惠州凹陷恩平组砂岩储层碳酸盐胶结物发育特征及成因分析

Development characteristics and genetic causes of carbonate cements in sandstone reservoirs of Enping Formation in Huizhou Sag

摘要

珠一坳陷惠州凹陷古近系恩平组为陆相淡水沉积背景，整体物性较好，局部发育碳酸盐矿物，导致储层致密胶结、物性变差。采用薄片鉴定、扫描电镜和地球化学分析等方法，分析惠州凹陷古近系恩平组砂岩碳酸盐胶结物的宏观沉积特征、微观岩矿特征和成因。结果表明：惠州凹陷恩平组砂岩中碳酸盐胶结物类型复杂多样，包括方解石、白云石、铁方解石、铁白云石，伴生石膏及硬石膏矿物；基底式胶结充填颗粒之间的碳酸盐胶结物形成于同生期及早成岩阶段，与沉积时期水介质条件有关，部分早期碳酸盐胶结物在成岩过程中发生重结晶而呈连晶状分布，或被晚期含铁方解石、含铁白云石交代；充填于孔隙或胶结、交代颗粒产出的碳酸盐胶结物为中-晚成岩期产物，形成与有机酸流体作用相关；恩平组三、四段沉积时期，基底式胶结碳酸盐矿物大多分布于由断裂活动引起的逆牵引古隆起附近；恩平组一、二段沉积时期，基底式胶结碳酸盐矿物分布于洼陷边缘及水下古隆起附近。孔隙式碳酸盐胶结物的分布与烃类运移及断裂体系有关。该结果明确不同期次碳酸盐胶结物特征、储层物性及非均质性特征，为古近系优质储层预测提供指导。

Abstract

The sediments of the Enping Formation in the Huizhou Sag in the Zhu I Depression were deposited in terrestrial freshwater environment, with carbonate cements which leads to decrease of physical properties and densification in sandstone reservoirs. Based on the data of casting thin section, scanning electron microscope, geochemical analysis, the characteristics, distribution and genetic mechanism of carbonate cements were studied. The results showed that: multiple minerals including calcite, dolomite, ferrocalcite and ankerite were observed as well as gypsum and anhydrite. Basal cement of carbonate occurs where the water of sedimentary environment was partly salinized during syndepositional and syndiagenesis process. Recrystallization of early carbonate minerals leads to formation of crystal stock. The parts of this kind of cement were replaced by ferrocalcite or ankerite in the diagenetic process later. The carbonate minerals which fill in the pores, cement the granules and replace the existing minerals were late authigenic minerals. Their carbon isotope values and the oxygen isotope values showed the generation of carbonate cements might be related to the decarboxylation of organic matters during the early diagenetic stage. During the sedimentary period of the lower member of Enping Formation, basal cement of carbonate could be found in the sedimentary sites near the uplifts caused by faults. During the sedimentary period of the upper member of Enping Formation, basal cement of carbonate could be found at the edge of the sag or in the sedimentary sites near the uplifts under the water. The distribution of porous carbonate cements was related to hydrocarbon migration and fracture system. Studying different kinds of carbonate cements could be beneficial to learn the physical properties and heterogeneity of reservoirs and do good to identify better reservoirs.

关键词

碳酸盐胶结物 / 发育特征 / 成因 / 砂岩储层 / 流体环境 / 恩平组 / 惠州凹陷

Key words

carbonate cement / developmental characteristics / cause / sandstone reservoir / fluid environment / Enping Formation / Huizhou Sag

参考文献

[1] CARLOS R, RAFAELA M, KARL R. Facies-related diagenesis and multiphase siderite cementation and dissolution in the reservoir sand-stones of the Khatatba Formation,Egypt western desert[J]. Journal of Sedimentary Research, 2001, 71(3):459-472.

[2] 王思琦, 鲜本忠, 万锦峰, 等. 南堡凹陷滩海地区东营组和沙河街组一段储层特征及其成因机制[J]. 东北石油大学学报, 2015, 39(4): 54-62.

[3] WANG Siqi, XIAN Benzhong, WAN Jinfeng, et al. Reservoir characteristics and controlling factors in the offshore areas,the Eocene period of the Nanpu Sag[J]. Journal of Northeast Petroleum University, 2015, 39(4):54-62.

[4] 谭先锋, 蒋威, 吴康军, 等. 陆相碎屑岩中钙质胶结物沉淀机制及油气储集意义:来自济阳坳陷孔店组和川西须家河组的对比研究[J]. 石油实验地质, 2016, 38(3):293-302.

[5] TAN Xianfeng, JIANG Wei, WU Kangjun, et al. Sedimentation mechanism and petroleum significance of calcareous cements in continental clastic rocks:comparison between the Kongdian Formation in the Jiyang Depression and the Xujiahe Formation in the Western Sichuan Basin[J]. Petroleum Geology & Experiment, 2016, 38(3):293-302.

[6] 陈秀艳, 王剑, 张立平, 等. 塔里木盆地哈拉哈塘地区石炭系东河砂岩段碳酸盐胶结物沉积特征及其成因[J]. 吉林大学学报(地球科学版), 2020, 50(2):509-517.

[7] CHEN Xiuyan, WANG Jian, ZHANG Liping, et al. Sedimentary characteristics and genesis of carbonate cements in Carboniferous Donghe Sandstone Member,Hanilcatam Area of Tarim Basin[J]. Journal of Jilin University(Earth Science Edition), 2020, 50(2): 509-517.

[8] 徐北煤, 卢冰. 硅质碎屑岩中碳酸盐胶结物及其对储层的控制作用的研究[J]. 沉积学报, 1994, 12(3):56-63.

[9] XU Beimei, LU Bing. The study of diagenetic carbonate in siliciclastic rock and its control on the reservoir[J]. Acta Sedimentologica Sinica, 1994, 12(3):56-63.

[10] 王琪, 郝乐伟, 陈国俊, 等. 白云凹陷珠海组砂岩中碳酸盐胶结物的形成机理[J]. 石油学报, 2010, 31(4):553-565.

[11] WANG Qi, HAO Lewei, CHEN Guojun, et al. Forming mechanism of carbonate cements in siliciclastic sandstone of Zhuhai Formation in Baiyun Sag[J]. Acta Petrolei Sinica, 2010, 31(4):553-565.

[12] 田亚铭, 施泽进, 李庭艳, 等. 姬塬地区长 8 油层组碳酸盐胶结物特征与成因[J]. 西安石油大学学报(自然科学版), 2011, 26(3):26-30.

[13] TIAN Yaming, SHI Zejin, LI Tingyan, et al. Characteristics and origin of the carbonate cements of Chang 8 Member in Jiyuan Area, Ordos Basin[J]. Journal of Xían Shiyou University(Natural Science Edition), 2011, 26(3):26-30.

[14] 常思远, 陈冬霞, 汪成, 等. 深层储层原生孔隙成岩作用保存机制及模式:以珠江口盆地惠州凹陷南部恩平组和文昌组为例[J]. 东北石油大学学报, 2022, 46(2):72-85.

[15] CHANG Siyuan, CHEN Dongxia, WANG Cheng, et al. Preservation mechanism and model of primary pore diagenesis in deep reservoirs:taking the Enping Formation and Wenchang Formation in the south of Huizhou Sag,Pearl River Mouth Basin as examples[J]. Journal of Northeast Petroleum University, 2022, 46(2):72-85.

[16] 王翔, 高吉宏, 庞玉东, 等. 鄂尔多斯盆地 M34 区块侏罗系延10段砂质辨状河储层特征及控制因素[J]. 东北石油大学学报, 2024, 48 (3):23-39.

[17] WANG Xiang, GAO Jihong, PANG Yudong, et al. Reservoir characteristics and controlling factors of Jurassic Yan 10 Member sandy braided river of M34 Block,Ordos Basin[J]. Journal of Northeast Petroleum University, 2024, 48(3):23-39.

[18] 钟玉婷, 董艳蕾, 李顺利, 等. 珠三坳陷珠海组海陆过渡相沉积特征及储层控制因素[J]. 东北石油大学学报, 2023, 47(4):39-56.

[19] ZHONG Yuting, DONG Yanlei, LI Shunli, et al. Sedimentary characteristic and reservoir controlling factors of sea-land transition in Zhuhai Formation,Zhu-3 Depression[J]. Journal of Northeast Petroleum University, 2023, 47(4):39-56.

[20] MARCO A S, RONALD C S. Diagenetic heterogeneity and reservoir quality:fluvial,deltatic and turbiditic sandstone reservoirs,potigular and reconcavo rift basins,Brazil[J]. AAPG Bulletin, 1993,77:1142-1156.

[21] KEITH M L, WEBER J N. Carbon and oxygen isotopic composition of selected limestones and fossils[J]. Geochimica et Cosmochimica Acta, 1964, 28(10/11):1787-1816.

[22] 姚泾利, 王琪, 张瑞, 等. 鄂尔多斯盆地中部延长组砂岩中碳酸盐胶结物成因与分布规律研究[J]. 天然气地球科学, 2011, 22(6): 943-950.

[23] YAO Jingli, WANG Qi, ZHANG Rui, et al. Origin and spatial distribution of carbonate cements in Yanchang Fm.(Triassic)sandstones within the lacustrine center of Ordos Basin,NW China[J]. Natural Gas Geoscience, 2011, 22(6):943-950.

[24] 孙福宁, 胡文瑄, 胡忠亚, 等. 断裂一层序双控机制下的热液活动及成储效应:以塔里木盆地塔河、玉北地区下奥陶统为例[J]. 石油与天然气地质, 2020, 41(3):558-575.

[25] SUN Funing, HU Wenxuan, HU Zhongya, et al. Impact of hydrothermal activities on reservoir formation controlled by both faults and sequences boundaries:a case study from the Lower Ordovician in Tahe and Yubei Areas,Tarim Basin[J]. Oil & Gas Geology, 2020, 41(3):558-575.

[26] 崔景伟, 朱如凯.致密砂岩层内强钙质胶结物成因机制及其意义:以鄂尔多斯盆地三叠系延长组长 7 油层组为例[ J ]. 吉林大学学报 (地球科学版), 2020, 50(4):957-967.

[27] CUI Jingwei, ZHU Rukai. Mechanism of strong calcium cementation in tight sandstone and its significance:a case study on Triassic Chang 7 oil formation of Yanchang Formation in Ordos Basin[J]. Journal of Jilin University(Earth Science Edition), 2020, 50(4): 957-967.

[28] 张月霞, 丁琳, 周凤娟, 等. 珠江口盆地珠一坳陷古近系砂岩储层渗透率和埋深下限研究[J]. 海相油气地质, 2023, 28(3):311-322.

[29] ZHANG Yuexia, DING Lin, ZHOU Fengjuan, et al. Study on the lower limits of permeability and buried depth of Paleogene sandstone reservoirs in the Zhu I Depression,Pearl River Mouth Basin[J]. Marine Origin Petroleum Geology, 2023, 28(3):311-322.

[30] 王绪诚, 杜家元, 张琴, 等. 惠西南地区古近系转换带型源-汇系统研究及其勘探意义[J]. 中国海上油气, 2020, 32(5):44-53.

[31] WANG Xucheng, DU Jiayuan, ZHANG Qin, et al. Study of source-sink system of transfer zone type of Palaeogene in southwestern area of the Huizhou Sag and its exploration significance[J]. China Offshore Oil and Gas, 2020, 32(5):44-53.

[32] 龙更生, 施和生, 郑荣才, 等. 珠江口盆地惠州凹陷深部古近系储层特征及发育控制因素[J]. 海相油气地质, 2011, 16(3):71-78.

[33] LONG Gengsheng, SHI Hesheng, ZHENG Rongcai, et al. Characteristics and development controlling factors of Paleogene deep reservoirs in Huizhou Depression,Pearl River Mouth Basin[J]. Marine Origin Petroleum Geology, 2011, 16(3):71-78.

[34] 刘培, 彭光荣, 熊万林, 等. 珠江口盆地惠州凹陷惠东新区恩平组烃源岩生烃特征及成藏贡献[J]. 中国海上油气, 2024, 36(1):49-60.

[35] LIU Pei, PENG Guangrong, XIONG Wanlin, et al. Hydrocarbon generation characteristics and reservoir forming contribution of Enping Formation source rocks in Huidong New Area,Huizhou Sag,Pearl River Mouth Basin[J]. China Offshore Oil and Gas, 2024, 36(1):49-60.

[36] 曾智伟. 南海北部珠江口盆地古近纪源一汇系统耦合研究[D]. 武汉: 中国地质大学(武汉),2020:113-136.

[37] ZENG Zhiwei. Source-to-sink(S2S) system analysis of the Paleogene in the Pearl River Mouth Basin,Northern South China Sea[D]. Wuhan: China University of Geoscience(Wuhan),2020:113-136.

[38] 刘振宇. 惠州凹陷恩平组烃源岩发育与沉积相关系[D]. 北京: 中国地质大学(北京),2020:31-42.

[39] LIU Zhenyu. Relationship between source rocks and sedimentary facies of Enping Formation in Huizhou Sag[D]. Beijing: China U- niversity of Geoscience(Beijing),2020:31-42.

