Wellbore friction modeling is considered as an important assessment to aid real-time drilling analysis and predict drilling troubles such as tight holes, poor hole cleaning, onset of pipe sticking etc. The torque and drag are typically the limiting factors facing the drilling industry to go beyond a certain measured depth in extended reach drilling. In extended reach drilling, surface measurement of weight on the bit and torque differ from downhole measurement due to the friction between the drill string and the wellbore. This friction force can be used to estimate an overall friction coefficient. The overall friction coefficient value versus measured depth while drilling can be used as an indicator during different drilling operations.

In this paper, for wellbore friction analysis, a newly-developed analytical model was used to estimate the friction coefficient versus measured depth. A field case is drawn from a deviated well drilled in western Canada where the drillstring got stuck during drilling operations. The time-based field data were analyzed in detail to find onset of drill string sticking from the recorded data while tripping drillstring in. Also, the study provided an opportunity to examine the validity of the new wellbore friction model using a field case.

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