摘要
针对海上热采气(汽)窜问题,室内考察了一种耐温高强度环保型碱木素冻胶封窜体系的表观黏度、成胶温度、pH值对体系成胶时间、成胶强度的影响,研究了该体系的热稳定性和岩心封堵能力。研究表明,组成为5%碱木素+2%潜在醛类交联剂HDI+1.5%酚类交联促进剂DB+0.5%酰胺类耐温改进剂UR+1%高分子腈类韧性改进剂PL的碱木素封窜体系在常温(25℃)下的黏度为4.7 mPa·s,具有良好的可泵注性;体系成胶温度≥75℃,75℃下成胶时间为30 h,成胶强度为0.084 MPa,温度升高后体系的成胶时间缩短,成胶强度略降,当温度达到280℃时,成胶时间为5 h,成胶强度为0.068 MPa;体系使用的最佳pH值为7.0~9.0之间;该体系在250℃放置60 d后仅有少量脱水,重量变化在5%以内,成胶强度达0.067 MPa,说明体系热稳定性强,可满足高温储层的使用需求。岩心封堵实验表明,该体系封堵岩心后残余阻力因子为114.3;将碱木素封窜体系与泡沫复合使用的碱木素泡沫复合体系(碱木素封窜体系+2.5%磺酸盐类阴离子起泡剂COSL-07),残余阻力因子123.2,封堵效果良好。双管实验表明,碱木素泡沫复合体系使高渗管产液体积分数由80%降至55%,低渗管产液体积分数由20%升至45%,双管综合采出程度提高16.9%,说明该体系具有优良的选择性封窜和分流能力,可起到良好的调堵封窜作用,从而有效提升蒸汽驱驱油效果。
Aiming at the problem of gas(steam)channeling in offshore thermal recovery,a kind of temperature resistant,high-strength and environmental friendly channeling blockage system was investigated,and the effect of apparent viscosity,gel temperature and pH value on gel forming time and gelation strength was investigated and the thermal stability and blockage ability of the system were measured.The experimental results showed that the viscosity of the system,composed of 5%alkali lignin+2%potential aldehyde crosslinking agent HDI+1.5%phenol crosslinking accelerator DB+0.5%amide temperature resistant modifier UR+1%high molecular nitrile toughness modifier PL,was 4.7 mPa·s at temperature(25℃),indicated that the system had good pumpability.The gelation temperature of the system was≥75℃,and the gelation time at 75℃was 30 h.When the temperature increased,the gelation time of the system shortened,and the gelation strength decreased slightly.When the temperature was up to 280℃,the gelation time was 5 h and the gelation strength was 0.068 MPa.The optimal pH value of the system was 7.0—9.0.When the system was placed at 250℃for 60 days,only a small amount of water was dehydrated,and the strength could still reach 0.067 MPa,meanwhile the weight changed within 5%,which showed that the system had strong thermal stability and could meet the demand of high temperature reservoir.Core plugging experiments showed that the residual resistance factor of the system was 114.3.And when the system was combined with foam system(2.5%sulfonate anionic foaming agent COSL-07),the residual resistance factor was 123.2,showing good plugging effect.In parallel core experiment,the composite system reduced the volume fraction of liquid produced by high permeability pipe from 80%to 55%,and increased the volume fraction of liquid produced by low permeability pipe from 20%to 45%,the comprehensive recovery increased by 16.9%.It was indicated that the system had excellent selective channeling sealing effect and diverting ability,which could play a good role in channeling control and plugging,and effectively improve the oil displacement effect of steam flooding.
作者
吴春洲
王少华
孙玉豹
蒋平
肖洒
汪成
WU Chunzhou;WANG Shaohua;SUN Yubao;JIANG Ping;XIAO Sa;WANG Cheng(COSL Production Optimization,Tanggu Marine High-tech Development Zone,Tianjin 300459,P R of China;Institute of Petroleum Engineering,China University of Petroleum(East China),Qingdao,Shandong 266500,P R of China)
出处
《油田化学》
CAS
CSCD
北大核心
2021年第1期68-74,共7页
Oilfield Chemistry
关键词
海上稠油热采
碱木素封窜体系
成胶强度
成胶时间
调堵封窜
offshore heavy oil thermal recovery
alkali lignin sealing system
gelation strength
gelation time
plugging and sealing
