Key controlling factors and enrichment mechanisms of tight reservoirs in 6th member of Triassic Yanchang Formation, Chaishangyuan area, southeastern Ordos Basin
-
摘要: 鄂尔多斯盆地东南部柴上塬区位于中国陆上发现的第一个油田——七里村油田,主力含油层为三叠系延长组长6油层。目前,对该区长6致密油成藏主控因素还缺乏全面深入研究。在综合分析钻井、录井、电测井、岩心、试油、生产动态等资料的基础上,结合室内实验观测,并引入下伏砂地比和上覆泥地比概念,对研究区长6油藏成藏特征以及烃源岩、储层、构造、盖层、运移条件等因素对长6致密油藏的控制作用进行了全面剖析。研究区长6致密油藏为边底水不发育的岩性油藏,具有集群准连续分布特征,形成和分布受烃源、输导条件、储层、直接盖层四大因素控制,且四者对油藏的控制作用依次减弱。区内东部烃源较差,原油富集区为砂体发育较好的下段地层;而西部烃源较好,盖层和输导条件则更多控制着原油的富集程度,是否利于成藏取决于两者耦合关系的好坏。Abstract: Chaishangyuan area locates in the Qilicun Oilfield of the southeastern Ordos Basin, the first onshore oil field discovered in China, and its main layer for oil-producing is the 6th member of Triassic Yanchang Formation (Chang 6). At present, the comprehensive study on the key controlling factors of Chang 6 tight oil reservoir in this area is not clear. In this paper, a large number of drilling, logging, core, production test and other data, combined with laboratory experimental observation were carried out to progress the understanding of the factors controlling reservoir formation. In addition, the concepts of the ratio of underlying sand thickness to formation thickness and the ratio of overlying mud thickness to formation thickness were introduced to comprehensively analyze the forming characteristics of Chang 6 reservoir in the study area and the controlling effects of source rocks, reservoirs, structures, caprocks and migration conditions on Chang 6 tight reservoirs. The Chang 6 tight reservoir in the study area is a lithologic reservoir with undeveloped edge and bottom water, which has the characteristics of clustered and quasi-continuous distribution, and its formation and distribution were controlled by four factors: hydrocarbon source, transport condition, reservoir and direct caprock, and the controlling effect of the four factors on the reservoir is weakened in turn. In the eastern area where source rock quality is poor, crude oil was mainly enriched in the lower strata where sand bodies were well developed, while in the western area where source rock quality is relatively better, the enrichment of crude oil was more controlled by caprock and transport conditions. The better the coupling relationship between them, the more conducive to reservoir formation.
-
Key words:
- main controlling factor /
- enrichment rule /
- Chang 6 reservoir /
- Chaishangyuan area /
- Ordos Basin
-
图 2 鄂尔多斯盆地东南部柴上塬区丛12-2井—南22-2井连井油藏剖面
连井剖面位置见图 4的AA′。
Figure 2. Reservoir profile from well C12-2 to N22-2 in Chaishangyuan area, southeastern Ordos Basin
图 10 鄂尔多斯盆地东南部柴上塬区烃源岩荧光照片
a.东探016井,454.2 m,长73,黑色页岩,荧光下(左),垂直缝中见黄褐色荧光,单偏光下(右),微裂缝中见深褐色残余油质;b.郑085井,447.25 m,长64,暗色泥岩,荧光下(左),垂直缝中见黄褐色荧光,单偏光下(右),微裂缝中见深褐色残余油质;c.东探016井,462.35 m,长73,黑色页岩,荧光下(左),垂直缝中见暗黄色荧光,单偏光下(右),微裂缝中见黄褐色残余油质;d.东探016井,462.80 m,长73、暗色泥岩,荧光下(左),垂直缝中见亮黄色荧光,单偏光下(右),微裂缝中见深褐色残余油质
Figure 10. Fluorescence photos of source rocks in Chaishangyuan area, southeastern Ordos Basin
图 13 鄂尔多斯盆地东南部柴上塬区郑058井—东探014井NW—SE向油藏剖面
连井剖面位置见图 4a的BB′。
