Microstructure characteristics of Wufeng-Longmaxi shale gas reservoirs with different depth, southeastern Sichuan Basin
-
摘要: 采用薄片、X衍射、常规扫描电镜、高分辨率氩离子抛光扫描电镜及压汞、氮气吸附等方法，结合有机碳含量（TOC）与孔隙度的分析，对川东南不同深度上奥陶统五峰组-下志留统龙马溪组页岩储层的矿物组成、微观结构和微孔体积进行了研究。该区深层D1井和浅层J1井页岩储层硅质、黏土、碳酸盐等矿物除含量上略有差异，纵向变化规律相近，仅硅质含量大于40%的优质页岩层厚度不同。深、浅层五峰组-龙马溪组页岩储层微孔隙都以有机质内微孔为主，常见粒缘缝（隙）、微层（页）理缝，粒间微孔因有机质充填而不发育；底部优质页岩储层表现为结构各向同性，向上纵横向结构各向异性变强，单一微纹层厚度变薄，微层理缝密度增加；底部优质页岩层段TOC高，向上明显降低；底部储层孔隙度高，向上降低，表明有机孔隙的贡献大，但孔隙度降幅明显小于TOC，应与页岩中存在较多的无机孔隙有关。深、浅层五峰组-龙马溪组页岩纵向上矿物组成、微观结构、TOC、孔隙度随深度具有相似的变化规律。与浅层J1井相比，深层D1井底部优质储层具有微孔、介孔、大孔与总孔体积数量更大的特点，这与深层D1井储层存在较多的粒缘缝等无机孔有关。川东南五峰组-龙马溪组页岩储层在深埋条件下孔隙保持较好，具有良好的储集空间。Abstract: Thin section analysis, X-ray diffraction, conventional scanning electron microscopy (SEM), high-resolution Ar+ ion polishing SEM, mercury intrusion, nitrogen adsorption, total organic carbon (TOC) content and porosity analyses were used to determine the mineral composition, microstructure and micro-pore volume of shale reservoirs from different depths in the Upper Ordovician Wufeng Formation and Lower Silurian Longmaxi Formation in southeastern Sichuan Basin. There are slight differences in the content of siliceous, clay, carbonate and other minerals in shale reservoirs of well D1 in the deep layer and well J1 in the shallow layer, and the longitudinal changes are similar. Only high-quality shale layers with a silica content greater than 40% have different thicknesses. The shale reservoirs of the Wufeng-Longmaxi formations in the deep and shallow layers are dominated by micro-pores in organic matter disseminated in the shale matrix, and the microfractures around the boundaries of silt particles or organic grains and micro-foliation seams parallel to bedding plane are also common, while and intergranular pores are not developed. The high quality shale reservoir at the bottom is structurally isotropic, and the vertical and horizontal structural anisotropy becomes stronger upwards, with thinner micro-lamina and more foliation seams. The TOC content is high at the bottom, and diminishes upwards. The porosity at the bottom shows the same changing trend, indicating a large contribution of organic pores; however, the decrease in porosity is significantly smaller than that of TOC, which is inferred to be related to the existence of more inorganic pores in the shale. The mineral composition, microstructure, TOC and porosity of the Wufeng-Longmaxi shales in the deep and shallow layers have similar changes with depth. Compared with well J1 in the shallow layer, the high-quality reservoir in well D1 in the deep layer has a larger number of micro-pores, meso-pores, macro-pores and total pore volume, which might be explained by more inorganic pores such as grain boundary pores.The shale reservoirs of the Wufeng-Longmaxi formations in the southeastern Sichuan Basin maintain a good porosity under deep burial conditions and have good storage space.
