准噶尔盆地阜康凹陷东部中/上二叠统不整合结构特征及控藏作用

不整合纵向结构体中的高孔渗带与不同结构层组成的储盖组合常形成类型多样的岩性、地层圈闭。为此，通过井震结合，综合不整合之上、下地震反射特征，可将准噶尔盆地阜康凹陷东部中/上二叠统不整合划分为平行—平行、平行—削截、平行—褶皱、超覆—削截和超覆—褶皱等五种类型；利用测井资料构建判别参数，识别不整合体结构，分析其发育规律及控制因素；根据钻探成果，建立不整合结构体控藏模式。研究表明，不整合体结构主要受剥蚀量、母岩岩性及构造部位高低的控制，不整合结构体上层与中层厚度呈负相关；超覆—削截不整合区域为油气藏有利发育区；不整合上层结构中的水进砂体，是不整合体油气勘探的有利目标，湖(海)湾区易形成地层超覆油气藏。该成果对其他类似地区不整合油气藏勘探具有借鉴意义。

Characteristics and reservoir-control effect of Upper/Middle Permian unconformity structures in the east of Fukang Sag,Junggar Basin

The high porosity and permeability zones in longitudinal structures of unconformity and the reservoir-cap combinations composed of different structural layers can form various types of litholo-gic stratigraphic traps. Therefore, through the combination of logging and seismic data and the integration of the upper and lower seismic reflection characteristics of unconformity, the Middle/Upper Permian unconformity in the east of Fukang Sag in Junggar Basin are divided into five types: parallel-parallel, parallel-cut, parallel-fold, overlap-cut, and overlap-fold. The logging data is used to construct the determinant parameter to identify unconformity structures and analyze their development laws and controlling factors. Then, the reservoir-control model of unconformity structures is built on the basis of the drilling results. The research reveals that the unconformity structures are mainly controlled by the erosion amount, lithology of mother rock, and the depth of the structures, and the thickness of the upper layer is negatively correlated with that of the intermediate layer in the unconformity structures. The unconformity area of overlap-cut is a favorable zone for developing oil and gas reservoirs. The water in the unconformity superstructure entering the sand body is a favora-ble target for oil and gas exploration of unconfor-mity, and it is easy to form stratigraphic overlying oil and gas reservoirs in the lake (sea) bay area. The research result can provide a reference to the exploration of unconformity reservoirs in other similar areas.