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• Fishing tools

Releasing Overshots Type OV and OVT

Application:

The STS Releasing Overshot is an external catch fishing tool designed to retrieve tubular items from the oil, gas and exploratory well bores.

Construction

The basic overshot consists of a bowl, control guide, top sub and a set of replacement elements including spiral and basket grapples, and grapple control. When the fish diameter approaches the maximum catch of the overshot, a spiral grapple is required. In other cases a basket grapple is used. It must be assembled with either a basket grapple or a mill control, which cleans up the fish from burrs and other deposits. The catching process carried out by the helix-shaped configuration inside the overshot bowl provides a tapered spiral surface onto which the grapple will attach. If the “overshot-fish” connection needs to be sealed, packers must be placed in an overshot bowl: type “A” – for spiral grapples and type “P” c/w rings - for basket grapples. The overshot should be equipped with the proper size mill control and packers.

The overshot may be furnished with:

• Extensions mounted between bowl and sub to catch the fish much lower than the top end;
• Control guides with bigger diameter used during fishing jobs into wells or strings with bigger ID diameter than OD of overshot;
• Basket grapple control manufactured from high-strength steel or armored by infusible build-up;
• Retaining rings used during box or lock tubing catching;
• Basket grapple with retaining flange on the top end.

When ordering, please specify:

• Assembly name and size;
• Version (LH or RH);
• Top connection, if different the table;
• Quantity and length of extensions (400 …1000 mm);
• Diameter of control guide (bigger size);
• Nominal sizes and quantity of spiral and basket grapples taking into account that operating range both spiral and basket grapples are +0.8…-3 mm of nominal size.

Recommended spares for the overshot:

• 4 (four) spiral grapples of each nominal size;
• 1 (one) spiral grapple control for each 5 (five) spiral grapples of all sizes;
• 3 (three) basket grapples for each nominal size;
• 1 (one) basket grapple control for each 8 (eight) basket grapples of all sizes.

It is possible to produce any sizes not listed in the table