致密砂岩气藏孔喉结构和渗流特征差异及其对水锁的影响——以鄂尔多斯盆地神木气田山西组、太原组和石盒子组为例

Differences in pore-throat structure and seepage characteristics of tight sandstone gas reservoirs and their effects on water-blocking: a case study of Shanxi, Taiyuan and Shihezi Formations in Shenmu Gas Field, Ordos Basin

摘要

鄂尔多斯盆地东部神木气田主力致密砂岩气藏存在水锁伤害,气相相对渗透率的下降影响单井产能。采用薄片观察、扫描电镜观察、高压压汞实验、核磁共振实验和气-水相相对渗流实验方法,分析孔喉结构和渗流特征差异对水锁伤害的影响及控制因素。结果表明:神木气田太原组孔喉尺度较大且相对均质,是渗透率较高的原因;山西组与盒8段孔喉结构相似,孔喉尺度较小、连通性和均质程度较优,渗透率略高。太原组可动流体赋存最多,其次是山西组的,盒8段可动孔隙最少;盒8段束缚水饱和度最高,其次是山西组的,太原组的最低;盒8段平均含水饱和度最高,水锁最严重,相对渗透率最低,山西组共渗能力略强于太原组的,受束缚水影响较多,可动气量偏低。孔喉结构质量决定可动流体赋存,制约气-水相相对渗流能力,体现为优质的孔喉条件赋存更多的可动流体,更有利于流体渗流,水锁伤害相对较低;毛细管压力约束的渗流差异是水锁伤害的主控因素,生产压差和成藏过程对水锁也有一定影响。在开发阶段均衡毛细管压力、控制气相相对渗透率下降是缓解水锁伤害的关键。该结果为致密砂岩气藏渗流特征评价和增产策略优化提供依据。

Abstract

The main tight sandstone reservoirs in the Shenmu Gas Field, located in the Eastern Ordos Basin, exhibit differences in pore-throat structure and permeability. Closed-coring tests confirm the presence of water-blocking damage, and the decrease in gas relative permeability affects the productivity performance of individual wells. Based on methods such as thin slice observation, SEM observation, high-pressure mercury injection, nuclear magnetic resonance (NMR), and gas-water phase permeability experiments, this study analyzes the impact of differences in pore-throat structures and flow characteristics on water-blocking damage, as well as the controlling factors involved. The results show that the pore-throat size in the Taiyuan Formation of the Shenmu Gas Field is relatively large and homogeneous, which contributes to its higher permeability. In contrast, the pore-throat structures of the Shanxi Formation and the He8 Member are similar, with the Shanxi Formation having smaller pore-throat sizes, better connectivity, and higher homogeneity, resulting in slightly higher permeability. The Taiyuan Formation contains the highest amount of movable fluids, followed by the Shanxi Formation, with the He8 Member having the least movable porosity. The distribution of bound water saturation follows a similar trend. The He8 Member has the highest average water saturation, the most severe water-blocking damage, and the lowest relative permeability. The Shanxi Formation exhibits slightly better common seepage capacity than the Taiyuan Formation, but it is more affected by bound water, resulting in a lower volume of movable gas. The quality of pore-throat structures determines the storage of movable fluids and governs the relative permeability of gas and water phases. High-quality pore-throat conditions facilitate the presence of more movable fluids, enhance fluid flow, and result in relatively lower water-blocking damage. The difference in seepage capacity controlled by capillary pressure in pore-throat structures is the primary factor governing water-blocking damage. Production pressure difference and the reservoir formation process also have a certain impact on water-blocking. During the development stage, balancing capillary pressure and controlling the decline in gas relative permeability are key strategies to mitigate water-blocking damage. These findings provide a basis for evaluating the seepage characteristics of tight sandstone gas reservoirs and optimizing production enhancement strategies.

关键词

鄂尔多斯盆地 / 神木气田 / 山西组 / 太原组 / 石盒子组 / 致密砂岩气藏 / 孔喉结构 / 气-水相相对渗流 / 水锁伤害

Key words

Ordos Basin / Shenmu Gas Field / Shanxi Formation / Taiyuan Formation / Shihezi Formation / tight sandstone gas reservoir / pore-throat structure / gas-water relative permeability / water-blocking damage

参考文献

[1] 魏国齐, 张福东, 李君, 等 . 中国致密砂岩气成藏理论进展[J]. 天然气地球科学, 2016, 27(2): 199-210.

