The PathFinder Sonic tools were developed as the industry's first sonic LWD tools in the World and have become a successful part of our service offering worldwide.
Compensated Long-Spaced Sonic (CLSS) for Real-time Compressional Slowness Measurement
The CLSS tools were developed as the industry's first sonic LWD tools in the World and have become a successful part of our service offering worldwide.
The CLSS collars have 2 transmitters 4 ft. above and below a 4-receiver array with 1 ft. spacings. This particular configuration provides significant measurement redundancy and the opportunity for borehole compensation. An ultrasonic transducer at the center of the receiver array measures standoff, an important quality indicator.
Two compressional slowness (Dtc) measurements are computed downhole using a Semblance Technique and are available for real-time transmission to the surface along with standoff. Full waveforms are stored in tool memory for retrieval when the tool is tripped to the surface for enhanced processing.
Slim Compensated Long-Spaced Sonic (SCLSS) for logging in 6-inch hole sizes.
The PathFinder SCLSS tool provides a real-time compressional and shear porosity measurements in hole sizes as small as 6-inches
The PathFinder SCLSS tool, combined with the PathFinder Directional Gamma tool (HSD-1L) and Slim Compensated Wave Resistivity (SCWR), provides the most complete set of formation data available in 6-inch hole sizes.
The PathFinder SCLSS tool, combined with the PathFinder Directional Gamma tool (HSD-1L) and Slim Compensated Wave Resistivity (SCWR), provides the most complete set of formation data available in 6-inch hole sizes.
Applications include:
- Seismic time-to-depth correlation
- Acoustic Porosity determination
- Real-time Pore Pressure evaluation
- Borehole Stability information
- Natural Fracture identification
E-Sonic Dual Frequency Expanded Mesurement Range
Building on our existing reliable technology of the CLSS tool, the e-sonic service expands the measurement range of the LWD tool to include slow shear analysis. The measurement range is currently 40 - 340/500 microseconds per foot. The two unipole transmitters excite compressional and shear body waves in hard rock as well as compressional and flexural modes in soft formations. The e-sonic tool is a dual frequency LWD sonic tool.
The 15 kHz signal is mainly used for compressional arrival processing and shear analysis in hard rock. The compressional and the shear are computed downhole and are available for transmission to the surface in real-time.
The 7 kHz signal enhances the flexural arrivals and is used for flexural wave processing in softer rock. This processing is provided in the PathFinder computing centers. An advanced dispersion correction algorithm was developed to convert the flexural slowness into the true formation shear slowness. The dispersion algorithm is based on a rigorous solution of the wave equation and uses compressional and shear slownesses together with density, caliper, frequency and borehole fluid parameters to compute the true shear slowness.