-
图 1 四川盆地及周缘下志留统底界埋深及深层D1井和浅层J1井位置
据参考文献[2]修改。
Figure 1. Bottom depth of Lower Silurian in Sichuan Basin and locations of deep well D1 and shallow well J1
图 2 川东南地区深层D1井(a)和浅层J1井(b)五峰组—龙马溪组矿物组成变化
Figure 2. Mineral composition of Wufeng-Longmaxi formations in deep well D1 (a) and shallow well J1 (b), southeastern Sichuan Basin
图 3 川东南地区深层D1井和浅层J1井五峰组—龙马溪组孔隙度、TOC垂向变化与对比
Figure 3. Porosity and TOC contents with depth of Wufeng-Longmaxi formations in deep well D1 (a) and shallow well J1 (b), southeastern Sichuan Basin
图 4 川东南地区深层D1井五峰组—龙马溪组页岩储层微层(页)理缝随深度分布
Figure 4. Micro fracture distribution with depth of Wufeng-Longmaxi shale in deep well D1, southeastern Sichuan Basin
图 5 川东南地区深、浅层五峰组—龙马溪组页岩储层微观结构薄片分析
页岩自深向浅，结构各向异性变强：a.D1井, 4 225 m；b.D1井, 4 218 m；c.D1井, 4 170 m；d.J1井，2 407 m；e.J1井，2 392.84 m；f.J1井，2 352 m
Figure 5. Thin-section micrographs of Wufeng-Longmaxi shale in deep and shallow layers, southeastern Sichuan Basin
图 6 川东南地区深、浅层五峰组—龙马溪组页岩不同深度储层微观结构扫描电镜分析
页岩自深向浅为均匀致密状、厚纹层和薄纹层：a.D1井，4 224 m；b.D1井，4 199 m；c.D1井，4 183 m；d.J1井, 2 411 m；e.J1井, 2 401 m；f.J1井, 2 335 m
Figure 6. SEM analyses of micro-structure of different depth of Wufeng-Longmaxi shale in deep and shallow layers, southeastern Sichuan Basin
图 7 川东南地区深、浅层五峰组—龙马溪组页岩储层氩离子抛光高分辨率扫描电镜微孔隙结构分析与对比
a.D1井，有机质内微孔隙，4 226 m；b.D1井，粒缘隙较发育，4 226 m；c.D1井，与笔石有关的微层理缝，4 220 m；d.J1井，有机质内较大微孔隙，2 407 m；e.J1井，粒缘隙发育，2 386 m；f.J1井，与笔石有关的微纹理缝，2 406 m
Figure 7. Argon ion polishing high resolution SEM analyses of micro-structure of Wufeng-Longmaxi shale in deep and shallow layers, southeastern Sichuan Basin
图 8 川东南地区深层D1井五峰组—龙马溪组页岩储层微层(页)理缝及粒缘隙扫描电镜分析
Figure 8. SEM analyses of micro-fractures and grain boundary fissures in Wufeng-Longmaxi shale in deep well D1, southeastern Sichuan Basin
-
[1] 周庆凡, 孙鹏. 美国东部页岩气项目回顾及启示[J]. 石油科技论坛, 2014, 33(5): 44-48. doi: 10.3969/j.issn.1002-302x.2014.05.009ZHOU Qingfan, SUN Peng. Review of shale gas project in East US[J]. Oil Forum, 2014, 33(5): 44-48. doi: 10.3969/j.issn.1002-302x.2014.05.009 [2] 龙胜祥, 曹艳, 朱杰, 等. 中国页岩气发展前景及相关问题初探[J]. 石油与天然气地质, 2016, 37(6): 847-853. https://www.cnki.com.cn/Article/CJFDTOTAL-SYYT201606008.htmLONG Shengxiang, CAO Yan, ZHU Jie, et al. A preliminary study on prospects for shale gas industry in China and relevant issues[J]. Oil & Gas Geology, 2016, 37(6): 847-853. https://www.cnki.com.cn/Article/CJFDTOTAL-SYYT201606008.htm [3] 郭旭升, 胡东风, 魏志红, 等. 涪陵页岩气田的发现与勘探认识[J]. 中国石油勘探, 2016, 21(3): 24-37. doi: 10.3969/j.issn.1672-7703.2016.03.003GUO Xusheng, HU Dongfeng, WEI Zhihong, et al. Discovery and exploration of Fuling Shale Gas Field[J]. China Petroleum Exploration, 2016, 21(3): 24-37. doi: 10.3969/j.issn.1672-7703.2016.03.003 [4] 陈作, 曾义金. 深层页岩气分段压裂技术现状及发展建议[J]. 