摘要
为了更加深入地探究特低-超低渗透储层油水的微观流动特征及其表现出差异性的因素,以马岭油田长8_1储层为代表,对典型样品进行了微观渗流实验,并结合物性、铸体薄片、扫描电镜、恒速压汞及核磁共振等多种实验测试结果对储层流体的微观驱替机理及导致驱油效率高低不同的因素进行了研究。结果表明:研究区块长8_1油藏按微观渗流通道类型可分为溶孔-粒间孔型、溶孔型、微孔型3类,其驱油效率逐类降低,不同微观渗流通道类型样品的渗流特征表现出较大的差异性,其中溶孔-粒间孔型样品平均驱油体积为0.010 cm~3,最终平均驱油效率高达45.60%,驱替效果最为理想。储层微观条件中,喉道半径大小及分布状况对驱油效率的大小起决定性的作用,物性和可动流体饱和度两者对驱油效率的大小均具有较低程度的控制作用;外部实验条件中,对驱油效率产生较大控制作用的为注入水体积倍数和驱替压力。因此,在油藏实际水驱采油过程中应当采用较为合理的注水压力和注入水体积倍数。
In order to further explore the microscopic flow characteristics of oil and water in extra-ultra low permeability reservoirs and the factors that show differences, this paper takes the Chang 8_1 reservoir of Maling Oilfield as the representative, and carries out microscopic seepage experiments on typical samples, and combines physical properties, cast thin sections, scanning electron microscopy, constant-velocity mercury intrusion and nuclear magnetic resonance to test fluids. This paper explores in detail the microscopic displacement mechanism and the factors that lead to different oil displacement efficiencies. The results show that the Chang 8_1 reservoir in the study block can be divided into three types: dissolved pore-intergranular pore type, dissolved pore type and microporous type. The oil displacement efficiency is reduced by class, and different microscopic seepage channel type samples are obtained. The percolation characteristics show a large difference. The average oil displacement volume of the dissolved pore-intergranular pore sample is 0.010 cm~3, and the final average oil displacement percentage is as high as 45.60%. The displacement effect is the most ideal. In the microscopic characteristics of reservoirs, the size and distribution of throat radius play a decisive role in the efficiency of oil displacement. Both physical properties and dynamic fluid saturation have a lower degree of control over the efficiency of oil displacement. Among the external experimental conditions the injection water volume and the displacement pressure are greatly responsible for the oil displacement efficiency. Therefore, a reasonable water injection pressure and volume of injection water should be used in the actual waterflooding process of the reservoir.
引文
[1] 杨平.长庆超低渗储层特征及渗流规律实验研究[D].北京:中国科学院研究生院,2011.
[2] 王瑞飞,陈军斌,孙卫.特低渗透砂岩油田开发贾敏效应探讨:以鄂尔多斯盆地中生界延长组为例[J].地质科技情报,2008,27(5):82-86.
[3] 王友净,宋新民,田昌炳,等.动态裂缝是特低渗透油藏注水开发中出现的新的开发地质属性[J].石油勘探与开发,2015,42(2):222-228.
[4] 杨华,付金华,何海清,等.鄂尔多斯华庆地区低渗透岩性大油区形成与分布[J].石油勘探与开发,2012,39(6):641-648.
[5] 任大忠,孙卫,赵继勇,等.鄂尔多斯盆地岩性油藏微观水驱油特征及影响因素:以华庆油田长81油藏为例[J].中国矿业大学学报,2015,44(6):1043-1052.
[6] 黎盼,孙卫,高永利,等.致密砂岩储层差异性成岩演化对孔隙度定量演化表征影响:以鄂尔多斯盆地马岭地区长81储层为例[J].地质科技情报,2018,37(1):135-142.
[7] 孙卫,曲志浩,李劲峰.安塞特低渗透油田见水后的水驱油机理及开发效果分析[J].石油实验地质,1999,31(3):256-260.
[8] 王瑞飞,孙卫.特低渗透砂岩微观模型水驱油实验影响驱油效率因素[J].石油实验地质,2010,32(1):93-97.
[9] 庞振宇,李艳,王蓓蕾,等.特低渗储层驱油效率影响因素分析[J].非常规油气,2017,4(4):76-81.
[10] 高辉,解伟,杨建鹏,等.基于恒速压汞技术的特低-超低渗砂岩储层微观孔喉特征[J].石油实验地质,2011,33(2):206-211.
[11] 张茜.马岭油田长81储层微观孔隙结构特征和渗流特征研究[D].西安:西北大学,2015.
[12] 王伟,朱玉双,陈大友,等.低渗透油藏微观渗流特征及影响因素研究:以鄂尔多斯盆地姬塬地区长6油层组为例[J].地质科技情报,2015,34(2):159-164.
[13] 全洪慧,朱玉双,张洪军,等.储层孔隙结构与水驱油微观渗流特征:以安塞油田王窑区长6油层组为例[J].石油与天然气地质,2011,32(6):952-960.
[14] 祝海华,钟大康,姚泾利,等.鄂尔多斯西南地区长7段致密油储层微观特征及成因机理[J].中国矿业大学学报,2014,43(5):853-863.
[15] 王瑞飞,吕新华,国殿斌.深层高压低渗砂岩储层微观孔喉特征参数研究[J].中国矿业大学学报,2012,41(1):64-68.
[16] 付晓燕,孙卫.低渗透储集层微观水驱油机理研究:以西峰油田庄19井区长82集层为例[J].新疆石油地质,2005,26(6):79-81.
[17] 李振泉,侯健,曹绪龙,等.储层微观参数对剩余油分布影响的微观模拟研究[J].石油学报,2005,26(6):69-73.
[18] 孙卫,史成恩,赵惊蛰,等.X-CT扫描成像技术在特低渗透储层微观孔隙结构及渗流机理研究中的应用:以西峰油田庄19井区长82储集层为例[J].地质学报,2006,80(5):775-779.
[19] 师调调,孙卫,何生平.低渗透储层微观孔隙结构与可动流体饱和度关系研究[J].地质科技情报,2012,31(4):81-85.
[20] 任颖,孙卫,张茜,等.低渗透储层不同流动单元可动流体赋存特征及生产动态分析:以鄂尔多斯盆地姬塬地区长6段储层为例[J].地质与勘探,2016,52(5):974-984.
[21] 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.
[22] 田选华,陆正元,胡罡,等.水驱油田合理注采压力系统[J].石油与天然气地质,2015,36(1):142-147.