Formation Evaluation While Drilling
Definition - What does Formation Evaluation While Drilling mean?
Formation Evaluation While Drilling is a method of transporting logging tools to a wellbore as a part of bottom hole assembly. It is an innovative technology that provides tailored and reliable solutions to undertake geological challenges. Since early 1970's, the technique is subject to drilling as it is capable of logging in any direction and in a tough environment. Specific tools used for Formation Evaluation While Drilling include large drill collars, sensors, batteries and electronics. Formation Evaluation While Drilling can increase the production of the well and reduce well construction costs. It is also known as Logging While Drilling (LWD).
Petropedia explains Formation Evaluation While Drilling
Unlike conventional wireline logging which is run on wireline after the well is drilled to the required depth and the bit is pulled out of the hole, Formation Evaluation While Drilling or Logging While Drilling measures the reservoir characteristics while drilling the well. The LWD tools are run as part of the bottom hole assembly and they use the mud as a medium to receive signals at the surface to record the reservoir data.
There are various types of Logging While Drilling techniques such as electromagnetic drilling, acoustic logging, nuclear logging and nuclear magnetic resonance logging. As from 1970 to 2010 lot of improvements were made so as to improvise the technology. LWD is widely used for evaluating a formation, geo-steering and other drilling purposes. The benefits of LWD include:
- Complete analysis of the rock mechanical properties.
- It improves pore pressure estimates.
- More efficient drilling process.
- Real-time adjustments of mud weight.