有机硅吸水膨胀型选择性堵水剂的合成与性能评价

Development and Performance Evaluation of an Organic Silicon Water-Absorbing Expansion Selective Water Shutoff Agent

油井出水后会造成油井出砂、井底流压增大、自喷井停喷、井下设备被腐蚀,甚至造成严重的油井故障。国内外已研制开发的选择性堵水剂存在选择性不够理想、成本较高等不足,推广应用受到限制。采用水溶液聚合反应,在阳离子、阴离子及非离子单体的三元共聚物中引入有机硅活性官能团,合成了一种新型有机硅吸水膨胀型选择性堵水剂,其配方为:40mL水+6.2g丙烯酰胺+5.0g甲基硅酸+4.2g 2-丙烯酰胺-2-甲基丙磺酸+1.0g四甲基氯化铵+0.03g硅偶联剂GL-1+0.10g硅偶联剂GL-2+0.025g K2S2O8+0.05g NaHSO3;合成条件是在60℃下反应8h。性能评价试验结果表明:新型选择性堵水剂对油水具有很好的选堵性,堵水率在95%以上,堵油率低于10%;可选择封堵高渗透大孔道及出水层位,对低渗透油层损害小;具有较高的封堵强度,水的突破压力梯度大于10MPa/m,满足油井现场堵水作业的工程要求。

Water production from oil wells would result in sand production,bottomhole flowing pres sure increase, flowing stop of the natural flowing well, underground equipments corrosion, and even more serious accidents of oil wells. The application of selective water shutoff agent developed worldwide is limited due to their undesirable selectivity and high cost. Organic silicon active functional groups were introduced into anionic,cationic and nonionic monomer terpolymer through water solution polymerization reaction,a new organic silicon waterabsorbing expansion selective water shutoff agent was developed. In the synthetic formula,it contains water 40 mL, acrylamide 6. 2 g, methanesiliconic acid 5.0 g, 2-acrylamide-2- methyl propane sulfonic acid 4. 2 g, tetramethylammonium chloride 1.0 g, organosilicon coupler GL-1 0. 03 g,organosilicon coupler GL-2 0.10 g,K2S2O8 0. 025 g,and NaHSO3 0.05 g. The synthetic condition was to reacte for 8 h under 60 ℃. Test results of the performance evaluation showed that. new selective water shutoff agent has good selective plugging ability for oil and water, water shutoff rate is more than 95% while oil shutoff rate is lower than 10%. It can selectively seal high penetration throats and water layers while have little damages to low permeability reservoirs. It also has high sealing strength, and its water breakthrough pressure gradient is more than 10 MPa/m,which meets the engineering requirements of water shutoff for oil well onsite.