摘要:
采用理论分析与试验研究相结合的方法,系统地开展了低密度复合水泥基固井材料研究。首先,分析了煤层气井固井的特点以及常用的低密度固井水泥浆体系,提出了基于油井水泥与硫铝酸盐复合的“水化协同效应”,采用空心玻璃微珠为减轻剂、葡萄糖酸钠为缓凝剂,进而研发低密度复合水泥基固井材料的新思路;然后,按不同比例对油井水泥与硫铝酸盐水泥进行复合,研究复合浆液的流动性、凝结时间、可泵期、抗压强度等基本性能,确定复合水泥浆液基础配方。在此基础上,分析不同加量的空心玻璃微珠及葡萄糖酸钠对基础配方性能的影响,进而研制获得适于煤层气固井的低密度复合水泥基固井材料优化配方。最后,对优化配方的主要性能进行评价。结果表明,所研究的低密度复合水泥基固井材料具有浆液密度较低、流动性好、凝结时间可控、快硬早强、绿色环保等特点。
Abstract:
Based on the combination of theoretical analysis and experimental research, the research on coalbed methane low density composite cement-based cementing materials was systematically carried out. Firstly, the characteristics of coalbed methane cementing and the commonly used low-density cementing slurry system are analyzed. The “hydration synergy effect” based on the combination of oil well cement and sulphoaluminate is proposed. The hollow glass microbeads are used as the reducing agent and sodium gluconate as the retarder, a new idea of low-density composite cement-based cementing materials is developed. Then, the oil well cement and sulphoaluminate cement are compounded according to different proportions to study the fluidity, setting time and pumpability of the composite slurry. Basic properties such as period and compressive strength determine the basic formula of composite cement slurry. On this basis, the effects of different amounts of hollow glass microspheres and sodium gluconate on the properties of the base formulation were analyzed, and then the optimized formula of low-density composite cement-based cementing materials suitable for coalbed methane cementing was developed. Finally, the main performance of the optimized formulation is evaluated. The results show that the low-density composite cement-based cementing materials studied have the characteristics of low slurry density, good fluidity, controllable coagulation time, fast and hard, early strength, and environmental protection.
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