Wellbore Quality Adrián Ledroz

Wellbore Quality - Definitions Smooth wellpath, in-gauge, no spiraling Trouble-free casing run, no buckling Good cementing job Wellbore follows the plan – meets the plan objectives Can wellbore quality be measured? 100 ft survey data High definition survey data Indirectly Torque and drag Vibration ROP Etc., etc. Validation of the wellbore placement

Wellbore Quality - Background Several papers have been writing on the topic of Wellbore Quality: Hole quality: why it matters The perfect Wellbore! The Wellbore Quality Scorecard Wellbore Quality Characterization for drilling and running casing… Improved Wellbore Quality using … Wellbore trajectory Quality Management… Monitoring Wellbore Quality in Real-time… Tortuosity: the rest of the hidden story Study the impact of wellbore tortuosity on drilling… As most of you know, the subject of wellbore quality is not new. Moreover, there are quite a few great papers on the subject. The perfect Wellbore is the first one of a series of papers and presentations by Dr Mason and Dr Chen in 2005. In their work, they aimed at finding a tangible relationship, something that can be assigned a value to, that would allow comparisons between the common understanding of wellbore quality and its claimed benefits. They also introduced the idea of the Wellbore Quality Scorecard that combines many different aspects of wellbore quality. Wellbore quality characterization for drilling and casing running in challenges wells is a SPE DL presentation from 2007 that follows those papers. Wellbore Trajectory Quality Management was produced by DrillScan in 2017 with the goal predicting stuck casings or lockup situations when running casing or completions. Monitoring Wellbore Quality in Real-time is the work people from the University of Texas and their goal was to characterize the overall tortuosity of a well (open hole) in real-time. There are many more papers and presentations and yet, we are still here talking about wellbore quality. Part of the problem, I believe, is related to the different disciplines involved with the extraction of oil and the different incentives and metrics. When we talk about wellbore quality, does it mean the same for Reservoir folks, for the drilling guys, for the company running casing? And finally, does it mean the same for production, do they even care much on how smooth the wellbore was when the casing or the production tubing has collapsed or have high tortuosity. As the presentation progresses, it will be clear what I am referring to.

Tortuosity Different names for similar or equal concepts: Tortuosity, tortuosity index, scaled tortuosity index, real-time 3D tortuosity index, cumulative tortuosity, absolute tortuosity, relative tortuosity, plan tortuosity, microtortuosity, macrotortuosity, large-scale tortuosity… Rugosity, undulation, cumulative dls, curvature… Desire to use standard 100 ft survey data Some definitions are related to the drilling process Some are related to the drilling plan Desire to assign a value (number) To the whole well For all purposes

High density field data

High density field data

High density field data

High density field data

High density field data

Closing remarks There is a need for standardization of terminology and calculations Specific applications required specific metrics 100 ft survey interval does not provide adequate information Measure the tubular of interest provides the best data quality

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