In this post, we will discuss two other dysfunctions that can occur when slide drilling with a mud motor, namely buckling and poor toolface control.
With respect to buckling, the most dangerous scenario is helical buckling. Here the drill pipe deforms as a spring pressing against the formation, increasing friction severely and potentially locking up the drillstring into the wellbore. Estimating the WOB at which such buckling might happen is therefore important. The calculation steps are noted in Slide 2.
On slide 4, you can see an example where the buckling belief goes up as the estimated DWOB goes above the min helical buckling limit. Being alerted to this when slide drilling is extremely useful.
Tracking poor toolface control is relatively straightforward in comparison. We track the current toolface with respect to the average toolface over the course of the current slide, and draw a metric from it to use as an input to the network. Slide 5 details the features that influence poor toolface belief. As a note, all of this material is detailed in SPE-205984.
We will go into corrective actions for these dysfunction next week. Stay tuned.
For slides on this topic click below: