低渗透砂岩油气成藏特征及其勘探启示

现代地质 ›› 2009, Vol. 23 ›› Issue (4): 755-760.

低渗透砂岩油气成藏特征及其勘探启示

曾溅辉^1,2，孔旭^1,2，程世伟^1,2，王志欣^1,2，朱志强^1,2

1中国石油大学油气资源与探测国家重点实验室，北京102249;2中国石油大学资源与信息学院，北京102249

收稿日期:2009-02-08 修回日期:2009-05-13 出版日期:2009-08-20 发布日期:2011-12-21
作者简介:曾溅辉，男，教授，博士生导师，1962年出生，水文地质、工程地质专业，主要从事油气运移和聚集、盆地流体分析等方面的教学和科研工作。E-mail:zengjh@cupeducn。
基金资助:
国家自然科学基金项目（40772088）

Hydrocarbon Accumulation Characteristics of the Low Permeability Sandstone Reservoir and Their Implication for Petroleum Exploration

ZENG Jian-Hui^1,2，KONG Xu^1,2，CHENG Shi-Wei^1,2，WANG Zhi-Xin^1,2，ZHU Zhi-Qiang^1,2

1State Key Laboratory for Petroleum Resources and Prospecting, China University of Petroleum, Beijing102249,China;
2Faculty of Natural Resources and Information Technology, China University of Petroleum, Beijing102249,China

Received:2009-02-08 Revised:2009-05-13 Online:2009-08-20 Published:2011-12-21

摘要/Abstract

摘要：

低渗透油气藏在国内外分布都非常广，占有很大的资源量和储量。低渗透砂岩具有特殊的成藏特征，主要表现在：（1）储层颗粒细、分选差、胶结物含量高，长石和岩屑含量普遍较高，成分成熟度和结构成熟度低，孔隙度、渗透率低，主要为细小孔微细喉型、微孔微喉型，裂缝相对发育，排驱压力大；（2）除了具有一般油气藏的异常高压外，低渗透砂岩油气藏还表现为异常低压，并且出现异常高压和异常低压共存；（3）油气藏内缺乏油（气）水分异，油水关系复杂，常出现油（气）水关系倒置；（4）浮力对低渗透砂岩油气运移的作用非常有限，油气运移的主要动力为异常高压等，油气的运移表现为非达西运移特征，输导体系以裂缝、相对高渗的砂体和局部不整合为主，运移距离比较短，侧向运移不强；（5）低渗透砂岩的含油（气）饱和度一般都小于60%，并且含油饱和度与孔隙度和渗透率的关系比较复杂，储量丰度比较低，主要聚集在岩性或岩性-构造复合圈闭中，受构造影响不大，油气呈大面积分布。因此，低渗透砂岩区的油气勘探应当突破传统的构造高点勘探油气的思想，在构造斜坡下倾部位或向斜区勘探油气，在勘探中注意寻找低渗透砂岩油气富集的“甜点”。


关键词: 低渗透砂岩, 油气运移和聚集, 勘探启示

Abstract:

With extensive distribution, low permeability reservoirs have large resource quantity. They have particular accumulation characteristics: (1)With fine and poor sorted grains, high content of cementing material, feldspar and cuttings, low permeability reservoirs are characterized by low compositional maturity, low textural maturity, low porosity and permeability. The types of pore structure are small pore-subtle throat and micro pore-micro throat. Fractures of the reservoir are relatively developed.(2).Not only abnormal pressure but also subnormal pressure can exist in the low permeability reservoirs.(3)With poor oil(gas)-water differentiation, the relationship between oil(gas) and water in low permeability reservoirs is complicate and usually inverted.(4)The effect of buoyancy on hydrocarbon migration in low permeability sandstone is very limited. The main driving force of hydrocarbon migration is abnormal pressure. The hydrocarbon migration is characterized by Non-Darcy flow. The fracture, higher permeability sand and local unconformity are main carriers. The distance of hydrocarbon migration is not far and there is less parallel migration.(5) Oil(gas) saturation of low permeability sand reservoir is always less than 60%. The oil(gas) saturation-porosity relationship and oilgas) saturationpermeability relationship are very complex. Reserves abundance is low and mainly accumulates in lithologic traps and lithostructural traps. Because the reservoirs are hardly controlled by structures, oilgas) always widely distributes. Oil and gas exploration of low permeability sandstone area should break the traditional thought that oil and gas are always accumulate in structural high. The declination area of structural slope and syncline are usually the favorable areas. The rich “sweet points” are also important in low permeability sand reservoir exploration.

Key words: low permeability sandstone, hydrocarbon migration and accumulation, exploration inspiration

中图分类号:

TE122.2

曾溅辉孔旭程世伟王志欣朱志强. 低渗透砂岩油气成藏特征及其勘探启示[J]. 现代地质, 2009, 23(4): 755-760.

ZENG Jian-Hui，KONG Xu，CHENG Shi-Wei，WANG Zhi-Xin，ZHU Zhi-Qiang. Hydrocarbon Accumulation Characteristics of the Low Permeability Sandstone Reservoir and Their Implication for Petroleum Exploration[J]. Geoscience, 2009, 23(4): 755-760.