BICO FASTER DRILLING TOOLS INCHydraulic-Mechanical Drilling Jars

BICO-Faster Hydromechanical Drilling Jars are effective insurance for many drillingprograms. When properly placed and operated, many stuck drill strings can be freedright away, thereby eliminating expensive fishing operations.

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Features of the BICO-Faster Hydromechanical Drilling Jar:

mechanical latch effectively eliminates unexpected firing while making connections ortripping in and out of the hole.

axial visco jet provides consistent hydraulic delays by compensating for hydraulic fluidviscosity changes caused by temperature variance.

rugged spline system for reliable power transfer

Can be run in tension or compression

Jar Operation

The operation of a hydromechanical jar differs when jarring up and down. When jarring upwards themechanical latch is released by applying an appropriate force, then once unlatched there is a hydraulicdelay before the jar fires. When used to jar down, the latch is released by applying the appropriateweight, then the jar fires immediately with no hydraulic delay. During normal drilling and tripping operationsthe jar should be run in the latched position. The position can be verified using the following table:

2107 - 7th StNisku, Ab, Can

Voice: 780 - 955 - 5969Fax: 780 - 955 - 4707

DriveHousing

DriveMandrel

ChromePlating

Length of Exposed Chrome

Jar O.D. Latched Fully Open

4 - 3/4" 5 " 14 "

6 - 1/4" to6 - 3/4"

6 " 14 "

2107 - 7th StNisku, Ab, Can

Voice: 780 - 955 - 5969Fax: 780 - 955 - 4707

BICO FASTER DRILLING TOOLS INCHydraulic-Mechanical Drilling Jars

Jar Placement Guidelines

Do not place between drill collars or drill pipe of differing diameter.

All tools, pipe, and collars above the jar should have a diameter smaller than or equal to that of the jar.

Ensure that the nearest stabilizer is at least 60 ft (18m) below the jar.

The buoyed weight of collars and pipe above the jar must be sufficient to overcome the down latch setting.

The buoyed weight of tools below the jar, plus pump open force and hole drag, should not exceed 70% ofthe up latch setting.

Jarring Up

When jarring up you must first apply more tension at the jar than the up-latch setting. Once the latch setting has beenovercome, the jar will begin its hydraulic delay. After the delay, the jar will fire.

To reset the jar, lower the drill string until the weight indicator gives a reading that is lower than the free string weight. Thismeans that the jar is in the latched position again. From there the jar can be fired again or you can continue drilling.

If circulating, the minimum amount you will have to pull to fire the jar is the Up-Latch setting, plus the free string weight,minus the pump open force.

If not circulating, you will have to pull the Up-Latch setting plus the free string weight.

Jarring Down

To jar down you must slack off weight to apply enough compression at the jar to overcome the Down-Latch setting. The jarwill come out of the latches and will fire immediately.

To reset the jar, raise the string until the weight indicator shows more than the free string weight. This means that the jar isin the latched position again. The jar is then ready to continue drilling, or to begin jarring again.

If circulating, the minimum amount of weight that must be applied to the jar is the Down-Latch setting plus the pump openforce.

Jar Replacement

Jar should be changed out on the trip following any periods of heavy jarring.

On each trip the jar should be visually inspected for excessive wear or leakage. Some drilling fluid shouldbe noticed draining from the compensation ports - this is normal and expected.

Before laying out a jar it should be flushed with water to remove all drilling fluid.

Care should be taken to ensure that tongs and slips are not used on the chrome mandrel nor on plugholes. Do not use the chrome mandrel as a lifting point.

Hole Drag:The amount of force needed to fire the jar will increase with the addition of hole drag.

Pump Open ForceWhen circulating there will be an extending force on the jar. This is the pump open force and it is calculated by multiplyingthe pressure drop across the bit (and motor) by the pump open area of the jar.

Free String WeightThe free string weight is the total weight of pipe and collars above the jar.