Characteristics and origin of Cambrian dolomite, northern Tarim Basin
-
摘要: 塔北地区横跨塔北隆起和库车坳陷南缘,是塔里木盆地最大油气富集区之一。该区寒武系台地相沉积厚达1 000 m,是重要的勘探目的层,其中白云岩厚度大、类型多、分布广,发育优质储层,是主要勘探对象。通过塔北地区寒武系钻井岩心和柯坪露头区寒武系白云岩岩石学及同位素、稀土元素地球化学对比分析,结合流体包裹体测温学研究,认为塔北地区寒武系白云岩具有泥微晶到细—中晶和粗晶等多种结构类型,其形成除准同生白云岩化和埋藏白云岩化作用外,还存在构造—热液白云岩化作用,后者受断裂—裂隙、不整合及热流体作用控制,常形成鞍形白云石和多种热液矿物共生组合,是优质白云岩储层形成的重要成岩作用。塔北地区受多旋回构造演化、成岩演化的控制,古隆起遭受多期剥蚀,寒武系白云岩与中生界形成角度不整合,发育强烈的风化壳岩溶作用;同时深大断裂形成通道,使得深部流体对白云岩进行溶蚀改造,形成不同成因类型叠加的复合型的优质白云岩储层。Abstract: From the Northern Tarim Uplift to the southern margin of the Kuche Depression,the northern Tarim region is one of the largest hydrocarbon enrichment regions in the Tarim Basin.The Cambrian platform sediment is 1 000 m thick,and is an important exploration layer.Due to big thickness,various types and wide distribution,dolomite in the region is favorable for reservoir generation and is the main exploration target.Based on lithologic,isotopic and REE analyses of well cores and outcrops of Cambrian dolomites in the northern Tarim region,combined with temperature studies of fluid inclusions,it has been concluded that the Cambrian dolomites in the northern Tarim region have various structural types,including mud microcrystal,fine-medium crystal and coarse crystal.Besides penecontemporaneous and burial dolomitization effects,they were also influenced by tectonic and hydrothermal dolomitization effects,which were controlled by fault-fracture,unconformity and thermal flow,usually resulting in the coexistence of saddle dolomite and multiple hydrothermal minerals.The tectonic and hydrothermal dolomitization effects were important for favorable dolomite reservoir generation.Controlled by cycles of tectonic and diagenesis evolutions,ancient uplifts in the northern Tarim region were eroded for several times.Angular unconformity took place between Cambrian dolomite and Meso-zoic,and strong weathering crust karst effect generated.Deep and big faults worked as pathways for deep fluid to flow into dolomite.The dolomite was transformed into complex high-quality reservoir of different origin.
-
Key words:
- origin /
- reservoir /
- dolomite /
- Cambrian /
- northern Tarim Basin
-
[1] 朱井泉,吴仕强,王国学,等.塔里木盆地寒武-奥陶系主要白云岩类型及孔凉发育特征[J].地学前缘,2008,15(2):67-79. [2] 叶德胜.塔里木盆地北部丘里塔格群(寒武系至奥陶系)白云岩的成因[J].沉积学报,1992,10(4):77-86. [3] 何莹,鲍志东,沈安江,等.塔里木盆地牙哈-英买力地区寒武系-下奥冉统白云岩形成机理[J].沉积学报,2006,24(6):806-816. [4] 吴仕爱,朱井泉,王目学,等.塔里木盆地寒武-奥陶系白云岩结构构造类型及其形成机理[J].岩石学报,2008,24(6):1390-1400. [5] 蔺军,周芳芳,袁国芬.塔河地区寒武系储层深埋藏白云石化特征[J].石油与天然气地质,2010,31(1):13-21. [6] 朱东亚,金之均,胡文瑄.塔中地区热液改造型白云岩储层[J].石油学报,2009,30(5):698-703. [7] 刘永福,桑洪,孙雄伟,等.塔里木盆地东部震旦-寒武白云岩类型及成因[J].西南石油大学学报(自然科学版),2008,30(5):27-31. [8] 马锋,徐怀先,顾家裕,等.塔东寒武系白云岩成因及储集层演化特征[J].石油勘探与开发,2009,36(2):144-155. [9] 胡九珍,刘树根,冉启贵,等.塔东地区寒武系-下奥陶统成岩作用特征及对优质储层形成的影响[J].成都理工大学学报(自然科学版),2009,36(2):138-145. [10] 于惹玲,马慧明,王蓉英.天山南地区前中生界油气成藏条件与勘探前景[J].中国西部油气地质,2007,3(1):22-26. [11] 邢秀娟,马慧明,王毅,等.塔里木盆地天山南地区碳酸盐岩储层形成主控因素探讨[C]//中国石化石油勘探开发研究院博士后科研工作站.油气成藏理论与勘探开发技术(二).北京:地质出版社,2009:33-42. [12] 高志前,樊太亮.塔里木盆地柯坪露头区寒武-奥陶纪层序构成样式[J].地学前缘,2005,12(4):352. [13] Machel H G.Saddle dolomite as a by-product of chemical compaction and thermochemical sulfate reduction[J].Geology,1987,15(10):936-940. [14] Wenk H R,Hu M,Frisia S.Partially disordered dolomite:microstructural characterization of Abu Dhabi sabkha carbonates[J].Am Mineral,1993,78 (7-8):769-774. [15] Land L S.The origin of massive dolomite[J].Journal of Geological Education,1985,33:112-125. [16] Choquette P W,Hiatt E E.Shallow-burial dolomite cement:A major component of many ancient sucrosic dolomites[J].Sedimentology,2008,55(2):423-460. [17] 陈德潜,陈刚.实用稀土元素地球化学[M].北京:冶金工业出版社,1990:180-183. [18] Qing H,Mountjoy E W.Origin of dissolution vugs,caverns,and hreccias in the Middle Devonian Presquseile barrier,host of the Pine Point MVT deposits[J].Economic Geology,1994,89(4):858-876. [19] 吴仕强,朱井泉,胡文瑄,等.塔里木盆地寒武系-奥陶系白云岩稀土元素特征和及其成因意义[J].现代地质,2009,23(4):638-647. [20] 王小林,金之均,胡文瑄,等.塔里木盆地下古生界白云石徽区REE配分特征及其成因研究[J].中国科学D辑:地球科学,2009,39(6):721-733. [21] 吕修祥,李建交,汪伟光,等.海相碳酸盐岩储层对断裂活动的响应[J].地质科技情报,2009,28(3):1-6. [22] 陈代铡.构造-热液白云岩化作用与白云岩储层[J].石油与天然气地质,2008,614-622. -
计量
- 文章访问数: 3314
- HTML全文浏览量: 54
- PDF下载量: 981
- 被引次数: 0