连续油管喷砂射孔和筛管改流跨隔压裂组合工艺

常用的漏掉产层增产技术主要为连续油管跨隔压裂、连续油管逐层填砂顶封压裂,这些技术通常应用于埋藏较浅的储层。但对于埋藏较深的漏掉产层进行改造作业时,存在摩擦损失大、井口压力高、施工排量小的问题。连续油管喷砂射孔具有无压实作用和降低地层破裂压力的优点;连续油管筛管改流跨隔压裂工艺,通过将筛管和双封隔器相结合,在上部封隔器处通过筛管将油套环空的压裂液改流进入油管,油管中的压裂液经过下部封隔器后由节流喷嘴喷出,实现对目的层改造作业,由于施工过程中压裂液大部分在油套环空中流动,降低了沿程摩阻。该组合工艺充分利用了连续油管的优点,并克服施工排量小、井口压力高的问题,在准噶尔盆地储层深度3 660 m的××井中成功应用,施工过程中的最高排量为4.6 m3/min,最高井口压力43.8 MPa,压裂后增产效果明显。

Application of combination technology of coiled tubing sand jet perforation and variation flow channel straddle fracturing with screen in missing production layer

The commonly used stimulation technique for missing pay zones are crossing-packer fracturing with coiled tubing and coiled tubing top seal fracturing fir each sand-packed zone.These techniques can be applied to shallow zones,but for the deep zones,there are some problems,such as large friction loss,high wellhead pressure and small displacement during the operation.The coiled tubing sand jet perforation has the advantages of non compaction and reducing the pressure of formation fracturing;the flow channel variation bv screen pipe with crossing-packer fracturing process combines the screen pipe with dual packer,in which the fracturing fluid in the tubing-casing annulus is changed into tubing with screen pipe,and ejects from throttle nozzle after flowing through the lower packer,finally finishing the fracturing operation of the target zone.As a result of the operation process,most of the fracturing fluid flows in the tubing-casing annulus,reducing the friction loss along the way.The combined process makes full use of the advantages of coiled tubing and overcomes the problems of low operation displacement and high wellhead pressure,which has been successfully applied in XX Well with the depth of 3 660 m in Junggar Basin.The maximum displacement and the highest wellhead pressure in the operation process are 4.6 m3/min and 43.8 MPa respectively,and the stimulation effect after fracturing is remarkahle.