西南石油大学学报(自然科学版) ›› 2011, Vol. 33 ›› Issue (3): 53-60.

• 地质勘探 • 上一篇    下一篇

塔河南部奥陶系海西早期岩溶的发现

严威1 王兴志1 丁勇2 吕海涛2 刘存革2
  

  1. 1. 西南石油大学资源与环境学院,四川成都610500;
    2. 中国石化西北分公司勘探开发研究院,新疆乌鲁木齐830011
  • 收稿日期:1900-01-01 修回日期:1900-01-01 出版日期:2011-06-20 发布日期:2011-06-20

he Discovery and Characteristics of Covered-pressurization Karst During Early Hercynian in South Tahe Oilfield

YAN Wei 1 WANG Xing-zhi 1 DING Yong 2 L¨U Hai-tao 2 LIU Chun-ge 2
  

  1. 1. School of Resources and Environment,Southwest Petroleum University, Chengdu, Sichuan 610500, China;
    2. Development Department of NWBC,SINOPEC, Urumqi, Xinjiang 830011, China
  • Received:1900-01-01 Revised:1900-01-01 Online:2011-06-20 Published:2011-06-20

摘要:

塔河油田奥陶系碳酸盐岩主要经历了加里东中期及海西早期岩溶作用。前人认为,桑塔木组泥岩隔水层控制了海西早期岩溶的分布范围:北部的桑塔木组缺失区是海西早期岩溶的发育区,并对先期的加里东中期岩溶产物加以全面改造;而南部的桑塔木组覆盖区则仅保留了加里东中期岩溶。通过岩石学、沉积学、地球化学及地震学等研究表明,海西早期岩溶可以在一定范围内突破桑塔木组的限制。桑塔木组的覆盖仅仅改变了海西早期岩溶作用的形式,即由裸露风化壳型岩溶转变为覆盖承压型岩溶。指出了与主体区相连的断裂带才是岩溶—缝洞型储层的发育区带,而孤立的、不与主体区相连的断裂带,岩溶作用不发育。该岩溶作用的发现,对于在塔河油田南部、西部桑塔木组覆盖区寻找岩溶缝洞型储层发育带具有重要的指导意义。

关键词: 塔河油田, 奥陶系, 桑塔木组尖灭线, 海西早期, 加里东中期, 覆盖承压岩溶

Abstract: The Ordovician formations of Tahe Oilfield mainly undergo two karsts of mid-Caledonian and early Hercynian. The predecessors considered that because of the thick aquifuge in Sangtamu Group(O3),the effecting range of early-Hercynian karst was controlled by the edge line of the Sangtamu Group: The Northern part which lack

the Sangtamu Group was the affecting area of early-Hercynian karst,while,the Southern part which was covered by the Sangtamu Group was the the affecting area of only mid-Caledonian karst. Recent research shows that for the reason of its favourable factors, such as high-uplift amplitude of structure,long time exposure,highly development of fractures,fluent hydrodynamic etc, it is extremely beneficial to karst effections. On top of that,the early Hercynian karstis able to break through the restriction of the Sangtamu aquifuge. The coverage of the Sangtamu group only
changes the model of early-Hercynian karst:from crust karst to Covered-Pressurization karst. The discovery of this karst has a great guiding significance to the exploration for cavity- reservoirs in the southern and southwestern areas. It points out that,only the fault zones which are connected with the main region can be the favourable reservoir zones,otherwise, Reservoir would be less developed.

Key words:

Tahe Oilfield, Ordovician, the edge line of the Sangtamu Group, early-Hercynian, mid-Caledonian, Covered-Pressurization karst

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