Characteristics and origin of the Lower Cretaceous dolomitic tight oil reservoir in Erenaor sag, Erlian Basin

doi:10.3969/j.issn.1672-7703.2017.03.009

Abstract

Abstract: In order to understand the origin of dolomitic tight oil reservoir of the Lower Cretaceous Arshan Formation in the Erenoar sag, the Erlian Basin, on the basis of sedimentary structure and volcanic activity analysis, the core observation, thin section identification and physical mercury analysis as well as geochemical analysis such as carbon and oxygen isotope were employed to systematically investigate the petrology, origin, distribution and reservoir space of dolomitic tight oil reservoir and to preliminarily discuss the exploration potential of this kind of reservoir. The research results show that the reservoir is mainly composed of dolomitic tuffite, dolomitic mudstone and dolomitic siltstone, with the porosity of 1%-5% and the permeability of 0.008-2.8 mD, suggesting as low-ultra low porosity and extra low-ultra low permeability type reservoir. The reservoir space comprises inter-crystalline pores and micro-fractures. The dolomite in the dolomitic rock is usually hypidiomorphic-allotriomorphic and micrite-powder crystal, with high carbon isotope (from -1.50‰ to 5.20‰) and high V/Ni (from 1.57 to 4.56), indicating terrestrial brackish-brine evaporating environment. The dolomite in the dolomitic mudstone and tuffite contains high carbon and oxygen isotopes, and the dolomite crystals exist in the tuffaceous and argillaceous matrix, mainly related to CH₄ generation. The dolomite in the dolomitic siltstone contains low carbon and oxygen isotopes, which is influenced by burial depth and hydrocarbon generation. The Mg²⁺ in the dolomitic rock came from the deep marble and granite, and also from the volcanic matter and the hydrolytic alteration of feldspar grain. In addition, during the development of dolomitic rock, the volcano eruption triggered the mass mortality of the lake organism, making organic matters endowed to facilitate the cultivation of methanogens bacteria, which provided the dynamic conditions for the dolomite growth during the early stage. The hydrocarbon generation and expulsion of the source rocks during the late stage enabled the oil and gas to preserve in the inter-crystalline pores and micro-fractures, providing good storage space for tight oil.

Key words: dolomitic rock, origin of dolomite, tight oil, Lower Cretaceous, Erenoar sag, Erlian Basin

CLC Number:

TE112.23

Wei Wei, Zhu Xiaomin, Zhu Shifa, He Mingwei, Wu Jianping, Wang Mingwei, Lü Sihan. Characteristics and origin of the Lower Cretaceous dolomitic tight oil reservoir in Erenaor sag, Erlian Basin[J]. China Petroleum Exploration, 2017, 22(3): 71-80.