[2] WEI Guoqi , ZHANG Fudong , LI Jun , et al. New progress of tight sand gas accumulation theory and favorable exploration zones in China[J]. Natural Gas Geoscience, 2016, 27(2): 199-210.

[3] 邹才能, 陶士振, 袁选俊, 等 . “连续型”油气藏及其在全球的重要性:成藏、分布与评价[J]. 石油勘探与开发, 2009, 36(6): 669-682.

[4] ZOU Caineng , TAO Shizhen , YUAN Xuanjun , et al. Global importance of ‘continuous’ petroleum reservoirs: accumulation, distribution and evaluation[J]. Petroleum Exploration and Development, 2009, 36(6): 669-682.

[5] 魏新善, 胡爱平, 赵会涛, 等 . 致密砂岩气地质认识新进展[J]. 岩性油气藏, 2017, 29(1): 11-20.

[6] WEI Xinshan , HU Aiping , ZHAO Huitao , et al. New geological understanding of tight sandstone gas[J]. Lithologic Reservoirs, 2017, 29(1): 11-20.

[7] 贾爱林, 位云生, 郭智, 等 . 中国致密砂岩气开发现状与前景展望[J]. 天然气工业, 2022, 42(1): 83-92.

[8] JIA Ailin , WEI Yunsheng , GUO Zhi , et al. Development status and prospect of tight sandstone gas in China[J]. Natural Gas Industry, 2022, 42(1): 83-92.

[9] 何江川, 余浩杰, 何光怀, 等 . 鄂尔多斯盆地长庆气区天然气开发前景[J]. 天然气工业, 2021, 41(8): 23-33.

[10] HE Jiangchuan , YU Haojie , HE Guanghuai , et al. Natural gas development prospect in Changqing gas province of the Ordos Basin[J]. Natural Gas Industry, 2021, 41(8): 23-33.

[11] 杨华, 刘新社, 闫小雄, 等 . 鄂尔多斯盆地神木气田的发现与天然气成藏地质特征[J]. 天然气工业, 2015, 35(6): 1-13.

[12] YANG Hua , LIU Xinshe , YAN Xiaoxiong , et al. The Shenmu Gas Field in the Ordos Basin: its discovery and reservoir-forming geological characteristics[J]. Natural Gas Industry, 2015, 35(6): 1-13.

[13] 梁天博, 马实英, 魏东亚, 等 . 低渗透油藏水锁机理与助排表面活性剂的优选原则[J]. 石油学报, 2020, 41(6): 745-752.

[14] LIANG Tianbo , MA Shiying , WEI Dongya , et al. Water blocking mechanism of low-permeability reservoirs and screening principle of flowback surfactants[J]. Acta Petrolei Sinica, 2020, 41(6): 745-752.

[15] 刘晓鹏, 刘燕, 陈娟萍, 等 . 鄂尔多斯盆地盒8段致密砂岩气藏微观孔隙结构及渗流特征[J]. 天然气地球科学, 2016, 27(7): 1225-1234.

[16] LIU Xiaopeng , LIU Yan , CHEN Juanping , et al. Characterisitics of micro pore structure and seepage in tight sandstone gas reservoir of the 8th section of Shihezi Formation in Ordos Basin, China[J]. Natural Gas Geoscience, 2016, 27(7): 1225-1234.

[17] 甘华军, 米敬奎, 肖贤明, 等 . 鄂尔多斯盆地中北部上古生界气田天然气气源与运聚研究[J]. 石油天然气学报, 2007, 29(1): 16-22.

[18] GAN Huajun , MI Jingkui , XIAO Xianming , et al. On natural gas source and migration-accumulation of Upper Palaeozoic gas field in the mid-north of Ordos Basin[J]. Journal of Oil and Gas Technology, 2007, 29(1): 16-22.

[19] 蒙晓灵, 张宏波, 冯强汉, 等 . 鄂尔多斯盆地神木气田二叠系太原组天然气成藏条件[J]. 石油与天然气地质, 2013, 34(1): 37-41.