石油钻探技术, 2016, 44(1): 6-11. https://www.cnki.com.cn/Article/CJFDTOTAL-SYZT201601003.htmCHEN Zuo, ZENG Yijin. Present situations and prospects of multi-stage fracturing technology for deep shale gas development[J]. Petroleum Drilling Techniques, 2016, 44(1): 6-11. https://www.cnki.com.cn/Article/CJFDTOTAL-SYZT201601003.htm [5] 蒋廷学, 卞晓冰, 王海涛, 等. 深层页岩气水平井体积压裂技术[J]. 天然气工业, 2017, 37(1): 90-96. https://www.cnki.com.cn/Article/CJFDTOTAL-TRQG201701018.htmJIANG Tingxue, BIAN Xiaobing, WANG Haitao, et al. Volume fracturing of deep shale gas horizontal wells[J]. Natural Gas Industry, 2017, 37(1): 90-96. https://www.cnki.com.cn/Article/CJFDTOTAL-TRQG201701018.htm [6] 董大忠, 高世葵, 黄金亮, 等. 论四川盆地页岩气资源勘探开发前景[J]. 天然气工业, 2014, 34(12): 1-15. https://www.cnki.com.cn/Article/CJFDTOTAL-TRQG201412001.htmDONG Dazhong, GAO Shikui, HUANG Jinliang, et al. A discussion on the shale gas exploration & development prospect in the Sichuan Basin[J]. Natural Gas Industry, 2014, 34(12): 1-15. https://www.cnki.com.cn/Article/CJFDTOTAL-TRQG201412001.htm [7] 王淑芳, 董大忠, 王玉满, 等. 中美海相页岩气地质特征对比研究[J]. 天然气地球科学, 2015, 26(9): 1666-1678. https://www.cnki.com.cn/Article/CJFDTOTAL-TDKX201509008.htmWANG Shufang, DONG Dazhong, WANG Yuman, et al. A comparative study of the geological feature of marine shale gas between China and the United States[J]. Natural Gas Geoscience, 2015, 26(9): 1666-1678. https://www.cnki.com.cn/Article/CJFDTOTAL-TDKX201509008.htm [8] 邹才能, 董大忠, 王社教, 等. 中国页岩气形成机理、地质特征及资源潜力[J]. 石油勘探与开发, 2010, 37(6): 641-653. https://www.cnki.com.cn/Article/CJFDTOTAL-SKYK201006003.htmZOU Caineng, DONG Dazhong, WANG Shejiao, et al. Geological characteristics, formation mechanism and resource potential of shale gas in China[J]. Petroleum Exploration and Development, 2010, 37(6): 641-653. https://www.cnki.com.cn/Article/CJFDTOTAL-SKYK201006003.htm [9] 龙胜祥, 冯动军, 李凤霞, 等. 四川盆地南部深层海相页岩气勘探开发前景[J]. 天然气地球科学, 2018, 29(4): 443-451. https://www.cnki.com.cn/Article/CJFDTOTAL-TDKX201804001.htmLONG Shengxiang, FENG Dongjun, LI Fengxia, et al. Prospect of the deep marine shale gas exploration and development in the Sichuan Basin[J]. Natural Gas Geoscience, 2018, 29(4): 443-451. https://www.cnki.com.cn/Article/CJFDTOTAL-TDKX201804001.htm [10] 董大忠, 邹才能, 戴金星, 等. 中国页岩气发展战略对策建议[J]. 天然气地球科学, 2016, 27(3): 397-406. https://www.cnki.com.cn/Article/CJFDTOTAL-TDKX201603002.htmDONG Dazhong, ZOU Caineng, DAI Jinxing, et al. Suggestions on the development strategy of shale gas in China[J]. Natural Gas Geoscience, 2016, 27(3): 397-406. https://www.cnki.com.cn/Article/CJFDTOTAL-TDKX201603002.htm [11] 曾义金, 陈作, 卞晓冰. 川东南深层页岩气分段压裂技术的突破与认识[J]. 