塔里木盆地孔雀河地区构造变形特征及其控油气作用

根据塔里木盆地孔雀河地区地层层序及接触关系,将沉积盖层分为3大构造层,按古生界和中生界2大构造层重新划分构造单元;将区内断裂按走向划分为4组,以北东和北西向为主,断裂—褶皱组合样式有5种类型,以挤压构造为主。构造变形具有复合叠加特征,东西向表现为不对称的复式背斜;南北向以斜坡加断鼻构造为主;垂向上,下古生界以大型古鼻隆为特征,主要形成于加里东晚期—海西期;石炭系表现为缓凹缓坡;中生界总体表现为南西倾的大型斜坡,在此背景上发育断裂背斜圈闭,形成于燕山早期。长期构造演化控制了各类圈闭的形成;继承性的古隆起、古斜坡是油气运移的有利指向区;通源断裂是油气成藏的基本条件;保存条件对油气成藏至关重要。最后指出该区油气勘探的4大领域:西北部库南地区寒武—奥陶系碳酸盐岩潜山—内幕构造,西部草湖地区石炭系背斜和地层超覆圈闭,中南部普惠地区和东部龙口—维马—开屏地区侏罗系、志留系背斜构造。 

STRUCTURAL DEFORMATION CHARACTERISTICS AND THEIR CONTROL ON OIL AND GAS IN KONGQUEHE AREA, THE TARIM BASIN

According to stratigraphic sequence and contact relationship,sediments in Kongquehe area of the Tarim Basin are divided into 3 tectonic layers,and structural units in the region are redetermined based on Paleozoic and Mesozoic structural layers.Faults,mainly striking in NE and NW directions,are divided into 4 groups.There are 5 types of fracture-fold combination patterns,among which the compressional structures are dominant.Structural deformations are both compounding and stacking,with unsymmetrical compound anticlines from east to west and fault-nose structures and slopes from south to north.Vertically,lower Paleozoic is characterized by large nose-1ike uplifts formed from late Caledonian to Hercynian;Carboniferous is characterized by gentle sags and gentle slopes;Mesozoic is characterized by a large slope dipping in southwest direction,forming faulted anticlines during early Yanshanian.Long term tectonic evolutions control the formation of various types of traps.Palaeohighs and palaeoslopes are favorable destinations for hydrocarbon migration.Faults linking to source rocks are basic conditions for hydrocarbon accumulation.Preservation conditions are also critical for oil and gas accumulation.Finally,4 favorable oil and gas exploration targets are pointed out,including interior structures of Cambrian—Ordovician buried carbonate hills in Kunan,Carboniferous anticlines and stratigraphic overlap traps in Caohu,Jurassic and Silurian anticlines in Puhui and Longkou—Weima—Kaiping.