石油学报 ›› 2011, Vol. 32 ›› Issue (4): 596-604.DOI: 10.7623/syxb201104006

• 地质勘探 • 上一篇    下一篇

鄂尔多斯盆地姬塬地区上三叠统延长组长8油层组成岩相

王昌勇 1  王成玉 2  梁晓伟 2  李士祥 2  辛红刚 2  郑荣才 1   

  1. 1成都理工大学沉积地质研究院  四川成都  610059; 2中国石油长庆油田公司勘探开发研究院  陕西西安  710021
  • 收稿日期:2010-11-25 修回日期:2011-03-04 出版日期:2011-07-25 发布日期:2011-09-22
  • 通讯作者: 王昌勇
  • 作者简介:王昌勇,男,1981年8月生,2003年毕业于江汉石油学院,现为成都理工大学沉积地质研究院讲师,主要从事沉积学及石油地质研究。
  • 基金资助:

    国家科技重大专项(2008ZX05003-001)“大型油气田及煤层气开发”资助。

Diagenetic facies of the Chang 8 oil-bearing layer of the Upper Triassic  Yanchang Formation in the Jiyuan area, Ordos Basin

WANG Changyong 1  WANG Chengyu 2  LIANG Xiaowei 2  LI Shixiang 2  XIN Honggang 2  ZHENG Rongcai 1   

  • Received:2010-11-25 Revised:2011-03-04 Online:2011-07-25 Published:2011-09-22

摘要:

在综合测试数据的基础上,系统地研究了姬塬地区长8油层组成岩作用类型、成岩期次与成岩流体性质,得到:①研究区长8油层组处于中成岩阶段A期,主要经历了压实-压溶、胶结、交代、溶蚀、自生矿物的充填及破裂等成岩作用;②沉积相对成岩作用的类型具有明显的控制作用,受古湖岸线位置控制的早期绿泥石环边胶结作用,是原生粒间孔得以保存的重要原因;③压实-压溶作用是造成孔隙缩减的主要原因,这一成岩作用贯穿整个成岩阶段;④自生矿物充填作用和碳酸盐胶结作用从早成岩阶段B期延续到中成岩阶段A1期,对储层造成不同程度的破坏;⑤溶蚀和破裂作用主要发生在早成岩阶段B期和中成岩阶段A1期,对改善储层物性意义重大。在上述研究基础上,将研究区长8油层组划为致密泥岩压实相、绿泥石环边胶结—溶蚀相、溶蚀—碳酸盐胶结相及方解石连生胶结相4个成岩相组合。储层的时空分布规律明显受沉积相和成岩相控制,研究区中部水下分流河道沉积区的绿泥石环边胶结—溶蚀成岩相带为最有利储集层发育相带。

关键词: 成岩流体, 成岩相, 长8油层组, 姬塬地区, 鄂尔多斯盆地

Abstract:

Based on comprehensive testing data, this paper discussed diagenetic types, timing and fluid properties of the Chang 8 oil-bearing layer in the Jiyuan area, Ordos Basin. Several lines of novel cognition were made as follows: ①The Chang 8 oil-bearing layer in the study area is at Phase A of the middle diagenesis that consists mostly of various diagenetic processes, such as compaction-pressolution, cementation, metasomatism, corrosion, filling of autogenous minerals and fracture. ②Sedimentary facies significantly dominate types of diagenesis, the early rim cementation of chlorites controlled by the location of paleo-lakeline is of importance to the preservation of primary intergranular pores. ③Compaction-pressolution leads to the most reduction of pores that lasts through the whole diagenesis. ④The filling of autogenous minerals and cementation of carbonates continue from Phase B of the early diagenesis to Phase A1 of the middle diagenesis and may destroy reservoirs in various degrees. ⑤Corrosion and disruption occur mostly at Phase B of the early diagenesis and Phase A1 of the middle diagenesis, significantly improving physical properties of reservoirs. On the basis of the above study, the Chang 8 oil-bearing layer of the study area was divided into four diagenetic types of facies combination, including dense-mudstone compaction, rim cementation-corrosion of chlorites, corrosion and carbonate cementation, and poikilitic cementation of calcites. The time-space distribution of reservoirs was obviously controlled by sedimentary and diagenetic facies, and chlorite-rim cementation-corrosion belts distributed in subaqueous distributary channels of the middle study area were proposed to be the most favorable places for reservoir development.

Key words: diagenetic fluid, diagenetic facies, Chang 8 oil-bearing layer, Jiyuan area, Ordos Basin