[20] MENG Xiaoling , ZHANG Hongbo , FENG Qianghan , et al. Gas accumulation conditions of the Permian Taiyuan Formation in Shenmu Gas Field, Ordos Basin[J]. Oil & Gas Geology, 2013, 34(1): 37-41.

[21] 曹青, 赵靖舟, 胡爱平, 等 . 鄂尔多斯盆地神木地区山2段、太原组天然气聚集条件研究[J]. 地质科技情报, 2013, 32(4): 119-126.

[22] CAO Qing , ZHAO Jingzhou , HU Aiping , et al. Gas accumulation conditions research of Shan 2 section and Taiyuan Formation in Shenmu Area, Ordos Basin[J]. Geological Science and Technology Information, 2013, 32(4): 119-126.

[23] 吴伟涛, 冯炎松, 费世祥, 等 . 鄂尔多斯盆地神木气田二叠系石千峰组5段致密气富集因素及有利区预测[J]. 石油与天然气地质, 2024, 45(3): 739-751.

[24] WU Weitao , FENG Yansong , FEI Shixiang , et al. Enrichment factors and play fairway mapping for tight gas in the 5th member of the Permian Shiqianfeng Formation, Shenmu Gas Field, Ordos Basin[J]. Oil & Gas Geology, 2024, 45(3): 739-751.

[25] 孙建伟, 赖雅庭, 鲁莎, 等 . 神木气田太原组气水判识及分布模式[J]. 西安石油大学学报(自然科学版), 2020, 35(5): 30-37.

[26] SUN Jianwei , LAI Yating , LU Sha , et al. Gas-water identification and distribution mode of Taiyuan Formation in Shenmu Gas Field[J]. Journal of Xi'an Shiyou University (Natural Science Edition), 2020, 35(5): 30-37.

[27] 陈朝兵, 杨友运, 邵金辉, 等 . 鄂尔多斯东北部致密砂岩气藏地层水成因及分布规律[J]. 石油与天然气地质, 2019, 40(2): 313-325.

[28] CHEN Zhaobing , YANG Youyun , SHAO Jinhui , et al. Origin and distribution of formation water in tight sandstone reservoirs in the Northeastern Ordos Basin[J]. Oil & Gas Geology, 2019, 40(2): 313-325.

[29] 董悦, 滕藤, 盖龑秋, 等 . 低孔低渗储层成岩相测井识别:以神木气田上古生界为例[J]. 西安石油大学学报(自然科学版), 2015, 30(6): 33-40.

[30] DONG Yue , TENG Teng , GAI Yanqiu , et al. Logging identification of diagenetic facies of low-porosity low-permeability reservoir: taking Upper Paleozoic in Shenmu Gas Field as an example[J]. Journal of Xi'an Shiyou University (Natural Science Edition), 2015, 30(6): 33-40.

[31] 高辉, 王雅楠, 樊志强, 等 . 鄂尔多斯盆地神木气田山2段砂岩成岩相定量划分及其特征差异[J]. 天然气地球科学, 2015, 26(6): 1057-1067.

[32] GAO Hui , WANG Yanan , FAN Zhiqiang , et al. Quantitative classification and characteristics difference of diagenetic facies in Shan 2 sandstone of Shenmu Gas Field, Ordos Basin[J]. Natural Gas Geoscience, 2015, 26(6): 1057-1067.

[33] 滕藤, 金江宁, 屈元基, 等 . 基于孔隙分形特征的神木气田山西组成岩相定量分类[J]. 断块油气田, 2018, 25(4): 431-434.

[34] TENG Teng , JIN Jiangning , QU Yuanji , et al. Quantitative fractal dimension classification of diagenetic facies of Shanxi Group in Shenmu Gasfield[J]. Fault-Block Oil & Gas Field, 2018, 25(4): 431-434.

[35] 周拓, 周兆华, 谷江瑞, 等 . 神木气田二叠系气藏有利区预测[J]. 东北石油大学学报, 2013, 37(1): 38-44.

[36] ZHOU Tuo , ZHOU Zhaohua , GU Jiangrui , et al. Prediction of favorable areas for Permian gas reservoir in Shenmu Gas Field[J]. Journal of Northeast Petroleum University, 2013, 37(1): 38-44.

