大庆长垣南部黑帝庙浅层生物气的断层侧向封闭性  

Lateral sealing of faults for shallow biogas in Heidimiao Formation of the southern Daqing placanticline

作　　者：付晓飞[1] 潘国强[1] 贺向阳 玄昌姬[1] 吕亚娟[1] 

机构地区：[1]大庆石油学院地球科学学院,黑龙江大庆163318 [2]北京吉泰公司,北京100083

出　　处：《石油学报》2009年第5期678-684,共7页Acta Petrolei Sinica

基　　金：中国石油风险创新基金项目"三肇凹陷多边断层成因机制及对油成藏控制作用研究"(07-06D-01-04-01-06)资助

摘　　要：在大庆长垣南部黑帝庙油层中发现了大量的生物气,大部分聚集在断层圈闭中,断层侧向封闭性影响浅层气的聚集规模。黑帝庙油层具有埋藏浅、成岩程度低、砂岩物性普遍较好的特点,因此断裂变形形成的碎裂岩难以形成较强的封闭。对含气圈闭断层SGR统计表明:长垣南部断层封闭SGR临界值为0.375,对应的风险断距普遍小于50m,因此断距小于50m的断层侧向封闭性可能相对较差;同时证实层状硅酸盐—框架断层岩在该区不起封闭作用,主要封闭类型应该是对接封闭和泥岩涂抹封闭。利用Knipe图解和Allan图,结合断距—距离曲线对全区断层进行定量评价,断层封闭具有垂向的差异性和平面的分段性,因此有些圈闭只在个别小层中存在。据圈闭的断层封闭分段性分析,与未评价断层侧向封闭性之前相比,本区圈闭存在3种变化:①断层侧向封闭,幅度和面积不变的圈闭;②断层侧向部分封闭,幅度和面积变小的圈闭;③断层侧向不封闭,不存在的圈闭。其中前两种圈闭是首钻的目标,结合生物气成藏条件,认为长垣南部黑帝庙浅层生物气潜力巨大。Abundant biogas was found in Heidimiao Formation of the southern Daqing placanticline.Most gas accumulated in fault trap.The lateral sealing of faults controlled the accumulation of shallow gas.The fragmented rock resulted from the deformation of faults was difficult to bear strong sealing because of shallow burying,low diagenetic grade and good physical property.According to the SGR values of fault in the gas-bearing trap,the minimum SGR value of fault sealing is 0.375,and the corresponding risk fault throw is less than 50m. The lateral sealing of the fault with the throw less than 50m is worse, and the layer silicate-fault rock in this area has no sealing action on the faults. The main sealing types are interface sealing and mudstone smear sealing. The sealing of faults are evaluated quantitatively by the curves of fault throw-distance using the Knipe and Allen maps, the result shows that there are differences in the vertical sealing and segmentation in the plane, so some traps only exist in a certain small formation. The risk of trap were analyzed according to segmentation of faults, there are three kinds of changes compared with the non-evaluated lateral seal- ing of faults, including the good lateral sealing and traps with constant amplitude and area, the partial lateral sealing and traps with reduced amplitude and area, the non existing traps without lateral sealing. The main drilling targets should be focused on the first and second kinds of traps. The analyses on the biogas accumulation condition show that there is a potential capacity of biogas in Heidimiao Formation of the southern Daqing placantieline.

关 键 词：大庆长垣南部 黑帝庙油层 断层侧向封闭性 Knipe图解 Allan图解 定量评价 

分 类 号：TE112.3[石油与天然气工程—油气勘探]