石油学报 ›› 2018, Vol. 39 ›› Issue (5): 554-563.DOI: 10.7623/syxb201805006

• 地质勘探 • 上一篇    下一篇

高孔隙性砂岩内变形带特征及对流体流动的影响——以柴达木盆地西缘油砂山背斜为例

王海学1,2, 刘志达1,2, 沙威3, 付晓飞1,2, 孙永河1,2, 赵政权4, 卢明旭5, 吴桐1,2   

  1. 1. 东北石油大学地球科学学院 CNPC断裂控藏研究室 黑龙江大庆 163318;
    2. 东北石油大学非常规油气成藏与开发省部共建国家重点实验室培育基地 黑龙江大庆 163318;
    3. 中国石油青海油田公司勘探开发研究院 甘肃敦煌 736202;
    4. 中国石油华北油田公司第五采油厂 河北辛集 052360;
    5. 大庆油田有限责任公司第四采油厂 黑龙江大庆 163511
  • 收稿日期:2017-11-29 修回日期:2018-04-08 出版日期:2018-05-25 发布日期:2018-06-06
  • 通讯作者: 刘志达,女,1994年1月生,2014年获东北石油大学学士学位,现为东北石油大学博士研究生,主要从事高孔隙性岩石变形伴生构造方面的研究工作。Email:lzd6536@163.com
  • 作者简介:王海学,男,1987年1月生,2009年获大庆石油学院学士学位,2016年获东北石油大学博士学位,现为东北石油大学讲师,主要从事断层生长机制及控藏作用研究。Email:wanghaixue116@163.com
  • 基金资助:

    国家自然科学基金(No.41602129)、国家自然科学基金重点联合基金(No.U1562214)、东北石油大学优秀科研人才培育基金黑龙江省创新后备人才项目(2017-KYYWF-0063)和国家科技重大专项(2016ZX05054-009,2016ZX05003-002)资助。

Characteristics of deformation bands in high-porosity sandstone and their influence on fluid flow: a case study of Youshashan anticline at the western margin of Q aidam Basin

Wang Haixue1,2, Liu Zhida1,2, Sha Wei3, Fu Xiaofei1,2, Sun Yonghe1,2, Zhao Zhengquan4, Lu Mingxu5, Wu Tong1,2   

  1. 1. College of Earth Science, CNPC Fault Controlling Reservoir Research Laboratory, Northeast Petroleum University, Heilongjiang Daqing 163318, China;
    2. Accumulation and Development of Unconventional Oil and Gas, State Key Laboratory Cultivation Base Jointly-constructed by Heilongjiang Province and the Ministry of Science and Technology, Northeast Petroleum University, Heilongjiang Daqing 163318, China;
    3. Exploration and Development Institute of PetroChina Qinghai Oilfield Company, Gansu Dunhuang 736202, China;
    4. NO.5 Production Plant, PetroChina Huabei Oilfield Company, Hebei Xinji 052360, China;
    5. No.4 Oil Recovery Plant, Daqing Oilfield Limited Company, Heilongjiang Daqing 163511, China
  • Received:2017-11-29 Revised:2018-04-08 Online:2018-05-25 Published:2018-06-06

摘要:

传统观点认为岩石受力变形发生破裂作用形成裂缝,对流体流动起到输导作用。实际上,高孔隙性岩石受力变形,发生颗粒的旋转、滚动、重排和(或)破碎,应变集中形成与裂缝特征截然不同的变形带,降低了储层的孔隙度和渗透率,影响流体的流动。基于野外观察描述和室内分析测试资料,以柴达木盆地西缘油砂山背斜下油砂山组地层为研究对象,从变形带形成机制出发,系统描述了高孔隙性砂岩中变形带的宏观、微观特征,剖析了变形带和未变形母岩的物性特征,明确了变形带形成时期和油气成藏期的耦合关系,探讨了变形带对流体流动的影响。研究结果表明:油砂山背斜带转折端处下油砂山组高孔隙性砂岩受力变形发生了碎裂作用,形成了典型的碎裂型变形带。碎裂型变形带的颜色发白,比母岩浅;呈正风化地形特征,以"肋状"凸出的形态发育;极少单条发育,多呈"簇状"等组合特征发育。微观上,碎裂型变形带表现为颗粒发生旋转、滚动,沿着颗粒接触边界摩擦导致颗粒破碎,颗粒尺寸明显减小、分选变差,带内颜色相对变深和孔隙坍塌、孔隙空间明显降低的特征。与母岩相比,变形带的孔隙度平均降低约17.4%。应用母岩与变形带渗透率比值与流体流动效率的定量图版分析,当变形带渗透率较母岩降低3个数量级以上时,对流体流动起到阻碍作用,油砂山背斜带变形带渗透率降低1~2个数量级,对流体流动基本无明显阻滞作用。

关键词: 高孔隙性砂岩, 变形带, 碎裂作用, 油砂山背斜, 柴达木盆地

Abstract:

It is traditionally considered that the rocks are deformed by force to induce fracturing, and thus form the fractures playing a role of conduction in fluid flow. In fact, the deformation of high-porosity rocks by force leads to the rotation, sliding, disaggregation and/or rupture of particles. The strain concentration results in the deformation bands with characteristics obviously different from fracture, reducing the reservoir porosity and permeability as well as influencing fluid flow. Based on field observation and description and laboratory analysis test data, the Lower Youshashan Formation strata of Youshashan anticline at the western margin of Qaidam Basin is taken as the research object to systematically describe the macro and micro characteristics of deformation bands in high-porosity sandstones in term of deformation-band formation mechanism. Meanwhile, this paper analyzes the petrophysical properties of deformation bands and un-deformed parent rocks, makes clear the coupling relationship between the forming period of deformation band and hydrocarbon accumulation period, and discusses the influence of deformation bands on fluid flow. Research results indicate that the high-porosity sandstones in Youshashan Formation at the hinge zone of Youshashan anticline are deformed by force to induce cataclasis, thus forming the typical cataclastic deformation band. The cataclastic deformation band is white, lighter than parent rock, characterized by positive weathering landform and rib protruding morphology. It rarely shows singular development, dominated by "clustered" assemblage development. On a microscopic level, the cataclastic deformation bands are characterized by rotation and sliding of particles; the frictions along grain contact boundaries lead to the fractured pariticles, obviously decreased grain size, poor sorting, darkening band color, pore collapse, and significant decline of pore space. Compared with parent rock, the porosity of deformation band is reduced by about 17.4% on average. Through applying the quantitative chart of flow efficiency versus the permeability ratio of parent rock and deformation band for analysis, it is found that when the permeability of deformation band is reduced by three orders of magnitude over parent rock, fluid flow is hindered. When the permeability of deformation band in Youshashan Anticline is reduced by 1-2 orders of magnitude, there is basically no obvious hindering effect on fluid flow.

Key words: high-porosity sandstone, deformation band, cataclasis, Youshashan anticline, Qaidam Basin

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