正注反挤固井技术在套管开窗侧钻井中的应用

Application of Injection with Opposite Squeeze for Cementing to Casing Sidetracking

中原油田套管开窗侧钻井固井属于典型的小尺寸、窄间隙固井范畴。在下完套管循环过程中极易发生井漏,但由于环空间隙小,大颗粒堵漏材料无法使用,只好强行固井,固井质量往往达不到设计要求,造成后期挤水泥补救固井质量,浪费大量的人力、物力和财力。通过可行性分析和研究后,提出实施正注反挤固井工艺技术,介绍了实施该技术的前提条件,技术方案及要点和现场应用情况。该技术的关键是既要保证水泥上下可以有效对接,又要保证入井钻具的安全;"反挤"水泥浆量,以水泥浆稠化时间为依据,保证挤堵达到一定压力,避免二次挤水泥。

Casing sidetracking cementing in Zhongyuan oilfield belongs to a typical one featured by small size and narrow gap. Lost circulation often takes place after casing is loaded. Due to the small annular space, plugging material of big particles can ’ t be used. Therefore, a forced cementing has to be carried on but not meet design requirement, resulting in squeezing slurry during later cementing. So, a great deal of manpower, material and financial resources have been wasted. According to the feasibility analysis, a cementing technology named ' injection with opposite squeeze ' is implemented in this study. The key to the technology is to guarantee a good abutting joint of slurry up and down as well as the safety of drilling tools. The slurry volume of ' opposite squeeze ' is based on its thickening time in order to obtain a certain pressure and avoid squeezing again.