摘要
原油中的沥青质会随温度和压力变化发生沉淀,从而导致孔吼及油流通道堵塞,流动阻力增大,造成不可逆的储层伤害。为了在开发过程中预防沥青质严重沉积影响原油生产,采用近红外光散射技术和过滤法对沥青质初始沉淀压力进行研究。选取草舍油田区块典型井原油样品,采用近红外光散射技术测定油样在井口温度、井筒中部温度以及油藏温度下的沥青质初始沉淀压力,确定沥青质发生沉淀的热力学条件,并对热力学曲线拟合得到三项式回归方程;采用过滤法测定多组压力下的四组分含量,绘制胶质与沥青质比率曲线。结果表明:油样在实验温度为35、50、61、70、84℃时的沥青质沉淀初始压力分别为17.57、17.14、16.52、15.84、14.94 MPa,泡点压力分别为8.51、9.86、10.56、11.14、11.65 MPa;原油沥青质初始沉淀压力在井筒温度范围内呈线性反比例关系,且压力变化时胶质和沥青质呈相反的变化趋势。结合三项式回归方程和井筒温度压力曲线可预测开始出现沥青质沉淀的深度,对于地层防堵、井筒防沥青质沉淀具有参考意义。
The asphaltene in crude oil will precipitate with the change of temperature and pressure,which will lead to the blockage of pore roar and oil flow channel,and the increase of flow resistance,resulting in irreversible reservoir damage.In order to prevent severe asphaltene deposition affecting crude oil production during development,near-infrared light scattering technology and filtration method were used to study the onset precipitation pressure of asphaltene.The crude oil samples of typical wells in Caoshe Oilfield are selected,and the onset precipitation pressure of asphaltene at wellhead temperature,middle wellbore temperature and reservoir temperature is determined by near infrared light scattering technology.The thermodynamic conditions of asphaltene precipitation are determined,and the trinomial regression equation is obtained by fitting the thermodynamic curve.The four-component content under multiple sets of pressures is determined by filtration method,and the ratio curve of resin to asphaltene was drawn.The results show that the onset pressure of asphaltene precipitation at the experimental temperature of 35,50,61,70 and 84℃ is 17.57,17.14,16.52,15.84 and 14.94 MPa,respectively,and the bubble point pressure is 8.51,9.86,10.56,11.14 and 11.65 MPa,respectively.The onset precipitation pressure of crude oil asphaltene is linearly inversely proportional to the wellbore temperature range,and the resin and asphaltene show the opposite trend when the pressure changes.Combined with the trinomial regression equation and wellbore temperature and pressure curve,the depth of asphaltene precipitation can be predicted,which is of reference significance for formation plugging prevention and wellbore asphaltene precipitation prevention.
作者
程云龙
蒋子扬
杨子腾
王杰
沈忱
CHENG Yunlong;JIANG Ziyang;YANG Ziteng;WANG Jie;SHEN Chen(Sinopec East China Branch of Taizhou Production Plant,Taizhou 225300,Jiangsu,China;College of Petroleum Engineering,China University of Petroleum(East China),Qingdao 266580,Shandong,China)
出处
《科技和产业》
2023年第23期270-275,共6页
Science Technology and Industry
关键词
草舍油田
光散射技术
过滤法
沥青质沉淀
初始沉淀压力
Caoshe Oilfield
light scattering technology
filtering method
asphaltene precipitation
onset precipitation pressure
