倾斜裂缝垂向封闭性演化特征研究——以海拉尔盆地贝尔凹陷布达特群为例  

Study on evolutional features of vertical seal of dip fractures——A case study from the Budate Group in the Buir Sag,Hailar Basin

作　　者：付广[1] 王有功[1] 黄劲松[1] 

机构地区：[1]大庆石油学院,黑龙江大庆163318

出　　处：《地质科学》2008年第1期23-33,共11页Chinese Journal of Geology(Scientia Geologica Sinica)

基　　金：国家973重点基础研究项目"高效大气田形成机理与分布研究"(编号:2001CB209104);"高等学校博士学科点专项科研基金(编号:20060220002)资助

摘　　要：岩心观察和成像测井资料分析,发现海拉尔盆地贝尔凹陷布达特群断裂伴生和派生的裂缝以倾斜裂缝为主,其形成与分布主要受区域构造演化控制,3期不同特征的构造裂缝反映了区域构造应力场经历了挤压、剪切和伸展3大阶段。利用裂缝面压力和泥岩塑性变形极限,对贝尔凹陷布达特群倾斜裂缝目前的垂向封闭性进行了评价,结果是:不同角度的倾斜裂缝在凹陷中部均是封闭的,仅在凹陷西北和东南边部开启,且随裂缝倾角增大,开启区面积增大。通过布达特群倾斜裂缝古裂缝面压力的恢复,对其垂向封闭性演化特征进行了研究,认为不同角度倾斜裂缝垂向开启区从伊敏组沉积末期至今逐渐减小。目前已发现的油气藏表明倾斜裂缝不是主要的储集空间,凹陷周边(缘)地区才是倾斜裂缝储集油气的有利地区。The core observation and analysis of imaging logging data demonstrated that the dip fractures were main fractures of the Budate Group in the Buir Sag, Hailar Basin. The formation and development of dip fractures were controlled by three generations of faulting in the regional tectonic evolution during Meso-Cenozoic. Using pressure on fracture surface and plastic deformed limit of mudstone, the vertical seal of dip fractures of the Budate Group in the Buir Sag was studied. The dip fractures with varied dip angles in central and southwestern parts of the sag were sealed, while the dip fractures only in northwestern part and eastern edges of the sag were not sealed. With increasing of dip angles of fracture, open areas of dip fractures increased gradually. By restoration of ancient pressure on fracture surface of dip fractures, the evolutional features of vertical seal of dip fractures in the Budate Group were studied. The open areas of dip fractures of the Budate Group in the Buir Sag decressed gradually from the end of sedimentary period of Early Cretaceous Yimin Formation （K1y）. The discovered oil-gas reservoirs revealed that the dip fractures were not main spaces for oil-gas gathering and accumulation in the Budate Group, and the favorable targets might be in periphery or marginal areas of the sag.

关 键 词：倾斜裂缝垂向封闭 演化特征 裂缝面压力 布达特群 海拉尔盆地贝尔凹陷 

分 类 号：P542[天文地球—构造地质学]