Acta Petrolei Sinica ›› 2016, Vol. 37 ›› Issue (11): 1381-1393.DOI: 10.7623/syxb201611006

• Petroleum Exploration • Previous Articles     Next Articles

Relationship between hydrocarbon bearing fluid and the differential corrosion of potash feldspar and albite:a case study of Baikouquan Formation in Aihu oilfield, Junggar Basin

Kang Xun1, Hu Wenxuan1, Cao Jian1, Yang Zhao2, Wu Haiguang1, Xiang Baoli2   

  1. 1. School of Earth Sciences and Engineering, Nanjing University, Jiangsu Nanjing 210023, China;
    2. Research Institute of Experiment and Detection, PetroChina Xinjiang Oilfield Company, Xinjiang Karamay 834000, China
  • Received:2016-05-27 Revised:2016-09-02 Online:2016-11-25 Published:2016-12-10

钾长石和钠长石差异溶蚀与含烃类流体的关系——以准噶尔盆地艾湖油田百口泉组为例

康逊1, 胡文瑄1, 曹剑1, 杨召2, 吴海光1, 向宝力2   

  1. 1. 南京大学地球科学与工程学院 江苏南京 210023;
    2. 中国石油新疆油田公司实验检测研究院 新疆克拉玛依 834000
  • 通讯作者: 胡文瑄,男,1959年10月生,1982年获山东矿业学院地质学专业学士学位,1988年获中国地质大学(北京)矿床学专业博士学位,现为南京大学教授、博士生导师,主要从事石油天然气成藏机理、流体地质作用与成矿方面的教学与科研工作。Email:huwx@nju.edu.cn
  • 作者简介:康逊,男,1989年8月生,2011年获中国石油大学(华东)资源勘查工程专业学士学位,现为南京大学博士研究生,主要从事储层沉积学方面的研究工作。Email:kangxunk@163.com
  • 基金资助:

    国家自然科学基金重点项目(No.1230312)和国家自然科学基金项目(No.41573054)资助。

Abstract:

The relationship between hydrocarbon bearing fluid and the differential corrosion of potash feldspar and albite as well as reservoir effect are controversial scientific issues in the study of reservoir geology and mineralogy, which were explored with a case study of the Lower Triassic Baikouquan Formation in Aihu oilfield on the northwestern margin of Junggar Basin. The differential corrosion phenomenon of potash feldspar and albite was first discovered in reservoirs, i.e., dissolved potash feldspar, undissolved albite, and even secondary enlargement. The differential corrosion shows a close interlayer difference with hydrocarbon bearing fluid. In the three members of Baikouquan Formation, the corrosion intensity of potassium feldspar (albite insolubilization/secondary enlargement) gradually decreases with the decreasing abundance of hydrocarbon bearing fluid from bottom to top (the 1st to the 3rd Member of Baikouquan Formation). This positive correlation lies in the fact that oil and gas charging-related acidic fluid promotes potash feldspar dissolution and filling intensity of hydrocarbon is decreased from the 1st to the 3rd Member of Baikouquan Formation, thus leading to the continuous decrease of potash feldspar corrosion. Therefore, the differential corrosion indicates the interaction strength of acidic hydrocarbon bearing fluid and rock, which produces secondary pores and improves physical property, indicating the exploration prospect of the updip position of Well Ma 18-Aihu in the study area.

Key words: potassium feldspar, albite, differential corrosion, hydrocarbon bearing fluid, dissolved pore, Baikouquan Formation, Junggar Basin

摘要:

钾长石和钠长石差异溶蚀及与含烃类流体的关系和成储效应是储层地质学与矿物学研究中有争议的科学问题,以准噶尔盆地西北缘艾湖油田下三叠统百口泉组为例,对该问题进行了探讨。首次在储层中发现了钾长石和钠长石的差异溶蚀现象,即钾长石溶解,而钠长石不溶解,甚至次生加大。这种差异溶蚀具有与含烃类流体密切相关的层间差异性,自下而上百口泉组一段-百口泉组三段,随含烃类流体丰度逐渐降低,钾长石溶蚀(钠长石不溶/次生加大)强度逐渐减弱。这种正相关性的原因在于,与油气充注相关的酸性流体促进了钾长石溶蚀,并且百口泉组一段-百口泉组三段,烃类充注强度不断减弱,从而导致了钾长石溶蚀程度不断降低。因此,这一差异溶蚀过程指示了酸性的含烃类流体与岩石相互作用强度,并产生了次生孔隙,改善了物性,指示研究区玛18-艾湖2井区的上倾位置具有勘探远景。

关键词: 钾长石, 钠长石, 差异溶蚀, 含烃类流体, 溶蚀孔隙, 百口泉组, 准噶尔盆地

CLC Number: