Occurrence Characteristics and Influencing Factors of Micro Remaining Oil in Different Displacement Stages

doi:10.3969/j.issn.1006-6535.2023.03.014

Abstract

Abstract: In order to further clarify the detailed description of the distribution characteristics of the micro remaining oil in the reservoir in the middle and high water-cut stage, CT nondestructive analysis was combined with conventional displacement test to analyze the distribution characteristics and influencing factors of micro remaining oil in different displacement stages by means of in-situ comparison technology. The results show that the production effect of micro remaining oil is affected by the size of micro pore throat, the connectivity of pore throat and the spatial distribution of pore throat, etc. The characteristics of remaining oil distribution and occurrence are affected jointly by the main driving force formed by various micro forces and the micro pore throat structure. In the water flooding stage, the production effect is mainly affected by the micro-pore structure, the micro remaining oil in the large pore channel with good connectivity can be migrated for a long distance, with high production effect, while the oil droplets in the small channels with poor connectivity will only be thinned slightly along the edge, with poor production effect. Polymer-surfactant composite flooding is followed by water flooding is conducted, the heterogeneity of micro-pore throat distribution is the most important factor affecting the production effect, and the production effect of low-permeability and high-permeability cores with high micro-heterogeneity is more obvious. Different injection and production strategies should be applied in different development stages of the oilfield. Homogeneous intervals with large pores should be selected for development in water flooding stage, while heterogeneous intervals with poor water flooding sweep effect should be preferentially selected for development in the polymer-surfactant composite flooding stage. The results of the study are of guiding significance for the occurrence and enhanced oil recovery of micro remaining oil in the reservoirs.

Key words: CT scan, in situ comparison, microscopic residual oil, reservoir characteristics, enhanced recovery

CLC Number:

TE327

Liu Weiwei, Chen Shaoyong, Cao Wei, Wang Li'na, Liu Zhenlin, Wang Haikao. Occurrence Characteristics and Influencing Factors of Micro Remaining Oil in Different Displacement Stages[J]. Special Oil & Gas Reservoirs, 2023, 30(3): 115-122.

References

[1] 王立辉,夏惠芬,韩培慧,等.剩余油分布的微观特征及其可动用程度的定量表征[J].岩性油气藏,2021,33(2):147-154.
WANG Lihui,XIA Huifen,HAN Peihui,et al.Microscopic characteristics of remaining oil distribution and quantitative characterization of its producibility[J].Lithologic Reservoirs,2021,33(2):147-154.
[2] 印森林,陈恭洋,陈玉琨,等.砂砾岩储层孔隙结构模态控制下的剩余油分布——以克拉玛依油田七东1区克下组为例[J].岩性油气藏,2018,30(5):91-102.
YIN Senlin,CHEN Gongyang,CHEN Yukun,et al.Control effect of pore structure modality on remaining oil in glutenite reservoir:a case from lower Karamay Formation in Block Qidong 1 of Karamay Oilfield[J].Lithologic Reservoirs,2018,30(5):91-102.
[3] 宋明明,韩淑乔,董云鹏,等.致密砂岩储层微观水驱油效率及其主控因素[J].岩性油气藏,2020,32(1):135-143.
SONG Mingming,HAN Shuqiao,DONG Yunpeng,et al.Microsc
opic water flooding efficiency and main controlling factors of tight sandstone reservoir[J].Lithologic Reservoirs,2020,32(1):135-143.
[4] 李宜强,张津,潘登,等.高含水期微观剩余油赋存规律——以大港油田小集区块和港西区块为例[J].新疆石油地质,2021,42(4):444-449.
LI Yiqiang,ZHANG Jin,PAN Deng,et al.Occurrence laws of microscopic remaining oil in high water-cut reservoirs:a case study on blocks Xiaoji and Gangxi in Dagang Oilfield[J].Xinjiang Petroleum Geology,2021,42(4):444-449.
[5] 张西龙.冷冻制片荧光分析法在分析聚驱后剩余油赋存状态中的应用[J].石油地质与工程,2022,36(1):68-71,77.
ZHANG Xilong.Application of frozen slice fluorescence analysis in analyzing the occurrence state of remaining oil after polymer flooding[J].Petroleum Geology & Engineering,2022,36(1):68-71,77.
[6] 谭龙,聂振荣,熊志国,等.砾岩油藏化学驱微观孔隙剩余油分级动用机理——以克拉玛依油田砾岩油藏K7区块为例[J].油气地质与采收率,2021,28(4):107-112.
TAN Long,NIE Zhenrong,XIONG Zhiguo,et al.Study on graded production mechanism of remaining oil in micro-pores of chemical flooding in conglomerate reservoirs:a case of conglomerate reservoir in Block K7,Karamay Oilfield,Xinjiang[J].Petroleum Geology and Recovery Efficiency,2021,28(4):107-112.
[7] 张田田.基于CT成像技术的剩余油微观分布及流动特征研究[D].成都:西南石油大学,2017.
ZHANG Tiantian.Study on microscopic distribution and flow characteristics of residual oil based on CT imaging technology[D].Chengdu:Southwest Petroleum University,2017.
[8] 于东海,任允鹏,王真,等.多层系油藏剩余油分布的精细数值模拟技术[J].油气地质与采收率,2002,9(5):34-36.
YU Donghai,REN Yunpeng,WANG Zhen,et al.Applying fine numerical simulation technique to remaining oil distribution in oil reservoir with multiple series of strata[J].Petroleum Geology and Recovery Efficiency,2002,9(5):34-36.
[9] 沈渭滨,王飞,张林,等.ZC油区剩余油分布特征研究及评价[J].非常规油气,2018,5(3):52-55.
SHEN Weibin,WANG Fei,ZHANG Lin,et al.Study and evaluation of the distribution characteristics of residual oil in ZC Oil Area[J].Unconventional Oil & Gas,2018,5(3):52-55.
[10] 苏明,吴小斌,王立宁,等.低渗河道水驱砂岩油藏剩余油分布规律——以鄂尔多斯盆地胡尖山A21井区长2油藏为例[J].非常规油气,2018,5(4):58-64,74.
SU Ming,WU Xiaobin,WANG Lining,et al.Remaining oil distribution law of water drive sandstone reservoir in low permeability channel:a case study from Chang-2 Reservoir in Hujianshan A21 Block,Ordos Basin[J].Unconventional Oil & Gas,2018,5(4):58-64,74.
[11] 李石权,范莉红,邓彩云,等.特高含水油藏开发后期剩余油精准挖潜技术[J].非常规油气,2019,6(1):62-68.
LI Shiquan,FAN Lihong,DENG Caiyun,et al.Precise drilling technology for residual oil in the later stage of development of extra-high water-cut reservoir[J].Unconventional Oil & Gas,2019,6(1):62-68.
[12] 刘丽杰,张先敏,魏祥祥,等.特高含水期剩余油分类评价方法[J].油气地质与采收率,2022,29(5):83-90.
LIU Lijie,ZHANG Xianmin,WEI Xiangxiang,et al. Classification and evaluation method of remaining oil in ultra-high water cut stage[J].Petroleum Geology and Recovery Efficiency,2022,29(5):83-90.
[13] 郭长春.基于密闭取心井的非均相复合驱后剩余油分布特征与变化规律——以孤岛油田中一区Ng₃为例[J].油气地质与采收率,2022,29(5):111-117.
GUO Changchun.Distribution characteristics of remaining oil after heterogeneous combination flooding based on sealed cored well:a case study in Zhongyi Area Ng₃,Gudao Oilfield[J].Petroleum Geology and Recovery Efficiency,2022,29(5):111-117.
[14] 韩卓,陈晓燕,马道荣,等.激光扫描共聚焦显微镜实验技术与应用[J].科技信息,2009,19(5):27-28.
HAN Zhuo,CHEN Xiaoyan,MA Daorong,et al.Technique and application skills of laser scanning confocal microscopy[J].Science & Technology Information,2009,19(5):27-28.
[15] AMBER T,KRUMMEL S S,DATTA S M,et al.Visualizing multiphase flow and trapped fluid configurations in a model three-dimensional porous medium[J].Aiche Journal,2013,59(3):1022-1029.
[16] 周宗良,张凡磊,刘斌,等.高含水油藏微观剩余油渗流机理与孔喉动用特征[J].新疆地质,2021,39(2):275-279.
ZHOU Zongliang,ZHANG Fanlei,LIU Bin,et al.Microscopic residual oil seepage mechanism and pore throat producing characteristics in high water-cut reservoirs[J].Xinjiang Geology,2021,39(2):275-279.
[17] 刘红现,许长福,胡志明.用核磁共振技术研究剩余油微观分布[J].特种油气藏,2011,18(1):96-97.
LIU Hongxian,XU Changfu,HU Zhiming.Research on microcosmic remaining oil distribution by NMR[J].Special Oil & Gas Reservoirs,2011,18(1):96-97.
[18] 孙国忠.饱含油岩心样品薄片的制作技术[J].石油实验地质,2002,24(6):566-567.
SUN Guozhong.The preparation of thin section for oil-saturated rock samples[J].Petroleum Geology & Experiment,2002,24(6):566-567.
[19] 王朴,蔡进功,谢忠怀,等.用含油薄片研究剩余油微观分布特征[J].油气地质与采收率,2002,9(1):60-61.
WANG Pu,CAI Jingong,XIE Zhonghuai,et al.Using oil-bearing thin section to study microscopic distribution feature of remaining oil[J].Petroleum Geology and Recovery Efficiency,2002,9(1):60-61.
[20] LI Junjian,JIANG Hanqiao,WANG Chuan,et al.Pore-scale investigation of microscopic remaining oil variation characteristics in water-wet sandstone using CT scanning[J].Journal of Natural Gas Ence & Engineering,2017,48:36-45.
[21] 董怀民,孙建孟,林振洲,等.基于CT扫描的天然气水合物储层微观孔隙结构定量表征及特征分析[J].中国石油大学学报(自然科学版),2018,42(6):40-49.
DONG Huaimin,SUN Jianmeng,LIN Zhenzhou,et al.Quantitati
ve characterization and characteristics analysis of microscopic pore structure in natural gas hydrate based on CT scanning[J].Journal of China University of Petroleum(Edition of Natural Sciences),2018,42(6):40-49.
[22] 屈乐,孙卫,杜环虹,等.基于CT扫描的三维数字岩心孔隙结构表征方法及应用——以莫北油田116井区三工河组为例[J].现代地质,2014,28(1):190-196.
QU Le,SUN Wei,DU Huanhong,et al.Characterization technique of pore structure by 3D digital core based on CT scanning and its application:an example from Sangonghe Formation of 116 Well Field in Mobei Oilfield[J].Geoscience,2014,28(1):190-196.