摘要
针对煤层气层的低温固井以及深水表层套管固井中油井水泥早期强度发展缓慢的问题,通过将胶体SiO_2、硫酸盐和醇胺类物质三元复配,开发出一种复合型无氯早强剂AA。研究了该早强剂不同加量对油井水泥的影响,采用XRD、SEM分析水泥水化产物和微观形貌,并结合早强剂中各组分作用,分析了它的作用机理。通过向水泥中加入减轻材料和配套外加剂,形成了一套密度为1.35~1.87g/cm^3的低温固井水泥浆体系。研究结果表明,早强剂AA可以加速水泥熟料C_3S、C_2S的水化反应进程,同时消耗水泥水化生成的Ca(OH)_2,胶体SiO_2可以与Ca(OH)_2发生火山灰反应生成C—S—H凝胶,它可以填充水泥颗粒之间的微孔隙,显著提高水泥石早期强度;该低温固井水泥浆在30℃下的24 h抗压强度大于13 MPa,稠化时间在196~258 min之间,失水量为24 mL,游离液为0,流动度大于20 cm。此外,该水泥浆体系具有直角稠化、防气窜性能优异等优点。
A chlorine-free early-strength agent AA was developed by compounding colloidal SiO2, sulfate and alcohol amine. The development of AA is aimed at solving the troubles existed in cementing low temperature coalbed methane wells and cementing the surface hole section of deep water offshore wells. Effects of AA on the performance of oil well cement were studied. Using XRD and SEM, the hydrate of cement and the functioning mechanism of AA were analyzed. A 1.35-1.87 g/cm3 cement slurry suitable for low temperature well cementing was prepared using light weight material and other additives. Laboratory study shows that AA simultaneouslyaccelerates the hydration of cement clinkers C3S and C2S, and consumes the Ca（OH）2 produced. Pozzlanic reaction between SiO2 and Ca（OH）2 give birth to a C--S--H gel, which fills the pores and spaces formed by cement particles. Early strength of set cement is thus remarkably enhanced. This low temperature cement slurry has 24 h compressive strength of 13 MPa at 30 ℃, thickening time of 196-258 min, filter loss of 24 mL, free liquid of 0, and mobility greater than 20 cm. Other advantages of this cement slurry include short transient time and gas channeling prevention.
出处
《钻井液与完井液》
CAS
北大核心
2016年第1期79-83,共5页
Drilling Fluid & Completion Fluid
基金
973计划"海洋深水油气安全高效钻完井基础研究"(2015CB251202)
教育部长江学者创新团队"海洋油气井钻完井理论与工程"(IRT1086)
关键词
水泥浆
低温
早强剂
固井
煤层气
Cement slurry
Low temperature
Early strength agent
Well cementing
Coalbed methane
