新型低温固井早强剂性能研究

Study on the Performance of a New Low Temperature Early Strength Agent for Well Cement Slurries

针对浅层低温导致水泥浆强度发展缓慢的问题,通过分散-共沉淀法制备了一种新型低温固井早强剂ES-22,并对制备早强剂的粒径及微观结构进行分析。比较了在低温条件下,新型早强剂ES-22与其他无机早强剂对水泥浆强度发展的影响,并研究了新型早强剂不同加量对水泥浆性能的影响规律。研究表明,制备的早强剂ES-22粒径主要集中在15~25μm之间。与其他早强剂相比,新型早强剂ES-22对水泥石早期抗压强度提升最大,且制备的早强剂在低温环境下对水泥石力学性能提升更大。早强剂掺入水泥浆中对水泥浆流变性影响不大,稠化时间无大幅度缩短,失水量降低。在20℃下养护24 h后,含4%早强剂水泥石的抗压强度和抗折强度比空白水泥石分别提高了204%和136%。新型早强剂在固井水泥浆中有很好的应用效果。

A new low temperature early-strength agent ES-22 has been developed through dispersion-coprecipitation method to solve the slow strength development of cement slurries in shallow and low temperature well cementing.In laboratory experiment,the particle size distribution and micro-structure of ES-22 were analyzed,the effects of ES-22 and other inorganic early-strength agents on the strength development of cement slurries at low temperatures were compared.The effects of ES-22 of different concentrations on the properties of cement slurries were also studied.It was found that ES-22 has particle sizes distributed between 15μm and 25μm.Compared with other early-strength agents,ES-22 is the best early-strength agent for the development of the early compressive strength of set cement.At low temperatures,ES-22 has even greater contribution to the development of the mechanical property of the set cement.ES-22 has little,if any,effects on the rheology of the cement slurry,the thickening time of the cement slurry becomes only a little short,and the volume of filter loss is reduced.In laboratory experiment,a set cement containing 4%ES-22 had its compressive strength and flexural strength increased by 204%and 136%respectively over the compressive strength and flexural strength of the blank set cement after aging at 20℃for 24 hours.These results indicate that the early-strength agent ES-22 performs very well in oil well cement slurries.