石油与天然气地质 ›› 2001, Vol. 22 ›› Issue (2): 123-127,136.doi: 10.11743/ogg20010208

• 油气空间 • 上一篇    下一篇

盆地埋藏史及其对砂岩储层物性演化的影响──以陕北延长油区砂岩储层为例

罗静兰1, 张成立1, 阎世可2, 武富礼2, 李玉宏2   

  1. 1. 西北大学大陆动力学实验室, 陕西西安710069;
    2. 延长石油管理局, 陕西永坪717208
  • 收稿日期:2000-06-27 出版日期:2001-06-25 发布日期:2012-01-16

EFFECT OF BURIAL HISTORY ON PHYSICAL PROPERTY OF SANDSTONE RESERVOIRS: TAKE YANCHANG OIL REGION IN NORTH SHAANXI AS AN ECAMPLE

Luo Jinglan1, Zhang Chengli1, Yan Shike2, Wu Fuli2, Li Yuhong2   

  1. 1. Northwest University, Xian, Shaanxi;
    2. Yanchang Petroleum Administration, Yongping, Shaanxi
  • Received:2000-06-27 Online:2001-06-25 Published:2012-01-16

摘要:

延长油区自晚三叠世以来经历了两次明显的抬升剥蚀事件、一次沉积间断和三次沉降作用过程.第一次沉降阶段(225~208Ma)以挤压环境下的构造沉降起主导作用,沉降速率较高,东部区的总沉降量高于西部区,第二、三次沉降阶段(203~157 Ma和 138~97 Ma)主要以拉伸背景下的沉积载荷沉降为主,沉降作用相对减弱.西部区由于褶皱和逆冲断裂,其沉积速率和构造沉降量高于东部区.岩石物性模拟结果显示,下、中侏罗统延安组储集层的物性明显好于下伏上三叠统延长组.孔隙度和渗透率的高值区受河道砂体分布带的控制,呈NE方向展布.三叠系砂岩储集层孔隙度的变化主要发生于第二次沉降阶段,侏罗系砂岩储集层孔隙度的变化主要发生于第三次沉降阶段,两者在97Ma时达到与现今基本相似的最低值.埋藏压实作用是造成砂岩孔隙丧失的主要原因,它使侏罗系砂岩和三叠系砂岩孔隙度分别丧失15%和20%.碳酸盐胶结物是导致砂岩孔隙度降低的主要胶结物.西部区储集层物性低于东部区可能缘于二、三次沉降阶段上覆地层载荷所引起的机械压实作用西部区大于东部区所致.

关键词: 延长油区, 盆地埋藏史, 储层物性演化

Abstract:

Yanchang Oildom has undergone two uplift-erosion, one hiatus and three subsidence processes since Late Tri-assic. The first subsedence stage(225~208 Ma)were mainly tectonic subsidence under comression; the second and the third subsedence stages(203~157 Ma and 138~97 Ma respectively) were mainly sedimentary loading subsidence in-tension environment. Simulation results show that the physicd property of Middle-Lower Jurassic Yanchang Formation resenoir is much better than that of the underlying Upper Triassic Yanchang Formation. Burial compaction was the primary cause resulting in 1500 porosity decrease of the sandstone of Jurassic sandstone and 200o that of of Triassic sandstone Mechamical compaction of overlying sedimentary loading formed in the second and the third subsidences resulted in worse physical property of the reservoir in the west part than that in the east part of the study area. It is suggested that the 4 +5 members of the Yanchang Formation have favourable trap function and could be regional caprock of Chang-6 member

Key words: Yanchang Oil region, burial history, evolution, reservoir physical property

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