References

[1] 贾承造,郑民,张永峰. 中国非常规油气资源与勘探开发前景[J]. 石油勘探与开发,2012,39(2):129-136. Jia Chengzao, Zheng Min, Zhang Yongfeng. Unconventional hydrocarbon resources in China and the prospect of exploration and development[J]. Petroleum Exploration and Development, 2012,39(2):129-136.
[2] 邹才能,陶士振,侯连华. 非常规油气地质[M]. 北京:地质出版社, 2011. Zou Caineng, Tao Shizhen, Hou Lianhua. Unconventional petroleum[M]. Beijing:Geological Publishing House, 2011.
[3] 邹才能,张国生,杨智,陶士振,侯连华,朱如凯,等. 常规油气概念、特征、潜力及技术——兼论非常规油气地质学[J]. 石油勘探与开发, 2013,40(40):385-399. Zou Caineng, Zhang Guosheng, Yang Zhi, Tao Shizhen, Hou Lianhua, Zhu Rukai, et al. Geological concepts, characteristics, resource potential and key techniques of unconventional hydrocarbon:on unconventional petroleum geology[J]. Petroleum Exploration and Development, 2013,40(40):385-399.
[4] 王社教,蔚远江,郭秋麟,汪少勇,吴晓智. 致密油资源评价进展[J]. 石油学报,2014,35(6):1095-1105. Wang Shejiao, Wei Yuanjiang, Guo Qiulin,Wang Shaoyong, Wu Xiaozhi. New advance in resources evaluation of tight oil[J]. Acta Petrolei Sinica, 2014,35(6):1095-1105.
[5] 葸克来,操应长,朱如凯,邵雨,薛秀杰,王小军,等. 吉木萨尔凹陷二叠系芦草沟组致密油储层岩石类型及特征[J]. 石油学报, 2015,36(12):1495-1507. Xi Kelai, Cao Yingchang, Zhu Rukai, Shao Yu, Xue Xiujie, Wang Xiaojun, et al. Rock types and characteristics of tight oil reservoir in Permian Lucaogou Formation,Jimsar sag[J]. Acta Petrolei Sinica, 2015,36(12):1495-1507.
[6] 赵靖舟. 非常规油气有关概念分类及资源潜力[J]. 天然气地球科学, 2012,23(3):393-406. Zhao Jingzhou. Conception, Classification and resource potential of unconventional hydrocarbons[J]. Natural Gas Geoscience, 2012,23(3):393-406.
[7] 林森虎,邹才能,袁选俊,杨智. 美国致密油开发现状及启示[J]. 岩性油气藏,2011,23(4):25-30. Lin Senhu, Zou Caineng, Yuan Xuanjun, Yang Zhi. Status quo of tight oil exploitation in the United States and its implication[J]. Lithologic Reservoirs, 2011,23(4):25-30
[8] 朱世发,刘欣,马勋,马爱钰,朱筱敏,贾业. 准噶尔盆地下二叠统风城组致密碎屑岩储层发育特征[J]. 高校地质学报,2015,21(3):461-470. Zhu Shifa, Liu Xin, Ma Xun, Ma Aiyu, Zhu Xiaomin, Jia Ye. The development characteristics of tight clastic reservoirs in the Lower Permian Fengcheng Formation in Wu-Xia area of the Junggar Basin[J]. Geological Journal of China Universities, 2015,21(3):461-470.
[9] 鲍海娟,刘旭,周亚丽,杨翼波,郭旭光. 吉木萨尔凹陷致密油有利区预测及潜力分析[J]. 特种油气藏,2016,23(5):38-42. Bao Haijuan, Liu Xu, Zhou Yali, Yang Yibo, Guo Xuguang. Favorable area and potential analyses of tight oil in Jimsar sag[J]. Special Oil & Gas Reservoirs, 2016,23(5):38-42.
[10] 朱世发,朱筱敏,刘继山,姚远,鲜本忠,牛花朋,等. 富孔熔结凝灰岩成因及油气意义——以准噶尔盆地乌-夏地区风城组为例[J]. 石油勘探与开发,2012,39(2):162-171. Zhu Shifa, Zhu Xiaomin, Liu Jishan, Yao Yuan, Xian Benzhong, Niu Huapeng, et al.Genesis and hydrocarbon significance of vesicular ignimbrite:a case study from Fengcheng Formation, Wu-Xia area, Junggar Basin, NW China[J]. Petroleum Exploration and Development, 2012,39(2):162-171.
[11] 刘俊田,卿忠,张品,韩润净,师效飞. 马朗凹陷致密油藏烃源岩评价及油源分析[J]. 特种油气藏,2015,22(6):35-39. Liu Juntian, Qing Zhong, Zhang Pin, Han Runjing, Shi Xiaofei. Evaluation of source rocks and analysis of oil-sources in Malang depression tight reservoirs[J]. Special Oil & Gas Reservoirs, 2015,22(6):35-39.
[12] 牛小兵,冯胜斌,尤源,梁晓伟,王芳,李卫成,等. 鄂尔多斯盆地致密油地质研究与试验攻关实践及体会[J]. 石油科技论坛, 2016,35(4):38-46. Niu Xiaobing, Feng Shengbin, You Yuan, Liang Xiaowei, Wang Fang, Li Weicheng, et al. Geological study and pilot test of tight oil in Ordos Basin[J]. Oil Forum, 2016,35(4):38-46.
[13] 贾承造,邹才能,李建忠,李登华,郑民. 中国致密油评价标准、主要类型、基本特征及资源前景[J]. 石油学报,2012,33(3):343-350. Jia Chengzao, Zou Caineng, Li Jianzhong, Li Denghua, Zheng Min. Assessment criteria, main types, basic features and resource prospects of the tight oil in China[J]. Acta Petrolei Sinica, 2012,33(3):343-350.
[14] 李建忠,郑民,张国生,杨涛,王社教,董大忠,等. 中国常规与非常规天然气资源潜力及发展前景[J]. 石油学报,2012,33(增刊1):89-98. Li Jianzhong, Zheng Min, Zhang Guosheng, Yang Tao, Wang Shejiao, Dong Dazhong, et al. Potential and prospects of conventional and unconventional natural gas resource in China[J]. Acta Petrolei Sinica, 2012,33(Supp.1):89-98.
[15] 贾国娜. 二连盆地阿南凹陷腾一段层序地层及沉积体系研究[D]. 北京:中国地质大学(北京), 2012. Jia Guona. Sequence stratigraphy and depositional system research of strata of Et₁ in A'nan depression,Erlian Basin[D]. Beijing:China University of Geosciences (Beijing), 2012.
[16] 李秀英,肖阳,杨全凤. 二连盆地阿南洼槽岩性油藏及致密油勘探潜力[J]. 中国石油勘探, 2013,18(6):56-61. Li Xiuying, Xiao Yang, Yang Quanfeng. Lithologic reservoir and tight oil exploration potential in A'nan subsag, Erlian Basin[J]. China Petroleum Exploration, 2013,18(6):56-61.
[17] 蓝宝锋,杨克兵,彭传利,黄金川,高正原. 二连盆地阿南凹陷致密油勘探潜力分析[J]. 复杂油气藏,2014,7(2):9-12. Lan Baofeng, Yang Kebing, Peng Chuanli, Huang Jinchuan, Gao Zhengyuan. Analysis of the exploration potential of tight oil in A'nan sag,Erlian Basin[J]. Complex Hydrocarbon Reservoirs, 2014,7(2):9-12.
[18] 王会来,高先志,杨德相,李浩,张志遥,王旭. 二连盆地下白垩统湖相云质岩分布及控制因素[J]. 现代地质,2014,28(1):163-172. Wang Huilai, Gao Xianzhi, Yang Dexiang, Li Hao, Zhang Zhiyao, Wang Xu. Distribution characteristics and controlling factors of the Lower Cretaceous lacustrine dolomitic rock in Erlian Basin[J]. Geoscience, 2014,28(1):163-172.
[19] 赵贤正,柳广弟,金凤鸣,黄志龙,卢学军,孙明亮,等. 小型断陷湖盆有效烃源岩分布特征与分布模式——以二连盆地下白垩统为例[J]. 石油学报,2015,36(6):641-652. Zhao Xianzheng, Liu Guangdi, Jin Fengming, Huang Zhilong, Lu Xuejun, Sun Mingliang, et al. Distribution features and pattern of effective source rock in small faulted lacustrine basin:a case study of the Lower Cretaceous in Erlian Basin[J]. Acta Petrolei Sinica, 2015,36(6):641-652.
[20] Lin C S, Kenneth E, Li S T, Wan Y X, Ren J Y, Zhang Y M. Sequence architecture, depositional systems, and controls on development of lacustrine Basin fills in part of the Erlian Basin, northeast China[J]. AAPG Bulletin, 2001,85(11):2017-2043.
[21] 祝玉衡,张文朝. 二连盆地下白垩统沉积相及含油性[M]. 北京:科学出版社,2000:167-189. Zhu Yuheng, Zhang Wenzhao. Sedimentary facies and hydrocarbon-bearing of Lower Cretaceous strata in Erlian Basin[M]. Beijing:Science Press, 2000:167-189.
[22] Ding X, Liu G D, Zha M, Huang Z L, Gao C H, Lu X J, et al. Relationship between total organic carbon content and sedimentation rate in ancient lacustrine sediments, a case study of Erlian Basin, northern China[J]. Journal of Geochemical Exploration, 2015,149:22-29.
[23] 周多,陈安霞,张彬,张尧. 内蒙古二连盆地额仁淖尔凹陷断裂系统特征[J]. 地质与资源,2014,23(增刊1):83-89. Zhou Duo, Chen Anxia, Zhang Bin, Zhang Yao. Characteristics of the fault system in the Erenaor sag in Erlian Basin, inner Mongolia[J]. Geology and Resources, 2014,23(Supp.1):83-89.
[24] Swart P K, Eberli G. The nature of the delta C-13 of periplatform sediments:Implications for stratigraphy and the global carbon cycle[J]. Sedimentary Geology, 2005,175:115-129.
[25] 兰德. 白云化作用[M]. 北京:石油工业出版社,1985,1-12. Land L S. Dolomitization[M]. Beijing:Petroleum Industry Press, 1985:1-12.
[26] 黄思静. 碳酸盐岩的成岩作用[M]. 北京:地质出版社,2010. Huang Sijing. Diagenesis of carbonate[M]. Beijing:Geological Publishing House, 2010.
[24] 杨威,王清华,刘效曾. 塔里木盆地和田河气田下奥陶统白云岩成因[J]. 沉积学报, 2000,18(4):544-547. Yang Wei, Wang Qinghua, Liu Xiaozeng. Dolomite origin of Lower Ordovician in Hetian River gas field, Tarim Basin[J]. Acta Sedimentologica Sinica, 2000,18(4):544-547.
[25] Keith M L, Weber J N. Carbon and oxygen isotopic composition of selected limestones and fossils[J]. Geochimica et Cosmochimica Acta, 1964,28(10):1786-1816.
[26] Wilson E N, Hardie L A, Phillips O M. Dolomitization front geometry, fluid flow patterns, and the origin of massive dolomite:the Triassic Latemar buildup, northern Italy[J]. American Journal of Science, 1990,290:741-796.
[27] Vincent B, Emmanuel L, Houel P, Loreau J P. Geodynamic control on carbonate diagenesis:petrographic and isotopic investigation of the Upper Jurassic Formations of the Paris Basin (France)[J]. Sedimentary Geology, 2007,197(3-4):267-289.
