筛管外水泥环挤压酸洗管柱研制与应用

在筛管完井注水泥过程中,封隔器破损或卡封部位井径扩大,水泥浆会漏入筛管段将油层封固。为了打开油层重新建立油气生产通道,基于自主研制的水泥环挤压装置,形成了水泥环挤压酸洗管柱。水泥环挤压装置两端的封隔总成能够密封挤压装置与筛管之间的环空,然后利用节流传压总成传递的高压破碎筛管外的水泥环,而管柱底部的密封插管可打开人工井底的洗井阀并建立反循环洗井通道,将筛管外的水泥碎渣反洗至地面,恢复近井地带的渗透率。水泥环挤压酸洗管柱在胜利油田5口井进行了现场试验,成功率100%,试挤作业施工后,被封固的筛管段与地层连通性恢复正常。水泥环挤压酸洗管柱的成功研制,为解决筛管顶部注水泥完井后筛管段漏入水泥的问题提供了一种新的处理方法。 

The Development and Application of Cement Sheath Squeezing and Acid Washing String

In the process of cementing in screen pipe during or after well completion, cement slurry may leak into the screen pipe section and cause damage to the formation due to packer failure or wellbore enlargement at the packer setting position. In order to reopen the oil zone and rebuild access for oil and gas production, the cement sheath squeezing with an acid washing string were developed on the basis of the independently-developed cement sheath squeezing device. The packer assembly at both ends of the cement sheath squeezing device can seal the annulus between the extrusion device and the screen pipe. Then, the cement sheath outside the screen pipe is crushed due to high pressure from throttling and pressure-transmitting assembly. The seal tube at the bottom of the string can open the washing valve at the bottom of the artificial hole and thus build a back-cycling well washing access. In this way, the crushed cement sheath can be backwashed out to the ground and formation permeability near the wellbore can be recovered. The cement sheath squeezing and acid washing string have been tested in five wells in the Shengli Oilfield, with 100% success. After the execution of squeezing, the communication between the plugged screen pipe section and the formation was regained. The successful development of the string provided a new method to solve the problem of cement leaking into the formation in the screen pipe section after well completion of cementing at the top of the screen pipe.