Survey at any inclination, at any depth, and at higher latitudes without changing batteries or recalibrating between runs.
An onshore field in Ecuador is typically drilled among congested clusters of 26-in and 16-in tophole sections. MWD surveys and magnetic toolface measurements are compromised by dense offset well proximities, that cause external magnetic interference and resulting in the need to use drop gyros. This adds approximately 9–12 hours of rig time per well.
Many wells begin with the 26-in hole section using a conventional BHA to drill the vertical through boulder formations until 400-ft MD. Drop gyros are run inhole prior to drilling 16-in sections.
The number of drop gyro runs depends on lateral kickoff points, nudges, and external magnetic interference, but drilling programs generally require 6 to 10 gyro surveys per well.
Schlumberger recommended replacing drop gyros by incorporating the GyroSphere MEMS gyro-while-drilling service into the BHA. The BHA would be run inhole through the tophole sections to the 16-in section at 400-ft MD to commence gyro surveying. The MEMS technology of the GyroSphere service enables taking surveys while drilling during connections. This is especially critical for making proactive steering decisions when drilling in a field where nearby wells create magnetic interference.
This was the first oilfield use of inertial toolface with microelectromechanical gyroscopic surveying in the western hemisphere. Using GyroSphere service eliminated flat time associated with slickline or drop gyro operations, saving 32 hours of rig time on three wells. Additionally, the customer effectively and proactively managed collision risk with confidence. Consequently, the operator replaced conventional gyro surveying with the GyroSphere service for the remaining drilling operations.
Challenge: Overcome interference while drilling tophole sections in congested well clusters.
Solution: Deploy GyroSphere MEMS gyro-while-drilling service.