overshot dog manufacturer

Externally engage, pack off, and pull a fish with our wide range of overshot tools. The first fishing choice when screwing into the fish is not an option, our overshot tools are simply designed but ruggedly built. Choose from options including:

Kelo socket overshots are proven to catch small-diameter workstrings and sucker rods inside casing as well as recover coiled tubing that has parted and remains in hole.

The t-dog, mouse-trap, and flipper-dog (TMF) overshot can be dressed in three different ways for different washover applications. Deploy the t-dog assembly option to washover and recover mud-stuck or sanded-up square-collared pipe in one trip. Use the mouse-trap assembly to catch sucker rods, integral joint tubing, or cables. And with the flipper-dog assembly, you can confidently catch a fish with different ODs.

In this article we discuss some of the innovations that have been introduced by equipment manufacturers to eliminate some of the hazards associated with inner-tube head assemblies and overshots

Jammed latches are a common occurrence and commonly occurs when the inner-tube is overfilled. The process of trying to release the latches involves jarring with the overshot which will accelerate wear of critical components and can bring the wireline cable to its yield point or even its failure point. If the wireline cable snaps then a series of events are triggered that introduce many other hazards to the operation and so it is considered essential that incidences of jammed inner-tubes are eliminated completely.

To overcome the problem of jamming at the latches, a manufacturer developed an inner-tube head assembly that uses a different latch configuration – commonly called the “link-latch” system. These latches are not “retracted” by a latch retracting case, they are released when the spearpoint id pulled upwards by the overshot. The latches move slightly downwards and then inwards when the spearpoint is pulled upwards and so reducing the load on the latches and the base of the locking coupling. This latch system effectively eliminates the incidence of stuck inner-tubes.

De-latching of the inner-tube assembly from the overshot can have serious consequences and so all of the major drilling equipment manufacturers (MBI Drilling Products, Epiroc, Sandvik and Boart Longyear) have released what are commonly referred to as “safety overshots” – these are overshots that positively lock the overshot lifting dogs onto the spearpoint of the inner-tube head assembly.

The MBI type and the Longyear type safety overshots can be used with and standard or link latch type inner-tube head assemblies but the Epiroc and Sandvik types are completely new inner-tube and overshot assemblies.

The main feature of the Longyear Ezy-lock safety overshot is the locking sleeve that can be rotated into a position where the lifting dogs are locked in the engaged position onto the spearhead assembly.

Th MBI safety overshot works in a different way. In this overshot the lifting dogs are able to slide longitudinally inside the overshot body. When the overshot is dropped onto the spearpoint, the lifting dogs engage the spearpoint and as the overshot is pulled upwards the overshot body slides upwards relative to the lifting dogs and the bottom of the lifting dogs are forced inwards onto the spearpoint by a taper cut into the inside of the slots for the lifting dogs. The greater the upward pull on the overshot the more that the lifting dogs are forced inwards. Once engaged, the spearpoint cannot de-latch when under axial load.

The Series 10 Sucker Rod Overshot is a small, rugged tool designed for engaging and retrieving sucker rods, couplings, and other items from inside tubing strings.

Series 20 Short Catch Sucker Rod Overshots are designed for conditions when sucker rods, couplings, and other portions of a fish are too short for retrieval with a standard overshot.

The Hydraulic Release Overshot was designed to aid in the recovery of a stuck fish in a horizontal drilling application where normal rotation for release is not obtainable.

The Series 150 Releasing and Circulating Overshot consists of three main external parts: a Top Sub, a Bowl, and a Guide. Internal catch and pack-off parts are determined by the diameter of the fish. Each assembly is designed for a maximum catch diameter.

A Series 160 Side Door Overshot is recommended when fishing for cable tools or conductor lines in cased holes. The side door overshot is run in on tubing or drill pipe.

I debated on where to go next, but at the end of the day the most widely used fishing tool has to be an overshot. Some will say why not a spear? Well if you must ask, always go with the strongest fishing tool you can run to catch the fish. And if you run a spear, never plug the I.D. of your fish by breaking it off. Done with that!

