Symmetric Propagation Resistivity Tool

NOV’s Tolteq SPR tool records formation-resistivity measurements that can be transmitted in real time for well-placement or geosteering applications.

National Oilwell Varco (NOV) recently launched its Tolteq symmetric propagation resistivity (SPR) tool. The tool uses an array of symmetrically placed transmitters and receivers to measure formation resistivity while drilling. When run in conjunction with the Tolteq iSeries measurement-while-drilling platform, the SPR tool’s formation-resistivity measurements can be transmitted in real time for well-placement or geosteering applications. The tool provides independent service companies with access to a critical technology required to deliver logging-while-drilling (LWD) services. Operating at dual frequencies (400 kHz and 2 MHz), the tool measures attenuation and phase shift between the two receivers and correlates them with the formation resistivity. It has a robust mechanical design, comes in multiple sizes to suit a broad range of hole sizes and well designs, and provides borehole-compensated formation resistivities with multiple depths of investigations and vertical resolutions. With eight different formation resistivity measurements, the SPR tool has high-resolution memory data with fast-data-download capability. When combined with multiple transmitter-receiver combinations, it provides better delineation of bed boundaries during well-placement operations and improves the estimate of total hydrocarbon in place.

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