天然气工业, 2016, 36(1): 61-67. https://www.cnki.com.cn/Article/CJFDTOTAL-TRQG201601012.htmZENG Yijin, CHEN Zuo, BIAN Xiaobing. Breakthrough in staged fracturing technology for deep shale gas reservoirs in SE Sichuan Basin and its implications[J]. Natural Gas Industry, 2016, 36(1): 61-67. https://www.cnki.com.cn/Article/CJFDTOTAL-TRQG201601012.htm [12] 贾长贵, 路保平, 蒋廷学, 等. DY2HF深层页岩气水平井分段压裂技术[J]. 石油钻探技术, 2014, 42(2): 85-90. https://www.cnki.com.cn/Article/CJFDTOTAL-SYZT201402019.htmJIA Changgui, LU Baoping, JIANG Tingxue, et al. Multi-stage horizontal well fracturing technology in deep shale gas well DY2HF[J]. Petroleum Drilling Techniques, 2014, 42(2): 85-90. https://www.cnki.com.cn/Article/CJFDTOTAL-SYZT201402019.htm [13] 甘振维. 理论创新和技术进步支撑引领百亿气田建设[J]. 天然气工业, 2016, 36(12): 1-9. https://www.cnki.com.cn/Article/CJFDTOTAL-TRQG201612003.htmGAN Zhenwei. Theoretical innovation and technical progress will usher in a production period of gas fields with an annual capacity of ten billion cubic meters[J]. Natural Gas Industry, 2016, 36(12): 1-9. https://www.cnki.com.cn/Article/CJFDTOTAL-TRQG201612003.htm [14] 张春明, 张维生, 郭英海. 川东南-黔北地区龙马溪组沉积环境及对烃源岩的影响[J]. 地学前缘, 2012, 19(1): 136-145. https://www.cnki.com.cn/Article/CJFDTOTAL-DXQY201201016.htmZHANG Chunming, ZHANG Weisheng, GUO Yinghai. Sedimentary environment and its effect on hydrocarbon source rocks of Longmaxi Formation in southeast Sichuan and northern Guizhou[J]. Earth Science Frontiers, 2012, 19(1): 136-145. https://www.cnki.com.cn/Article/CJFDTOTAL-DXQY201201016.htm [15] 梁狄刚, 郭彤楼, 陈建平, 等. 中国南方海相生烃成藏研究的若干新进展(一)南方四套区域性海相烃源岩的分布[J]. 海相油气地质, 2008, 13(2): 1-16. https://www.cnki.com.cn/Article/CJFDTOTAL-HXYQ200902003.htmLIANG Digang, GUO Tonglou, CHEN Jianping, et al. Some progresses on studies of hydrocarbon generation and accumulation in marine sedimentary regions, southern China (part 1): distribution of four suits of regional marine source rocks[J]. Marine Origin Petroleum Geology, 2008, 13(2): 1-16. https://www.cnki.com.cn/Article/CJFDTOTAL-HXYQ200902003.htm [16] 张晓明, 石万忠, 徐清海, 等. 四川盆地焦石坝地区页岩气储层特征及控制因素[J]. 石油学报, 2015, 36(8): 926-939. https://www.cnki.com.cn/Article/CJFDTOTAL-SYXB201508004.htmZHANG Xiaoming, SHI Wanzhong, XU Qinghai, et al. Reservoir characteristics and controlling factors of shale gas in Jiaoshiba area, Sichuan Basin[J]. Acta Petrolei Sinica, 2015, 36(8): 926-939. https://www.cnki.com.cn/Article/CJFDTOTAL-SYXB201508004.htm [17] 郭彤楼, 刘若冰. 复杂构造区高演化程度海相页岩气勘探突破的启示: 以四川盆地东部盆缘JY1井为例[J]. 天然气地球科学, 2013, 24(4): 643-651. https://www.cnki.com.cn/Article/CJFDTOTAL-TDKX201304000.htmGUO Tonglou, LIU Ruobing. Implications from marine shale gas exploration breakthrough in complicated structural area at high thermal stage: taking Longmaxi Formation in well JY1 as an example[J]. Natural Gas Geoscience, 2013, 24(4): 643-651. https://www.cnki.com.cn/Article/CJFDTOTAL-TDKX201304000.htm [18] 郭彤楼, 张汉荣. 四川盆地焦石坝页岩气田形成与富集高产模式[J]. 石油勘探与开发, 2014, 41(1): 28-36. https://www.cnki.com.cn/Article/CJFDTOTAL-SKYK201401003.htmGUO Tonglou, ZHANG Hanrong. Formation and enrichment mode of Jiaoshiba Shale Gas Field, Sichuan Basin[J]. Petroleum Exploration and Development, 2014, 41(1): 28-36. https://www.cnki.com.cn/Article/CJFDTOTAL-SKYK201401003.htm [19] 郭旭升, 胡东风, 文治东, 等. 四川盆地及周缘下古生界海相页岩气富集高产主控因素: 以焦石坝地区五峰组-龙马溪组为例[J]. 中国地质, 2014, 41(3): 893-901. https://www.cnki.com.cn/Article/CJFDTOTAL-DIZI201403016.htmGUO Xusheng, HU Dongfeng, WEN Zhidong, et al. Major factors controlling the accumulation and high productivity in marine shale gas in the Lower Paleozoic of Sichuan Basin and its periphery: a case study of the Wufeng-Longmaxi Formation of Jiaoshiba area[J]. Geology in China, 2014, 41(3): 893-901. https://www.cnki.com.cn/Article/CJFDTOTAL-DIZI201403016.htm [20] 刘友祥, 俞凌杰, 张庆珍, 等. 川东南龙马溪组页岩的矿物组成与微观储集特征研究[J]. 石油实验地质, 2015, 37(3): 328-333. doi: 10.11781/sysydz201503328LIU Youxiang, YU Lingjie, ZHANG Qingzhen, et al. Mineral composition and microscopic reservoir features of Longmaxi shales in southeastern Sichuan Basin[J]. Petroleum Geology & Experiment, 2015, 37(3): 328-333. doi: 10.11781/sysydz201503328 [21] 胡宗全, 杜伟, 刘忠宝. 页岩气源储耦合机理及其应用[M]. 北京: 地质出版社, 2018: 20-35.HU Zongquan, DU Wei, LIU Zhongbao. Shale gas-reservoir coupling mechanism and its application[M]. Beijing: Geological Publishing House, 2018: 20-35. [22] 卢龙飞, 秦建中, 申宝剑, 等. 川东南涪陵地区五峰-龙马溪组硅质页岩的生物成因及其油气地质意义[J]. 石油实验地质, 2016, 38(4): 460-465. doi: 10.11781/sysydz201604460LU Longfei, QIN Jianzhong, SHEN Baojian, et al. Biogenic origin and hydrocarbon significance of siliceous shale from the Wufeng-Longmaxi formations in Fuling area, southeastern Sichuan Basin[J]. Petroleum Geology & Experiment, 2016, 38(4): 460-465. doi: 10.11781/sysydz201604460 [23] LOUCKS R G, REED R M, RUPPEL S C, et al. Morphology, genesis, and distribution of nanometer-scale pores in siliceous mudstones of the Mississippian Barnett shale[J]. Journal of Sedimentary Research, 2009, 79(12): 848-861. [24] SONDERGELD C H, AMBROSE R J, RAI C S, et al. Micro-structural studies of gas shales[C]//SPE Unconventional Gas Conference. Pittsburgh, PA, USA: SPE, 2010: 1-17. [25] SLATT R M, O'BRIEN N R. Pore types in the Barnett and Woodford gas shales: contribution to understanding gas storage and migration pathways in fine-grained rocks[J]. AAPG Bulletin, 2011, 95(12): 2017-2030. [26] 郭旭升, 李宇平, 刘若冰, 等. 四川盆地焦石坝地区龙马溪组页岩微观孔隙结构特征及其控制因素[J]. 天然气工业, 2014, 34(6): 9-16. https://www.cnki.com.cn/Article/CJFDTOTAL-TRQG201406002.htmGUO Xusheng, LI Yuping, LIU Ruobing, et al. Characteristics and controlling factors of micro-pore structures of Longmaxi Shale Play in the Jiaoshiba area, Sichuan Basin[J]. Natural Gas Industry, 2014, 34(6): 9-16. https://www.cnki.com.cn/Article/CJFDTOTAL-TRQG201406002.htm [27] 魏志红, 魏祥峰. 