[37] 安文宏, 石小虎, 杨勇, 等 . 神木气田早二叠世太原期海侵事件与砂体展布的关系[J]. 天然气工业, 2013, 33(4): 43-47.

[38] AN Wenhong , SHI Xiaohu , YANG Yong , et al. Relationship between Early Permian Taiyuan transgression and sand bodies distribution in the Shenmu Gas Field, Ordos Basin[J]. Natural Gas Industry, 2013, 33(4): 43-47.

[39] 张涛, 巩肖可, 黄朝, 等 . 鄂尔多斯盆地神木气田太原组低品质气藏储层微观特征及形成机理[J]. 石油实验地质, 2024, 46(1): 32-45.

[40] ZHANG Tao , GONG Xiaoke , HUANG Chao , et al. Micro characteristics and formation mechanism of low-quality gas reservoir in Taiyuan Formation of Shenmu Gas Field, Ordos Basin[J]. Petroleum Geology & Experiment, 2024, 46(1): 32-45.

[41] 兰朝利, 张永忠, 张君峰, 等 . 神木气田太原组储层特征及其控制因素[J]. 西安石油大学学报(自然科学版), 2010, 25(1): 7-11.

[42] LAN Chaoli , ZHANG Yongzhong , ZHANG Junfeng , et al. Reservoir characteristics of Upper Carboniferous Taiyuan Formation in Shenmu Gas Field and their controlling factors[J]. Journal of Xi'an Shiyou University (Natural Science Edition), 2010, 25(1): 7-11.

[43] 彭磊, 石磊, 朱玉杰, 等 . 鄂尔多斯盆地东部神木地区太原组微观储层特征及其产能影响因素分析[J]. 兰州大学学报(自然科学版), 2022, 58(4): 451-457.

[44] PENG Lei , SHI Lei , ZHU Yujie , et al. Micro pore structure and impact factors of the productivity of the Taiyuan Formation in Shenmu Area, Eastern Ordos Basin[J]. Journal of Lanzhou University (Natural Sciences), 2022, 58(4): 451-457.

[45] 王烽 . 鄂尔多斯盆地东部神木区块二叠系山西组致密砂岩气低产主控因素分析[J]. 天然气地球科学, 2017, 28(5): 687-695.

[46] WANG Feng . Main controlling factors of low production of tight sandstone gas of Permian Shanxi Formation in the Shenmu Block, Eastern Ordos Basin, China[J]. Natural Gas Geoscience, 2017, 28(5): 687-695.

[47] 夏玉磊, 兰建平, 姚伟 . 致密砂岩储层微观孔喉结构及可动流体分布特征:以鄂尔多斯盆地东部神木地区盒8段储层为例[J]. 地质科技通报, 2024, 43(2): 41-51.

[48] XIA Yulei , LAN Jianping , YAO Wei . Micro pore structure and movable fluid distribution characteristics of tight sandstone reservoirs: taking the He8 Reservoir in the Shenmu Area of the Eastern Ordos Basin as an example[J]. Bulletin of Geological Science and Technology, 2024, 43(2): 41-51.

[49] 马云峰, 赵建国, 孙龙, 等 . 应力作用下气藏水体微观赋存特征及渗流规律:以鄂尔多斯盆地神木气田二叠系盒8段致密储层为例[J]. 石油实验地质, 2023, 45(3): 466-473.

[50] MA Yunfeng , ZHAO Jianguo , SUN Long , et al. Microscopic occurrence characteristics and seepage law of water bodies in gas reservoir under stress: a case study of tight reservoir in the eighth member of Permian Shihezi Formation, Shenmu Gas Field, Ordos Basin[J]. Petroleum Geology and Experiment, 2023, 45(3): 466-473.

[51] 盛军, 孙卫, 段宝虹, 等 . 致密砂岩气藏水锁效应机理探析:以苏里格气田东南区上古生界盒8段储层为例[J]. 天然气地球科学, 2015, 26(10): 1972-1978.

[52] SHENG Jun , SUN Wei , DUAN Baohong , et al. Water lock effect mechanism of tight sandstone gas reservoir: an example of the He 8 Reservoir of the Upper Paleozoic in the southeast region of Sulige Gas Field[J]. Natural Gas Geoscience, 2015, 26(10): 1972-1978.

