Survey Programme Example

If the maximum dogleg severity or maximum inclination is exceeded, the Drilling Supervisor must be consulted prior to taking any corrective action. An additional MMS should be taken while drilling, if doubt exists.

Generally, at depths of +/-5 000 ft target size is sufficient to allow exclusive use of TOTCO inclinometer surveys because the radius of uncertainty is small enough to ensure the bottomhole position is within the target. However, an MMS survey is required to define the bottomhole position before commencing the main build section.

Due to the increase in surveying uncertainty with inclination, more accurate surveying methods are required in deviated wells.

MSS surveys are used to monitor deviation while drilling. Accurate bottomhole position is obtained from the FMS4-AMS dipmeter runs at both 12.1/4in, and 8.1/2in TD’s in the production hole section. The option to run an additional MMS shall be exercised if doubt exists.

Survey programme example: