JAR INTENSIFIERS Instruction Manual 4019 Jar Intensifiers O n e C o m p a n y U n l i m i t e d S o l u t i o n s Jar Intensifiers Jar Intensifiers General Description ..................................................... 3 Use ............................................................................... 3 Construction ................................................................ 3 Operation ..................................................................... 4 Maintenance ................................................................ 4 Dressing Area Maintenance ........................................ 4 Filling with Fluid ....................................................... 4 Testing ..................................................................... 5 Complete Disassembly ........................................... 6 Complete Assembly ................................................ 7 General Data .............................................................. 12 Strength Data ............................................................. 13 Service Kit .................................................................. 14 Specifications and Replacement Parts .............. 15 – 18 I N D E X The designs and specifications for the tools described in this instruction manual were in effect at the time this manual was approved for printing. National Oilwell Varco, whose policy is one of continuous improvement, reserves the right to discontinue models at any time, or to change designs and specifications without notice or without incurring obligation. Twenty-second Printing, September 2005 General Description An important secondary contribution of The Bowen Jar Intensifier is designed the Bowen Jar Intensifer is to utilize its to be run in conjunction with the Type Z contained hydraulic fluid to cushion the Bowen Oil Jar. Its function is to supply shock of the running string as it re- acceleration to the collars and the upper bounds, after each jarring stroke. This portion of the Hydraulic Rotary Jar during reduces the inherent tendency to cause its (jarring) free stroke. shock-damage to the tool and running Each Bowen Jar Intensifier is designed string to a minimum. to match a corresponding Type Z Bowen Use of the Bowen Jar Intensifer allows Oil Jar. The Bowen Jar Intensifier is less drill collars to be used in a specific essentially a hydraulic fluid spring which case than would otherwise be possible. stores energy when a strain is pulled This is particularly true at shallow oper- on the running string. When the strain is ating depths, where excessive numbers removed by the free stroke of the Jar, of drill collars are sometimes used, to this stored energy is released, accelerat- utilize mass in place of available stretch. ing the drill collars and jar upward until Use of too many drill collars with their a blow of high impact is struck. great mass is often damaging to the tools and the running string, and should Use be avoided. During conventional jarring operations with either mechanical or hydraulic jars, Construction the intensity of the blow struck is a func- The Bowen Jar Intensifer is composed tion of, and proportional to the acceler- essentially of a Mandrel Assembly (or ated rapid movement of the entire run- Top Sub and Mandrel), Mandrel Body ning string above the jar. This acceler- Insert, Mandrel Body, Middle Body, ated movement will often be consider- Washpipe Body, Washpipe, Knocker and ably diminished by friction of the running Piston Assembly. The tool is completely string against the wall of the hole. In filled between the Mandrel Body Insert such cases much of the energy will be and Washpipe Body, with silicone fluid lost. Also, at very shallow depth, the lack of high compressibility index. of available stretch in the running string causes a great loss in the effectiveness The Mandrel has a ruggedly built splined of expected acceleration, due to very section near its lower end, which is small amount of stretch in the running always engaged with matching splines in string being available. the lower end of the Mandrel Body. This allows torque to be transmitted in either The Bowen Jar Intensifer provides the direction and at all times, whether open, means to store the required energy closed or in any position of stroke. immediately above the jar and drill collars, to effectively offset the loss of The high pressures produced within the stretch in, or drag on the running string. Bowen Jar Intensifier during operation, are maintained by the same patented Bowen Non-Extrusion Seal Ring Assem- blies which are used in the Bowen Hy- draulic Rotary Jar. Use of these assem- blies prevents radical rupture of seal rings, and keeps wear to an absolute Bowen Jar Intensifier minimum. 3 The Piston Assembly is composed of a Operation Filling with Fluid Top Adapter, Bottom Adapter and a set Prior to operation, the Bowen Jar Inten- Proper filling of the Bowen Jar Intensifier of Chevron Packing Rings, usually five sifier should be examined to assure that requires the use of both Fill Plugs; in the rings per set. This Piston Assembly is it is completely assembled and in good Mandrel Body Insert. Proceed as follows: assembled on the lower end of the Man- working order. 