[53] 唐洪明, 朱柏宇, 王茜, 等 . 致密砂岩气层水锁机理及控制因素研究[J]. 中国科学:技术科学, 2018, 48(5): 537-547.

[54] TANG Hongming , ZHU Boyu , WANG Xi , et al. Mechanism and control factors of water blocking in tight sandstone gas reservoir[J]. Scientia Sinica (Technologica), 2018, 48(5): 537-547.

[55] 柯从玉, 魏颖琳, 张群正, 等 . 低渗透气藏水锁伤害及解水锁技术研究进展[J]. 应用化工, 2021, 50(6): 1613-1617.

[56] KE Congyu , WEI Yinglin , ZHANG Qunzheng , et al. Progress of water lock damage and water lock release technology in low permeability gas reservoir[J]. Applied Chemical Industry, 2021, 50(6): 1613-1617.

[57] ZHU Honglin , LIU Xiangjun , YAO Guanghua , et al. Determination of water-lock critical value of low-permeability sandstones based on digital core[J]. Natural Gas Industry B, 2016, 3(3): 253-259.

[58] LIANG Tianbo , ACHOUR H , LONGORIA A , et al. Flow physics of how surfactants can reduce water blocking caused by hydraulic fracturing in low permeability reservoirs[J]. Journal of Petroleum Science and Engineering, 2017, 157: 631-642.

[59] LI Xuejiao , ZHANG Qingjiu , LIU Peng , et al. Investigation on the microscopic damage mechanism of fracturing fluids to low-permeability sandstone oil reservoir by nuclear magnetic resonance[J]. Journal of Petroleum Science and Engineering, 2022, 209: 109821.

[60] LAI Fengpeng , LI Zhiping , WANG Yining . Impact of water blocking in fractures on the performance of hydraulically fractured horizontal wells in tight gas reservoir[J]. Journal of Petroleum Science and Engineering, 2017, 156: 134-141.

[61] SU Xianbo , WANG Qian , SONG Jinxing , et al. Experimental study of water blocking damage on coal[J]. Journal of Petroleum Science and Engineering, 2017, 156: 654-661.

[62] LIU Dameng , YAO Yanbin , YUAN Xuehao , et al. Experimental evaluation of the dynamic water-blocking effect in coalbed methane reservoir[J]. Journal of Petroleum Science and Engineering, 2022, 217: 110887.

[63] 向英杰, 娄林, 孙静 . 鄂尔多斯盆地东南缘晚石炭系-早二叠系海陆过渡层序及聚煤模式[J]. 东北石油大学学报, 2023, 47(2): 104-116.

[64] XIANG Yingjie , LOU Lin , SUN Jing . Marine-continental transitional sequence and coal accumulation model during Late Carboniferous to Early Permian in the southeast margin of Ordos Basin[J]. Journal of Northeast Petroleum University, 2023, 47(2): 104-116.

[65] 吴泽宇, 孙梦迪, 蒋恕, 等 . 鄂西地区深层页岩气储层岩相孔隙结构特征差异及其控制因素:以YT1和YT3井五峰-龙马溪组页岩为例[J]. 东北石油大学学报, 2023, 47(1): 15-29.

[66] WU Zeyu , SUN Mengdi , JIANG Shu , et al. Characteristics and controlling factors of pore structure in different lithofacies of deep shale gas reservoirs: a case study of Wufeng-Longmaxi Formation shales from wells YT1 and YT3 in Western Hubei[J]. Journal of Northeast Petroleum University, 2023, 47(1): 15-29.

[67] 蒲宇新, 李伟, 罗顺社, 等 . 鄂尔多斯盆地陇东地区长7油层组深水水道型重力流沉积特征及沉积模式[J]. 东北石油大学学报, 2023, 47(4): 70-81.

[68] PU Yuxin , LI Wei , LUO Shunshe , et al. Sedimentary characteristics and sedimentary model of deep water channel-induced gravity flow of Chang7 oil layer group in Longdong Area of the Ordos Basin[J]. Journal of Northeast Petroleum University, 2023, 47(4): 70-81.

[69] 付炜, 胡望水, 王晓晨, 等 . 致密砂岩储层特征及质量影响因素:以鄂尔多斯盆地西北部二叠系下石盒子组为例[J]. 东北石油大学学报, 2023, 47(5): 36-48.

