MWD/LWD Telemetry Systems
Telemetry is conversion of a logging tool measurement to a signal suitable for transmission to the surface. Sperry Drilling services offers four MWD/LWD telemetry systems: positive mud pulse, annular venting mud pulse, electromagnetic and via wired drillpipe.
Sperry Drilling’s mud pulse telemetry systems use positive and annular venting mud-pulse telemetry with a high rate of transmission to generate real-time MWD/LWD logs on the surface. The mud pulse systems use valves to modulate the flow of drilling fluid in the bore of the drillstring, generating pressure pulses that propagate up the column of fluid inside the drillstring and then are detected by pressure transducers at the surface.
The electromagnetic MWD/LWD system transmits data via low-frequency electromagnetic waves that propagate through the earth and are detected by a grounded antenna at the surface. It provides higher data rates and greater reliability than traditional mud pulse systems. Electromagnetic telemetry is particularly applicable for drilling with air, foam or aerated muds that preclude the use of mud pulse.
The IXO interface is the link that connects the Sperry MWD/LWD systems to NOV’s IntelliServ® Network. The IntelliServ Network provides two-way communication between downhole MWD/LWD sensors and the surface at speeds up to 10,000 times faster than current mud pulse telemetry rates.