深井钻井液碳酸根和碳酸氢根污染的处理

Treatment of drilling fluid contamination by carbonate and bicarbonate in deep drilling

关键词:  碳酸根  碳酸氢根  钻井液污染  硅酸盐  井眼稳定

Key words:  carbonate  bicarbonate  drilling fluid contamination  silicate  hole stability

摘要:

阐述了在深井钻探过程中遇到碳酸根和碳酸氢根离子污染后钻井液的性能特征,提出了针对不同程度污染的处理方法。针对中生界下部易跨塌泥岩、膏泥岩和含煤线地层单纯靠提高pH值和使用CaO进行处理已不能满足井下的需要,提出了使用硅酸盐的处理方法。通过室内实验和几口井的现场应用,使用硅酸盐进行调整处理,在处理碳酸根和碳酸氢根污染的同时,能够及时有效地起到防塌作用,保证钻井液具有良好的流变性和防塌能力。

Abstract:

The performance features of drilling fluid contaminated by carbonate and bicarbonate in deep well drilling were described and the treatment method to different contamination level was proposed.In view of easy collapse shale at the lower part of the Mesozoic strata,mudstone and coal-bearing strata lines,simply increasing the pH value and using CaO can’t satisfy the need of down hole,the application of silicate treatment was proposed.The laboratory experiments and field applications have proved that the use of silicate can not only deal with pollution of carbonate and bicarbonate,but also play an effective role in preventing collapse,which ensure that drilling fluid has a good ability of rheology behavior and anti-collapse.