为明确CO2在页岩储层纳米孔隙中的流动机理及其对沥青质沉淀的影响,采用自主研发的高温高压过滤容器和复合纳米滤膜,进行纳米滤膜过滤实验,模拟了单(多)层岩石切片作用下的CO2驱替过程,开展储层参数和注入参数对CO2驱替效果及沥青质沉淀的影响研究。研究结果表明:CO2驱会引发沥青质沉淀,导致剩余油中的沥青质含量远大于产出油中的沥青质含量;产出油中沥青质含量随CO2注入压力和滤膜孔径的增加而增大,但随温度、闷井时间、滤膜厚度和非均质性的增加而降低;剩余油中的沥青质含量变化则与产出油沥青质含量相反;储层参数和注入参数对沥青质沉淀的影响程度依次为滤膜厚度(40.63%)、注入压力(20.74%)、非均质性(16.84%)、温度(10.86%)、滤膜孔径(7.37%)、闷井时间(3.56%)。研究成果可为CO2驱提高页岩油采收率提供参考和借鉴。
In order to clarify the mechanism of CO2 flowing in the nano-pores of shale reservoirs and its influence on asphaltene deposition, a nano-filtration experiment was conducted with self-developed high-temperature and high-pressure filtration vessel and composite nano-filtration membrane to simulate the CO2 flooding process under the action of single (multi)-layer rock slices, and to study the influence of reservoir parameters and injection parameters on CO2 flooding effect and asphaltene deposition. The results showed that CO2 flooding caused asphaltene deposition, resulting in the asphaltene content in the remaining much higher than that in the produced oil; the asphaltene content in the produced oil increased with the increase of CO2 injection pressure and filter membrane pore size, but decreased with the increase of temperature, shut-in duration, membrane thickness and heterogeneity; the influence degree of reservoir parameters and injection parameters on asphaltene deposition was as follows: membrane thickness (40.63%), injection pressure (20.74%), heterogeneity (16.84%), temperature (10.86%), membrane pore size (7.37%), and shut-in duration (3.56%). The study results provide reference and basis for enhancing the recovery efficiency of shale oil reservoirs by CO2 flooding.
[1] 韩海水,李实,陈兴隆,等.CO2对原油烃组分膨胀效应的主控因素[J].石油学报,2016,37(3):392-398.
HAN Haishui,LI Shi,CHEN Xinglong,et al.Main control factors of carbon dioxide on swelling effect of crude hydrocarbon components[J].Acta Petrolei Sinica,2016,37(3):392-398.
[2] 沈平平,黄磊.二氧化碳-原油多相多组分渗流机理研究[J].石油学报,2009,30(2):247-251.
SHEN Pingping,HUANG Lei.Flow mechanisms of multi-phase multi-component CO2-crude oil system in porous media[J].Acta Petrolei Sinica,2009,30(2):247-251.
[3] 胡伟,吕成远,王锐,等.水驱转CO2混相驱渗流机理及传质特征[J].石油学报,2018,39(2):201-209.
HU Wei,LYU Chengyuan,WANG Rui,et al.Porous flow mechanisms and mass transfer characteristics of CO2 miscible flooding after water flooding[J].Acta Petrolei Sinica,2018,39(2):201-209.
[4] 唐梅荣,张同伍,白晓虎,等.孔喉结构对CO2驱储层伤害程度的影响[J].岩性油气藏,2019,31(3):1-8.
TANG Meirong,ZHANG Tongwu,BAI Xiaohu,et al.Influence of pore throat structure on reservoir damage with CO2 flooding[J].Lithologic Reservoirs,2019,31(3):1-8.
[5] 陈龙龙,余华贵,汤瑞佳,等.沥青质沉积对轻质油藏CO2驱的影响[J].油田化学,2017,34(1):87-93.
CHEN Longlong,YU Huagui,TANG Ruijia,et al.Effect of asphalt deposition on CO2 flooding in light oil reservoir[J].Oilfield Chemistry,2017,34(1):87-93.
[6] WANG Zhilin,YANG Shenglai,LEI Hao,et al.Oil recovery performance and permeability reduction mechanisms in miscible CO2 water alternative-gas (WAG) injection after continuous CO2 injection:an experimental investigation and modeling approach[J].Journal of Petroleum Science and Engineering,2017,150(2):376-385.
[7] SRIVASTAVA R K,HUANG S S,DONG M Z.Asphaltene deposition during CO2 flooding[J].SPE Production & Facilities,1999,14(4):235-245.
[8] 雷浩.低渗储层CO2驱油过程中沉淀规律及防治对策研究[D].北京:中国石油大学(北京),2017.
LEI Hao.Deposition mechanisms and reservoir protection countermeasures of a low-permeability formation in CO2 flooding process[D].Beijing:China University of Petroleum(Beijing),2017.
[9] FAKHER S,IMQAM A.Asphaltene precipitation and deposition during CO2 injection in nano shale pore structure and its impact on oil recovery[J].Fuel,2019,237:1029-1039.
[10] BENHBAHANI T J,GHOTBI C,TAGHIKHANI V,et al.Investigation on asphaltene deposition mechanisms during CO2 flooding processes in porous media: a novel experimental study and modified model based on multilayer theory for asphaltene adsorption[J].Energy & Fuels,2012,26(8):5080-5091.
[11] WANG X Q,GU Y A.Oil recovery and permeability reduction of a tight sandstone reservoir in immiscible and miscible CO2 flooding process[J].Industrial & Engineering Chemistry Research,2011,50(4):2388-2399.
[12] PAPADIMITRIOU N I,ROMANOS G E,CHARALAMBOPOU G C,et al.Experimental investigation of asphaltene deposition mechanism during oil flow in core samples[J].Journal of Petroleum Science and Engineering,2007,57(3):281-293.
[13] WEI Bing,ZHANG Xiang,LIU Jiang,et al.Supercritical CO2-EOR in an asphaltenic tight sandstone formation and the changes of rock petrophysical properties induced by asphaltene precipitation[J].Journal of Petroleum Science and Engineering,2020,184(2):376-385.
[14] QIAN Kun,YANG Shenglai,DOU Hong′en,et al.Formation damage due to asphaltene precipitation during CO2 flooding processes with NMR technique[J].Oil & Gas Science and Technology-Revue d′IFP Energies nouvelles,2019,74(11):1121-1134.
[15] 王翠红,罗爱兰,王子军.石油沥青质四组分测定方法:NB/SH/T 0509—2010[S].北京:中国石化出版社,2010:3-5.
WANG Cuihong,LUO Ailan,WANG Zijun.Test method for separation of asphalt into four fractions:NB/SH/T 0509-2010[S].Beijing:China Petrochemical Press,2010:3-5.
[16] LEI H,YANG S L,QIAN K,et al.Experimental investigation and application of asphaltene precipitation envelop[J].Energy & Fuels,2015,29(11):6920-6927.
[17] HOSSEINI E.Experimental investigation of effect of asphaltene deposition on oil relative permeability,rock wettability alteration and recovery in WAG process[J].Petroleum Science and Technology,2019,20(37):2150-2159.
辽公网安备 21110002000031号 辽ICP备18011648号-1
