Method to Assess Uncertainties and Correlations Resulting From Multi-Station Analysis of Survey Data

[0016]FIG. 1 illustrates an exemplary drilling system 100 that includes a drilling rig engaged in drilling operations. The exemplary drilling rig includes a derrick 1, drawworks 2, cable 3, crown block 4, traveling block 5, and hook 6 supporting a drillstring 50 disposed in a borehole penetrating formation 52. The drill string 50 includes a swivel joint 7, kelly 8, drillpipe 9, drill collars 10, and drill bit 11. Pumps 12 circulate drilling fluid through a standpipe 13 and flexible hose 14, down through the hollow drillstring 50 and back to the surface through the annular space 15 between the drillstring 50 and the borehole wall 16. A steering device 40 is disposed on the downhole portion of the drill string 50 in order to provide a physical mechanism by which an orientation or direction of the drill bit 11 may be altered to deviate from its current drilling direction towards another drilling direction. This steering device 40 may therefore be used to produce deviated sections or cu...