Figure 13. Reservoir profile in NW-SE direction from well Z058 to DT014 in Chaishangyuan area, southeastern Ordos Basin
表 1 鄂尔多斯盆地东南部柴上塬区三叠系长6原油物性统计
Table 1. Physical properties of crude oils of Chang 6 in Chaishangyuan area, southeastern Ordos Basin
原油物性 最大值 最小值 平均值 密度(20 ℃)/(g·cm-3) 0.86 0.81 0.83 黏度(50 ℃)/(mPa·s) 5.95 2.69 4.22 含硫/% 0.07 0 0.04 含蜡/% 19.32 0 11.95 凝固点/℃ 17.50 5.50 6.55 表 2 鄂尔多斯盆地东南部柴上塬区三叠系长6原油族组分含量
Table 2. Crude oil group composition of Chang 6 in Chaishangyuan area, southeastern Ordos Basin
井名 饱和烃/% 芳烃/% 非烃/% 沥青质/% 总烃/% 饱芳比 郭807 65.68 13.24 6.05 1.17 78.92 4.96 南110-4 64.40 10.20 4.48 6.21 74.60 6.31 东探022 59.26 11.09 13.81 2.88 70.35 5.34 七平5 52.84 9.84 26.21 11.05 62.68 5.37 七平10 55.14 9.90 20.76 0.68 65.04 5.57 南71 65.08 11.15 7.74 4.36 76.23 5.84 米291 68.18 10.58 4.78 2.36 78.76 6.44 吴34 61.82 9.60 3.50 10.80 71.42 6.44 郑058 73.44 10.90 5.34 3.50 84.34 6.74 军407 72.52 4.25 4.39 5.44 76.77 17.07 -
[1] 邹才能, 张国生, 杨智, 等. 非常规油气概念、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(4): 385-399. https://www.cnki.com.cn/Article/CJFDTOTAL-SKYK201304000.htmZOU Caineng, ZHANG Guosheng, YANG Zhi, et al. Geological concepts, characteristics, resource potential and key techniques of unconventional hydrocarbon: on unconventional petroleum geology[J]. Petroleum Exploration and Development, 2013, 40(4): 385-399. https://www.cnki.com.cn/Article/CJFDTOTAL-SKYK201304000.htm [2] 朱如凯, 邹才能, 吴松涛, 等. 中国陆相致密油形成机理与富集规律[J]. 石油与天然气地质, 2019, 40(6): 1168-1184. https://www.cnki.com.cn/Article/CJFDTOTAL-SYYT201906002.htmZHU Rukai, ZOU Caineng, WU Songtao, et al. Mechanism for generation and accumulation of continental tight oil in China[J]. Oil & Gas Geology, 2019, 40(6): 1168-1184. https://www.cnki.com.cn/Article/CJFDTOTAL-SYYT201906002.htm [3] 姚泾利, 王克, 宋江海, 等. 鄂尔多斯盆地姬塬地区延长组石油运聚规律研究[J]. 岩性油气藏, 2007, 19(3): 32-37. https://www.cnki.com.cn/Article/CJFDTOTAL-YANX200703007.htmYAO Jingli, WANG Ke, SONG Jianghai, et al. Petroleum migration and accumulation of Yanchang Formation in Jiyuan area, Ordos Basin[J]. Lithologic Reservoirs, 2007, 19(3): 32-37. https://www.cnki.com.cn/Article/CJFDTOTAL-YANX200703007.htm [4] 夏东领, 伍岳, 夏冬冬, 等. 鄂尔多斯盆地南缘红河油田长8致密油藏非均质性表征方法[J]. 石油实验地质, 2021, 43(4): 704-712. doi: 10.11781/sysydz202104704XIA Dongling, WU Yue, XIA Dongdong, et al. Characterization method of heterogeneity for Chang 8 tight reservoir in Honghe oil field, southern margin of Ordos Basin[J]. Petroleum Geology & Experiment, 2021, 43(4): 704-712. doi: 10.11781/sysydz202104704 [5] 刘秀婵, 陈西泮. 鄂尔多斯盆地富县地区长8油层组致密油成藏主控因素分析[J]. 油气藏评价与开发, 2019, 9(1): 1-7. https://www.cnki.com.cn/Article/CJFDTOTAL-KTDQ201901002.htmLIU Xiuchan, CHEN Xipan. Analysis on main controlling factors of tight oil reservoirs in Chang-8 reservoir of Fu County, Ordos Basin[J]. Reservoir Evaluation and Development, 2019, 9(1): 1-7. https://www.cnki.com.cn/Article/CJFDTOTAL-KTDQ201901002.htm [6] 任战利, 李文厚, 梁宇, 等. 鄂尔多斯盆地东南部延长组致密油成藏条件及主控因素[J]. 