The info that follows has been taken from the manuals published on overshots. I realize that paper manuals are a thing of the past, yes, yes at one time fishing tool hands carried massive catalog brief cases full of reference material. Now you have the luxury of your laptop loaded with information. If you have never sat down and read an overshot manual, now might be a good time.

The overshot is highly versatile and efficient tool. There are several different types of overshots, however each overshot is designed to engage a specific size of tubing, pipe, coupling, tool joint, drill collar or smooth OD tool.

The original overshot was developed by Bowen Oil Tools, which is now part of NOV. One thing I will point out is that in the catalogs you will see more than one assembly number for a given OD of Overshot, this came about due to the two locations developing their own variations. I found this information on NOV’s website and thought it was interesting to share.

Bowen™ became a leader in innovation with the creation of the first overshot, the Series 150, in 1935. This tool set the standard for fishing equipment, and the quick acceptance of the tool assured the company partners that their business would be successful. The company continued to create new products, building a reputation for their well tool design and construction.

Currently there are several manufacturers of overshots, NOV (Bowen), Rubicon (Logan) and Applied Oil Tools (Gotco). These overshots are designated by a series number as follows:Series 10 - Sucker Rod Overshot

Overshots may be identified by one of the following, known as “type”:Full Strength (FS) - engineered to withstand all pulling, jarring and torsional strain

The basic overshot (from top down) consists of a top sub, a bowl, grapple, control, and a guide. In addition to the basic components, some overshots (Series 10 and 150) can be dressed with either a:Spiral grapple used if the fish diameter is near the maximum catch of the overshot, or a

The Series 150 Overshot features the ability to packoff on the fish. When the circulating packoff is not used, the fluid circulates down the drillpipe, aroundthe top outside of the fish, through the slip or grapple assembly, around the guide shoe and up the annulus.

When the circulating packoff is used, the annular space between the top outside of the fish and the inside of the lower part of the overshot is packed off, diverting the fluid flow down into the fish, making it easier to release and recover the fish. Packoffs usually are not high pressure devices but will often withstand sufficient pressure to establish circulation through the fish. Third party high pressure packoffs are available from various sources.

The extension can be installed between the top sub and the bowl of the Series 10, 70, and 150 overshots. It is used to extend the overshot bowl to:Allow the grapple to catch farther down on a fish that may be necked down at the top by having been pulled in two, or latched by an overshot and released several times, or to

A stop ring must be used where a fish OD reduces immediately below the catch area to allow the grapple to bite on full-size pipe.Example - catching a Hydril upset or EUE collar. If the upset of collar should pass completely through the grapple, the overshot may not be releasable.

The Series 10 Sucker Rod Overshot is designed to engage and recover sucker rods, couplings, and similar items from inside tubing strings.Basket grapples are recommended for fishing for hardened and ground boxes (Sucker Rod Box).

The Series 20 Sucker Rod Overshot is a short catch tool which provides a means for engaging the exposed portion of a fish too short to be engaged with a Series 10 overshot.Uses basket grapples only

The Series 70 Short Catch Overshot is designed to engage the exposed portion of a fish too short to engage with Series 150 overshots.Uses basket grapple only

The Series 150 Releasing and Circulating Overshot is used to engage, packoff, and retrieve twisted-off lost tubing, drillpipecoupling, tool joint, casing or other similar fish.

A right hand wicker grapple converts a normal right release overshot to left hand release. This grapple is used where you expect to apply excessive right hand torque to release a packer, safety joint, etc. Note: Overshot will have to be released by left hand rotation.

High Pressure Packoff Assemblies:The High Pressure Packoff Assembly is an accessory to the Series 150 Overshots. It is used when high pressure circulation to the fish is required. It consists of a packoff sub with packing and packing rings and is installed between the top sub and bowl of the overshot. By running the packoff sub above the bowl, this design prevents the application of high internal pressures to the overshot bowl. The design of the High Pressure Packoff Assembly allows pressures two to three times the standard overshot packoff to be applied to the fish.

This information comes directly from the NOV manual for the Wide Catch Overshot. This is probably the first and only change to this common tool I know of in my career.

