The following directional surveying standard are recommended:
- All exploration wells shall be surveyed from the surface conductor shoe to TD
- All development wells shall be surveyed from the wellhead to at least the lowest hydrocarbon bearing zone
- Survey tool selection for definitive surveys shall be based on the anti-collision requirements, survey tool accuracy, target size and depth. Survey accuracy objectives shall be specified for each well.
- All survey data reported shall be required to have azimuths pre-corrected to UTM. The values for convergence and declination used shall be reported on all definitive surveys. Survey tool accuracy shall be specified on all definitive surveys. Survey results shall be referenced to the local grid.
- Downhole survey instruments shall have a valid inspection certificate valid for a period of up to 12 months. If any tool has been subjected to rough treatment or has produced erroneous survey data, then it shall be returned to the service provider for re-calibration and testing
- The following criteria must be satisfied regarding surveying for relief well drilling:
* Tools of known performance must be used thereby generating surveys of known accuracy
* Regular surveys (every 100ft) of azimuth and inclination must be taken while drilling
* Each hole section in a well, where a section of the well has an inclination of greater than 5°, or a collision possibility exists with other wells, must have a verification survey made which uses an alternative azimuth reading method.
Note: The surveying requirements for relief well drilling can be relaxed for wells with an inclination of less than 5° where it can be proven the hole section considered cannot blowout.
- All deviation data stored in the database shall be stored after applying the required corrections for declination and grid convergence. Declination and grid convergence applied to the surveys shall be stored in the Directional Drilling Contractor database.
- Only survey data obtained from the survey database shall be used for well planning or sidetracking purposes. No other source is acceptable.