[40] 周凤娟, 丁琳, 李晓艳, 等. 珠一坳陷文昌组锆石定年物源示踪及其对储层的影响[J]. 非常规油气, 2023, 10(3):46-54.

[41] ZHOU Fengjuan, DING Lin, LI Xiaoyan, et al. Provenance tracing of zircon dating from Wenchang Formation in Zhu I Depression and its influence on reservoir[J]. Unconventional Oil & Gas, 2023, 10(3):46-54.

[42] 吴国瑄, 覃军干, 茅绍智. 南海深海相渐新统孢粉记录[J]. 科学通报, 2003, 48(17):1868-1871.

[43] WU Guoxuan, QIN Jungan, MAO Shaozhi. Deep-sea pollen records of Oligocene in South China Sea[J]. Chinese Science Bulletin, 2003, 48(17):1868-1871.

[44] 米立军. 珠江口盆地油气储层[M]. 北京: 科学出版社,2021:5-7.

[45] MI Lijun. Reservoirs of oil and gas in Pearl River Mouth Basin[M]. Beijing: Science Press,2021:5-7.

[46] 郭巧珍, 陈峰, 杨香华, 等. 珠江口盆地惠州凹陷恩平组浅水辩状河三角洲沉积例[J]. 海洋地质与第四纪地质, 2013, 33(1):25-32.

[47] GUO Qiaozhen, CHEN Feng, YANG Xianghua, et al. Shallow braided deltaic system in Enping Formation of Huizhou Depression, Pearl River Mouth[J]. Marine Geology & Quaternary Geology, 2013, 33(1):25-32.

[48] 高阳东, 林鹤鸣, 汪旭东, 等. 幕式裂陷控洼背景下的烃源岩分布及岩浆改造:以珠一坳陷番禺4洼为例[J]. 海洋地质与第四纪地质, 2021, 41(4):151-160.

[49] GAO Yangdong, LIN Heming, WANG Xudong, et al. Source rock distribution pattern in an episodic rifting sag and later stage magmatic reformation:a case from Panyu 4 Sag,Zhu I Depression[J]. Marine Geology & Quaternary Geology, 2021, 41(4):151-160.

[50] 谢世文, 王宇辰, 舒誉, 等. 珠一坳陷湖盆古环境恢复与优质烃源岩发育模式[J]. 海洋地质与第四纪地质, 2022, 42(1):159-169.

[51] XIE Shiwen, WANG Yuchen, SHU Yu, et al. Environmental reconstruction for the paleo-lake of Zhu I Depression and the depositional model for high-quality source rocks[J]. Marine Geology & Quaternary Geology, 2022, 42(1):159-169.

[52] 丁琳, 舒誉, 蓝倩, 等. 惠州凹陷古近系恩平组层序地层划分及展布特征[J]. 中国海上油气, 2008, 20(6):159-169.

[53] DING Lin, SHU Yu, LAN Qian, et al. Sequence stratigraphy and distribution of Palaeogene Enping Formation in Huizhou Depression[J]. China Offshore Oil and Gas, 2008, 20(6):159-169.

[54] 杨超群, 贺同兴, 翁世劼, 等. 广东省区域地质志[M]. 北京: 地质出版社,1988:603-606.

[55] YANG Chaoqun, HE Tongxing, WENG Shijie, et al. Regional geology of Guangdong Province[M]. Beijing: Geological Publishing House,1988:603-606.

[56] 韩俊, 尤东华, 钱一雄, 等. 微区原位碳氧同位素分析技术对碳酸盐岩成岩流体性质的约束[J]. 石油实验地质, 2023, 45(1):135-144.

[57] HAN Jun, YOU Donghua, QIAN Yixiong, et al. Constraints on carbonate diagenetic fluid properties by microzone in situ analysis of carbon and oxygen isotopes:a case study of Cambrian-Ordovician,Tarim Basin[J]. Petroleum Geology & Experiment, 2023, 45(1): 135-144.

[58] SCHOBBEN M, ULLMANN C V, LEDA L, et al. Discerning primary versus diagenetic signals in carbonate carbon and oxygen isotope records:an example from the Permian-Triassic boundary of Iran[J]. Chemical Geology, 2016,422:94-107.

[59] WU H, HU W, TANG Y, et al. The impact of organic fluids on the carbon isotopic compositions of carbonate-rich reservoirs:case study of the Lucaogou Formation in the Jimusaer Sag,Junggar Basin,NW China[J]. Marine and Petroleum Geology, 2017,85:136-150.

