邓宝康,李军建,高银山,王新星,郭愿刚
DENG Baokang,LI Junjian,GAO Yinshan,WANG Xinxing,GUO Yuangang

• 1:四川奥吉特油田科技开发有限公司
• 2:中国石油长庆油田分公司第五采油厂

摘要(Abstract)：

注CO_2吞吐是提高致密油藏原油采收率的重要技术,研究吞吐过程中剩余油分布特征是提高CO_2吞吐效果的关键。基于核磁共振T_2谱测试原理,以鄂尔多斯盆地姬塬油田长7储层为研究对象,分别开展了不同注气压力下CO_2吞吐岩心驱替实验,研究了注气压力、吞吐次数和闷井时间对不同直径孔隙中剩余油分布的影响。结果表明:随着注气压力的升高,驱油方式发生变化,原油最终采收率不断增大,所需吞吐次数不断减少,平均采油速度不断提高;当注气压力大于最小混相压力(MMP)时,CO_2能够进入微细孔隙,甚至抽提出死孔隙中的原油,降低最小孔隙动用下限;当注气压力保持恒定时,增加吞吐次数无法降低微细、小孔隙中剩余油饱和度,但却能够有效降低中等、大孔隙内的剩余油饱和度;当注气压力大于最小抽提压力(MEP)时,增加闷井时间不但能够提高中等、大孔隙中原油采收率,还能降低最小孔隙动用下限;中等孔隙和大孔隙内的剩余油仍然是CO_2吞吐挖潜的主要方向。研究成果为姬塬油田长7段储层的注气开发提供了方法和依据。
CO_2 huff and puff is the important technology to enhance the oil recovery in tight oil reservoirs,and the study on the distribution characteristics of the remained oil during the huff and puff is the key to improve the effects of CO_2 huff and puff. Based on the principle of the nuclear magnetic resonance(NMR) T_2 spectrum test, taking Reservoir Chang-7 in Jiyuan Oilfield of Ordos Basin as the study object, the core displacing experiments of CO_2 huff and puff at different injection pressures were carried out to study the effects of the injection pressure, huff and puff times and soaking time on the remained oil distribution of different-diameter pores. The results show that with the increase of the injection pressure, the mode of the oil displacement changes as well, the ultimate oil recovery increases gradually, the needed times of the huff and puff decreased continuously, and the average oil recovery rate increases; when the injection pressure is higher than MMP, CO_2 can enter the micro-pores, and even extract the crude oil from the dead pores, the lower limit of the minimal pore development can be reduced; while the injection pressure is constant, the increase of the huff and puff times cannot reduce the remained oil saturation in the micro and small pores, but can effectively reduce the oil saturation in the medium and large pores; when the injection pressure is larger than the minimal extraction pressure(MEP), the increase of the soaking time can not only improve the oil recovery in the medium and large pores, but also reduce the lower limit of the minimal pore development; the remained oil in the medium and large pores is still the main potential-tapping direction by CO_2 huff and puff. The research results have provided the method and evidence for the gas injection for Reservoir Chang-7 in Jiyuan Oilfield.

关键词(KeyWords)： CO_2吞吐;剩余油分布;鄂尔多斯盆地;核磁共振;注气吞吐;孔隙直径;闷井时间
CO_2 huff-puff;remained oil distribution;Ordos Basin;nuclear magnetic resonance(NMR);gas injection huff and puff;pore diameter;soaking time

Abstract:

Keywords:

基金项目(Foundation): 国家自然科学基金项目“变形介质复杂储层应力敏感性的岩石流变学机理及动态模型”(51104119)

作者(Author): 邓宝康,李军建,高银山,王新星,郭愿刚
DENG Baokang,LI Junjian,GAO Yinshan,WANG Xinxing,GUO Yuangang

