新疆石油地质

›› 2017, Vol. 38 ›› Issue (1): 1-1.doi: 10.7657/XJPG20170105

• 论文 •    

西峰油田DZ—ZY地区长8储集层长石溶蚀特征及溶蚀强度计算

刘翰林1，王凤琴1，杨友运1，南祥2，杨烁3，曹学刚1，   

  1. (1.西安石油大学 地球科学与工程学院,西安 710065;2.中国石油 长庆油田分公司 勘探开发研究院,西安 710004;3.中国石油大学 地球科学学院,北京 102249)
  • 出版日期:2019-01-01 发布日期:1905-07-13

Characteristics and Intensity Calculation of Feldspar Dissolution in Chang-8 Reservoir of District DZ-ZY, Xifeng Oilfield

LIU Hanlin1, WANG Fengqin1, YANG Youyun1, NAN Junxiang2, YANG Shuo3, CAO Xuegang1   

  1. (1.School of Geosciences and Engineering, Xi’an Shiyou University, Xi’an, Shaanxi 710065, China; 2.Research Institute of Exploration and Development, Changqing Oilfield Company, PetroChina, Xi’an, Shaanxi 710004, China; 3.School of Geosciences, Chian University of Petroleum, Beijing 102249, China)
  • Online:2019-01-01 Published:1905-07-13

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摘要： 长石溶蚀作用是鄂尔多斯盆地西峰油田DZ—ZY地区长8储集层次生孔隙发育的主控因素。为了分析研究区长8储集层长石溶蚀特征，综合利用铸体薄片、扫描电镜、电子探针等分析技术，同时基于长石非全等溶解的性质，通过对各长石溶蚀理论次生孔隙度和溶解率的计算，准确划分长石溶蚀强度：弱溶蚀（溶解率小于25%）、中溶蚀（溶解率25%~50%）、强溶蚀（溶解率50%~75%）和极强溶蚀（溶解率大于75%）。研究表明：长石溶蚀现象在研究区普遍存在，长石溶孔对储集空间贡献率高达60%. 但不同长石类型溶蚀程度存在明显差异，其中，钾长石溶蚀程度高于斜长石，且钾长石溶孔比例最大。研究区长石溶蚀强度以中溶蚀（约占40%）和强溶蚀（约占36%）为主；钾长石溶蚀贡献率随溶解率的增加而增加，斜长石则相反，即钾长石溶孔率将会直接影响长石溶蚀强度，而斜长石溶孔对孔隙度的贡献较小，尤其是在溶蚀强度较高的情况下。

Abstract: Feldspar dissolution is the main controlling factor of secondary pores in Chang-8 reservoir of District DZ-ZY, Xifeng oilfield. This study uses the thin section, scanning electron microscopy(SEM), electron microprobe (EMPA) and other analytical techniques to analyze the characteristics of feldspar dissolution. Meanwhile, based on the properties of incongruent dissolution and theoretical calculations of secondary porosity and dissolution rate of feldspar, 4 kinds of feldspar dissolution intensity are determined: weak dissolution (dissolution rate <25%), medium dissolution (dissolution rate of 25%~50%), strong dissolution (dissolution rate of 50%~75%) and extremely strong dissolution (dissolution rate >75%). Feldspar dissolution commonly occurs in the study area and the contribution of feldspar dissolution pores to reservoir spaces reaches 60%. But there are significant differences among the dissolution degrees of different feldspar. The degree of dissolution of potassium feldspar is higher than that of plagioclase, and the dissolution pores of potassium feldspar accounts for the largest proportion. The dissolution of feldspar in the study area is dominated by medium dissolution (about 40%) and strong dissolution (about 36%). The contribution rate of potassium feldspar dissolution increases along with the dissolution rate and that of plagioclase is the opposite especially under the conditions of relatively high dissolution intensity

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