蒸汽驱用碱木素高温冻胶交联剂的研制及评价

碱木素冻胶是一种具有热稳定性且易于进入地层深部的高温堵剂,首先合成了碱木素冻胶的交联剂——水溶性酚醛树脂,优化了其合成反应条件,然后评价了碱木素高温冻胶的性能.研究结果表明:水溶性酚醛树脂的最佳合成条件为催化剂NaOH质量分数9%,甲醛与苯酚摩尔比1.8,反应温度85℃,自缩聚反应时间30 min.脱水后的水溶性酚醛树脂中羟甲基质量分数为83.54%,游离醛质量分数为0.35%,黏度为2 950 mPa.s,可在25℃下保存1个月,贮存稳定性好.在酚醛树脂质量分数为3.5%、碱木素质量分数为10%、体系pH值为9.75、高温200℃条件下碱木素冻胶的成胶时间为1.5 h,冻胶强度为0.092 MPa.成胶时间短,冻胶强度高,热稳定性好,具有较好的蒸汽调驱性能和应用前景.

Preparation and evaluation of a cross-linking agent of alkali lignin jelly for steam flooding

Alkali lignin jelly is a kind of high-temperature resistant plugging agent,which is of good thermal stability and easy to get into deep formation.A cross-linking agent for alkali lignin jelly-water-soluble phenolic resin is prepared,and its synthesis conditions are optimized.The performance of alkali lignin jelly is evaluated.The results show that,the optimal synthesis conditions of water-soluble phenolic resin are catalyst NaOH of 9%(mass fraction),the molar ratio of formaldehyde to phenol of 1.8,the reaction temperature of 85 ℃ and the reaction time of 30 min.In dehydrated phenolic resin,the mass fraction of methylol is 83.54%,and the mass fraction of formaldehyde is 0.35%.The viscosity of the dehydrated phenolic resin is 2 950 mPa.s.The phenolic resin is of good stability,and it can be stored one month at 25 ℃.The formation of alkali lignin jelly needs 1.5 h at 200 ℃ and 9.75 pH and under the conditions of alkali lignin of 10%,and phenolic resin of 3.5%(mass fraction),the strength of the formed jelly is 0.092 MPa.So the alkali lignin jelly is of the characteristics of short gelling time,high strength and good thermal stability.It has good application prospects in steam flooding.