Zeroth Technology Ltd., an affiliate of Baker Hughes, introduced a new high-expansion, metal-to-metal sealing technology. According to several recent case studies, the Z-Seal’s expanding metal concept withstands pressure that commonly causes traditional elastomeric

Metal-to-metal seal technology eliminates the need of an elastomeric element in bridge plug applications. (Photo courtesy of Zeroth Technology Ltd.)
seals to fail. This new technology is now used in a range of bridge plug applications, both retrievable/ releasable and permanent, and is aiding in the elimination of failures due to explosive decompression, chemical incompatibility, extrusion gap shearing, compression load failure, dynamic fatigue under pressure conditions and shock load failures.

The Z-Seal uses load to provide a fully formed pressure barrier and is capable of expanding to 160% of its original run-in diameter. Aside from its use in standard oilfield applications, the seal has also proven effective in hostile high-pressure/high-temperature environments where pressure exceeds 10,000 psi and temperatures exceed 400°F (204°C).

A recent example of the benefits provided by Z-Seal’s metal-to-metal process occurred in late 2005 in Norway. An operator needed a frac job in a well that was not producing from the lower four intervals. The operator used a Z-Seal rather than cement to isolate these zones.

The plug maintained its position during initial pressure tests of up to 7,500 psi. The operator deployed the plug to its setting depth of 11,713 ft (3,572 m) and applied weight to confirm its integrity. The operator then carried out the perforation using TCP guns at a depth of 6 ft (1.8 m) above the plug. The plug withstood the shock load under these conditions, and the proppant frac operation was completed. The well eventually returned to a stable production rate at 1,800 b/d of oil.