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Named Semantic Graph


Name
Measurement of bit depth
Goal
Convey TVD uncertainty with reference to measured depth
Description
Bit depth is calculated by the integration of the vertical motion of the bit and drillstring. The vertical motion of the bit is a function of top drive vertical motion, block height vertical motion, change in surface hookload, and change in downhole WOB. The measured vertical motion of the top drive is affected by rig heave; the measured vertical motion of the block is affected by calibration and measurement accuracy and the top drive may be slightly bent, leading to uncertainty in block height. The integration is reset (“truthed”) on “pipe-down” using the pipe tally, which leads to jumps in measured bit depth. The integration is started with recognition of “bit on-bottom” which is remotely evaluated on surface, and is uncertain.

Statements


Subject Name Subject Category Predicate Name Object Name Object Category
Bit on bottom uncertainty #1 DDQUD.Drilling.Uncertainty is estimated using Confidence Factor #1 DDQUD.Drilling.ConfidenceFactor
Truthed event #1 DDQUD.Drilling.OperationEvent is caused by e-tally #1 DDQUD.Drilling.ElectronicTally
Truthed event #2 DDQUD.Drilling.OperationEvent is caused by Bit on bottom event #1 DDQUD.Drilling.OperationEvent
MD uncertainty #1 DDQUD.Drilling.Uncertainty is estimated using Confidence Factor #1 DDQUD.Drilling.ConfidenceFactor
Bit Depth RT Source #1 DDQUD.Drilling.RealTimeSignal belongs to Current operation #1 DDQUD.Drilling.ActualOperation
Wellbore Position Uncertainty #1 DDQUD.Drilling.Uncertainty is estimated using Confidence Factor #1 DDQUD.Drilling.ConfidenceFactor
Wellbore #1 DDQUD.Drilling.WellBore has a Survey #1 DDQUD.Drilling.Trajectory
Bit Depth RT Source #1 DDQUD.Drilling.RealTimeSignal is reset using Truthed event #1 DDQUD.Drilling.OperationEvent
Bit on bottom event #1 DDQUD.Drilling.OperationEvent has a Bit on bottom uncertainty #1 DDQUD.Drilling.Uncertainty
MD uncertainty #1 DDQUD.Drilling.Uncertainty is estimated using Heave compensation 1 DDQUD.Drilling.Compensation
MD uncertainty #1 DDQUD.Drilling.Uncertainty is estimated using Tide compensation 1 DDQUD.Drilling.Compensation
Survey #1 DDQUD.Drilling.Trajectory has a Wellbore Position Uncertainty #1 DDQUD.Drilling.Uncertainty
Survey #1 DDQUD.Drilling.Trajectory is measured using Survey Instrument #1 DDQUD.Drilling.SurveyInstrument
Bit Depth RT Source #1 DDQUD.Drilling.RealTimeSignal is reset using Truthed event #2 DDQUD.Drilling.OperationEvent
Bit Depth RT Source #1 DDQUD.Drilling.RealTimeSignal has a MD uncertainty #1 DDQUD.Drilling.Uncertainty
Wellbore #1 DDQUD.Drilling.WellBore has a Current operation #1 DDQUD.Drilling.ActualOperation
Survey #1 DDQUD.Drilling.Trajectory belongs to Current operation #1 DDQUD.Drilling.ActualOperation
Wellbore #1 DDQUD.Drilling.WellBore has a e-tally #1 DDQUD.Drilling.ElectronicTally
Survey #1 DDQUD.Drilling.Trajectory is relative to Bit Depth RT Source #1 DDQUD.Drilling.RealTimeSignal
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