瓜尔胶低分子量化降解条件研究  

Enzyme Degradation Conditions for Preparing Low Molecular Mass Guar Gum as Hydrofracturing Fluid Thickener

作　　者：王丽伟[1] 卢拥军[1] 单文文[1] 张汝生[1] 

机构地区：[1]中国石油勘探开发研究院廊坊分院,河北廊坊065007

出　　处：《油田化学》2006年第1期32-35,共4页Oilfield Chemistry

基　　金：国家十五科技攻关课题"低渗透油田增产改造关键技术研究"(编号2003BA613A-07)

摘　　要：为了制备压裂液用低分子量瓜尔胶，以反应液25℃、170s^-1黏度减小幅度△η为控制指标，实验考察了用β甘露聚糖酶降解瓜尔胶的条件，确定瓜尔胶水溶液浓度10g/L（黏度291mPa·s．分子量2．435×10^6）；pH值7；酶用量0．2g／L；降解温度45℃；降解时间视对瓜尔胶分子量的要求而定，约40min。随pH值升高（4～11）和温度升高（10～80℃），△η／经过最大值。将原料瓜尔胶在0．2moL／LNaCI水溶液中配成2g／L溶液，用p甘露聚糖酶在45℃降解不同时间（0～90min），得到10个反应液样，用同一NaCl溶液稀释至适当浓度，用激光光散射法在25℃测定其重均分子量‰及其中5个样的特性黏数[η]，用线性回归方法求得Mark-Houwink[η]-M^-w关系式中的常数K=0．075mL／g，α=0，662（分子量范围2．435×10^6-2．210×10^5）。图4表3参5。For the purpose of preparing low molecular mass guar gum （GG） for hydrofracturing fluids, the conditions of enzyme degradation of commercial GG of M^- = 2.435×10^5 are studied experimentally with viscosity reduction, △η, of reaction mixture at 25℃ and 170 s^-1 as a criterion of appraisal and established as follows： GG concentration in aqueous solution 10 g/L with visoosity 291 mPa·s; dosage of β-mannase 0.2 g/L; pH of reaction solution 7; degradation temperature 45℃ ; degradation time as needed, -40 rain. △η goes through a maximum with increasing pH value from 4 to 11 or temperature from 10 to 80℃. Original GG in 2 g/L solution prepared with 0.2 mol/L NaCI aqueous solution is degradated at the presence of β-mannase at 45℃ in different time, 0-90 min, to give 10 reaction mixture samples, the laters are diluted with the same NaCl solution to various proper concentration and taken for determing weight average molecular mass, M^-w, by a laser light scattering method and 5 of them-characteristic viscosity, [η], at 25℃. Substituting these sets of data into Mark-Houwink＇s [℃]-M^- equation, 2 equation constantsare obtained by the way of linear regression： K = 0.075 mL/g; a = 0.662 for M^- in range 2.435 ×10^6-2.210×10^5.

关 键 词：瓜尔胶 低分子量 酶降解 Β-甘露聚糖酶 降解反应条件 分子量测定 Mark-Houwink方程 压裂液稠化剂 

分 类 号：TE357.12[石油与天然气工程—油气田开发工程] TE39