单因素法分析钻井液处理剂对水泥浆性能的影响

Impact of drilling fluid additives on performance of the cement slurry by single-factor

钻井液与水泥浆相容性差,混浆后易产生接触污染,即混浆段流体出现流动性恶化、水泥浆稠化时间缩短、水泥环强度降低等问题。实践表明,钻井液处理剂是造成接触污染的主要原因之一。为此,采用单因素法考察了13种钻井液处理剂对水泥浆性能的影响规律,利用红外光谱对处理剂进行了结构表征,用环境扫描电子显微镜对污染后的水泥石结构进行微观形貌分析。结果表明,生物增黏剂、聚丙烯酰胺钾盐能使水泥浆急剧变稠;SMT、SMP-1、JN-A能够缩短水泥浆稠化时间,但加量在1%(w)以内影响较小;其余钻井液处理剂加量在一定范围内对水泥浆性能影响较小。生物增黏剂和聚丙烯酰胺钾盐参与水泥水化、影响水泥浆结构形成过程是造成污染的重要原因;同时,高聚物大分子链发生卷曲、吸附架桥和电中和作用使水泥浆产生絮凝现象。污染机理的提出为钻井液合理选材、钻井液性能调整、减少钻井液与水泥浆的污染提供了理论依据。

The compatibility of drilling fluid and cement slurry is poor,and pollution will occurs as long as they contact,namely liquidity deterioration of mix slurry fluid,shortage of slurry thickening time and decrease of the cement ring strength.This paper studied the impact of drilling fluid additives used in Sichuan and Chongqing on the performance of the cement slurry by single-factor.The composition of additives was characterized by infrared spectroscopy,and the structure of cement stone was analyzed by environmental scanning electron microscope.The results show that biological tackifier and polyacrylamide potassium(KPAM)can make the slurry thicken quickly;SMT,SMP-1and JN-A will shorten the thickening time,while the effect is small within the dosage of less than 1%.The rest additives have less affect within a certain range.Then the pollution reason was analyzed.One of the important reasons is that some additives participate in cement hydration,and affect the process of slurry formation.Polymer macromolecular chains curled and adsorption bridging will make the cement slurry flocculate.The proposal of pollution mechanism provides a theoretical basis for reasonable selection of drilling fluid additives,and can reduce the pollution of drilling fluid and cement slurry.