Procedures To Get Free From Differential Stuck Pipes
- Pull the Drill String immediately to the Maximum Safe Overpull for the Bottom Hole Assembly BHA.
- Start circulation
- Start jarring up to release the Drill String Differential Stuck.
- If the Overpull and the jarring up didn't work immediately. Prepare pipe free pill while that apply right hand torque to release the stuck Drill String.If using 5 in Drill Pipe, the amount of torque will be around half a turn for each 1000 ft of Drill Pipe above the suspected stuck point.
- Spot pipe free pill at the drill string Differential Stuck point as soon as possible.
Consider The Following When You Have A differential Stuck Pipe
|Differential Sticking Force|
Minimize The Hydrostatic Pressure To Free Differential Stuck PipeDecreasing hydrostatic pressure is one of the things to think about for decreasing Sticking force and loosening Differential Stuck in the Drill String.
But off course take in your consideration the following:
- It should not affect on the Well Control issue as it shall not be reduced below the maximum hydrostatic pressure on the well.
- It should not affect or your drilling mud in other meaning don't decrease you OBM weight with water only and this can be done by dilution of your drilling mud with the base fluid or by pumping light weight pills.
- While reducing hydrostatic pressure, take care of any Kick Indicators / Signs.
Spotting Pipe Release Agents To Free Differential Stuck PipeDifferentially Sticking on the Drill String can be solved by spotting a pill called pipe free pill as soon as stuck happen. These agents work on attacking and breaking down the drilling mud filter cake, so that It reduces the bonding in between the mud cake and the Drill String.
It will be a good practice to pump a volume which cover the suspected Differential Sticking point with an excess up to 100% and displace it so that it will be around the Differential Stuck zone. you can reduce your pumping rate while it passes through the Differential Stuck point.
In some cases you may leave the pill to soak while continuously work the torque and jarring down or jarring up without torque. The soaking time may be up to 12 hours but the problem that you may have other problems from not circulating the well in the same time so you have another choice to circulate with lower rate and prepare another pill.
Bottom Hole Assembly BHA) was differentially stuck in a permeable shale interval at 3,626 meters (11,896 feet) while reaming the well before running the 178-mm casing. The first attempt to free the downhole instrument was to spot 28 m3 of crude oil and to allow four hours for reaction and soaking, and was no success.
Drill Pipe. When drilling with 1.32 SG mud, operator encountered Kick. An initially calculated 1.40 SG became insufficient and the mud weight was increased to 1.67 SG. And the Drill Pipe got stuck.