1. Thoroughly clean and inspect all drel, between the Knocker and Wash- parts. Give special attention to the The Jar Intensifier should be located in pipe. The Piston Assembly is moderately seals, replacing any that show signs the running string immediately above the pre-compressed at its ID against the of damage, wear or too pronounced drill collars; just below the running string mandrel and at its OD against the middle a “permanent set.” lower end. The jar should be located body. This forms a leak-proof, continu- immediately below the drill collars and 2. Assemble all parts except the fill ous, sliding seal. just above the fishing tools. The se- plugs. Refer to “Complete Assembly” In operation, the fluid is compressed as quence from the fish upward should be: for detailed assembly instructions. tension is applied by the running string, fishing tool, jar, drill collars, Jar Intensifier 3. Clamp the Intensifier in a vise at by the travel upward of the Piston in the and running string. approximately 30° angle with the Middle Body. When the jar reaches its The fishing operation should be run in mandrel end up. Fill plug holes free stroke and trips, the sudden release conventional manner; the fish is engaged should be oriented vertically to each of stored energy in the Intensifier by the fishing tool, and a strain is pulled other. accelerates the drill collars upward at on the fishing string. This will cause the tremendous and intensifying velocity. 4. Attach the fill hose from the fill pump Jar Intensifier to stroke 6" to 13", depend- When the jar reaches its maximum travel, to the fill plug hole on bottom. Attach ing on size, compressing the hydraulic a blow of high impact is delivered directly the exhaust hose to the fill plug hole fluid and storing energy at the Intensifier. to the fish. The action is essentially on top. This stored energy will cause the jar to independent of the running string. The operate. When the jar trips, the Intensifier 5. Pump the Intensifier full of fluid. Intensifier tends to confine movement imparts its stored energy to the drill Operate hand pump at moderate primarily to the drill collars, and does not collars and jar mandrel, in the form of speed until bubble-free flow comes rely on movement of the entire running acceleration, causing the jar to strike a through the clean exhaust hose. string. This confines the impact of the jar blow of very high impact value. and drill collars to the fish, where it is 6. As the tool fills, oil will begin to flow most effective and least damaging; This procedure is repeated as many out the exhaust hose. Air bubbles will regardless of depth. times as is required to free the fish. be observed in the exhaust oil. Con- tinue to pump until all air bubbles It should be noted that there is no hazard For complete detailed instructions on cease to appear in the outflowing oil. in filling or using the Bowen Jar Intensifier Type Z Bowen Oil Jars, see Bowen 7. When air bubbles cease, detach since the tool is filled with fluid, and un- Instruction Manual 5/4065. exhaust hose and insert fill plug. der only the low hand pump pressure Detach the volume pump hose and required to fill it. Maintenance install fill plug. Maintenance of the Bowen Jar Intensifier is minimal, but important. The primary 8. Tighten the fill plugs to specifications. maintenance is normally confined to Test the tool in an appropriate tester. complete inspection and redressing after each use. Magnetic particle inspection of stressed components should be per- formed after each use. 4 Testing The operator will note too, that during Test the action of the Intensifier in a service the fluid will become discolored Bowen Jar Tester or other suitable test by traces of brown or amber stain. This Mandrel rack which has a readout for the applied is caused by bleeding of seals, while pull load. The tool should be pulled open under high pressure, and from thread to its full stroke in the tester. The pull dope, where this is used on the con- load required to open the tool should be nections. These traces of discoloration Non-Extrusion Ring Seal Protector Ring within 2,000 pounds, plus or minus, of are not detrimental to the fluid or to the the load value listed in the data sheet Mandrel Body Insert Seal tool, unless the concentration is heavy Mandrel Body Insert for the specific intensifier. enough to include solid particles such Middle Body Seal Large CAUTION: Do not stand beside tool during as small slivers of rubber. tests. Extremely high pressures develop Bowen Liquid Spring Intensifier Fluid Seals and metal body failure could cause serious injury. should be kept clean and as free of contamination as possible. It is a special When the applied load is removed, the purpose fluid, and relatively expensive. tool should close within 11/2" of complete Mandrel Body closure (measured where the Mandrel Bowen Jar Intensifer Fluid Shoulder meets the Mandrel Body Bleeding Prior to Field Use If the anticipated bottom hole tempera- Insert).