摘要
准噶尔盆地玛湖凹陷斜坡区三叠系百口泉组获得工业油气流,而断裂作为油气运移的通道,起着重要的作用。通过对斜坡区三维、二维地震资料的精细解释,结合区域构造背景,建立了玛湖凹陷斜坡区构造、断裂样式,利用构造导向滤波、分频相干等技术相结合在平面上对断裂进行了预测及平面组合,并根据断裂形成时间、断裂样式和控制地层结构等要素把断裂划分为3个级别,其中Ⅰ级断裂近平行于西北缘山前逆掩断裂带,具有控"鼻隆"作用,形成时间为海西中期至印支期;Ⅱ级断裂为近垂直于边界断裂的走滑断裂,将Ⅰ级断裂错断相交叉形成断块,同时起着山前推覆体运动过程中调节横向应力的作用,形成时间为海西中期至喜马拉雅期;Ⅲ级断裂为Ⅰ级断裂和Ⅱ级断裂呈剪切关系形成的断裂,多为层间断裂,也发育走滑断裂伴生的羽状剪切断裂,在剖面呈"Y"字型,多形成于中印支期—燕山期。断裂在垂向上不但作为油气运移通道,同时将与二叠系油气运移相伴随的有机酸流体从Ⅰ级、Ⅱ级断裂进入百口泉组后,在优势运移通道内的长石被溶解,形成次生孔隙储层发育带,从而形成成岩圈闭。次生孔隙发育带的提出,突破了以前埋深大于3 500m的勘探禁区,极大拓展了勘探深度范围。
Recently,Large amount of industrial petroleum has been found in the Triassic Baikouquan Formation in the Mahu slope area,and the faults have key roles on oil and gas migration paths.Under constrains of the tectonic background of the area,the authors built the structural and fault styles through the interpretation of 2Dand 3Dseismic data.The authors also used the structural guidance filters technique and coherent sections technique to predict and make groups of faults and classify them into 3groups based on the formation time,fault styles and cutting strata.type I faults are parallel to the mountains leding to the formation of the nose uplift from middle Hercynian to Indosinian stage,typeⅡ faults are perpendicular to mountains and are crosscut with type I faults and their formation time was middle Hercynian to Himalayan stage,which is served as adjusting faults.TypeⅢfaults are sheared by typeⅠandⅡfaults and have'Y'shape in sections accompanied with strike slip faults and are formed during the middle Indosinian to Yanshanian stage.Type I andⅡfaults served as paths of both oil and gas and organic acid moved from the Permian,and feldspar are dissolved resulting the formation of secondary pores and diagenetic traps.This study breaks through the exploration limited depth of 3 500 m,and enlarges the exploration depth area.
出处
《天然气地球科学》
EI
CAS
CSCD
北大核心
2015年第S1期11-24,共14页
Natural Gas Geoscience
基金
国家重大科技专项(编号:2011ZX05003-003)资助
关键词
玛湖凹陷斜坡区
等时地层格架剖面
断裂样式
断裂期次及级别
油源断裂
成岩圈闭
Mahu slope area
Isochronous stratigraphic framework
Fault styles
Formation periods and grades of faults
Oil-migrating faults
Diagenetic traps
