903 Well Site Completion and Servicing Safety

Repairing Liners and Casing

Liners and casing are essentially the same and repair procedures are the same for both. Casing can be damaged by corrosion, abrasion, pressure, or other forces that create holes or splits.

A packer is run down the well to locate the hole in the casing. Fluid, usually salt water or oil, but sometimes mud, is pumped into the casing above the packer. A packer is a piece of downhole equipment that consists of a sealing device, a holding or setting device, and an inside passage for fluids.

A loss of fluid pressure indicates that there may be a hole, split, or other leak in the casing. When fluid is pumped into the casing above the packer, the pressure should remain relatively stable if the casing is intact. If the pressure drops unexpectedly, it suggests that the fluid is escaping through a damaged section of the casing. By moving the packer to different depths and repeating the pressure test, technicians can narrow down the location of the leak. Once the damaged area has been identified, the appropriate repair method, such as installing a casing patch or performing other remedial work, can be planned and carried out.

Potential Hazards

• Getting pinched fingers and hands from tongs and slips
• Being struck by swinging tubing and tubing elevators
• Getting caught between the joint and tongs or stump
• Being struck by the tubing hanger wrench if it should slip
• Getting fingers and hands pinched and caught between tubing hanger and tubing head

Possible Solutions

• Keep all fingers and hands away from pinch points.
• Instruct workers to be on alert when on the rig floor and pipe racking area.
• Avoid placing hands on the end of the tubing stump.
• Use the correct tools for each task.
• Inspect the tools before use.
• Use coiled tubing.

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