低渗透油藏注水诱导裂缝特征及形成机理——以鄂尔多斯盆地安塞油田长6油藏为例

doi:10.11743/ogg20180407

摘要/Abstract

摘要： 以鄂尔多斯盆地安塞油田长6油藏为例，在分析低渗透油藏注水开发动态特征的基础上，阐明了注水诱导裂缝的基本特征并研究其形成机理，最后利用数值模拟技术对该区注水诱导裂缝的主要形成机理进行了模拟。注水诱导裂缝指低渗透油藏在长期的注水开发过程中，当注水压力超过各类裂缝开启压力或地层破裂压力而形成的以水井为中心的高渗透性开启大裂缝或快速水流通道。它是低渗透油藏长期注水开发过程中所表现出的新的开发地质属性和最主要的非均质性，对于长期水驱的低渗透油藏来说具有普遍性和必然性。注水诱导裂缝有3种形成机理，当注水压力过高，超过天然裂缝的开启压力使天然裂缝张开、扩展和延伸，或超过地层破裂压力使地层中不断产生新的破裂，或使注水井周围因射孔、压裂等生产或增产措施所导致的不同类型的人工裂缝张开等均可形成注水诱导裂缝。安塞油田长6油藏普遍发育与现今最大水平主应力方向近一致的以雁列式排列的高角度构造剪切裂缝，当注水压力超过这类裂缝的开启压力并使裂缝张开、延伸扩展并相互连通，是该区注水诱导裂缝的主要形成机理。油藏数值模拟表明，随着注水诱导裂缝规模的不断扩大，注水井井底压力相应的表现出连续的不规则的周期性变化。

关键词: 注水诱导裂缝, 注水开发, 低渗透油藏, 安塞油田, 鄂尔多斯盆地

Abstract: The study took Chang 6 reservoir in Ansai oilfield of Ordos Basin as an object to demostrate the essential ch-aracteristics and the formation mechanisms of waterflood induced fractures,based on the analysis of dynamic production features of the water-injecting lowpermeability reservoir.And the main formation mechanisms of waterflood induced fractures in the study area were numerically simulated in the end.Waterflood induced fracture is an injector-centered open fracture or a fast flow channel,which is formed when the water injection pressure exceeds the opening pressure of various fractures or the formation fracture pressure during the long-period waterflooding of low-permeability reservoirs.The fractures are an artificial geological attribute and the main cause of heterogeneity for waterflood development of low-permeability reservoirs,and they are widely occurring and inevitable in these reservoirs.Three formation mechanisms of waterflood induced fractures were summarized as follows:(1) when the water injection pressure exceeds the opening pressure of natural fractures,the natural fractures become open and are extended; (2) When the water injection pressure exceeds the formation fracture pressure,new fractures are developed throughout the injection life; (3) Other types of artificial fractures are generated by production or stimulation measures such as perforating and fracturing around the injector.In Chang 6 reservoir,high angle structural shearing fractures,in en echelon arrangement,are widespread approximately along the direction of major principal stress,and the dominate fractures are the first type of waterflood induced fractures.According to numerical simulation results,the bottom hole pressure of the injeciton well exhibits a continuous irregular periodic change with the continuous expansion of the waterflood induced fractures.

Key words: waterflood induced fracture, waterflooding development, low-permeability reservoir, Ansai oilfield, Ordos Basin

中图分类号:

TE348

赵向原,曾联波,靳宝光,等. 低渗透油藏注水诱导裂缝特征及形成机理——以鄂尔多斯盆地安塞油田长6油藏为例[J]. 石油与天然气地质, 2018, 39(4): 696-705. doi: 10.11743/ogg20180407 Zhao Xiangyuan,Zeng Lianbo,Jin Baoguang,et al. Characteristics and formation mechanisms of waterflood induced fractures in low-permeability reservoirs: A case study from Chang 6 reservoir in Ansai oilfield,Ordos Basin[J]. Oil & Gas Geology, 2018, 39(4): 696-705. doi: 10.11743/ogg20180407

参考文献

[1] 李德勇,张金亮,于孝玉,等.松辽盆地南部海坨子地区超低渗透储层特征与形成因素[J].地质科学,2012,47(2):454-469. Li Deyong,Zhang Jinliang,Yu Xiaoyu,et al.Characteristics and form factors of ultralow permeable reservoir in Haituozi area in the southern Songliao Basin[J].Chinese Journal of Geology,2012,47(2):454-469.
[2] 李阳,才巨宏.渤南油田三区沙三段4砂组低渗透砂岩储集层裂缝特征研究[J].石油勘探与开发,2000,27(6):39-41. Li Yang,Cai Juhong.Characteristics of fracture systems in the 4th low permeability sandstone zone of Member S3 of Block 3,Bonan oil field[J].Pertroleum Exploration and Development,2000,27(6):39-41.
[3] 邓秀芹,刘新社,李士祥.鄂尔多斯盆地三叠系延长组超低渗透储层致密史与油藏成藏史[J].石油与天然气地质,2009,30(2):156-161. Deng Xiuqin,Liu Xinshe,Li Shixiang.The relationship between compacting history and hydrocarbon accumulating history of the super-low permeability reservoirs in the Triassic Yanchang Formation in the Ordos Basin[J].Oil & Gas Geology,2009,30(2):156-161.
[4] 石玉江,肖亮,毛志强,等.低渗透砂岩储层成岩相测井识别方法及其地质意义-以鄂尔多斯盆地姬塬地区长8段储层为例[J].石油学报,2011,32(5):820-828. Shi Yujiang,Xiao Liang,Mao Zhiqiang,et al.An identification method for diagenetic facies with well logs and its geological significance in low-permeability sandstones:A case study on Chang 8 reservoirs in the Jiyuan region,Ordos Basin[J].Acta Petrolei Sinica,2011,32(5):820-828.
[5] 操应长,远光辉,王艳忠,等.准噶尔盆地北三台地区清水河组低渗透储层成因机制[J].石油学报,2012,33(5):758-771. Cao Yingchang,Yuan Guanghui,Wang Yangzhong,et al.Genetic mechanisms of low permeability reservoirs of Qingshuihe Formation in Beisantai area,Junggar Basin[J].Acta Petrolei Sinica,2012,33(5):758-771.
[6] 赵向原,曾联波,祖克威,等.致密储层脆性特征及对天然裂缝的控制作用——以鄂尔多斯盆地陇东地区长7致密储层为例[J].石油与天然气地质,2016,37(1),62-71. Zhao Xiangyuan,Zeng Lianbo,Zu Kewei,et al.Brittleness characteristics and its control on natural fractures in tight reservoirs:A case study from Chang 7 tight reservoir in Longdong area of the Ordos Basin[J].Oil & Gas Geology,2016,37(1),62-71.
[7] 胡文瑞.中国低渗透油气的现状与未来.中国工程科学,2009,11(8):29-37. Hu Wenrui.The present and future of low permeability oil and gas in China[J].Engineering Sciences,2009,11(8):29-37.
[8] 范天一,宋新民,吴淑红,等.低渗透油藏水驱动态裂缝数学模型及数值模拟[J].石油勘探与开发,2015,42(4):496-501. Fan Tianyi,Song Xinmin,Wu Shuhong,et al.A mathematical model and numerical simulation of waterflood induced dynamic fractures of low permeability reservoirs[J].Pertroleum Exploration and Development,2015,42(4):496-501.
[9] 吴志宇.安塞特低渗透油田开发稳产技术[M].北京:石油工业出版社,2013. Wu Zhiyu.Stable yield technology in development of Ansai low-permeability oilfield[M].Beijing:Petroleum Industry Press,2013.
[10] 刘洪涛,曾联波,房宝才,等.裂缝对大庆台肇地区低渗透砂岩储层注水的影响[J].石油大学学报(自然科学版),2005,29(04):74-78. Liu Hongtao,Zeng Lianbo,Fang Baocai,et al.Influence of fractures on injection for low-permeability sandstone reservoir in Taizhao area,Daqing Oilfield[J].Journal of the University of Petroleum(Science and Technology),China,2005,29(04):74-78.
[11] 韩德金,张凤莲,周锡生,等.大庆外围低渗透油藏注水开发调整技术研究[J].石油学报,2007,28(1):83-86. Han Dejin,Zhang Fenglian,Zhou Xisheng,et al.Study on adjustment technology of waterflood development of low-permeability reservoirs in the periphery of Daqing Oilfield[J].Acta Petrolei Sinica,2007,28(1):83-86.
