Published: 02/02/2010
Published: 02/02/2010
Acquiring good downhole sonic-while-drilling measurements is challenging and complex. However, because of the multiple applications of acoustic data it has been a major goal of the industry to develop tools that achieve this objective. Applications for sonic-while-drilling data cover a wide spectrum, including real-time determination of pore pressure and overburden gradients, seismic calibration, complex lithology identification, gas detection, fracture evaluation, and estimation of mechanical properties. These are used by a broad spectrum of disciplines including drillers, geophysicists, geologists, petrophysicists, and reservoir and completion engineers.
Recent developments in multipole sonic measurements provide robust compressional and shear data irrespective of mud speed, as well as Stoneley information, that can be used for advanced sonic applications.
A novel hardware design, coupled with a reassessment of data handling and processing in parallel with extensive modeling now allows advanced answers to be acquired and delivered while drilling.
There are numerous examples in the literature that demonstrate the importance of multipole acoustic data for real-time pore pressure, wellbore stability and seismic correlation. This paper will look at some other applications of great benefit to the drilling and completion community, including top-of-cement identification, rock mechanics, gas detection and other sonic uses that can potentially be an aid in the overall goal of drilling optimization. Data will be shown from deviated, highly deviated and horizontal wells and other challenging logging environments.