海拉尔盆地贝尔凹陷盖层发育特征及封闭性  

DEVELOPMENT CHARACTERISTICS AND SEALING EVALUATION FOR THE CAP ROCKS IN BEIER SAG OF HAILAR BASIN

作　　者：杨勉[1] 陈艳丽[1] 付广[1] 

机构地区：[1]东北石油大学地球科学学院,黑龙江大庆163318

出　　处：《大庆石油地质与开发》2013年第4期1-6,共6页Petroleum Geology & Oilfield Development in Daqing

基　　金：国家大型油气田及煤层气开发科技重大专项"中国大型气田形成条件;成藏机制与富集规律研究"(2011ZX05007-002)

摘　　要：根据已有探井的岩性组合、测井曲线变化规律，并结合盆地发育演化过程，发现贝尔凹陷下白垩统可识别出3套区域性盖层和10套局部性盖层。研究认为贝尔凹陷的区域性盖层分布广、厚度大，局部性盖层分布小、厚度薄；各套盖层的封闭性好坏主要受盖层的厚度、展布连续性、排替压力、成岩程度及断裂对盖层的破坏程度等因素控制。选取沉积旋回、成岩演化阶段、盖层单层及累计厚度，断裂破坏程度、泥地比和排替压力等作为评价指标，对凹陷内的各套盖层的封闭性进行了综合评价。结果表明：整体上贝西次凹和贝中次凹的盖层封盖能力相对较好，贝中断隆带中、南部盖层封盖能力相对最差；层序Sqd1^1、Sqd1^2、Sqd1^2内的3套区域性盖层和层序Sqn1、Sqn2内的局部性盖层封盖能力以中等、好级别为主，层序Sqtb、Sqd2内的局部性盖层封盖能力以中等、差级别为主。According to the lithologic combination of the existed exploration wells, the changed laws of the well loggings, and moreover the integration of the basin development-evolution process, 3 sets of regional cap rocks and 10 sets of local cap rocks are discovered and recognized in Lower Cretaceous Beier Sag. The studies show that the regional cap rocks are characterized by wide distribution, big thickness, whereas the local cap rocks are small and thin. The sealing abilities of each set of cap rock are mainly determined by pressure and diagenesis degree of the cap rocks distribution and moreover the the thickness, continuity, expulsion damaged faults etc. By means of choosing the following evaluating indexes such as sedimentary stage, monolayer thickness and cumulative thickness, damaged degree by the faults, degree of the rocks by the cycle, diagenesis evolution mud-strata ratio, expulsion pressure and so on, the sealing abilities of each set of cap rocks in the sag are comprehensively evaluated. The re- sults show that the abilities of the cap rocks in Beixi Subsag and Beizhong Subsag are relatively better in a whole, on the contrary, the abilities in the middle and southern parts of Beizhong Fault-uplift Belt are comparatively theworst; the middle-good and Sqd; and moreover cap rocks in Sqtb and sealing degrees are mainly presented for the three sets of regional cap rocks in Sqd1^1, Sqd1^2 the local cap rocks in Sqn1 and Sqn2; the middle-bad degrees are shown for the the local cap rocks in Sqtb and Sqd2.

关 键 词：海拉尔盆地 贝尔凹陷 盖层发育特征 封闭性 评价 

分 类 号：TE122.25[石油与天然气工程—油气勘探]