[70] FU Wei , HU Wangshui , WANG Xiaochen , et al. Characteristics of tight sandstone reservoir and influencing factors of reservoir quality: a case study in Lower Shihezi Formation of Permian, Northwestern Ordos Basin[J]. Journal of Northeast Petroleum University, 2023, 47(5): 36-48.

[71] 阎珍, 任大忠, 王虎, 等 . 鄂尔多斯盆地神木地区侏罗系延安组煤层孔隙结构及可动流体饱和度影响因素[J]. 非常规油气, 2024, 11(5): 122-131.

[72] YAN Zhen , REN Dazhong , WANG Hu , et al. Factors affecting movable fluid saturation and pore structures of Jurassic Yan'an Formation in the Shenmu Area of the Ordos Basin[J]. Unconventional Oil & Gas, 2024, 11(5): 122-131.

[73] 郭顺, 周进松, 郭兰, 等 . 延安气田上古生界山西组致密砂岩储层微观特征及主控因素[J]. 特种油气藏, 2024, 31(2): 10-18.

[74] GUO Shun , ZHOU Jinsong , GUO Lan , et al. Microscopic characteristics and main controlling factors of tight sandstone reservoir in the Upper Paleozoic Shanxi Formation, Yan'an Gas Field[J]. Special Oil & Gas Reservoirs, 2024, 31(2): 10-18.

[75] 倪春华, 朱建辉, 刘光祥, 等 . 鄂尔多斯盆地杭锦旗地区上古生界煤系烃源岩生烃潜力再评价[J]. 石油实验地质, 2021, 43(5): 826-834.

[76] NI Chunhua , ZHU Jiahui , LIU Guangxiang , et al. Re-evaluation of hydrocarbon generation potential of the Upper Paleozoic coal-measure source rocks in the Hangjinqi Area of Ordos Basin[J]. Petroleum Geology & Experiment, 2021, 43(5): 826-834.

[77] TONG Qiang , HE Dongbo , XIA Zhaohui , et al. Influence of reservoir pore-throat structure heterogeneity on water-flooding seepage: a case study of Yanchang Formation in Ordos Basin[J]. Minerals, 2022, 12: 1243.

[78] 张浩, 康毅力, 陈一健, 等 . 致密砂岩气藏超低含水饱和度形成地质过程及实验模拟研究[J]. 天然气地球科学, 2005, 16(2): 186-189.

[79] ZHANG Hao , KANG Yili , CHEN Yijian , et al. The study of geology course and experiment simulation for forming ultra-low water saturation in tight sandstone gas reservoir[J]. Natural Gas Geoscience, 2005, 16(2): 186-189.

[80] 刘丽萍, 白海涛, 王西强, 等 . 鄂尔多斯盆地白豹油田长81储层水驱油特征及驱油效率影响因素[J]. 东北石油大学学报, 2022, 46(6): 63-74.

[81] LIU Liping , BAI Haitao , WANG Xiqiang , et al. Water flooding characteristics and influencing factors of oil displacement efficiency of Chang81 Reservoir in Baibao Oilfield, Ordos Basin[J]. Journal of Northeast Petroleum University, 2022, 46(6): 63-74.

[82] 杨宸, 杨二龙, 安艳明, 等 . 致密储层孔隙结构对渗吸的影响研究进展[J]. 特种油气藏, 2024, 31(4): 10-18.

[83] YANG Chen , YANG Erlong , AN Yanming , et al. Research progress on the impact of tight oil reservoir pore structure on spontaneous imbibition[J]. Special Oil & Gas Reservoirs, 2024, 31(4): 10-18.

[84] 王嘉曼, 熊靖, 师金鸽, 等 . TiO₂催化剂催化CO₂还原的研究进展 [J]. 石油化工高等学校学报, 2024, 37(4): 1-11.

[85] WANG Jiaman , XIONG Jing , SHI Jinge , et al. An overview of carbon dioxide catalyzed by titanium dioxide catalyst[J]. Journal of Petrochemical Universities, 2024, 37(4): 1-11.

基金资助

国家科技重大专项(2016ZX05050-006)

国家自然科学基金项目(41802140)

陕西省自然科学研究基础计划项目(2019JQ-257)