Problems and solutions in petroleum well drilling: Pipe Sticking

It is impossible to drill an oil well without any operational problem associated with drilling stoppage or economic losses due to loss of time. However, not all problems are the same, so a correct identification is key to be able to apply the most appropriate solutions, for this case I will explain the sticking of pipe as that problem that occurs in the drilling of wells that prevents to continue with the continuity of the drilling of the well.

Perhaps it is thought that the planning of the operations embodied in the drilling program should not include the possible potential problems that may occur in the drilling of an oil well, in fact it should be the opposite, that is to say, the possible potential problems should be contemplated, also the way in which they should be prevented and how they should be solved in case they occur, Of these problems, pipe sticking is very common, that is why it is essential to contemplate a well drilling design that explains from an engineering point of view the way in which pipe sticking can be avoided, without underestimating the importance of knowing the different ways in which the pipe can be unstuck.

There are oilfields whose formation pressure has decreased over time because the pressure decreases as time passes through the production time, with the drilling of new wells in these reservoirs of depleted pressure zones, there must be a control in the density of the drilling fluid, because if the hydrostatic pressure of the drilling fluid exceeds by 500 psi differential to the formation pressure, then it is very likely that the drill pipe sticks to the walls of the well while we are drilling.

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It is important to mention that due to the increase in the pressure differential in favor of the drilling fluid circulation pressure, the drill pipe sticks to the plaster generated by the drilling fluid on the walls of the well, and the longer we take to try to uncouple the drill pipe, the more we will reduce the probabilities of succeeding in uncoupling the pipe.

In the handling that is taken in the takeoff operations should not overstress the tubing string above the tension values that it supports, because if it is exceeded, the tubing can be broken, leading to the loss of the well.

It is advisable to work with rotary movements the string, drive the hammer and also tension the string upwards so that it tries to take off, but as I mentioned without exceeding the tension resistance values, although the most advisable is to apply the correct operational practices so that the pipe does not stick.

The drill pipe can also stick to the formation at the bottom of the hole due to a bad effective hole cleaning, because if the flow rate of the drilling fluid is not enough to drag the cuttings that cut the drill bit from the bottom to the surface, then those cuttings will accumulate at the bottom and lock the drill bit causing the drilling to stop.

As a conclusion I say that, once the pipe is stuck you must find a way to free and unstuck, however the corrective must be oriented to drill with the best operational practices to help minimize the risks of sticking pipe.

References

[1] Isambourg, P., Ottesen, S., Benaissa, S. et al. 1999. Down-Hole Simulation Cell for Measurement of Lubricity and Differential Pressure Sticking.

[2]Santos, H. 2000. Differentially Stuck Pipe: Early Diagnostic and Solution. Presented at the IADC/SPE Drilling Conference, New Orleans, 23-25 February.