What is Logging While Drilling (LWD) ?

Logging While Drilling:

• Logging while drilling (LWD) is an oilfield service that provides a tool within the drill string that transmits real-time formation information. The LWD tools are located near the end of the drillstring. The measurements recorded provide drilling engineers with critical well information so they may make time sensitive decisions about future well operations.

• LWD is the most effective tool for measuring physical properties, where standard wireline systems previously acquired either no data or poor-quality data. LWD acquires a continuous log of physical properties from directly above the drill bit, where hole conditions are optimal for logging.

• LWD measurement ensures that some measurement of the subsurface is captured in the event that wireline operations are not possible. Timely LWD data can also be
used to guide well placement so that the wellbore remains within the zone of interest which is called as Geosteering.

• LWD tools consists of Gamma Ray Log, Resistivity log, Neutron porosity and density porosity logs which tells us whether the zone is shaly or non shaly, whether the
zone consists of hydrocarbon or water and tells how porous the zone is.