石油与天然气地质 ›› 2020, Vol. 41 ›› Issue (4): 744-754.doi: 10.11743/ogg20200408

• 油气地质 • 上一篇    下一篇

鄂尔多斯盆地临兴地区上古生界致密气成藏特征及物理模拟

郑定业1,2(), 庞雄奇1,2,*(), 姜福杰1,2, 刘铁树3, 邵新荷1,2, 李龙龙1,2, 呼延钰莹1,2, 国芳馨1,2   

  1. 1. 中国石油大学(北京) 油气资源与探测国家重点实验室, 北京 102249
    2. 中国石油大学(北京) 地球科学学院, 北京 102249
    3. 中海油研究总院有限责任公司, 北京 100028
  • 收稿日期:2019-08-26 出版日期:2020-08-01 发布日期:2020-08-11
  • 通讯作者: 庞雄奇 E-mail:272024982@qq.com;pangxqcup@163.com
  • 作者简介:郑定业(1991—),男,博士,深层、非常规油气成藏机理。E-mail:272024982@qq.com
  • 基金资助:
    国家自然科学基金重点基金项目(U1262205);中海石油(中国)有限公司综合科研项目(YXKY-2016-ZY-04)

Characteristics and physical simulation of the Upper Paleozoic tight gas accumulation in Linxing area, Ordos Basin

Dingye Zheng1,2(), Xiongqi Pang1,2,*(), Fujie Jiang1,2, Tieshu Liu3, Xinhe Shao1,2, Longlong Li1,2, Yuying HuYan1,2, Fangxin Guo1,2   

  1. 1. State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum(Beijing), Beijing 102249, China
    2. College of Geosciences, China University of Petroleum(Beijing), Beijing 102249, China
    3. CNOOC Research Institute Co., Ltd., Beijing 100028, China
  • Received:2019-08-26 Online:2020-08-01 Published:2020-08-11
  • Contact: Xiongqi Pang E-mail:272024982@qq.com;pangxqcup@163.com

摘要:

鄂尔多斯盆地临兴地区上古生界致密砂岩气藏资源勘探潜力巨大,但是成藏规律及运移方式较为模糊。基于构造、沉积相和砂体展布特征,临兴地区上古生界源-储组合关系可分为源内、近源和远源3种类型。利用岩石热解、热成熟度测定、岩心描述、薄片鉴定、扫描电镜观察,物性分析以及地震和测井等资料,对烃源岩、储层、充注动力及断裂的发育进行分析。结果表明:临兴地区发育煤、炭质泥岩和暗色泥岩3套烃源岩,干酪根类型为Ⅲ和Ⅱ2型,有机质丰度较高,普遍进入成熟-高成熟阶段,生气潜力较大;储层岩石类型以成熟度中等的长石岩屑砂岩为主,非均质性强,孔喉类型多样,包括原生粒间孔、溶解粒间孔、溶解粒内孔、晶间孔和微裂缝。物性以低孔-低渗为主,平均孔隙度为6.81%,平均渗透率为0.610×10-3 μm2,属于典型致密储层;地层超压普遍发育,气体膨胀力是源内、近源组合成藏的关键动力;断裂十分发育,既可为天然气垂向充注至远源组合提供运移通道,又能改善储层品质,提高天然气横向运移能力。在此基础上,对建立起的成藏模式进行物理模拟实验,发现储层非均质性及断裂的发育是影响气水关系的主要因素,源内组合处于成藏优势区,可作为后期勘探开发的重点。

关键词: 成藏特征, 物理模拟, 致密气藏, 上古生界, 临兴地区, 鄂尔多斯盆地

Abstract:

The exploration potential of the Upper Paleozoic tight sandstone gas reservoirs in Linxing area, Ordos Basin is huge, but the accumulation patterns and migration pathways are relatively controversial.Based on the characteristics of structure, sedimentary facies and sand-body distribution, the source-reservoir combination relationship of the Upper Paleozoic in Linxing area can be categorized into three types:in-source-, near-source- and far-source-reservoir combinations.Using the data of rock pyrolysis, thermal maturity measurement, core description, thin-section observation, scanning electron microscopy, petrophysical property analysis, seismic and well logging interpretation, we analyzed the development characteristics of the source rock, reservoir, charging dynamics and faults.The results show that there are three sets of hydrocarbon source rocks in Linxing area, including coal, carbonaceous mudstone and dark mudstone source rocks with Type Ⅲ and Ⅱ2 kerogens.The source rocks have high abundance of organic matter and are mostly mature to highly mature, thus are large in hydrocarbon generation potential.The reservoir rocks are dominated by feldspar lithic sandstone of moderate maturity, and are characterized by high heterogeneity and multiple pore throat types, including primary intergranular pores, dissolved intergranular pores, dissolved intragranular pores, intercrystalline pores and micro-cracks.The reservoirs mostly have low porosity and low permeability, with an average porosity of 6.81% and an average permeability of 0.61×10-3 μm2, which reflects a typical tight reservoir.Overpressure is common and gas expansion force is the main driving force for gas accumulation of the in-source- and near-source-reservoir combinations.The well-developed faults can serve as the migration pathways for the natural gas vertically charging to the far-source-reservoir combination and can also improve the reservoir quality and strengthen the lateral migration ability of natural gas.Physical simulation experiments were carried out on the established accumulation model, and it was found that reservoir heterogeneity and faults are the main factors affecting the gas-water relationship.The in-source-reservoir combination is the favorable area for hydrocarbon accumulation, and can be selected as the focus of later exploration and development.

Key words: accumulation characteristics, physical simulation, tight gas reservoir, Upper Paleozoic, Linxing area, Ordos Basin

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