摘要
为了探索高-特高含水期稠油油藏不同提液方式下提高剩余油采出程度的机理,设计不同提液方式、不同原油黏度下的海相砂岩稠油油藏驱替实验,采用在室内搭建长岩心物理模拟实验,研究高含水期、特高含水期时不同提液方式、原油黏度等因素对提高采收率的影响,结合核磁共振成像和T_(2)图谱研究不同注水方式下剩余油分布。研究表明,提液相比于恒定低速驱,可提高11%左右的采出程度;以驱替至含水率大于99%作为驱替结束条件,高含水期油藏通过多次控幅提液采出程度最高;岩心低速水驱至特高含水期后,岩心核磁共振图像饱和度明显降低,随着驱替的进行,孔隙度分量逐渐降低,即剩余油逐渐减少;高含水期多次提液对不同孔径动用程度比一次大幅提液效果好,微孔、小孔和中孔均有不同程度波及,整体采出程度提高17.01%,其中,中小孔导致采出程度提高13.31%,占提高幅度的78.2%;特高含水期,多次提液比一次大幅提液原油采出程度提高9.2%,其中中孔采出程度的提高作出主要贡献,占提高幅度的97.2%,微小孔波及程度较小。研究成果可为高-特高含水期稠油油藏提高采收率提供技术支持。
To explore the mechanism of enhancing the recovery degree of remaining oil in heavy oil reservoir with different liquid extraction methods in high and ultra-high water cut stage,a displacement experiment of heavy oil reservoirs in marine sandstone under different extraction methods and crude oil viscosity was designed.One dimensional displacement simulation experiment was carried out by constructing interior long core physics to study the effects of different liquid extraction methods and crude oil viscosity on EOR in high and ultra-high water cut stage.Then,the distribution of remaining oil under different water injection methods was studied by combining nuclear magnetic resonance imaging with T_(2) spectrum.The research shows that the recovery degree for the 100 mPa·s crude oil can be increased by about 11% compared with constant low-speed drive.Taking the water cut is more than 99% as a termination condition for displacement completion,the recovery degree of oil reservoir in high water cut stage is the highest through multiple amplitude control and liquid extraction.When it reaches ultra-high water cut stage for core low-speed water flooding,the core saturation showing in NMR image decreases obviously.With the progress of displacement,porosity component decreases gradually,that is,remaining oil decreases gradually.Compared withone large liquid extraction,multiple liquid extraction shows better effect on the production degree of different pore sizes than during the high water cut stage.Micropores,pores and mesopores are affected with different degrees,and the overall recovery degree is increased by 17.01%.The development of small and medium pores results in the increase of recovery degree by 13.31%,accounting for 78.2% of the increase range.In the ultra-high water cut stage,the dominant seepage channels are easily formed under the condition of both one large liquid extraction and multiple liquid extraction,and the oil recovery degree of multiple liquid extraction is 9.2% higher than that of one large liquid extraction.Under different liquid extraction methods,the medium pore makes main contribution to improve the recovery degree,accounting for 97.2% of the increase range,and the sweep degree of micro pore wave is the smallest.The research results indicate that multiple amplitude control and liquid extraction technology can provide technical support for EOR of heavy oil reservoir in high and ultra-high water cut stage.
作者
张伟
戴建文
王亚会
涂乙
Zhang Wei;Dai Jianwen;Wang Yahui;Tu Yi(Shenzhen Branch,CNOOC China Limited,Shenzhen Guangdong 518000,China)
出处
《地质科技通报》
CAS
CSCD
北大核心
2022年第3期193-199,共7页
Bulletin of Geological Science and Technology
基金
中国海洋石油总公司“十三五”科技重大项目(CNOOC-KJ135ZDXM22LTD02SZ2016)。
关键词
含水时机
提液变速驱
气测渗透率
原油黏度
核磁共振
稠油油藏
提高采收率
timing of water cut
variable speed flooding with fluid extraction
gas permeability
crude oil viscosity
nuclear magnetic resonance
heavy oil reservoir
enhanced oil recovery