石油与天然气地质, 2014, 35(2): 190-198. https://www.cnki.com.cn/Article/CJFDTOTAL-SYYT201402005.htmREN Zhanli, LI Wenhou, LIANG Yu, et al. Tight oil reservoir formation conditions and main controlling factors of Yanchang Formation in southeastern Ordos Basin[J]. Oil & Gas Geology, 2014, 35(2): 190-198. https://www.cnki.com.cn/Article/CJFDTOTAL-SYYT201402005.htm [7] ZHOU Yong, JI Youliang, XU Liming, et al. Controls on reservoir heterogeneity of tight sand oil reservoirs in Upper Triassic Yanchang Formation in Longdong area, southwest Ordos Basin, China: implications for reservoir quality prediction and oil accumulation[J]. Marine and Petroleum Geology, 2016, 78: 110-135. [8] WU Songtao, ZOU Caineng, ZHU Rukai, et al. Characteristics and origin of tight oil accumulations in the Upper Triassic Yanchang Formation of the Ordos Basin, North-Central China[J]. Acta Geologica Sinica(English Edition), 2016, 90(5): 1821-1837. [9] 白玉彬, 赵子龙, 赵靖舟, 等. 鄂尔多斯盆地安塞地区长9致密油成藏机理与主控因素[J]. 中南大学学报(自然科学版), 2014, 45(9): 3127-3136. https://www.cnki.com.cn/Article/CJFDTOTAL-ZNGD201409027.htmBAI Yubin, ZHAO Zilong, ZHAO Jingzhou, et al. Oil reservoir forming mechanisms and main controlling factors of tight oil of Chang-9 member in Ansai area, Ordos Basin[J]. Journal of Central South University (Science and Technology), 2014, 45(9): 3127-3136. https://www.cnki.com.cn/Article/CJFDTOTAL-ZNGD201409027.htm [10] 葛云锦, 任来义, 贺永红, 等. 鄂尔多斯盆地富县—甘泉地区三叠系延长组7油层组致密油富集主控因素[J]. 石油与天然气地质, 2018, 39(6): 1190-1200. https://www.cnki.com.cn/Article/CJFDTOTAL-SYYT201806010.htmGE Yunjin, REN Laiyi, HE Yonghong, et al. Main factors controlling the tight oil enrichment in the 7th oil layer group of the Triassic Yanchang Formation in Fuxian-Ganquan area, Ordos Basin[J]. Oil & Gas Geology, 2018, 39(6): 1190-1200. https://www.cnki.com.cn/Article/CJFDTOTAL-SYYT201806010.htm [11] 邵晓岩, 田景春, 樊勇杰, 等. 鄂尔多斯盆地马坊地区延长组长8油层组油藏特征与富集规律[J]. 石油与天然气地质, 2015, 36(2): 203-208. https://www.cnki.com.cn/Article/CJFDTOTAL-SYYT201502005.htmSHAO Xiaoyan, TIAN Jingchun, FAN Yongjie, et al. Characteristics and accumulation pattern of oil reservoirs in the 8th member of the Yangchang Formation in Mafang area, Ordos Basin[J]. Oil & Gas Geology, 2015, 36(2): 203-208. https://www.cnki.com.cn/Article/CJFDTOTAL-SYYT201502005.htm [12] JIA Jingkun, YIN Wei, QIU Nansheng, et al. Migration and accumulation of crude oil in Upper Triassic tight sand reservoirs on the southwest margin of Ordos Basin, Central China: a case study of the Honghe Oilfield[J]. Geological Journal, 2018, 53(5): 2280-2300. [13] 姚泾利, 赵彦德, 邓秀芹, 等. 鄂尔多斯盆地延长组致密油成藏控制因素[J]. 吉林大学学报(地球科学版), 2015, 45(4): 983-992. https://www.cnki.com.cn/Article/CJFDTOTAL-CCDZ201504002.htmYAO Jingli, ZHAO Yande, DENG Xiuqin, et al. Controlling factors of tight oil reservoir in Triassic Yanchang Formation in Ordos Basin[J]. Journal of Jilin University (Earth Science Edition), 2015, 45(4): 983-992. https://www.cnki.com.cn/Article/CJFDTOTAL-CCDZ201504002.htm [14] 杨俊杰, 李克勤, 张东生, 等. 中国石油地质志[M]. 北京: 石油工业出版社, 1992.YANG Junjie, LI Keqin, ZHANG Dongsheng, et al. Petroleum geology of China[M]. Beijing: Petroleum Industry Press, 1992. [15] 杨华. 