石油学报 ›› 2016, Vol. 37 ›› Issue (2): 145-159.DOI: 10.7623/syxb201602001

• 地质勘探 •    下一篇

油气藏形成与分布:从连续到不连续——兼论油气藏概念及分类

赵靖舟, 曹青, 白玉彬, 耳闯, 李军, 吴伟涛, 沈武显   

  1. 西安石油大学地球科学与工程学院 西安石油大学陕西省油气成藏地质学重点实验室 陕西 西安 710065
  • 收稿日期:2015-08-25 修回日期:2016-01-07 出版日期:2016-02-25 发布日期:2016-03-11
  • 通讯作者: 赵靖舟,男,1962年11月生,1983年获西北大学学士学位,2002年获中国石油勘探开发研究院博士学位,现任西安石油大学学术委员会副主任委员、陕西省油气成藏地质学重点实验室主任、二级教授,主要从事油气成藏地质学、非常规油气地质与勘探研究。Email:jzzhao@xsyu.edu.cn
  • 作者简介:赵靖舟,男,1962年11月生,1983年获西北大学学士学位,2002年获中国石油勘探开发研究院博士学位,现任西安石油大学学术委员会副主任委员、陕西省油气成藏地质学重点实验室主任、二级教授,主要从事油气成藏地质学、非常规油气地质与勘探研究。Email:jzzhao@xsyu.edu.cn
  • 基金资助:

    国家重大科技专项(2011ZX05007-004,2011ZX05018001-004)、国家自然科学基金项目(No.41402121,No.41502132)、陕西省自然科学基础研究计划项目(2013JM5007)和陕西省自然科学基金项目(2013JQ503)资助。

Petroleum accumulation from continuous to discontinuous:concept, classification and distribution

Zhao Jingzhou, Cao Qing, Bai Yubin, Er Chuang, Li Jun, Wu Weitao, Shen Wuxian   

  1. School of Earth Sciences and Engineering, Shaanxi Key Laboratory of Petroleum Accumulation Geology, Xi'an Shiyou University, Shaanxi Xi'an 710065, China
  • Received:2015-08-25 Revised:2016-01-07 Online:2016-02-25 Published:2016-03-11

摘要:

根据对常规与非常规油气藏成藏特征的综合研究,探讨了油气藏的概念、分类及其形成和分布的基本规律。重新厘定的油气藏概念为:储层中连续的油气聚集,具有独立或统一的压力系统。按照油气藏的聚集方式或分布样式将其划分为连续型、准连续型和不连续型油气聚集,认为含油气盆地中油气藏的形成往往是一个由连续到不连续的过程,在此过程中形成了以上3种类型的油气聚集。1连续型聚集:形成于烃源岩内,典型代表为页岩油气藏和煤层气藏。其主要特点是:储层致密-超致密,渗透率在纳达西-毫达西之间;油气呈游离态、吸附态、溶解态等多相态形式存在;一个连续型聚集实际上仅由一个油气藏构成,其油气在有效烃源岩分布范围内广泛而连续分布,缺乏明确边界,不存在边水和底水;油气主要是原位或就近聚集成藏,无需经过显著运移;油气聚集基本不受圈闭控制。2准连续型聚集:主要形成于邻近烃源岩的致密储层中,大多数致密油气藏属于此类。其特点是:油气呈大面积准连续分布,一个准连续聚集由多个彼此相邻的中小型油气藏组成;油气聚集缺乏明确边界,边、底水无或仅局部分布,无区域性油气水倒置;油气为大面积弥漫式充注,初次运移直接成藏或短距离二次运移成藏;油气运移聚集主要为非浮力驱动,非达西流运移;油气聚集基本不受背斜圈闭控制,而主要受非背斜圈闭特别是岩性圈闭控制。3不连续型聚集:又称为常规圈闭型油气聚集,主要形成于常规储层中,少数致密油气藏、煤层气藏甚至页岩油气藏亦属此类。其特点是:油气藏呈孤立分散不连续分布;油气藏边界明确,通常具有完整边、底水;油气藏形成一般需要经过二次运移,浮力是油气运移成藏的主要动力;油气藏形成严格受包括构造圈闭在内的各种圈闭控制。在含油气盆地中,上述3种油气聚集可同时存在,且往往形成于一个共同的烃源灶,其相互之间存在着密切联系,并具有各自独特的分布规律。因此,在油气勘探中,应当将三者作为一个统一体进行通盘考虑和研究,从而最大限度地提高勘探成效。

关键词: 油气藏概念, 油气藏分类, 连续型聚集, 准连续型聚集, 不连续型聚集

Abstract:

Based on an extensive investigation and a comprehensive study of conventional and unconventional petroleum reservoirs, we proposed a revised definition of petroleum reservoir and a new classification of petroleum accumulation. The revised concept defines petroleum reservoir as continuous hydrocarbon accumulation in a single reservoir or a set of reservoirs with an independent or unified pressure system. In terms of the accumulation style or patterns of hydrocarbon distribution, petroleum accumulation is classified into 3 basic types, namely, continuous accumulation, quasi-continuous accumulation and discontinuous accumulation. More significantly, we demonstrated that petroleum accumulation is a process from continuous to discontinuous accumulation and the three basic types of accumulation are resulted from this process.(1) Continuous accumulation. Such an accumulation is principally formed within a source rock that also acts as a reservoir. Most shale hydrocarbon and coalbed methane accumulations belong to this category. It is characterized by that hydrocarbons are stored in the state of free, sorbed and dissolved types; reservoirs are tight to ultra-tight, with permeability of nanodarcy to millidarcy; an accumulation actually has only a single reservoir, and the hydrocarbon distribution is extensive and continuous within the scope of effective source rocks; neither defined boundary nor bottom or edge water can be observed; accumulation is largely in situ or near where the hydrocarbons are generated and no prominent migration occurred; and accumulation is basically not controlled by traps.(2) Quasi-continuous accumulation. This type of accumulation occurs predominantly in tight reservoirs and the majority of tight oil and gas accumulations can be attributed to this type. It is distinguished by that hydrocarbon distribution is extensive geographically and each accumulation comprises numerous contiguous small-to medium-sized reservoirs; the accumulation has no defined boundaries and neither prominent water lag nor regional updip water is present,or only incomplete edge water is present; hydrocarbon charge is pervasive and accumulation is the direct result of primary migration or short distance secondary migration, and the migration is principally driven by non-buoyant forces and is primarily in non-Darcy flow; and hydrocarbon accumulation is basically not controlled by anticlinal traps, but largely by non-anticlinal traps especially stratigraphic(lithologic) traps.(3) Discontinuous accumulation. Also known as conventional trapped accumulation(i.e. the conventional accumulation), this type of accumulation occurs mostly in conventional reservoirs or quality reservoirs. But some accumulations of tight oil and gas, coalbed methane and even shale oil and gas also belong to this variety. The accumulations of this pattern are discrete geographically, and each accumulation has explicit boundaries and complete water lag is commonly existed. Migration is generally in the Darcy flow and can occur over long distance and the driving force is mainly buoyancy. And the accumulation is strictly governed by various traps including structural, stratigraphic and combination traps. Actually, the above 3 types of accumulation could be formed from a single source kitchen. In that case, close relationship and unique laws governing hydrocarbon distribution must exist among them. As a result, they ought to be taken into consideration as a closely related entity in the study and exploration of petroleum systems to enhance the success rate.

Key words: concept of petroleum reservoirs, classification of petroleum accumulation, continuous accumulation, quasi-continuous accumulation, discontinuous accumulation

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