摘要
针对当前钻井液和泥饼中聚合物降解机理研究不足的现状,通过DNS比色法和粘度测定法,考察了生物酶种类、生物酶质量分数、pH值和温度等对生物酶降解性能的影响。研究发现:随着生物酶质量分数的增加,钻井液粘度降低率增加,其中复合酶降解程度最高,淀粉酶次之,纤维素酶最低;生物酶(尤其是淀粉酶)对钻井液的粘度影响明显,温度越高,钻井液粘度降低速率越慢,超过95℃后,生物酶的降解能力基本消失;pH值对生物酶的作用效果影响显著,中性条件最适合生物酶降解聚合物。在所有生物酶中,复合酶的效果最佳,在温度为70℃的条件下,3 h内可完全分解聚合物。因此,采用适合的生物酶技术可有效地降解钻井液和泥饼中的聚合物。
Herein, we study the enzyme degradation of drilling and completion fluids by different bio-enzymes with DNS color comparison and viscosity determination for compensating the scarce of enzyme degradation mechanisms of the polymers in drilling fluids and mud-cakes, and then,analyze the effects of ambient conditions such as concentration,temperature,bulk pH and bioenzyme mass fraction on the enzyme degradation performance. The results show that, the bio-enzymes, especially starch enzyme, can affect the viscosity of drilling fluids considerably. Temperature can affect the viscosity reduction rate, and when the temperature is higher than 95℃, its degradation ability disappears. The pH affects the enzyme degradation remarkably, whose activity is maximum at moderate pH. Using enzyme mixture, the mud-cakes can be decomposed completely at 70℃ after 3h. Therefore, suitable bio-enzyme mixtures can effectively degrade different polymers in drilling fluids, therefore, it is an effective method for mud-cakes clean-up.
出处
《油气地质与采收率》
CAS
CSCD
北大核心
2011年第2期98-101,117-118,共4页
Petroleum Geology and Recovery Efficiency
基金
国家科技重大专项"低渗油气田高效开发钻井技术"课题四"低渗油气田储层保护技术"(2011ZX05022-004)
关键词
生物酶
降解性能
解堵作用
聚合物
环境因素
钻井液
starch enzymes
degradation performance
unplugging
polymer
ambient factors
drilling liquid
