石油与天然气地质 ›› 2007, Vol. 28 ›› Issue (2): 216-228.doi: 10.11743/ogg20070213

• 动力学机制研究 • 上一篇    下一篇

隐伏砂岩透镜体成藏动力学机制与基本模式

庞雄奇1,2, 陈冬霞1, 姜振学1,2, 张俊1,2, 李素梅1,2   

  1. 1. 中国石油大学, 石油与天然气成藏机理教育部重点实验室, 北京, 102249;
    2. 中国石油大学, 盆地与油藏研究中心, 北京, 102249
  • 收稿日期:2007-02-20 出版日期:2007-04-25 发布日期:2012-01-16
  • 基金项目:

    国家重点基础研究发展规划(973)项目(2006CB202300);国家"十五"科技攻关项目(2003BA615A02)

Mechanism and basic modes of petroleum accumulation dynamics in subtle sand lens reservoir

Pang Xiongqi1,2, Chen Dongxia1, Jiang Zhenxue1,2, Zhang Jun1,2, Li Sumei1,2   

  1. 1. Key Laboratory for Petroleum Accumulation Mechanism, Ministry of Education, Beijing 102249, China;
    2. Basin and Reservoir Research Center, Chinese University of Petroleum, Beijing 102249, China
  • Received:2007-02-20 Online:2007-04-25 Published:2012-01-16

PDF (PC)

450

被引次数

54

摘要：

隐伏砂岩透镜体聚集油气的主要动力包括砂、泥岩接触面上的毛细管压力差、生烃泥岩与砂体之间的烃浓度差引起的扩散力和泥岩内干酪根生成油气产生的体积膨胀力等;聚集油气的阻力主要包括油气进入砂岩体后遇到的毛细管力和油气将水挤出砂岩体外遇到的阻力.聚集油气的动力大于阻力是形成砂岩透镜体油气藏的基本条件.砂岩透镜体成藏受砂体孔渗及围岩含油气饱和度等因素的制约.围岩生成的油气进入到砂岩透镜体内的临界地质条件是围岩中的含油气饱和度超过5%～10%;砂岩体聚集油气的临界地质条件是孔隙度超过10%或渗透率超过1×10-3～2×10-3μm2.地史过程中砂岩透镜体成藏分为3个阶段.第一阶段为成藏条件准备阶段,此阶段油气没有大量生成,围岩微孔隙中强大的毛细管力是分散油滴运聚的阻力;第二阶段为油气运聚成藏阶段,此阶段油气已大量生成,围岩与砂体之间的毛细管力差是油气通过有机网络不断聚集成藏的主要动力;第三阶段为油气聚集后的保存阶段,此阶段油气已不再大量生成,围岩与砂体之间的毛细管力差不能克服油气聚集过程中的阻力.根据成藏动力学机制与控油气作用特点可以预测砂体的含油气性大小与变化规律.

关键词: 油气成藏门限, 油气成藏动力学, 圈闭含油气性预测, 隐伏砂岩透镜体

Abstract:

The major driving forces for hydrocarbon accumulation in subtle sand lens reservoirs includes differential capillary pressure on sand-shale boundary,diffusive force triggered by differential hydrocarbon concentration between source beds and sandbodies,and volume expansion caused by kerogen generating hydrocarbons;while the dominant forces that prevent hydrocarbons from pooling include capillary pressure the hydrocarbons faced when entering sandstones and resistance occurred when displacing water in sandstones.For hydrocarbons to accumulate in sandstones,the driving forces must be stronger than the resistances.Apart form that,the porosity and permeability of sandbodies and the hydrocarbon saturation of sourrouding rocks also control the accumulation of hydrocarbons in sandstones.The critical geologic condition for the hydrocarbons generated by the surrounding source rocks entering sandbodies is that hydrocarbon saturation of the surrounding source rocks exceeds 5%-10%,and while that for the hydrocarbons to accumulate in the sandbodies is that the porosity and permeability of sandstones are higher than 5%-10% and 1×10-3-2×10-3μm2 respectively.The accumulation of hydrocarbons in sand lens reservoirs can be divided into three stages.The first is preparation stage when no large quantity of hydrocarbons are generated by the source rocks and the strong capillary pressure in the micro pores of these rocks prevents the migration of dispersed oil drops.The second is migration and pooling stage when large amount of hydrocarbons are generated and accumulate in the reservoirs with the differential capillary pressure between the surrounding rocks and sandstones as the main driving force.The third is preservation stage when the hydrocarbon no longer generated in large amount and the differential capillary pressure between the surrounding rocks and sandstones is weaker than the resistant forces.The reservoiring dynamics and controls on hydrocarbon accumulation can be used to predict the hydrocarbon abundance and changing patterns.

Key words: hydrocarbon accumulation threshold, hydrocarbon accumulation dynamics, hydrocarbon abundance prediction, subtle sand lens

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