Mwd y Lwd

Logging while drilling
From Wikipedia, the free encyclopedia
Well logging |
|
Gamma ray logging
Spontaneous potential logging
Resistivity logging
Density logging
Sonic logging
Caliper logging
Mud logging
LWD/MWDv · d · e |
Logging While Drilling (LWD) is a technique of conveying well logging tools into the well borehole downhole as part of the bottom hole assembly (BHA).
LWDtools work with its Measurement While Drilling (MWD) system to transmit partial or complete measurement results to the surface via typically a drilling mud pulser or other improved techniques, while LWD tools are still in the borehole, which is called "Real Time Data". Complete measurement results can be downloaded from LWD tools after they are pulled out of hole, which is called "Memory Data".
LWDtechnology was developed originally as an enhancement to the earlier MWD technology to completely or partially replace wireline logging operation. With the improvement of the technology in the past decades, LWD is now widely used for drilling (including geosteering), formation evaluation (especially for real time and high angle wells).
[edit] Available LWD Measurements
LWD technology wasoriginally developed to partial or complete replace wireline logging. Over the years, majority of the measurements have been made available in LWD. Certain new measurements are also development in LWD only. The following is an incomplete list of available measurement in LWD technology.
* Natural Gamma Ray (GR)
* Total Gamma Ray
* Spectral Gamma Ray
* Azimuthal Gamma Ray
*Gamma ray close to drill bit.
* Density and Photoelectric Index
* Neutron Porosity
* Borehole Caliper
* Ultra sonic azimuthal caliper.
* Density Caliper
* Resistivity (ohm-m)
* Attenuation and phase shift resistivities at different transmitter spacings and frequencies.
* Resistivity at the drill bit.
* Deep directional resistivities
* Sonic* Compressional Slowness(Δtc)
* Shear Slowness (Δts)
* Borehole Images
* Density Borehole Image
* Resistivity Borehole Image
* Formation Tester and Sampler
* Formation Pressure
* Formation Fluid Sample
* Nuclear Magnetic Resonance (NMR)
* Seismic While Drilling (SWD)
* Drillbit-SWDhttp://en.wikipedia.org/wiki/Logging_while_drilling
Measurement while drilling
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Well logging |
|
Gamma ray logging
Spontaneous potential logging
Resistivity logging
Density logging
Sonic logging
Caliper logging
Mud logging
LWD/MWDv · d · e |
MWD stands for Measurement While Drilling in the oil industry. Is a system developed to perform drilling related measurements downhole and transmit information to thesurface while drilling a well. MWD tools are conveyed downhole as part of bottom hole assembly (BHA). The tools are either contained inside a drill collar (sonde type) or are built into the collars themselves.
MWD systems can take several measurements like natural gamma ray, directional survey, tool face, borehole pressure, temperature, vibration, shock, torque etc. Some advanced MWD tools can evenmeasure formation pressure and take formation samples. The MWD also provides the telemetry for operating rotary steering tools (RSTs).
The measured results are stored in MWD tools and some of the results can be transmitted digitally to surface using mud pulser telemetry through the mud or other advanced technology.
Certain MWD systems have the capability of receiving encoded control commands...