However, there are physical and structural limits as to just how long legs that are to hold up millions of pounds can be made. Now, the water can be a thousand feet deep or more, with no problem. But still the quest for depth has not ended. These can be multiple DGPS survey configurations, telemetry configurations, acoustics systems, etc. If we just have to monitor a derrick position, then all we need is a single survey system.
More systems dictate more equipment, and more equipment usually dictates more personnel and expense.
It is imperative that all aspects of the job at hand be discussed and considered in the pre-drilling planning stages in order to ensure that all of the correct survey equipment is employed to do the job properly. Let us delve into a couple of the many rig survey situations that can be set up. Although there are tremendous differences in each of these rig types, they actually have two survey parameters in common. First, each has a derrick to perform the drilling task. The derrick must be geographically positioned to get it as near the required location as possible.