煤层气U型井水平井固井技术研究

A Study on U-shaped Horizontal CBM Well Cementing Technology

U型井是煤层气资源开采的一种新型模式,在水平井固井施工时易出现水泥浆冲刷洞穴,部分水泥浆进入洞穴直井,破坏直井,另外,斜井段顶替效率低,容易造成泥浆窜槽,影响固井质量。为了解决这一问题,提出了分流水泥浆套管串结构和采用低密度水泥浆+速凝早强水泥浆体系固井技术。该工艺技术不仅保证了水泥浆能顺利返至地面,也避免了水泥浆对直井洞穴的冲刷,确保固井质量,因而在类似煤层气U型井固井作业时具有良好的应用前景,可逐步推广。

The U-shaped well is a new model in CBM exploitation.But during the operation of well cementing,cement slurry scouring is quite common,part of slurry will penetrate into vertical sector and cause damege.Besides,the replacement efficiency is too low in inclined sector,and easy to cause slurry channelling,thus impacting the cementing quality.In order to settle the issue,shuntting slurry casing strings configuration and using low-density cement slurry plus rapid setting early strength cement slurry well cementing system put forward.The technology can not only ensure the slurry return to ground surface smoothly,but also avoid vertical sector slurry scouring,thus quality of well cementing can be ensured.As such,the technology has good application prospect in similar U-shped CBM well cementing operation,and can be promoted gradually.