1994 · 13 citations · 5 references
EngineeringGeological EngineeringPetroleum EngineeringDrillingInstrumentationWell LoggingDrilling AutomationDrilling EquipmentDrilling OperationsTelemetry SystemsBorehole TelemetryDownhole Drilling ToolsDownhole InstrumentationDownhole LoggingMean Time Between FailuresMean Time To FailureMeasurement While DrillingTool Maintenance
ABSTRACT At the 1991 SPE Forum on MWD, participants expressed the need for more reliable tools, higher data rates and lower cost operations. This paper describes the efforts of one service company to meet those needs. A new tool was specified to meet a goal of 1000 hours Mean Time Between Failure (MTBF). Significant improvements in tool reliability have been achieved through a combination of new design, simplified maintenance procedures and operating practices. Innovative design features of mechanical and electrical components, including system testing, have nearly eliminated failures associated with manufacturing. For the first time in the industry, this tool can communicate with other downhole components through the use of wireless telemetry. This gives the ability to place other drilling tools between the MWD pulser and other measurement tools. The operating range of the tool has been extended to 175°C to be able to perform in high temperature wells. New technology has helped simplify maintenance procedures. The recent increase in the number of downhole logging measurements, and the development of geosteering techniques, have resulted in a need to increase the real time telemetry data rate so that geologists and petrophysicists can have access to higher resolution logs in real time. An order of magnitude improvement has been achieved by a combination of new design features and data compression. Operating costs have been reduced by: – improved reliability which minimizes trips to change failed tools – increased data rate which means that high resolution resistivity and porosity logs can be achieved in real time at faster penetration rates – two-way communication which means that the operator can switch focus from drilling mechanics to formation evaluation without tripping to change the tool – significantly reducing downtime through innovative processing which enables directional surveys to be made while rotating Field examples are shown from N. America and the North Sea which illustrate these points.
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