页岩不同类型孔隙的含气性差异: 以四川盆地焦石坝地区五峰组-龙马溪组为例[J]. 天然气工业, 2014, 34(6): 37-41. https://www.cnki.com.cn/Article/CJFDTOTAL-TRQG201406007.htmWEI Zhihong, WEI Xiangfeng. Comparison of gas-bearing property between different pore types of shale: a case from the Upper Ordovician Wufeng and Longmaxi Fms in the Jiaoshiba area, Sichuan Basin[J]. Natural Gas Industry, 2014, 34(6): 37-41. https://www.cnki.com.cn/Article/CJFDTOTAL-TRQG201406007.htm [28] HOUBEN M E, DESBOIS G, URAI J L. Pore morphology and distribution in the Shaly facies of Opalinus Clay (Mont Terri, Switzerland): insights from representative 2D BIB-SEM investigations on mm to nm scale[J]. Applied Clay Science, 2013, 71: 82-97. [29] 刘伟新, 俞凌杰, 张文涛, 等. 川东南龙马溪组页岩微观孔隙结构特征[J]. 海洋地质与第四纪地质, 2016, 36(3): 127-134. https://www.cnki.com.cn/Article/CJFDTOTAL-HYDZ201603015.htmLIU Weixing, YU Lingjie, ZHANG Wentao, et al. Micro-pore structure of Longmaxi shale from southeast Sichuan Basin[J]. Marine Geology & Quaternary Geology, 2016, 36(3): 127-134. https://www.cnki.com.cn/Article/CJFDTOTAL-HYDZ201603015.htm [30] 刘伟新, 鲍芳, 俞凌杰, 等. 川东南志留系龙马溪组页岩储层微孔隙结构及连通性研究[J]. 石油实验地质, 2016, 38(4): 453-459. doi: 10.11781/sysydz201604453LIU Weixin, BAO Fang, YU Lingjie, et al. Micro-pore structure and connectivity of the Silurian Longmaxi shales, southeastern Sichuan area[J]. Petroleum Geology & Experiment, 2016, 38(4): 453-459. doi: 10.11781/sysydz201604453 [31] 承秋泉, 陈红宇, 范明, 等. 盖层全孔隙结构测定方法[J]. 石油实验地质, 2006, 28(6): 604-608. doi: 10.11781/sysydz200606604CHENG Qiuquan, CHEN Hongyu, FAN Ming, et al. Determination of the total pore texture of caprock[J]. Petroleum Geology & Experiment, 2006, 28(6): 604-608. doi: 10.11781/sysydz200606604 [32] ROUQUEROL J, AVNIR D, FAIRBRIDGE C W, et al. Recommendations for the characterization of porous solids[J]. Pure and Applied Chemistry, 1994, 66(8): 1739-1758. [33] BARRETT E P, JOYNER L G, HALENDA P P. The determination of pore volume and area distributions in porous substances. Ⅰ. Computations from nitrogen isotherms[J]. Journal of the American Chemical Society, 1951, 73(1): 373-380. [34] MUSA M A A, YIN C Y, SAVORY R M. Analysis of the textural characteristics and pore size distribution of a commercial zeolite using various adsorption models[J]. Journal of Applied Sciences, 2011, 11(21): 3650-3654. [35] BRUNAUER S, EMMETT P H, TELLER E. Adsorption of gases in multimolecular layers[J]. Journal of the American Chemical Society, 1938, 60(2): 309-319. -
下载:
图(9)
计量
- 文章访问数: 1375
- HTML全文浏览量: 344
- PDF下载量: 167
- 被引次数: 0
苏公网安备32021102000780号