ElGizawy, Mahmoud (Schlumberger) | Lowdon, Ross (Schlumberger) | Breen, Michael (Schlumberger) | Brovko, Katerina (Schlumberger) | Edmunds, Michael (Schlumberger) | Bulychenkov, Konstantin (Schlumberger) | Mussa, Shadi (Schlumberger)
The drilled wellbore is surveyed while drilling at stationary interval when drilling operation stops to connect a new stand. A next generation measurement while drilling MWD tool is developed to take a definitive survey while drilling either rotating or sliding. This has never been possible before where the entire drilling operation had to stop to take surveys. This paper is presenting results of first runs in the region and the gained benefits in drilling cost and time savings.
The current practice is to hold the drill string stationary to take the survey and allow the direction and inclination sensors to survey the wellbore. The survey time varies from 3 minutes and up to 5 minutes for some MWD tools. Any movement to the drill string will compromise the measurements quality where surveys will fail field acceptance criteria and become invalid. A new technology is developed to allow taking continuous measurements from three magnetometers and three accelerometers to determine accurate inclination and azimuth during drilling the wellbore without a need to stop.
The encouraging results from different runs in the region are presented. Potential time and cost savings are quantified. Surveys are taken every stand approximately every 100 ft. An average 500 minutes (8.6 hours) are needed to take wellbore surveys when drilling 10,000 ft well. For the first time, the new next generation measurement while drilling wellbore surveying tool will save this invisible lost time spent to take the stationary surveys. It improves the average rate of penetration, directional control, allows to complete the well in shorter time and saves on drilling costs. The advantages of continuously taking surveys while drilling is further presented and compared the traditional stationary surveys with respect to the improved well placement.
For the first time in the drilling industry it is possible to take definitive MWD surveys while drill string is rotating and drilling on bottom. The surveying results are very encouraging and show the high potential to maximize the drilling performance while save the drilling time and cost.