The Wide Catch Overshot provides the strongest tool available to externally engage, pack-off, and pull a fish that has been significantly worn. This tool has similar rugged design features and construction as the industry standard, Bowen Series 150 overshot, with the ability to interchange the Bottom Guide with the full range of existing components used with the standard Bowen Series 150 overshot.

In service, the Wide Catch Overshot (WCOS) takes a positive grip over a large area of fish and is capable of withstanding heavy pulling, torsion, and jarring strains without damage to the tools or the fish.

The WCOS has been designed to significantly increase the catch range of the OD of the fish to be caught, compared to the standard overshot. This enables a greater opportunity for a successful fishing operation in a reduced number of trips, thus reducing overall intervention costs for the operator. In addition to the large catch range, the WCOS has the ability to seal across very large extrusion gaps at both standard and high pressure and provide full circulation through the fish, should it be required.

Connections between the Top Sub/Bowl and Extension Sub have been designed to create a seal. This will prevent the connection from washing out should the overshot be required to be flowed through for a long period of time. In order to lock the Top Sub/Extension Sub to the Bowl from backing off during operation, set screws have become standard and will gall the threads should the connection break free.

The operation of all overshots is identical. The exception being that the Series 150 carries a packoff which provides circulation through the fish. First, determine that the overshot is properly assembled and dressed with the proper size grapple. Make up the overshot on the fishing string (normally it is run connected to the bottom of the bumper sub) and run it into the well. As the top of the fish is reached make sure circulation has been established to clear overshot ID of any plugging. Lower the overshot onto the top of the fish with no rotation at first. A 5,000 pound set down weight will be sufficient to engage the grapple. While lowering the overshot over the top of the fish watch for pressure build up, shut off pumps if any pressure build up is noticed. Should any back pressure be noticed, release the back pressure to allow the grapple to engage the fish. By elevating the string it can be determined, if the grapple went over and engaged the fish. If unable to work overshot over top of fish without rotation, then slowly rotate the fishing string to the right and gradually lower the overshot over the fish. Combined rotation and lowering over top of the fish are important to keep the grapple in the release position. This provides the maximum clearance between the grapple and fish. While lowering the overshot over the top of the fish, watch for torque build up and an increase in pump pressure. A pump pressure build up indicates the overshot has gone over the top of the fish thereby reducing the flow area. Stop rotation (continued rotation could dull the wickers of the grapple) enabling the grapple to set. Allow the right hand torque to slack out of the string and then pull on the string by elevating the string to set the grapple.

To release from the fish, bump down, then simultaneously rotate to the right and slowly elevate the fishing string. It is best to have a clean fishing top before running the overshot.

Boart Longyear’s overshots are an integral part of the Q™ Wireline system. Once the inner-tube is full of core, the overshot is lowered to the bottom of the hole. Its heavy-duty lifting dogs grab a secure hold at the top of the inner-tube assembly.

The Ezy-Lock sleeve provides a quick, one-handed rotation of the sleeve 90° to lock the overshot lifting dogs to the spearpoint and protects against accidental release.  When combined with the use of the safety pin, the overshot minimizes the chances of accidentally dropping the inner tube assembly during handling.

The Ezy-Lock overshot features upgraded components, heavy duty lifting dogs, two compression springs for improved durability and a new re-usable press-fit pivot-pin, eliminating peening in the field for easy lifting dog maintenance.

The Ezy-Lock overshot has an upgraded threaded connection between the jar staff and overshot head for improved strength. The jar staff itself is high-strength alloy steel with an increased diameter and fail-safe stop to reduce the chance of fatigue failures.

Cameron diverters are fully customizable for your floater and jackup rig operations, respectively. Designed for reliable, efficient use, each system consists of a housing, outlet valves, running tools, controls system, diverter assembly, overshot packers, and storage skids.

The CF-A diverter supports up to 75.5-in rotary tables and has a hang-off capacity of up to 2,500,000 lbm. It uses a single annular packing element with a pressure rating up to 500 psi. The CF-A diverter features four hydraulic locking dogs that reduce hosing and simplify operation. It eliminates the need to secure hoses to the diverter assembly while providing hydraulic fluid for the operations.