[28] Warren, J. Dolomite:occurrence, evolution and economically important associations[J]. Earth-Science Reviews, 2000,52(1-3):1-81.
[29] Yuan J, Huang C, Zhao F, Pan X. Carbon and oxygen isotopic compositions, and palaeoenvironmental significance of saline lacustrine dolomite from the Qaidam Basin, Western China[J]. Journal of Petroleum Science and Engineering, 2015,135:596-607.
[30] Macaulay C I, Haszeldine R S, Anthony E. Fallick. Distribution, chemistry, isotopic composition and origin of diagenetic carbonates; Magnus Sandstone, North Sea[J]. Journal of Sedimentary Research, 1993,1:33-43.
[31] Irwin H, Curtis C D, Coleman M L. Isotopic evidence for source of diagenetic carbonates formed during burial of organicrich sediments[J]. Nature, 1977,164:209-213.
[32] Keith M L, Weber J N. Carbon and oxygen isotopic composition of selected limestones and fossils[J]. Geochimica et Cosmochimica Acta, 1964, 28(10):1787-1816.
[33] 刘传联,赵泉鸿,汪品先. 湖相碳酸盐氧碳同位素的相关性与生油古湖泊类型[J]. 地球化学, 2001,30(4):363-367. Liu Chuanlian, Zhao Quanhong, Wang Pinxian. Correlation between carbon and oxygen isotopic ratios of lacustrine carbonates and typeso foil-producing paleolakes[J]. Geochimica. 2001,30(4):363-367.
[34] Whiticar M J. Carbon and hydrogen isotope systematics of bacterial formation and oxidation of methane[J]. Chemical Geology, 1999,161:291-314.
[35] Van Lith Y, Warthmann R, Vasconcelos C, McKenzie J A. Microbial fossilization in carbonate sediments:a result of the bacterial surface involvement in dolomite precipitation[J]. Sedimentology, 2003,50:237-245.
[36] Sánchez-Román M, Vasconcelos C, Schmid T, Dittrich M, McKenzie J A, Zenobi R, et al. Aerobic microbial dolomite at the nanometer scale:Implications for the geologic record[J]. Geology, 2008,36(11):879-882.
[37] Mazzullo S J. Organogenic dolomitization in peritidal to deep-sea sediments[J]. Journal of Sedimentary Research, 2000,70(1):10-23.
[38] Roberts J A, Bennett P C, González L A, Macpherson G L, Milliken K L. Microbial precipitation of dolomite in methanogenic groundwater[J]. Geology, 2004,32(4):277-280.
[39] Epstein S, Buchsbaum H A, Lowenstam H, Urey H C. Revised carbonate-water isotopic temperature scale[J]. Geological Society of America Bulletin, 1953,64(11):1315-1326.
[40] Gasse F, Fontes J C, Plaziat J C, Caebonel P, Kaczmarska I, De Deckker P, et al. Biological remains, geochemistry and stable isotopes for the reconstruction of environmental and hydrological changes in the Holocene lakes from North Sahara[J]. Palaeogeography, Palaeoclimatology, Palaeoecology, 1987,60:1-46.
[41] Land L S. The origin of massive dolomite[J]. Journal of Geological Education, 1985,33:112-125.
[45] Baker P A, Kastner M. Constraints on the formation of sedimentary dolomite[J]. Science, 1981,213:214-216.
[46] 张杰,Brian Jones,张建勇. 不同埋藏深度交代白云石晶体结构及其对白云岩储层研究的意义[J]. 中国石油勘探,2014,19(3):21-28. Zhang Jie, Brian Jones, Zhang Jianyong. Crystal structure of replacement dolomite with different buried depths and its significance to study of dolomite reservoir[J]. China Petroleum Exploration, 2014,19(3):21-28.
[47] 甯濛,刘殊,龚文平. 川西坳陷三叠系雷口坡组顶部白云岩储层分布预测[J]. 中国石油勘探,2015,20(3):30-37. Ning Meng, Liu Shu, Gong Wenping. Prediction of dolomite reservoir distribution on top of Triassic Leikoupo Formation in Chuanxi Depression[J]. China Petroleum Exploration, 2015,20(3):30-37.
[48] 常少英, 沈安江, 李昌, 周进高, 余异志. 岩石结构组分测井识别技术在白云岩地震岩相识别中的应用[J]. 中国石油勘探, 2016,21(5):90-95. Chang Shaoying, Shen Anjiang, Li Chang, Zhou Jingao, Yu Yizhi. Application of rock structure component identification technology by well logging in dolomite seismic lithofacies identification[J]. China Petroleum Exploration, 2016,21(5):90-95.