bowen overshot factory

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 dates back more than 105 years, when S.R. Bowen founded his first company in Coalinga, California. Shortly after the United States entered World War I, S.R. sold the Coalinga shop. He formed a second company, the S.R. Bowen Company, in 1920 in Huntington Beach.

In the early 1930s, the consequences of the stock market crash prompted S.R. Bowen to consider starting a company in Houston, where oil exploration and drilling was accelerating. In the early spring of 1934, his son Walter and a friend formed Bowen Company of Texas.

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.

There are several other overshots available, but the Series 150 Bowen Overshot is the most popular and used throughout the world. Bowen also manufactures several other overshots that are very similar to the Series 150. We will discuss these later.

The Series 150 Bowen Overshot features positive engagement, and is a releasable overshot. It never requires left-hand rotation during it operation. It sets and releases using right-hand rotation and is releasable at any time during operation, should the need arise.

The Series 150 Bowen Overshot is available in many sizes and five different strengths. The five different strengths are designated by the following letters:

The Series 150 Bowen Overshot is used to engage, pack off, and retrieve twisted off or lost tubing, drill pipe, casing, tool joint, coupling, or other similar fish.

The Series 150 Bowen Overshot is considered a simple tool. It is, as far as the construction is concerned. It is made of three parts: the top sub, the bowl, and the guide. There are a multitude of accessories that can change the whole complexion of the overshot for many different circumstances.

The large spiral threads inside the overshot bowl are to accommodate the spiral threads on the outside of the grapple. They enable you to insert the grapple in the overshot. They also create a cone-like wedge that draws the grapple down when the overshot is picked up. The more you pickup, the harder the grapple will grip the fish. This cone-like wedge is referred to as the draw and these threads should always be cleaned and well lubricated before putting a grapple in the overshot. This will reduce friction and enable the grapple to pull farther down into the draw. It works very much like slips in a rotary.

Grapples for all Bowen overshots have a minimum catch range above and below the designated catch size. Check Bowen manual #5/1150 for these catch ranges.

All grapples for a give size overshot have the same part number. For example: the spiral grapple and the basket grapple for a 5 ¾” O.D. overshot assembly #8975 is 6112. You should familiarize yourself with these numbers and use them when ordering grapples.

There are two types of grapples for the Series 150 overshot; a spiral grapple and a basket grapple. The spiral grapple catch size begins where the basket grapple catch size becomes too thin to have any strength. The spiral grapple’s maximum size is also the maximum catch size of the overshot. You cannot get spiral and basket grapples in the same catch size.

The Grapple is locked in place by a control, which goes in the overshot below the grapple. There are four kinds of controls: a spiral grapple control (all spiral grapple controls are the same size), a plain control (also all the same size), control packoff, and mill control packoffs. The latter two come in sizes to correspond with the grapple you run. Both have a rubber packoff in them. The mill control packoff has milling teeth on the bottom to help get over a burred fish.

There are five different packoffs for the Series 150 Bowen Overshot. They are as follows: Mill control packoff and plain control packoff, as mentioned above. The type “A” packoff is used with a spiral grapple. The type “A” packoff goes in the top of the overshot bowl above the grapple and packs off around the outside of the fish. They also come in sizes to correspond with the grapple size. The type “D” packoff goes in the top of the overshot bowl above the grapple. It packs off in the inside of the fish in a collar or integral joint box and is limited to the sizes you can get it. The packoffs mentioned above are not dependable. So do not ever assure the customer that they will hold a specific amount of pressure. The only one that is dependable is the High Pressure Packoff. It has four elements that fit in a high-pressure packoff bowl. The high pressure bowl screws onto the overshot at the bottom where the guide normally goes, and the guide screws onto the bottom of it. The high-pressure packoff is available in nominal pipe sizes only, such as 2 3/8”, 2 7/8”, 3 ½”, etc. However, if you need to, and have a machine shop available, it is very easy to convert control packoffs to high-pressure packoff elements.