[60] CHEN J, LI G, YANG J, et al. Nd and Sr isotopic characteristics of Chinese deserts:implications for the provenances of Asian dust[J]. Geochimica et Cosmochimica Acta, 2007, 71(15):3904-3914.

[61] 梁俊红, 孙宝亮, 尹国英. 中国湖相碳酸盐岩碳氧同位素时空特征及其古湖泊学意义[J]. 地质找矿论丛, 2022, 37(4):469-483.

[62] LIANG Junhong, SUN Baoliang, YIN Guoying. Temporal and spatial characteristics of C-O isotopes of lacustrine carbonate in China and the paleolimnological significance[J]. Contributions to Geology and Mineral Resources Research, 2022, 37(4):469-483.

[63] 吕成福, 李晓燕, 陈国俊, 等. 酒东坳陷下白垩统砂岩中碳酸盐胶结物特征与储层物性[J]. 沉积学报, 2011, 29(6):1138-1143.

[64] LYU Chengfu, LI Xiaoyan, CHEN Guojun, et al. Characteritics of carbonate cements and reservoir quality of the Lower Cretaceous sandstone in Jiudong Sag[J]. Acta Sedimentologica Sinica, 2011, 29(6):1138-1143.

[65] 罗顺社, 吕奇奇, 席明利, 等. 湘北九溪、沅古坪下奥陶统等深岩类型、碳氧同位素特征及沉积环境[J]. 石油与天然气地质, 2015, 36 (5):745-755.

[66] LUO Shunshe, LYU Qiqi, XI Mingli, et al. Types,carbon/oxygen isotope characteristics and depositional environments of the Lower Ordovician contourites in Jiuxi and Yuanguping of North Hunan Province,China[J]. Oil & Gas Geology, 2015, 36(5):745-755.

[67] 佟恺林, 周安富, 罗强, 等. 四川盆地泸州中部地区龙马溪组构造裂缝期次及演化模式[J]. 东北石油大学学报, 2024, 48(5):17-26.

[68] TONG Kailin, ZHOU Anfu, LUO Qiang, et al. Tectonic fracture stages and evolution model of Longmaxi Formation in Central Luzhou Area,Sichuan Basin[J]. Journal of Northeast Petroleum University, 2024, 48(5):17-26.

[69] 王大锐. 油气稳定同位素地球化学[M]. 北京: 地质出版社,2000:116.

[70] WANG Darui. Stable isotope geochemistry of oil and gas[M]. Beijing: Geological Press,2000:116.

[71] 郭宏莉, 王大锐. 塔里木油气区砂岩储集层碳酸盐胶结物的同位素组成与成因分析[J]. 石油勘探与开发, 1999, 26(3):31-33.

[72] GUO Hongli, WANG Darui. Stable isotopic composition and origin analysis of the carbonate cements within sandstone reservoirs of Tarim oil-gas bearing area[J]. Petroleum Exploration and Development, 1999, 26(3):31-33.

[73] 袁才, 彭光荣, 温华华, 等. 珠江口盆地惠州凹陷恩平组源岩特征及勘探潜力[J]. 海洋地质与第四纪地质, 2017, 37(2):149-159.

[74] YUAN Cai, PENG Guangrong, WEN Huahua, et al. A new source rock in Huizhou Sag of Pearl River Mouth Basin and its exploration potential[J]. Marine Geology and Quaternary Geology, 2017, 37(2):149-159.

[75] 谢丽丽, 孟凡巍, 卓勤功, 等. 山东大汶口盆地石盐地球化学特征及其成因[J]. 盐湖研究, 2023, 31(3):59-68.

[76] XIE Lili, MENG Fanwei, ZHUO Qingong, et al. Geochemical characteristics of evaporites from halite deposits in Dawenkou Basin, Shandong Province[J]. Journal of Salt Lake Research, 2023, 31(3):59-68.

[77] 李延河, 段超, 范昌福, 等. 膏盐层在内生金属矿床成矿中的作用研究[J]. 矿产勘查, 2024, 15(8):1391-1408.

[78] LI Yanhe, DUAN Chao, FAN Changfu, et al. The role of evaporite layers in the mineralization of endogenetic metal deposits[J]. Mineral Exploration, 2024, 15(8):1391-1408.

基金资助

中海石油（中国）有限公司深圳分公司重大生产性科研项目(SCKY-2025-SZ-YJYKT-08)