瓜胶压裂液用杀菌剂评价指标有效性的影响因素

针对现场使用羟丙基瓜胶压裂液杀菌剂易出现腐败变质过快，影响现场压裂施工的现象，将企业产品标准评价条件与现场实际的对比，认为以下3个方面是引起腐败变质过快的主要原因:标准评价方法中，菌类来源未考虑来自罐体的菌类；碱性交联的羟丙基瓜胶用杀菌剂pH值应不小于7为宜，同时应考虑pH值0.1以上的变化引起的瓜胶原液黏度变化，杀菌剂的效果应优于羟丙基瓜胶压裂液pH值交联调节剂的效果；黏度保持率应结合不同浓度羟丙基瓜胶黏度值大小及交联携砂性来确定。 

Key Factors Affecting the Effectiveness of Evaluating Indicators for Bactericides Used in HPGG Fracturing

Bactericides used in hydroxyl propyl guar gum (HPGG) fracturing fluids are inclined to become decayed quickly, hence hindered well fracturing. In laboratory studies the conditions under which the bactericides were evaluated and the field conditions compared.Three factors were found affecting the decaying process of the bactericides.First, the bacteria used in standard evaluation process do not take into account those from fluid tanks. Second, the pH values of the bactericides used in HPGG (produced through alkaline crosslinking) fracturing fluids should not be less than 7. Consideration should be given to the changes in pH values by greater than 0.1 which will cause changes in the viscosity of the guar gum liquid, and the effectiveness of bactericides should be superior to that of pH value crosslinking modifiers used in HPGG fracturing fluids. Third, percent viscosity retention should be determined on the basis of the viscosities of HPGG of different concentrations and sand carrying capacity through crosslinking performance.