摘要
以渤海湾地区Z油田沙一下生物灰岩油藏为例，利用岩心、薄片及成像测井等资料，对天然裂缝特征及控制因素进行研究，并对裂缝的成因机理进行了分析。研究表明，z油田沙一下生物灰岩储层主要发育构造裂缝及成岩裂缝两种类型，其中构造裂缝又分为剪切裂缝及扩张裂缝两类；大多数构造裂缝为高角度缝，主要方位为北东一南西向、北西一南东向及近东西向；裂缝纵向高度一般小于170cm，裂缝平面长度主要分布在35m以内，裂缝开度主要在100μm以内；裂缝的发育受岩性、岩层厚度、断层等地质因素控制。该区构造裂缝主要在始新世一渐新世裂陷中后期北西一南东向引张应力场及东营末期北东东一南西西向反转挤压应力场两期构造应力作用下形成，其中早期主要形成北东一南西向的正断层型裂缝，晚期主要形成北东一南西向、北西一南东向的剪切裂缝及近东西向扩张裂缝。
Based on cores, thin sections and FMI data, the characteristics and controlling factors of natural fractures in biolimestone reservoir in Lower Member 1 of Shahejie Formation in Bohai Bay area were studied. The formation mechanism was then analyzed. The results showed that fractures were mostly generated by structure movement and diagenesis. The fractures caused by structure movement could be further divided into shear fractures and extension fractures. Most of the structural fractures were high-angle fractures and the strike were mainly NE-SW, NW-SE and near EW. The height of the fractures was always less than 170 cm, the length was less than 35 m and the aperture was less than 100 I^m. The distribution of the fractures was controlled by lithology and thickness of the reservoir and faults. The fractures were mainly formed in NW-SE extensional stress field in the mid-late rift period of Eocene-Oligocene and in NEE-SWW compressive stress field of Late Dongying period. The fractures formed in early stage were largely NE-SW normal fault style fractures and the fractures in late stage were mainly NE- SW, NW-SE shear fractures and near EW extensional fractures.
出处
《地质科学》
CAS
CSCD
北大核心
2016年第2期484-493,共10页
Chinese Journal of Geology(Scientia Geologica Sinica)
基金
国家科技重大专项（编号：2011ZX05013-004）资助.
关键词
天然裂缝
灰岩储层
形成机理
沙河街组
渤海湾盆地
Natural fracture, Limestone reservoir, Formation mechanism, ShahejieFormation, Bohai Bay Basin
