Discussion on integrated geological and geophysical identification method for spatial distribution of favorable source rocks in depression with lack of drilling data: a case study of Enping 17 Sag, Zhu Ⅰ Depression, Pearl River Mouth Basin
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摘要: 为解决珠江口盆地珠一坳陷低钻揭洼陷有利烃源岩展布的综合识别问题,以珠江口盆地珠一坳陷恩平17洼为例,在对烃源岩发育地质背景、沉积特征及岩石物理特征分析的基础上,以不同沉积环境烃源岩的岩石物理特征约束指导地震反演;根据钻揭烃源岩岩相与反演阻抗体关系统计,通过地质建模进行有利烃源岩空间展布的半定量预测;结合原油的地化成因类型及来源认识分析预测方法及结果的合理性,探讨低钻揭洼陷有利烃源岩空间展布的地质与地球物理综合识别方法。古近系文昌组烃源岩沉积环境越好,有利烃源岩段的阻抗值越低,与差烃源岩或非烃源岩段之间的阻抗差异越大。从预测结果看,文三段、文四段及文五段是恩平17洼的主力烃源岩段,这一认识得到了原油生物标志化合物研究的支持。在石油地质背景条件基本明确的珠江口盆地各小洼陷,建立烃源岩岩相与反演阻抗值之间的定量、半定量关系,有助于快速明确主力烃源岩发育层段及规模,这一方法具有较好的推广应用前景。Abstract: Due to the lack of drilling data in the Zhu 1 Depression of the Pear River Mouth Basin, the Enping 17 Sag is taken as an example in this paper to solve the problem of comprehensive identification of underground distribution of high-quality source rocks. Based on the analysis of the geological background, sedimentary characteristics and petrophysical characteristics of source rocks, seismic inversion is guided by the constraints of the petrophysical characteristics of the source rocks in different sedimentary environments. According to the statistics of the relationship between the lithofacies of drilled source rocks and the inversion resistance, a semi-quantitative prediction of the spatial distribution of favorable source rocks is made by geological modeling, and the rationality of prediction method and results is analyzed in combination with the recognition of the geochemical origin type and source of crude oil, to discuss the geological and geophysical identification method of the underground distribution of high-quality source rocks with lack of drilling data. The more reductive the depositional environment of source rocks in the Paleogene Wenchang Formation, the lower the impedance value of high-quality source rocks, and the greater the impedance difference between poor source rocks or non-source rocks. The third, fourth and fifth members of Wenchang Formation are the main source rocks of the Enping 17 Sag, which can be supported by the study of crude oil biomarkers. In the small sags of the Pearl River Mouth Basin with basically clear petroleum geological background conditions, establishing the quantitative and semi-quantitative relationship between the lithofacies of source rocks and the inversion impedance value is helpful to quickly clarify the development interval and scale of main source rocks. This method has a good prospect of popularization and application.
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图 3 珠江口盆地珠一坳陷恩平17洼过E4井纵测线方向反演波阻抗剖面
剖面位置见图 1a的AA′
Figure 3. Inversion wave impedance profile in the direction of longitudinal survey line through well E4, Enping 17 Sag, Zhu Ⅰ Depression, Pearl River Mouth Basin