[12] 李道品.低渗透砂岩油田开发[M].北京:石油工业出版社,1997. Li Daopin.Development of low permeability sandbody oilfield[M].Beijing:Petroleum Industry Press,1997.
[13] Jacques Hagoort,Brian D Weatherill,Antonin Settari.Modeling the propagation of waterflood-induced hydraulic fractures.SPE 7412,1980.
[14] Kuo M C T,Hanson H G,DesBrisay C L.Prediction of fracture extension during waterflood operations.SPE 12769,1984.
[15] Petter Eitvik,Tom Skoglunn,Antonin Settari.Waterflood-Induced Fracturing:water injection above parting pressure at Valhall.SPE 24912,1992.
[16] Steven L Bryant,Ramoj K Paruchuri,K Prasad Saripalli.Flow and solute transport around injection wells through a single,growing fracture.Advances in Water Resources.2003,26(8):803-813.
[17] 武富礼,李文厚,李玉宏,等.鄂尔多斯盆地上三叠统延长组三角洲沉积及演化[J].古地理学报,2004,6(3):307-315. Wu Fuli,Li Wenhou,Li Yuhong,et al.Delta sediments and evolution of the Yanchang Formation of Upper Triassic in Ordos Basin[J].Journal of Palaeogeography,2004,6(3):307-315.
[18] 赵振宇,郭彦如,王艳,等.鄂尔多斯盆地构造演化及古地理特征研究进展[J].特种油气藏,2012,19(5):15-20. Zhao Zhenyu,Guo Yanru,Wang Yan,et al.Study progress in tectonic evolution and paleogeography of Ordos Basin[J].Special Oil and Gas Reservoir,2012,19(5):15-20.
[19] 朱玉双,曲志浩,孔令荣,等.安塞油田坪桥区、王窑区长6油层储层特征及驱油效率分析[J].沉积学报,2000,18(2):279-283. Zhu Yushuang,Qu Zhihao,Kong Lingrong,et al.Analysis of oil displacement efficiency of Chang 6 reservoir in Wangyao and Pingqiao areas of Ansai oilfield[J].Acta Sendimentological Sinica,2000,18(2):279-283.
[20] 喻建,杨亚娟,杜金良.鄂尔多斯盆地晚三叠世延长组湖侵期沉积特征[J].石油勘探与开发,2010,37(2):181-187. Yu Jian,Yang Yajuan,Du Jinliang.Sedimentation during the transgression period in Late Triassic Yanchang Formation,Ordos Basin[J].Pertroleum Exploration and Development,2010,37(2):181-187.
[21] 赵虹,党犇,李文厚,等.安塞地区延长组沉积微相研究[J].天然气地球科学,2004,15(5):492-497. Zhao Hong,Dang Ben,Li Wenhou,et al.Microfacies characteristic of Yanchang Formation in Ansai District[J].Natual Gas Geology,2004,15(5):492-497.
[22] 曾联波,李忠兴,史成恩,等.鄂尔多斯盆地上三叠统延长组特低渗透砂岩储层裂缝特征及成因[J].地质学报,2007,81(2):174-180. Zeng Lianbo,Li Zhongxing,Shi Chengen,et al.Characteristics and origin of fractures in the extra low-permeability sandstone reservoirs of the upper Triassic Yanchang Formation in the Ordos Basin[J].Acta Geological Sinica,2007,81(2):174-180.
[23] 李志明,张金珠.地应力与油气勘探开发[M].北京:石油工业出版社,1997. Li Zhiming,Zhang Jinzhu.In-situ stress and peroleum exploration & developmend[M].Beijing:Petroleum Industry Press,1997.
[24] 赵向原,曾联波,靳宝光,等.裂缝性低渗透砂岩油藏合理注水压力——以鄂尔多斯盆地安塞油田王窑区为例[J].石油与天然气地质,2015,36(5):855-861. Zhao Xiangyuan,Zeng Lianbo,Jin Baoguang,et al.Discussion on optimal injection pressure of fractured low-permeability sandstone reservoirs-A case study from Wangyao Block in Ansai oilfield,Ordos Basin[J].Oil & Gas Geology,2015,36(5):855-861.
[25] Gadde P B,Sharma M M.Growing injection well fractures and their impact on waterflood performance[J].SPE 71614,2001.