Geology _ Geophysics in Oil Exploration

The spectral gamma ray tool uses the same sensor as

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Unformatted text preview: three-dimensional space, while extending a wellbore. MWD is now standard practice in offshore directional wells. The measurements are made downhole, stored in solid-state memory for some time and later transmitted to the surface. Data transmission methods vary from company to company, but usually involve digitally encoding data and transmitting to the surface as pressure pulses in the mud system. Some MWD tools have the ability to store the measurements for later retrieval with wireline or when the tool is tripped out of the hole if the data transmission link fails. 55 LWD tool Geology & Geophysics in Oil Exploration Mahmoud Sroor Geology & Geophysics in Oil Exploration Logging Tools: These are electronic devices that records data over depth. The tool is attached to the end of wireline cable & lowered to the borehole. There are many types of tools such BHC tool, GR tool, Density tool and many others Usually, these tools are integrated as measurement sensors in one tool called Sonde. Cartridge: The section of a wireline logging tool that contains the telemetry, the electronics and power supplies for the measurement, as distinct from the sonde that contains the measurement sensors. Caliper Tool: The Caliper Tool is a 3 armed device that measures the internal diameter (I.D.) of casing or open borehole completions. This information is crucial to all types of production logging. The caliper probe provides a “first look” at borehole conditions in preparation for additional logging. The log is used to measure borehole diameter, locate fracture zones, assess borehole quality and stability, and for calculation of bore volume for pile construction. Increasing in diameter of borehole indicates about Wash out Process (ex: Shale). Decreasing in diameter of borehole indicates about Invasion process (ex: Porous Sand). 56 Geology & Geophysics in Oil Exploration Mahmoud Sroor Geology & Geophysics in Oil Exploration Acoustic Tools: Borehole Compensated Sonic (BHC): Sonic logging shows a formation’s interval transit time designated ∆t. It is a me...
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This note was uploaded on 01/05/2011 for the course GEOL 1 taught by Professor Jenniferalford during the Spring '10 term at Indian Institute of Technology, Roorkee.

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