Imbibition Mechanism and Model of Bedding Fractures in Shale Oil Reservoir

doi:10.3969/j.issn.1006-6535.2021.05.023

Abstract

Abstract: Shale oil is mainly developed in line with the concept of making longitudinal fractures (tectonic fractures) by staged fracturing in horizontal well, without consideration of the imbibition effect of opening bedding fractures. To further study the role of bedding fractures on shale oil development, the imbibition efficiency of bedding and tectonic fractures was analyzed by means of core imbibition simulation experiment, cast slice observation and CT scanning, taking shale oil in Jimusaer Area, Xinjiang as an example. The results showed that the imbibition depth of tectonic fracture model was 1.5 cm, the imbibition depth of bedding fracture model was 1.0 cm, and the imbibition efficiency of bedding fracture was higher in surface layer; the imbibition efficiency can be increased by about 4.3% by opening the bedding fractures with the same area on the basis of opening tectonic fractures; according to the physical simulation experiment of imbibition, different oil-water imbibition conversion modes were established for tectonic fracture and bedding fracture, indicating that the development efficiency of shale oil can be greatly improved by the imbibition effect of bedding fracture on the basis of structural fracture imbibition. This study provides a theoretical basis for fracturing method optimization and shale oil recovery enhancement.

Key words: bedding fracture, tectonic fracture, shale oil, longitudinal seepage, resistivity method, seepage efficiency, imbibition pattern

CLC Number:

TE311

Xie Jianyong, Yuan Zhenzhu, Dai Bing, Wu Chengmei, Jia Chun, Xu Feng, Luo Qun, Cui Qian. Imbibition Mechanism and Model of Bedding Fractures in Shale Oil Reservoir[J]. Special Oil & Gas Reservoirs, 2021, 28(5): 161-167.