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[1] 施和生, 何敏, 张丽丽, 等. 珠江口盆地(东部)油气地质特征、成藏规律及下一步勘探策略[J]. 中国海上油气, 2014, 26(3): 11-22. https://www.cnki.com.cn/Article/CJFDTOTAL-ZHSD201403002.htmSHI Hesheng, HE Min, ZHANG Lili, et al. Hydrocarbon geology, accumulation pattern and the next exploration strategy in the eastern Pearl River Mouth Basin[J]. China Offshore Oil and Gas, 2014, 26(3): 11-22. https://www.cnki.com.cn/Article/CJFDTOTAL-ZHSD201403002.htm [2] 张向涛, 朱俊章, 熊万林, 等. 番禺4洼文昌组烃源岩生物标志化合物特征与油源判识[J]. 中国海上油气, 2020, 32(4): 12-23. https://www.cnki.com.cn/Article/CJFDTOTAL-ZHSD202004002.htmZHANG Xiangtao, ZHU Junzhang, XIONG Wanlin, et al. Biomarker characteristics and oil-source discrimination of source rocks in Wenchang Formation of Panyu 4 Sag[J]. China Offshore Oil and Gas, 2020, 32(4): 12-23. https://www.cnki.com.cn/Article/CJFDTOTAL-ZHSD202004002.htm [3] 田立新, 刘杰, 张向涛, 等. 珠江口盆地惠州26-6大中型泛潜山油气田勘探发现及成藏模式[J]. 中国海上油气, 2020, 32(4): 1-11. https://www.cnki.com.cn/Article/CJFDTOTAL-ZHSD202004001.htmTIAN Lixin, LIU Jie, ZHANG Xiangtao, et al. Discovery and accumulation pattern of HZ26-6 large-medium sized pan-buried hill oil and gas field in Pearl River Mouth Basin[J]. China Offshore Oil and Gas, 2020, 32(4): 1-11. https://www.cnki.com.cn/Article/CJFDTOTAL-ZHSD202004001.htm [4] 柳广弟, 牛子铖, 陈哲龙, 等. 珠江口盆地陆丰凹陷在洼陷迁移控制下的油气成藏规律[J]. 石油学报, 2019, 40(S1): 26-40. https://www.cnki.com.cn/Article/CJFDTOTAL-SYXB2019S1003.htmLIU Guangdi, NIU Zicheng, CHEN Zhelong, et al. Hydrocarbon accumulation patterns controlled by the migrated subsags in Lufeng Sag, Pearl River Mouth Basin[J]. Acta Petrolei Sinica, 2019, 40(S1): 26-40. https://www.cnki.com.cn/Article/CJFDTOTAL-SYXB2019S1003.htm [5] 庞雄, 任建业, 郑金云, 等. 陆缘地壳强烈拆离薄化作用下的油气地质特征: 以南海北部陆缘深水区白云凹陷为例[J]. 石油勘探与开发, 2018, 45(1): 27-39. https://www.cnki.com.cn/Article/CJFDTOTAL-SKYK201801004.htmPANG Xiong, REN Jianye, ZHENG Jinyun, et al. Petroleum geology controlled by extensive detachment thinning of continental margin crust: a case study of Baiyun Sag in the deep-water area of northern South China Sea[J]. Petroleum Exploration and Development, 2018, 45(1): 27-39. https://www.cnki.com.cn/Article/CJFDTOTAL-SKYK201801004.htm [6] 施和生, 舒誉, 杜家元, 等. 珠江口盆地古近系石油地质[M]. 北京: 地质出版社, 2017: 1-39.SHI Hesheng, SHU Yu, DU Jiayuan, et al. Petroleum geology of Paleogene in Pearl River Mouth Basin[M]. Beijing: Geological Publishing House, 2017: 1-39. [7] 朱明, 张向涛, 黄玉平, 等. 珠江口盆地烃源岩特征及资源潜力[J]. 石油学报, 2019, 40(S1): 53-68. https://www.cnki.com.cn/Article/CJFDTOTAL-SYXB2019S1005.htmZHU Ming, ZHANG Xiangtao, HUANG Yuping, et al. Source rock characteristics and resource potential in Pearl River Mouth Basin[J]. Acta Petrolei Sinica, 2019, 40(S1): 53-68. https://www.cnki.com.cn/Article/CJFDTOTAL-SYXB2019S1005.htm [8] 熊万林, 龙祖烈, 朱俊章, 等. 阳江凹陷恩平21洼不同沉积环境烃源岩发育特征及成藏贡献[J]. 油气地质与采收率, 2021, 28(5): 50-56. https://www.cnki.com.cn/Article/CJFDTOTAL-YQCS202105005.htmXIONG Wanlin, LONG Zulie, ZHU Junzhang, et al. Development characteristics and accumulation contribution of source rocks in different sedimentary environments in Enping 21 Subsag of Yangjiang Sag[J]. Petroleum Geology and Recovery Efficiency, 2021, 28(5): 50-56. https://www.cnki.com.cn/Article/CJFDTOTAL-YQCS202105005.htm [9] 熊万林, 朱俊章, 杨兴业, 等. 