地学前缘 ›› 2021, Vol. 28 ›› Issue (6): 95-104.DOI: 10.13745/j.esf.sf.2021.1.45

• 钾盐成矿新认识 • 上一篇    下一篇

四川盆地海相深层富钾锂层系沉积演化规律及储卤层响应特征

杨洪宇1, 张兵1, 方朝合2,*, 杨凯1, 曹倩2, 张赛民1, 林晓杨1   

  1. 1.成都理工大学 地球勘探与信息技术教育部重点实验室, 四川 成都 610059;
    2.中国石油勘探开发研究院, 北京 100083
  • 收稿日期:2021-01-28 修回日期:2021-09-29 出版日期:2021-11-25 发布日期:2021-11-25
  • 通讯作者: *方朝合(1976—),男,博士,高级工程师,主要从事新能源研究工作。E-mail:fangch69@petrochina.com.cn
  • 作者简介:杨洪宇(1994—),男,硕士,主要从事储层沉积学研究。E-mail:291486338@qq.com
  • 基金资助:
    国家重点研发计划项目“重点含钾盆地富钾规律、战略选区与深部探测技术示范(2017YFC0602806)”; 中石油项目“重点地区油田卤水型锂矿富集规律及资源评价(2018ycq04)”

Sedimentary evolution of deep marine potassium/lithium-rich brine reservoirs in the Sichuan Basin and a comprehensive response model for the brine storage layer

YANG Hongyu1, ZHANG Bing1, FANG Chaohe2,*, YANG Kai1, CAO Qian2, ZHANG Saimin1, LIN Xiaoyang1   

  1. 1. Ministry of Education Earth Exploration and Information Technology Key Laboratory, Chengdu University of Technology, Chengdu 610059, China;
    2. Research Institute of Petroleum Exploration and Development, PetroChina, Beijing 100083, China
  • Received:2021-01-28 Revised:2021-09-29 Online:2021-11-25 Published:2021-11-25

摘要: 随着国内钾锂盐需求不断增大,浅层盐湖卤水勘探开发技术趋于成熟,深层卤水资源已成为经济矿产目标。四川盆地在三叠系发育了面积广泛且巨厚的蒸发岩层,并赋存了优质且丰富的富钾锂卤水储层。针对以往岩相古地理“盐味”不足的特点,文章通过分析四川盆地蒸发岩分布规律、岩相古地理特征以及沉积演化,明确了膏盐盆的形成具有“多期多区”特征,揭示了三叠系嘉四段—雷三段重点成盐期的膏盐盆规模、分布、迁移规律;同时基于地质、测井资料,明确了四川盆地富钾锂卤水储层的地质和测井响应特征,认为四川盆地富钾锂卤水储层质量受层位、相带、孔隙类型的控制,表现出中-高伽马、低电阻率、高声波时差、低密度的耦合特征。研究成果将对国内外深层海相层系的富钾锂卤水储层勘探起到一定的指导意义。

关键词: 四川盆地, 深层卤水, 沉积演化模式, 岩性组合, 储卤层响应特征

Abstract: With the increasing demand for potassium/lithium salt, the technology for shallow salt lake brine exploration and development is maturing and the deep brine resources have become the next exploration goal. In the Sichuan Basin, a wide, ultra-thick layer of Triassic evaporites has developed with abundance of high-quality potassium-rich brine reservoirs. In this paper, taking on the issue of ‘lacking saltiness’ in lithofacies paleogeography, we analyzed the distribution pattern of evaporites, the characteristics of lithofacies paleogeography, and the sedimentary evolution in the Sichuan Basin. We demonstrated the formation of a gypsum-salt basin is multi-stage and multi-zoned and determined the scale, distribution, and migration law of gypsum-salt basins in the key salt-forming period T1j4-T2l3 in the Triassic. In a parallel investigation based on the geological and logging data, we determined the geological and logging response characteristics of brine reservoirs in the Sichuan Basin. We consider the quality of potassium/lithium-rich brine reservoirs is controlled by horizon, facies belt and pore type as implied by the coupled logging response characteristics, such as medium-high gamma, low resistivity, high acoustic transit time, and low density. Results from this study can be used to guide deep marine strata explorations for potassium/lithium-rich brine reservoirs at home and abroad.

Key words: Sichuan Basin, deep brine, sedimentary evolution, lithological combinations, response model of brine reservoir

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