聚磺钻井液中碳酸(氢)根来源分析及预防处理措施

Resource and Prevention Measures of CO_3^(2-) (or HCO_3^-) in Polysulfonate Drilling Fluid System

深井及超深井钻探过程中钻井液时常受到碳酸(氢)根离子的污染,造成钻井液黏度切力值和滤失量增大,但目前对其来源和影响规律研究甚少。基于此,采用pH计双指示滴定方法对钻井液中碳酸(氢)根的来源因素进行了评价。研究结果表明:大部分处理剂会增加碳酸(氢)根离子含量,尤其是腐植酸类、聚合物类降滤失剂表现尤为突出;地层岩石对其几乎没有影响;空气中二氧化碳对碳酸根和碳酸氢根离子影响很大。初步研究了碳酸(氢)根形成的原因和影响规律,并提出了预防二氧化碳侵入钻井液的技术思路和处理碳酸(氢)根的方法。

In deep or ultra-deep wells, the drilling fluid systems are often contaminated by CO32- (or HCO3-) that is hazardto rheology and filtration. In this paper, the pH apparatus is applied to evaluate the resource of CO32- (or HCO3-), and theresults show that most of the agents increase the concentration of CO32- (or HCO3-), especially the polymer filtration controlagent, the effect of formation rocks to CO32- (or HCO3-) is too low to observe, but the air and CO2 is very high. The measuresof prevention and treatment for CO32- (or HCO3-) are developed.