Schlumberger

Thru-Tubing Overshots

Hydraulic release overshot

The hydraulic release overshot engages external fishing necks while permitting circulation to the fish and tools below. By pumping fluid through the tool prior to latching, the hydraulic release overshot washes debris or fill from the top of the fish, ensuring a secure catch and enabling flow to tools mounted below the fish. This tool is activated mechanically by applying set-down weight, and it releases with a combination of set-down weight and differential pressure, making it ideal for horizontal fishing.

Continuous tubing overshot

Run on coiled tubing (CT) or jointed pipe, the continuous tubing overshot provides circulation through the fish to the workstring below. This overshot features a 340° contact grapple system that, combined with the ability to swallow the fish, makes it ideal for catching CT and other slickwall fish. Adding a high-pressure packoff above the overshot enables circulation to be restored to the fish.

Series 10-Type releasing overshot

The Series 10-Type releasing overshot is designed to engage, pack off, and retrieve tubular fish up to 2-in OD inside 2 7/8-in tubing, and up to 1 5/8-in OD inside 2 3/8-in tubing. Its tapered-helix internal construction provides 360° wall contact while distributing loads evenly on the tool and the fish. Spiral or basket grapples are available—helical spring spiral grapples for when the maximum catch size of the overshot is necessary and expandable cylinder basket grapples for when the fish OD is more than 1/2 in smaller than the tool’s maximum catch size.

Series 20-Type releasing overshot

The Series 20-Type releasing overshot is designed for use when the top of the fish is too short to be engaged with the Series 10-Type overshot. With the grapple positioned at the bottom of the tool, this overshot is able to successfully engage fish with short necks.

Series 150-Type releasing overshot

The Series 150-Type releasing overshot is designed to engage, pack off, and retrieve tubular fish and is especially suited to retrieving parted drillpipe and drill collars. It features a large bore for use in conjunction with wireline tools and is available in several strength categories for jarring and backoff operations.

Series 70-Type releasing overshot

The Series 70-Type releasing overshot is used when the top of the fish is too short to be engaged with the Series 150-Type releasing overshot. It has a tapered-helix internal construction for 360° wall contact and even load distribution on the tool and the fish.

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