During the drilling operations phase the positional uncertainty must be monitored, especially when drilling in hole sections which exhibit collision risk.
All borehole position calculations for well design, the survey database and well monitoring shall be performed with the Directional Drilling Contractor software.
Anti-Collision Preferences
Survey Tool Error System
The system used in Company is the Directional Drilling Contractor software.
Borehole Position Scan Method
Closest 3D Approach
Borehole Position Error Surface
Elliptical Conic
Clearance Ratio
The Clearance Ration is defined as:
CR = Centre to centre distance (Well A - Well B)
Well A ellipse radius of uncertainty + Well B ellipse radius of uncertainty
Ratio Warning Levels
Clearance Ratio < 1.0 Stop Drilling
Clearance Ratio < 1.25 Close in nearby well, cease drilling
Clearance Ratio < 1.5 Continue to drill cautiously advise base and monitor continually
Geomagnetic Model
Directional Drilling Contractor model.