DOI: 10.19597/j.issn.1000-3754.201907080

参考文献(References)：

• [1]李忠兴,屈雪峰,刘万涛,等.鄂尔多斯盆地长7段致密油合理开发方式探讨[J].石油勘探与开发,2015,42(2):217-221.LI Zhongxing,QU Xuefeng,LIU Wangtao,et al.Development modes of Triassic Yanchang Formation Chang 7 Member tight oil in Ordos Basin,NW China [J].Petroleum Exploration and Development,2015,42(2):217-221.
• [2]杨华,李士祥,刘显阳.鄂尔多斯盆地致密油、页岩油特征及资源潜力[J].石油学报,2013,34(1):1-11.YANG Hua,LI Shixiang,LIU Xianyang.Characteristics and resource prospects of tight oil and shale oil in Ordos Basin[J].Acta Petrolei Sinica,2013,34(1):1-11.
• [3]赵清民,伦增珉,章晓庆,等.页岩油注CO2动用机理[J].石油与天然气地质,2019,40(6):1333-1338.ZHAO Qingmin,LUN Zengmin,ZHANG Xiaoqing,et al.Mechanism of shale oil mobilization under CO2 injection[J].Oil & Gas Geology,2019,40(6):1333-1338.
• [4]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.
• [5]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.
• [6]陈兴隆,秦积舜,张可.CO2与原油混相及非混相条件下渗流机理差异[J].特种油气藏,2009,16(3):77-81.CHEN Xinglong,QIN Jishun,ZHANG Ke.Difference of flowing mechanism in miscible and immiscible phase of CO2 and crude oil[J].Special Oil & Gas Reservoirs,2009,16(3):77-81.
• [7]杨胜来,杭达震,孙蓉,等.CO2对原油的抽提及其对原油黏度的影响[J].中国石油大学学报(自然科学版),2009,33(4):85-88.YANG Shenglai,HANG Dazhen,SUN Rong,et al.CO2 extraction for crude oil and its effect on crude oil viscosity[J].Journal of China University of Petroleum(Edition of Natural Science),2009,33(4):85-88.
• [8]ABEDINI A,TORABI F.Oil recovery performance of immiscible and miscible CO2 huff and puff processes[J].Energy Fuels,2014,28:774-784.
• [9]MA J H,WANG X Z,GAO R M,et al.Enhanced light oil recovery from tight formations through CO2 huff ‘n’puff process[J].Fuel,2015,154:35-44.
• [10]周宇,魏国齐,郭和坤.核磁共振孔隙度影响因素分析与校准[J].测井技术,2011,35(3):210-214.ZHOU Yu,WEI Guoqi,GUO Hekun.Impact factors analysis and decision tree correction of NMR porosity measurements[J].Well Logging Technology,2011,35(3):210-214.
• [11]高涛,赵习森,党海龙,等.延长油田致密油藏注水吞吐机理及应用[J].特种油气藏,2018,25(4):134-137.GAO Tao,ZHAO Xisen,DANG Hailong,et al.Mechanism of cyclic water injection and its application in tight oil reservoirs in Yanchang Oilfield[J].Special Oil & Gas Reservoirs,2018,25(4):134-137.
• [12]曹永娜.利用CT扫描技术实现对岩心微观驱替过程的研究[J].科学技术与工程,2015,15(6):64-68.CAO Yongna.Study of microscopic blooding process using CT scanning technique [J].Science Technology and Engineering,2015,15(6):64-68.
• [13]喻建,杨孝,李斌,等.致密油储层可动流体饱和度计算方法:以合水地区长7致密油储层为例[J].石油实验地质,2014,36(6):767-772.YU Jian,YANG Xiao,LI Bin,et al.A method of determining movable fluid saturation of tight oil reservoirs:A case study of tight oil reserviors in seventh member of Yanchang Formation in Heshui area[J].Petroleum Geology & Experiment,2014,36(6):767-772.
• [14]杜殿发,郭乔乔,郑洋,等.砂体叠置关系与剩余油分布规律[J].特种油气藏,2018,25(4):62-66.DU Dianfa,GUO Qiaoqiao,ZHENG Yang,et al.Superposition of sandstone formations and patterns in residual oil distribution[J].Special Oil & Gas Reservoirs,2018,25(4):62-66.
• [15]代全齐,罗群,张晨,等.基于核磁共振新参数的致密油砂岩储层孔隙结构特征:以鄂尔多斯盆地延长组7段为例[J].石油学报,2016,37(7):887-897.DAI Quanqi,LUO Qun,ZHANG Chen,et al.Pore structure characteristics of tight-oil sandstone reservoir based on a new parameter measured by NMR experiment:A case study of Seven Member in Yanchang Formation,Ordos Basin [J].Acta Petrolei Sinica,2016,37(7):887-897.
• [16]郎东江,伦增珉,王海涛,等.致密砂岩储层CO2驱油特征的核磁共振实验研究[J].CT理论与应用研究,2016,25(2):141-147.LANG Dongjiang,LUN Zengmin,WANG Haitao,et al.Study of displacement characteristics of CO2 in tight sandstone reservoir by nuclear magnetic resonance [J].Computerized Tomography Theory and Application,2016,25(2):141-147.
• [17]高辉,程媛,王小军,等.基于核磁共振驱替技术的超低渗透砂岩水驱油微观机理实验[J].地球物理学进展,2015,30(5):2157-2163.GAO Hui,CHEN Yuan,WANG Xiaojun,et al.Experiment of microscopic water displacement mechanism based on NMR displacement technology in ultra-low permeability sandstone[J].Progress in Geophysics,2015,30(5):2157-2163.
• [18]QIAN K,YANG S L,DOU H E,et al.Experimental investigation on microscopic residual oil distribution during CO2 huff-and-puff process in tight oil reservoirs [J].Fuel,2018,11(10):28-43.
• [19]SAIFUR R,WASEF N,ABDUL A M,et al.Phase behavior aspects of carbon dioxide (CO2) miscible flooding in tight cores:A case study[R].SPE 128467,2010.
• [20]蒲万芬,王崇阳,李一波,等.致密油储层CO2驱核磁共振实验研究[J].科学技术与工程,2017,17(7):30-34.PU Wanfen,WANG Chongyang,LI Yibo,et al.Nuclear magnetic resonance experimental study of CO2 flooding in tight reservoir[J].Science Technology and Engineering,2017,17(7):30-34.
• [21]胡伟,吕成远,王锐,等.水驱油藏注CO2非混相驱油机理及剩余油分布特征[J].油气地质与采收率,2017,24(5):99-105.HU Wei,Lü Chengyuan,WANG Rui,et al.Mechanism of CO2 immiscible flooding and distribution of remaining oil in water drive oil reservoir [J].Petroleum Geology and Recovery Efficiency,2017,24(5):99-105.
• [22]秦积舜,张可,陈兴隆.高含水后CO2驱油机理的探讨[J].石油学报,2010,31(5):797-800.QIN Jishun,ZHANG Ke,CHEN Xinglong.Mechanism of the CO2 flooding as reservoirs containing high water[J].Acta Petrolei Sinica,2010,31(5):797-800.