On-site supervisors of top drill rig companies all agree in saying that stuck pipe in a wellbore is a bane in their line of work they dread the most. You can try just about anything you could think of just to get it out, only to realize in the end that your efforts were in vain.
A pipe system that is in very bad shape could easily cost you thousands of dollars every single day. Highly overpressured and abused drilling liquid hydrostatics, porous shale deposits, depleted reserves, and sloughing are some of the most common causes for such occurrences, stuck tubing.
Besides this, a stuck pipe scenario is time-consuming and taxing on your financial resources, too. Simply put, it is expensive.
Alongside that also, the wellbore is being put in harm’s way of becoming an utter failure if it is not drilled again one more time. Damages wrought out by a stuck pipe may lead to an inferior quality well that isn’t up to par with what was initially anticipated.
We are giving below a rundown on the common causes of stuck tubing.
Omitting the cleaning step before pulling out of the hole
According to top management personnel of leading drill rig companies, cleaning the borehole first is one of the best practices in veering away from stuck tubing. This can be done by distributing the drilling liquids, starting from the bottom up once before drawing out the drill string.
However, deliberately skipping this step will render the cuttings become disorganized in the annulus and thus get pulled downward by the natural force of gravity. The will lead to the piling up around the BHA or the bottom hole assembly.
Getting Out of the Hole Quickly!
Another factor that contributes to stuck tubing is premature pipe pulling. The accumulated pressure in the bottom hole can be minimized by the drill string with subtle jolts or movements.
As a result, at some point, this will set the stage for increased hydrostatic pressure in the mud. Consequently, the drilling proceeds to spew formation liquids into the surrounding environment.
Misplacing the Jar
Getting your bottom hole assembly stuck, then bringing the jar to a safe distance from BHA only to get fired off eventually will lay the groundwork for a stuck pipe issue. However, for a fruitful borehole venture, you might take into consideration wireline services to avoid being in such a situation.
Choosing to Ignore the Rheology of Mud
Drilling through Smectite or Illite minerals in some formations, for example, with water-based mud, could also lay the foundation for the occurence of stuck pipe. There is a strong possibility that these structures will swell because, just like mashed potato powder, they thirst for liquid.
As reactive shale gets hold of water-based mud, it gets hydrated along the way and this causes your wellbore to get stuffed. This event taking place will render clay balls adhere to your drill string.
However, a mud man needs to be aware that only by making use of high-quality oil-based mud can he put a stop to such swelling or keep it from taking place. As formation clay is combined with water-based mud, preparing the mud with KCl, polymer, or glycol will just help impede the chemical procedure.
The latter technique can also improve the mud viscosity level and its ability to gel together; discouraging the cuttings from being pulled down by the natural force of gravity and piling around at the drill bit, which is yet another reason why stuck piping takes place.
Mud rheology is constantly monitored during the process, and every single drill rig company we’ve come to have close contact with says that failure to do so will just raise the odds of stuck pipes.