石油与天然气地质 ›› 2012, Vol. 33 ›› Issue (5): 802-810.doi: 10.11743/ogg20120519

• 油气开发 • 上一篇    

苏里格气田西区致密砂岩储层地层水分布特征

王晓梅1,2, 赵靖舟2, 刘新社3, 范立勇3   

  1. 1. 西北大学 大陆动力学国家重点实验室, 陕西 西安710069;
    2. 西安石油大学 地球科学与工程学院, 陕西 西安710065;
    3. 中国石油 长庆油田分公司, 陕西 西安 710021
  • 收稿日期:2011-08-06 修回日期:2012-08-31 出版日期:2012-10-28 发布日期:2012-11-15
  • 第一作者简介:王晓梅(1975-),女,博士研究生,石油与天然气地质。
  • 基金项目:

    国家科技重大专项(2011ZX05007-004)。

Distribution of formation water in tight sandstone reservoirs of western Sulige gas field, Ordos Basin

Wang Xiaomei1,2, Zhao Jingzhou2, Liu Xinshe3, Fan Liyong3   

  1. 1. State Key Laboratory of Continental Dynamics, Northwest University, Xi’an, Shaanxi 710069, China;
    2. School of Earth Sciences and Engineering of Xi’an Shiyou University, Xi’an, Shaanxi 710065, China;
    3. PetroChina Company Limited Changqing Oilfield Branch, Xi’an, Shaanxi 710021, China
  • Received:2011-08-06 Revised:2012-08-31 Online:2012-10-28 Published:2012-11-15

摘要:

鄂尔多斯盆地苏里格气田西区正常地层水的判别标准为:矿化度≥50 g/L,钠氯系数(rNa+/rCl-)<0.5,钠钙系数(rNa+/rCa2+)<1,压裂液返排率≥100%。通过地层水化学特征、氢氧同位素和微量元素溴的综合分析认为,苏里格气田西区地层水来源于经过了强烈水-岩作用和蒸发浓缩作用的陆相沉积成因水。确认苏里格气田上古生界地层水封闭条件好,有利于天然气聚集和保存。进一步结合该区烃源岩、储层和盖层等成藏要素分析认为,该区地层水主要是弱动力成藏过程中的残余地层水,复杂的气-水分布源于低生烃强度和低构造位置背景下储层强非均质性和微构造的共同作用;而盆地东部的高矿化度地层水与奥陶纪盐岩的水-岩作用密切相关。

关键词: 气-水分布, 致密砂岩, 地层水, 苏里格气田, 鄂尔多斯盆地

Abstract:

The criteria for an acceptable formation watercut level in the western Sulige gasfield in Ordos Basin can be summarized as salinity≥50g/L,sodium-chlorine ratio<0.5,sodium-calcium ratio<1 and fracturing fluid flowback rate≥100%.Based on a comprehensive analysis of water formation chemical characteristics,hydrogen and oxygen isotopes as well as trace element "Br",the paper concludes that the formation water in the western Sulige gasfield was of continental sedimentary origin and experienced extensive water-rock interaction and evaporation processes.The analysis also indicates that sealing condition for the formation water in the Upper Paleozoic is good,thus which is favorable for gas accumulation and preservation.Further analysis in combination with consideration of hydrocarbon accumulation elements such as source rocks,reservoir and cap rocks reveals that the formation water is residual water from the process of weak dynamic hydrocarbon accumulation.The complicated gas-water distribution pattern is caused by reservoir heterogeneity and microstructures on the background of low hydrocarbon-generating intensity and low tectonic position.The formation water of high salinity in the eastern Ordos Basin is suggested to be related to the water-rock process of the Ordovician salinastone.

Key words: gas-water distribution, tight sandstone, formation water, Sulige gas field, Ordos Basin

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