区带资源定量评价方法及在苏北盆地溱潼凹陷的应用

Quantitative resource assessment methodology for play and its application to Zhentong depressions in Subei basin

徐旭辉 朱建辉 江兴歌

Xu Xuhui Zhu Jianhui Jiang Xingge

在TSM盆地模拟计算生、排烃量的基础上,通过势场分析,利用油气运移路径模型,探索建立区带以及构造带资源量动态、定量的计算方法,确定运聚资源量和所处位置,从而达到资源动态定量评价的目的。在苏北盆地溱潼凹陷的应用中,依据排烃势能,结合构造特征,把凹陷划分为断阶带、内斜坡带、枢纽带和外斜坡带4个区带共11个构造带,定量计算了三垛组沉积(35.2 Ma)以来,作为主要目的层的泰州组、阜宁组一段、阜宁组三段、戴南组、三垛组等在各带上的油气运聚量。计算结果表明,凹陷演化至今,主要油气运聚发生在盐城组沉积(23.2 Ma)以来。从这时期看,在三垛组运聚至断阶带的油气约为9.98×10t,占该层的52.0%;在戴南组运聚至内斜坡带的油气约为21.59×10t,占该层的为51.0%;在阜宁组三段运聚至内斜坡带的油气约为145.19×10t,占该层的58.4%;在阜宁组一段运聚至内斜坡带的油气约为54.80×10t,占该层的51.6%;在泰州组运聚至内斜坡带的油气约为46.86×10t,占该层的48.5%。从运聚至断阶带上的绝对量看,阜宁组三段约为61.70×10t、泰州组约为25.39×10t、阜宁组一段约为19.70×10t。因此,从资源定量评价的角度分析,勘探重点在断阶带应以阜宁组三段、三垛组为主,在内斜坡带应以泰州组、阜宁组一段、阜宁组三段、戴南组等为主。

Based on calculation of hydrocarbon generation and expulsion through TSM basin simulation,potential field analysis,and oil/gas migration channel modeling,dynamic and quantitative resources calculation methods are proposed for plays and structural zones in an attempt to determine the migrated and accumulated resources and pin down their locations,so as to realize dynamic assessment of resources.Zhentong depression in Subei basin is divided into four plays(fault terrace,inner slope,hinge belt,and outer slope) and 11 structural zones according to hydrocarbon expulsion potentials and structural features,and these methods are used to quantitatively calculate the total volume of oil and gas migrated and accumulated in the main targets across all the plays since the deposition of the Sanduo Formation(35.2Ma).The calculation indicates that the main period of hydrocarbon migration and accumulation is from the deposition of the Yancheng Formation(23.2Ma) till present.During this period,about 9.98Mt of hydrocarbons migrated from Sanduo Formation and accumulated in fault terrace play,accounting for 52.0% of the total hydrocarbons generated by this formation.While in the inner slope,the volume from the Dainan Formation is about 21.59 Mt(51.0% of the total),from the 3 member of Funin Formation is 145.19Mt(48.5% of its total).The absolute magnitudes of hydrocarbons migrated and accumulated in the fault terrace play are about 61.70 Mt from the 3 member of Funin,25.39 Mt from Taizhou Formation,and 19.70 Mt from the 1 member of Funin Formation.Therefore,in respect of quantitive resource assessment,the exploration focus shall be put on the 3 member of Funing Formation and Sanduo Formation in the fault terrace play,while in the inner slope play,it shall be put on the Taizhou Formation,1 and 3 members of Funin Formation,and Dainan Formation.

10.11743/ogg20070402