LWD Sonic Real Time Application Case Study
New Product Launch Manager, Drilling Services, Weatherford International
Operating companies have formed an old prospective that real-time LWD sonic data is unreliable and requires post-processing. Advances in the LWD technology allowed for having new generation sonic tools that can provide real-time sonic semblance image while drilling that is almost identical in quality to the recorded memory traditional sonic semblance image. Sonic as a real-time measurement is not a new LWD service, however, in the past; the data quality was not encouraging operating companies to use it as a real-time decision maker. And many of the sonic applications prove more valuable in getting them in real-time as opposed to after the fact recorded memory option.
The Latin America case study discusses a critical pore pressure prediction situation due to multiple faults surrounding the well bore, and how valuable the sonic real-time data was to ensure well integrity as well as well placement. A comparison between the real-time sonic semblance image and the recorded memory data in terms of resolution and data quality will show the reason behind the growing trust in utilizing the sonic data in critical real-time decisions.
In addition to the pore pressure application, the real-time sonic data proves very useful, when used in conjunction with density LWD data, in analyzing the rock mechanical properties while drilling. Rock mechanical properties such as Young's Modulus, Poisson's Ratio, and other brittleness indicators can be monitored and plotted while drilling based on high quality LWD data.
The case study will discuss the geological background of the field in which the operating company applied the LWD sonic services in real-time. The case study will provide basic background knowledge on the formations in the region highlighting the reasons why sonic and other LWD services were appropriate for the environment.
Technological advances in the logging while drilling services have directly impacted the ability of evaluating a reservoir and provide production planning on the foot-by-foot basis. The amount of downhole data processing and data compression that new tools provide plays a critical role in real-time data transmission while drilling.
The new sonic LWD generation has a unique hardware that is crucial in addressing new challenges from drilling in extreme drilling conditions, withstanding high vibrations, temperatures and pressures without altering the measurement quality.
High resolution real-time semblance images together with other formation evaluation curves are achievable and the uses and applications are expanding over traditional delta-t data acquisition. This is considered a step change in the way operating companies are using the sonic data for analysis as well as future production planning.
AAPG Search and Discovery Article #90203 © AAPG Geoscience Technology Workshop, Trinidad and Tobago Deep Horizon and Deep Water Frontier Exploration in Latin America and the Caribbean, March 9-11, 2014, Port of Spain, Trinidad