山东HM凹陷含油气性综合定量评价

Quantitative Evaluation of Oil-Gas in the Huiming Hollow,Shandong

从构造油气藏评价出发,按构造分区将HM凹陷总体划分为凹陷—向斜面、背斜—鼻状—披覆构造、地层超覆缓坡带、断裂陡坡带、隆起—凸起区等五大类。按1∶20万比例尺1cm×1cm进行网格单元划分,对各构造地质体进行变量取值,结合主要生储层沙三段的分布特征、T_1—T_r地震反射特征、γ能谱测量和重磁场分析,依据综合评价指标与已知油气藏之间的内在联系,建立了含油气性圈闭的定量模式。以地质异常值、沙三段砂岩含量、沙三段砂岩总厚、沙三段泥岩总厚、沙三段泥砂比、T_1T_r地震反射等深度、线积分异常、γ能谱测量异常值、重磁处理有关信息等18个指标作为输入层特征向量,进行了ART和BP人工神经网络含油气性综合评价。含油气性有利度高值区与已知油气田吻合,圈定了进一步油气勘查的有利区17个,据含油气性有利度的大小和所处的地质环境划分出一级有利区9个,二级有利区8个。

Proceeding from the evaluation of structural oil-gas deposits,five structural subareas in the Huiming hollow,Shandong,are distinguished:hollow-synclinal limb,anticline-nose-drape structure, stratal onlap-gentle slope zone,fault-steep slope zone,and uplift-rise area.According to a 1 cm×1 cm grid each structural geologic body is quantified.Then a quantification model of oil-gas traps is constructed according to the distribution characteristics of the Sha-3 Member of source and reservoir rocks,T_1-T_r seismic reflection features γ-ray spectrometry and gravity and magnetic analyses,as well as based on the inner relations between the synthetic evaluation indicalors and the known oil-gas deposits.Adaptive Resonance Theory (ART) and Back-Propagation (BP) artificial neural network (ANN) evaluation of oil-gas potentials are made using eighteen indicators such as geologic anomaly values.The high-value favorable regions coincide with the known oil-gas fields.A total of 17 favorable areas for further oil-gas exploration,including 9 first-class and 8 second-class favorable areas, have been delineated according to the degrees of advantages of oil-gas potentials and geological settings.