塔里木盆地麦盖提斜坡差异构造变形与油气聚集规律OA

The Maigaiti Slope in the Tarim Basin is an important petroleum exploration area.However,the complex differential tectonic deformation within the Maigaiti Slope and its controlling effects on hydrocarbon accumulation remain inadequately understood,which restricts major breakthroughs in oil and gas exploration and development.Based on the detailed structure interpretation of 2D and 3D seismic data,this paper identifies the third-order structural units within the Maigaiti Slope,and revises the division of its structural zones.The differences in the fracture characteristics among these third-order structural units are systematically reviewed.Furthermore,the differential tectonic deformation,evolutionary processes and formation mechanisms in the western and eastern Maigaiti Slope are analyzed,and the structural controls on hydrocarbon accumulation are discussed.The following results are obtained.First,the Maigaiti Slope can be divided into four third-order structural units,namely the North Bashituo Gentle Fold Belt,the Ba-Yue Structural Nose,the Yuxi Structural Nose,and the Yudong-Hotan Fault-Fold Belt.It exhibits a pronounced east-west structural zonation.Second,the western Maigaiti Slope is characterized by a large structural nose developed on the flank of the Late Hercynian Maixi Paleo-uplift,where the North Bashituo Gentle Fold Belt is dominated by nearly E-W-trending thrust-strike&slip faults on the north and the Ba-Yue Structural Nose by steep NW-and NE-trending strike-slip faults on the south.Third,the central Yuxi Structural Nose was formed by Himalayan inversion of the Hotan Paleo-uplift and is dominated by steep strike-slip faults developed predominantly within the sub-salt succession.Fourth,the eastern Yudong-Hotan Fault-Fold Belt is dominated by multiple thrust-fold belts developed within the Caledonian forebulge.In conclusion,differential tectonic deformation determines the hydrocarbon accumulation conditions and exploration potential of different structural units in the Maigaiti Slope,and the Ba-Yue and Yuxi structural noses represent the most prospective exploration targets.