鄂尔多斯盆地三叠系延长组沉积体系及含油性研究[D]. 成都: 成都理工大学, 2004.YANG Hua. Deposition system and oil accumulation research of Yanchang Formation in Triassic, Ordos Basin[D]. Chengdu: Chengdu University of Technology, 2004. [16] 孙肇才, 谢秋元. 叠合盆地的发展特征及其含油气性: 以鄂尔多斯盆地为例[J]. 石油实验地质, 1980, 2(1): 13-21. doi: 10.11781/sysydz198001013SUN Zhaocai, XIE Qiuyuan. Development characteristics and oil and gas-bearing characteristics of superimposed basins: a case study of Ordos Basin[J]. Experimental Petroleum Geology, 1980, 2(1): 13-21. doi: 10.11781/sysydz198001013 [17] 李德生. 重新认识鄂尔多斯盆地油气地质学[J]. 石油勘探与开发, 2004, 31(6): 1-7. https://www.cnki.com.cn/Article/CJFDTOTAL-SKYK200406001.htmLI Desheng. Return to petroleum geology of Ordos Basin[J]. Petroleum Exploration and Development, 2004, 31(6): 1-7. https://www.cnki.com.cn/Article/CJFDTOTAL-SKYK200406001.htm [18] 邓秀芹, 付金华, 姚泾利, 等. 鄂尔多斯盆地中及上三叠统延长组沉积相与油气勘探的突破[J]. 古地理学报, 2011, 13(4): 443-455. https://www.cnki.com.cn/Article/CJFDTOTAL-GDLX201104011.htmDENG Xiuqin, FU Jinhua, YAO Jingli, et al. Sedimentary facies of the Middle-Upper Triassic Yanchang Formation in Ordos Basin and breakthrough in petroleum exploration[J]. Journal of Palaeogeography, 2011, 13(4): 443-455. https://www.cnki.com.cn/Article/CJFDTOTAL-GDLX201104011.htm [19] 杨华, 李士祥, 刘显阳. 鄂尔多斯盆地致密油、页岩油特征及资源潜力[J]. 石油学报, 2013, 34(1): 1-11. https://www.cnki.com.cn/Article/CJFDTOTAL-SYXB201301000.htmYANG Hua, LI Shixiang, LIU Xianyang. Characteristics and resource prospects of tight oil and shale oil in Ordos Basin[J]. Acta Petrolei Sinica, 2013, 34(1): 1-11. https://www.cnki.com.cn/Article/CJFDTOTAL-SYXB201301000.htm [20] 杨华, 付金华, 何海清, 等. 鄂尔多斯华庆地区低渗透岩性大油区形成与分布[J]. 石油勘探与开发, 2012, 39(6): 641-648. https://www.cnki.com.cn/Article/CJFDTOTAL-SKYK201206002.htmYANG Hua, FU Jinhua, HE Haiqing, et al. Formation and distribution of large low-permeability lithologic oil regions in Huaqing, Ordos Basin[J]. Petroleum Exploration and Development, 2012, 39(6): 641-648. https://www.cnki.com.cn/Article/CJFDTOTAL-SKYK201206002.htm [21] 赵靖舟. 油气成藏地质学[M]. 北京: 石油工业出版社, 2013.ZHAO Jingzhou. Oil and gas accumulation geology[M]. Beijing: Petroleum Industry Press, 2013. [22] 赵靖舟, 白玉彬, 曹青, 等. 鄂尔多斯盆地准连续型低渗透—致密砂岩大油田成藏模式[J]. 石油与天然气地质, 2012, 33(6): 811-827. https://www.cnki.com.cn/Article/CJFDTOTAL-SYYT201206000.htmZHAO Jingzhou, BAI Yubin, CAO Qing, et al. Quasi-continuous hydrocarbon accumulation: a new pattern for large tight sand oilfields in the Ordos Basin[J]. Oil & Gas Geology, 2012, 33(6): 811-827. https://www.cnki.com.cn/Article/CJFDTOTAL-SYYT201206000.htm [23] FAN Jianming, QU Xuefeng, WANG Chong, et al. Natural fracture distribution and a new method predicting effective fractures in tight oil reservoirs in Ordos Basin, NW China[J]. Petroleum Exploration and Development, 2016, 43(5): 806-814. [24] 邓秀芹. 鄂尔多斯盆地三叠系延长组超低渗透大型岩性油藏成藏机理研究[D]. 西安: 西北大学, 2011.DENG Xiuqin. Accumulation machanism research on ultra-low-permeability and large scale lithogical reserviors of Triassic Yanchang Formation in Ordos Basin[D]. Xi'an: Northwestern University, 2011.