石油与天然气地质 ›› 2017, Vol. 38 ›› Issue (2): 323-333,406.doi: 10.11743/ogg20170212

• 油气地质 • 上一篇    下一篇

准噶尔盆地玛湖凹陷西斜坡百口泉组砂砾岩储层成岩作用及对储集性能的影响

靳军1, 康逊2, 胡文瑄2, 向宝力1, 王剑1, 曹剑2   

  1. 1. 中国石油 新疆油田分公司 实验检测研究院, 新疆 克拉玛依 834000;
    2. 南京大学 地球科学与工程学院,江苏 南京 210046
  • 收稿日期:2016-08-03 修回日期:2017-02-20 出版日期:2017-04-28 发布日期:2017-05-04
  • 通讯作者: 胡文瑄(1959-),男,博士、教授、博士生导师,石油天然气成藏机理、流体地质作用与成矿。E-mail:huwx@nju.edu.cn。 E-mail:huwx@nju.edu.cn
  • 作者简介:靳军(1970-),男,博士、高级工程师,石油实验地质与油气储层地质。E-mail:jinjun@petrochina.com.cn。
  • 基金资助:
    国家科技重大专项(2016ZX05001-005)。

Diagenesis and its influence on coarse clastic reservoirs in the Baikouquan Formation of western slope of the Mahu Depression,Junngar Basin

Jin Jun1, Kang Xun2, Hu Wenxuan2, Xiang Baoli1, Wang Jian1, Cao Jian2   

  1. 1. Research Institute of Experiment and Detection, PetroChina Xinjiang Oilfield Company, Karamay, Xinjiang 834000, China;;
    2. School of Earth Sciences and Engineering, Nanjing University, Nanjing, Jiangsu 210046, China
  • Received:2016-08-03 Revised:2017-02-20 Online:2017-04-28 Published:2017-05-04

摘要: 砂砾岩作为重要油气储层类型之一,以非均质性显著、易受成岩作用影响为特征,因而分析其成岩作用及对储集性能的影响是储层研究的关键。文章在准噶尔盆地西北缘玛湖凹陷地区,以最近勘探取得重大突破的西斜坡艾湖油田下三叠统百口泉组(T1b)缓坡扇三角洲砂砾岩储层为例,研究了成岩作用类型及对储集能力的影响。结果表明,研究区砂砾岩主要发育了四种成岩作用类型:压实、交代(碎屑长石的钠长石化和蒙皂石的伊利石化)、溶蚀(钾长石和方解石等)和胶结(方解石、高岭石和少量绿泥石)。它们对储集性能的影响差异显著。压实作用显著破坏了颗粒间的原生孔隙,降低了储层物性;矿物交代总体对储层物性影响有限;相比而言,在断裂沟通含烃流体促进下,钾长石等矿物的溶解在扇三角洲前缘的水下河道与颗粒流沉积等具有较好初始物性的砂砾岩,形成了次生孔隙发育带,显著改善了砂砾岩的储集性能;胶结作用不利于砂砾岩成岩中晚期孔隙的保存,特别是高岭石和方解石的局部富集导致了低渗透层的形成。据此,发现研究区不同段的储层发育有明显差异,由下至上百一段在油源断裂附近发育优质储层;百二段在油源断裂的上倾位置发育优质-较好储层;而百三段研究区储层几乎不发育。

关键词: 成岩作用, 储层, 物性, 砂砾岩, 百口泉组, 玛湖凹陷, 准噶尔盆地

Abstract: Coarse clastic reservoirs,one of the most commonly seen reservoir types in the world,feature in strong heterogeneity and are highly sensitive to diagenesis process.One of the key research areas for the reservoir is the study of the impact of diagenesis upon its storage capacity.The coarse clastic reservoirs in the slope delta fan of the Lower Triassic Bai-kouquan Formation (T1b) in Aihu oilfield (an exploration breakthrough was made recently) in western slope of the Mahu Depression in Juggar Basin were chosen to study the diagenesis types and their impact upon storage capacity of the reservoirs.The result indicates that there were mainly four types of diagenese process in the area:mechanical compaction,mineral replacement (albitization of detrital feldspar and illitization of smectite),dissolution (K-feldspar and calcite,etc.) and cementation (calcite,kaolinite and small amounts of chlorite).These processes had significant influence upon the quality of the reservoirs.Compaction undermined the primary intraparticle pores and soured physical properties of the layers.Mineral replacement had only limited impact over the properties; but relatively speaking,dissolution of minerals like potash feldspar and etc.facilitated by hydrocarbon-bearing fluids migrating along faults greatly increased storage capacity of the layers by forming secondary pore zones in coarse clastic rocks with fair primary physical properties such as underwater channel sands of fan delta fronts and granular flow deposits.Cementation was destructive to the preservation of pores formed during the middle and late diagenetic stages,and the local enrichment of kaolinite and calcite caused the formation of low-permeability layers.The understanding was confirmed by various reservoir properties in different members of the Formation:high-quality reservoirs were found in T1b1 near faults connecting source rocks,high-to good-quality reservoirs were found in T1b2,at an updip position adjacent to the faults connecting source rocks,but almost no reservoirs were found in T1b3.

Key words: diagenesis, reservoir, physical property, coarse clastic, Baikouquan Formation, Mahu Sag, Junngar Basin

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