References

[1] 郑民,李建忠,吴晓智,等.我国常规与非常规石油资源潜力及未来重点勘探领域[J].海相油气地质,2019,24(2):1-13.
ZHENG Min,LI Jianzhong,WU Xiaozhi,et al.The conventional and unconventional oil resource potential and key exploration fields in China[J].Marine Origin Petroleum Geology,2019,24(2):1-13.
[2] 贾承造,邹才能,李建忠,等.中国页岩油评价标准、主要类型、基本特征及资源前[J].石油学报,2012,33(3):333-350.
JIA Chengzao,ZOU Caineng,LI Jianzhong,et al.Assessment criteria,main types,basic features and resource prospects of the tight oil in China[J].Acta Petrolei Sinica,2012,33(3):333-350.
[3] 邹才能,陶士振,侯连华,等.非常规油气地质学(2版)[M].北京:地质出版社, 2013:110-112.
ZOU Caineng,TAO Shizhen,HOU Lianhua,et al.Unconventional oil and gas geology(2nd Edition)[M].Beijing:Geological Publishing House,2013:110-112.
[4] 童晓光.非常规油的成因和分布[J].石油学报,2012,33(增刊1): 20-26.
TONG Xiaoguang.Genesis and distribution of unconventional oil[J].Acta Petrolei Sinica,2012,33(S1):20-26.
[5] 杜金虎,胡素云,庞正炼,等.中国陆相页岩油类型、潜力及前景[J].中国石油勘探,2019,24(5):560-568.
DU Jinhu,HU Suyun,PANG Zhenglian,et al.The types, potentials and prospects of continental shale oil in China[J].China Petroleum Exploration,2019,24(5):560-568.
[6] 许琳,常秋生,杨成克,等.吉木萨尔凹陷二叠系芦草沟组页岩油储层特征及含油性[J].石油与天然气地质,2019,40(3):89-103.
XU Lin,CHANG Qiusheng,YANG Chengke,et al.Characteristics and oil-bearing capability of shale oil reservoir in the Permian Lucaogou Formation,Jimusaer Sag[J].Oil & Gas Geology,2019,40(3):89-103.
[7] 吴承美,郭智能,唐伏平,等.吉木萨尔凹陷二叠系芦草沟组页岩油初期开采特征[J].新疆石油地质,2014,35(5):570-573.
WU Chengmei,GUO Zhineng,TANG Fuping,et al.Early exploitation characteristics of Lucaogou tight oil of Permian in Jimusaer Sag,Junggar Basin[J].Xinjiang Petroleum Geology,2014,35(5):570-573.
[8] 曾联波,高春宇,漆家福,等.鄂尔多斯盆地陇东地区特低渗透砂岩储层裂缝分布规律及其渗流作用[J].中国科学:地球科学,2008,38(1):41-47.
ZENG Lianbo,GAO Chunyu,QI Jiafu,et al.Fracture distribution pattern and seepage effect of ultra-low permeability sandstone reservoir in Longdong Area,Ordos Basin[J].Scientia Sinica Terrae,2008,38(1):41-47.
[9] 丁文龙,王兴华,胡秋嘉,等.致密砂岩储层裂缝研究进展[J].地球科学进展,2015,30(7):737-750.
DING Wenlong,WANG Xinghua,HU Qiujia,et al.Progress in tight sandstone reservoir fractures research[J].Advances in Earth Science,2015,30(7):737-750.
[10] 金之钧,胡宗全,高波,等.川东南地区五峰组-龙马溪组页岩气富集与高产控制因素[J].地学前缘,2016,23(1):1-10.
JIN Zhijun,HU Zongquan,GAO Bo,et al.Controlling factors on the enrichment and high productivity of shale gas in the Wufeng-Longmaxi Formations,southeastern Sichuan Basin[J].Earth Science Frontiers,2016,23(1):1-10.
[11] 周凤军,陈文明.低渗透岩心渗吸实验研究[J].复杂油气藏,2009,2(1):58-60.
ZHOU Fengjun,CHEN Wenming.Study on spontaneous imbibition experiment of low permeability core[J].Complex Hydrocarbon Reservoirs,2009,2(1):58-60.
[12] 张云钊.吉木萨尔凹陷致密储层裂缝类型和成因机制研究[D].北京:中国石油大学(北京),2017.
ZHANG Yunzhao.Research on types and genetic mechanisms of tight reservoir in the Lucaogou Formation in Jimusar Sag[D].Beijing:China University of Petroleum(Beijing),2017.
[13] 罗群,魏浩元,刘冬冬,等.层理缝在页岩油成藏富集中的意义、研究进展及其趋势[J].石油实验地质,2017,39(1):1-7.
LUO Qun,WEI Haoyuan,LIU Dongdong,et al.Significance, research progress and trend of bedding fractures in shale oil accumulation and enrichment[J].Petroleum Geology & Experiment,2017,39(1):1-7.
[14] WANG Q,LI Y,YANG W,et al.Finite element simulation of multi-scale bedding fractures in tight sandstone oil reservoir[J].Energies,2019,13(1):1-20.
[15] 斯春松,陈能贵,余朝丰,等.吉木萨尔凹陷二叠系芦草沟组页岩油储层沉积特征[J].石油实验地质,2013,35(5):60-65.
SI Chunsong,CHEN Nenggui,YU Chaofeng,et al.Characteristics and oil-bearing capability of shale oil reservoir in the Permian Lucaogou Formation,Jimusaer Sag[J].Petroleum Geology & Experiment,2013,35(5):60-65.
[16] ZHAI M.Characteristic and controlling factors of micro-fracture on Quantou Formation forth segment tight sandstone reservoir in Da′an Oilfield[J].Scientific Journal of Earth Science,2015,5(3):61-65.
[17] 查明,苏阳,高长海,等.致密储层储集空间特征及影响因素——以准噶尔盆地吉木萨尔凹陷二叠系芦草沟组为例[J].中国矿业大学学报,2017,46(1):88-98.
ZHA Ming,SU Yang,GAO Changhai,et al.Tight reservoir space characteristics and controlling factors:an example from Permian Lucaogou Formation in Jimsar Sag,Junggar Basin,NW China[J].Journal of China University of Mining & Technology,2017,46(1):88-98.
[18] 许琳,常秋生,杨成克,等.吉木萨尔凹陷二叠系芦草沟组页岩油储层特征及含油性[J].石油与天然气地质,2019,40(3):535-549.
XU Lin,CHANG Qiusheng,YANG Chengke,et al.Characteristics and oil-bearing capability of shale oil reservoir in the Permian Lucaogou Formation,Jimusaer sag[J].Oil & Gas Geology,2019,40(3):535-549.
[19] 张金川,杨超,陈前,等.中国潜质页岩形成和分布[J].地学前缘,2016,23(1):74-86.
ZHANG Jinchuan,YANG Chao,CHEN Qian,et al.Deposition and distribution of potential shales in China[J].Earth Science Frontiers,2016,23(1):74-86.
[20] 王敉邦,蒋林宏,包建银,等.渗吸实验描述与方法适用性评价[J].石油化工应用,2015,34(12):102-105.
WANG Mibang,JIANG Linhong,BAO Jianyin,et al.Imbibition experimental description and evaluation of method applicability[J].Petrochemical Industry Application,2015,34(12):102-105.
[21] 徐永强,何永宏,卜广平,等.基于微观孔喉结构及渗流特征建立致密储层分类评价标准:以鄂尔多斯盆地陇东地区长₇储层为例[J].石油实验地质,2019,41(3):451-460.
XU Yongqiang,HE Yonghong,BU Guangping,et al.Establishment of classification and evaluation criteria for tight reservoirs based on characteristics of microscopic pore throat structure and percolation: a case study of Chang₇ reservoir in Longdong area,Ordos Basin[J].Petroleum Geology & Experiment,2019,41(3):451-460.
[22] 徐中一,方思冬.边界层对致密油藏逆向渗吸的数值模拟[J].石油与天然气地质,2020,41(3):638-646.
XU Zhongyi,FANG Sidong.Numerical simulation on tight oil reservoir reverse imbibition with boundary layers[J].Oil & Gas Geology,2020,41(3):638-646.