Es4构造油气藏最有利分布区12个,结果证明了其有效性和可行性。

Study on geological features and distribution of structural pools shows that the regional eaproek, sedimentary facies, paleohigh and source rock are four function elements controlling the formation and distribution of structural pools in Damintun Depression. Based on this, this paper gives the model of functional element（T-CDMS） combining hydrocarbon distribution and themethod predicting favorable areas of structural pools. Longitudinal sequential combinations of four elements control the strata of structural pool formation, and planar superimpositions and combinations control the distribution range of structural pool and their simuhaneous joint effects in geohistory determine the time of hydrocarbon accumulation. The probability of reservoir formation of single factor can be achieved by analyzing the hydrocarbon control function and quantitative characterization of every functionelement, and then the index of integrated probability of reservoir formation can be obtained by calculating the weighted mean of the probability of reservoir formation of single factor. According to the index, we can predict the favorable area of structural pool distribution. Based on the model, we predicted that the most favorable distribution areas of structural pool were twelve, which were distributed in Paleogene Es33, Es34 and Es4 strata in Damintun Depression. The results proved its feasibility and effectiveness.