There are several different types of basket grapples for the Series 150 Bowen Overshot. The threads inside the grapple are called Wickers. The wickers are spiraled like threads. This helps to screw off of a fish when releasing the overshot. You can get basket grapples with different size wickers. If you are catching a fish that is soft, then a deep, wide wicker is best. If the fish is of a very hard substance, then a fine wicker is best. There is a left-hand wicker used when extreme right-hand torque is put in the pipe below the overshot. There is an N.I.T or Nitroloy grapple that is very hard steel and should be used when catching a fish of very hard steel, like P-105 tubing. It is available in nominal sizes only. There are basket grapples with stops built in. They prevent the grapple from getting below a collar, an upset, integral joint or a shoulder of any kind. It is almost impossible to release the overshot if you get below an upset or collar or a shoulder of any kind. These grapples with stops cannot be used to go over a nipple that is above a collar or upset. The I.D. of the stop is not large enough to allow the grapple to close enough to catch the collar or upset. There is another type of stop available, called a steel stop. It is a donut shaped steel ring that fits in the top of the overshot bowl, where you put the type “A” and type “D” packoffs. It is available in most any I.D. needed if there is a machine shop available.

Other accessories for the Series 150 Bowen Overshot are Mill guides, Oversize guides, Bowl or Top extensions, Bottom extensions, and Crossover Bushings.

The Mill guide is used to mill over a fish that is distorted in some way (such as flat, flared, or split) and to bring it back to the original size before engaging it with a grapple. A bottom extension should be run between the overshot bowl and the mill guide to insure enough room to get over the fish without rotating the grapple over the fish. Another use for the bottom extension is to help line up a crooked fish with the overshot before it reaches the grapple.

The oversize guide is used when an overshot is not compatible with the hole size. For example: If you run a 5 ¾” overshot in 7” casing, the casing is approximately 6 ¼” I.D. Therefore, you would not have room to go by a fish or encounter trouble getting over the fish, but if you run a 5 ¾” overshot inside a 8 5/8” casing, (which is approximately 7 ½” I.D.), you would bypass a fish or have difficulty lining it up to go in the guide. So here you would run a 7” or 7 ¼” O.D. oversize guide. Another use for the oversize guide is where you are fishing for a small diameter fish in a large diameter hole, and cannot get a grapple with small enough catch for an overshot that is suitable for the hole size. You would run a smaller O.D. overshot that grapples were available for and an oversize guide that is compatible to the hole size.

The top extension should not be a larger I.D. than the maximum catch size of a basket grapple for the same size overshot. If it is, it has been modified and the yield strength is less than the book lists it. The crossover bushings are from the overshot threads to comparable sized washpipe on top of the overshot bowl as an extension when you need to cover a full joint of tubing and catch the collar. In a case like this, you would use a washpipe top bushing to eliminate one bushing. You would also use a steel stop in the overshot bowl. Another use for the crossover bushing is on the bottom of the overshot bowl to run a long extension, such as a long rotary shoe to line the fish up with the overshot before engaging the grapple.

Always check the I.D. of the top sub of the overshot to be sure it is not the same as the O.D. of the fish. If it is, you could get a friction bite when the fish goes in it and make it very difficult to release the overshot.

To release the overshot, you have to move the grapple up in the bowl so the grapple can open. You do this by jarring down on the work string. This is referred to as shucking the overshot. When you think you have done this, you pick up on the work string to a neutral weight and rotate the overshot to the right five or six rounds. Then pick up again and continue this way until the overshot is clear of the fish. If it will not rotate, then try again to shuck it. If you pick up too much weight after shucking it, it will not rotate.

When you have a fish in the rotary, it is sometimes hard to shuck the overshot. Here are some ways that work real well. If you still have your jar assembly on the overshot, close the bumper jars, then tie the cat line above the Mandrel. Pick up until the jars are opened, then drop them closed very rapidly. If you don’t have jars, latch a set of elevators around the same way. You should never have to force an overshot over a fish. In fact, most of the time, you will not get any indication that the grapple is over the fish.

It is not necessary to put the rotary tongs on an overshot guide to tighten it. A 36-inch pipe wrench booked on the lip and hit two or three times with a sledgehammer is sufficient. Some overshots are pinned at the top. Top extensions are also pinned to insure against backing off when left-hand torque is applied to the overshot.

The connections above the bowl should be tightened with rotary tongs, and then the pins tightened. Always use caution when tightening these connections. They are fine threads; therefore, easy to pull the threads or mash the overshot bowl.