The proximity part of the Wellsite Directional Controller is not promoted as suitable for an application that requires the use of sophisticated error models. The error values used are based on an error/1000. Although this may seem rather simplistic many major oil companies have used this method for many years.

The program will calculate accurate three-dimensional centre to centre closest distances, depending on the interpolation interval specified, and since the well should be drilled on pre-planned separation values the results obtained should be suitable for the majority of applications. The use of mega-dollar applications at the wellsite is not always required, the majority of the time the distance to a nearby well is a question of general interest rather than the subject of critical proximity analysis for anti-collision purposes. The input required is minimal and the reports are quickly obtained.