鄂尔多斯盆地北部杭锦旗地区油气圈闭类型研究

Types of hydrocarbon traps in Hangjinqi area of northern Ordos Basin.

杭锦旗地区位于鄂尔多斯盆地北部,从早古生代至晚古生代早期一直为隆起区,局部构造复杂,地层受古地貌的控制,横向变化大,后期受燕山期构造活动的改造,导致该区圈闭类型及成因复杂。综合分析认为,该区主要发育4类构造圈闭和2类岩性圈闭。构造圈闭包括挤压褶皱型背斜圈闭,潜山披覆型圈闭,鼻状构造圈闭,层逆牵引背斜圈闭。岩性圈闭有不整合地层圈闭和岩性尖灭圈闭。综合评价认为,该区具备了形成大中型天然气藏的基本地质条件,具有良好的天然气勘探前景。

Hangjinqi area locates in the north of Yimeng in northern Ordos Basin. This area is an uplifted area from eopaleozoic era through early neopaleozoic era, and is characterized by complex local structures. The strata are controlled by palaeogeomor-phology, leading to rapid lateral variations. Types of traps and their origins in this area were further complicated due to the restructure of Yanshan Movement Comprehensive analysis reveals that there are mainly 4 structural traps and 2 lithologic traps. The structural traps are compressive fold anticline, buried hill and drape, nose structure, and reverse drag anticline. The lithologic traps consist in unconformable stratigraphic trap and lithologic pinchout trap. Comprehensive evaluation indicates that this area has the basic geologic conditions for forming large-scale gas reservoir, therefore is a prospective area for gas exploration.