Casing anti-wearing sub

1. Prevent drill pipes wearing the casing while drilling; 2. Decrease the drilling torque dramatically. 3. Long service life.

The wear and tear of casing and the higher drilling torque has become a serious problem encountered when drilling the high angle deviated well, the horizontal well and the deep well. The casing anti-wearing tool can be used to solve these problems very well.

Structure

The casing anti-wearing sub is consisted of an upper sub, an upper stop collar, an anti-wearing case, a lower stop collar and a lower sub from up to down. The interfaces among the body, the anti-wearing case and both these stop collars are designed as hard-faced smooth surface,so that the anti-wearing casing can rotate around the body freely.

How to work

Assemble appropriate quantity of casing anti-wearing subs at the right position of the drill stem. During drilling process, these oversize anti-wearing cases of casing anti-wearing subs directly touch the inner wall of the casing and keep still with the casing because of the friction function, meanwhile the body of the casing anti-wearing sub rotates together with the drill stem, which can stop the galling of the casing dramatically. In addition, the friction factor between the anti-wearing case and the body of the casing anti-wearing sub is very small, so the drilling torque will decrease dramatically.

Specifications:

Model	Total length (mm)	Max. OD (mm)	Nozzle size (mm)	Connection	Suitable casing	Lubricant
AW-138	915	Φ138	Φ50	NC38	6-5/8”	Drilling fluid
AW-146	915	Φ146	Φ68	NC38	7”
AW-197	915	Φ197	Φ75	NC50	9-5/8”
AW-205	915	Φ205	Φ90	5-1/2” FH	9-5/8”
AW-240	915	Φ240	Φ90	5-1/2” FH	13-3/8”

Structural Features

1. Optimally designed tungsten carbide plain bearing is lubricated with the drilling fluid during the drilling process.                                                                                                                                                                                         2. This tool is designed for reducing the occurrence rate of the drilling problems caused by the excessive drilling torque when drilling the high angle deviated well, the horizontal well and the ultra-deep well.

On-site Application

Till now, over 10000 casing anti-wearing subs have been  used on about 800 wells.

Casing anti-wearing sub