恩平凹陷北部隆起构造带油气成因来源及成藏过程研究[J]. 中国海上油气, 2020, 32(1): 54-65. https://www.cnki.com.cn/Article/CJFDTOTAL-ZHSD202001006.htmXIONG Wanlin, ZHU Junzhang, YANG Xingye, et al. Study on the genetic sources and accumulation processes of oil and gas in the north uplift structural belt of Enping Sag[J]. China Offshore Oil and Gas, 2020, 32(1): 54-65. https://www.cnki.com.cn/Article/CJFDTOTAL-ZHSD202001006.htm [10] 傅宁, 丁放, 何仕斌, 等. 珠江口盆地恩平凹陷烃源岩评价及油气成藏特征分析[J]. 中国海上油气, 2007, 19(5): 295-299. https://www.cnki.com.cn/Article/CJFDTOTAL-ZHSD200705003.htmFU Ning, DING Fang, HE Shibin, et al. Source rocks evaluation and reservoir characteristics analysis in Enping Sag, Pearl River Mouth Basin[J]. China Offshore Oil and Gas, 2007, 19(5): 295-299. https://www.cnki.com.cn/Article/CJFDTOTAL-ZHSD200705003.htm [11] 刘强虎, 朱红涛, 杨香华, 等. 珠江口盆地恩平凹陷古近系文昌组地震层序地层单元定量识别[J]. 中南大学学报(自然科学版), 2013, 44(3): 1076-1082. https://www.cnki.com.cn/Article/CJFDTOTAL-ZNGD201303035.htmLIU Qianghu, ZHU Hongtao, YANG Xianghua, et al. Quantitative recognition of seismic sequence stratigraphic units in Wenchang Formation, Paleogene, Enping Sag, Pearl River Mouth Basin[J]. Journal of Central South University (Science and Technology), 2013, 44(3): 1076-1082. https://www.cnki.com.cn/Article/CJFDTOTAL-ZNGD201303035.htm [12] 曾智伟, 杨香华, 舒誉, 等. 恩平凹陷古近系文昌组构造古地貌特征及砂体展布规律: 少井条件下储集砂体预测与评价[J]. 现代地质, 2015, 29(4): 804-815. https://www.cnki.com.cn/Article/CJFDTOTAL-XDDZ201504008.htmZENG Zhiwei, YANG Xianghua, SHU Yu, et al. Structure palaeogeomorphology characteristics and sand bodies distribution regularities of Paleogene Wenchang Formation in Enping Sag: under the conditions of lack of drilling data to predict and evaluate the reservoir sand bodies[J]. Geoscience, 2015, 29(4): 804-815. https://www.cnki.com.cn/Article/CJFDTOTAL-XDDZ201504008.htm [13] 龚丽, 朱红涛, 舒誉, 等. 珠江口盆地恩平凹陷文昌组层序格架中中—深湖相烃源岩空间展布规律及发育模式[J]. 地球科学(中国地质大学学报), 2014, 39(5): 546-556. https://www.cnki.com.cn/Article/CJFDTOTAL-DQKX201405005.htmGONG Li, ZHU Hongtao, SHU Yu, et al. Distribution of middle-deep lacustrine source rocks within sequence stratigraphic framework of Wenchang Formation in Enping Depression, the Pearl River Mouth Basin[J]. Earth Science (Journal of China University of Geosciences), 2014, 39(5): 546-556. https://www.cnki.com.cn/Article/CJFDTOTAL-DQKX201405005.htm [14] 吴娟, 叶加仁, 施和生, 等. 恩平凹陷中央断裂构造带超压发育及成藏意义[J]. 中南大学学报(自然科学版), 2013, 44(7): 2801-2811. https://www.cnki.com.cn/Article/CJFDTOTAL-ZNGD201307025.htmWU Juan, YE Jiaren, SHI Hesheng, et al. Overpressure forming and its effect on petroleum accumulation in central faulted structural belt of Enping Depression, China[J]. Journal of Central South University (Science and Technology), 2013, 44(7): 2801-2811. https://www.cnki.com.cn/Article/CJFDTOTAL-ZNGD201307025.htm