Parted Casing or Parted tubing
The parted casing is the result of a tubular exceeding its mechanical limits due to overpressure rates during stimulation, excessive loading, or tectonic movement.
In the case of a parted casing string, the separation usually occurs at the coupling, due either to a fracture, the stripping of the threads, the collapsing of the end of a joint, the expanding of the coupling, or two or more factors in combination.
A sudden loss of weight and a decrease in circulating pressure usually means the pipe has parted downhole. Care is necessary when pulling out of the hole after the tubing has parted since there is no BHA to prevent the broken pipe being pulled right out the stripper and a consequent loss of containment.
Benefits in repairing parted tubular with Saltel casing Patch
- Sealing efficiency against the parted tubular. Once installed Saltel patch sealing design allows relative displacement. That means the parted section will slide around the patch without damaging the seal in case of thermal expansion of the tubular during production.
- Excellent resistance to temperature cycling. Extreme high-temperature patches were installed with success to repair 7in and 9-5/8in parted casings in Canadian CSS (Cyclic Steam Stimulation) wells, where temperature cycling is essential. Saltel casing Patch confirmed strong resistance in CSS wells.
- Optimized profile of the patch BHA to enter the parted section. The bottom of BHA has a good entry guide profile to reach setting depth, even in a parted section. This statement is valid only if the misalignment of the parted sections remains minimal.