Imdex has been granted a patent for a magnetic susceptibility and conductivity tool that measures geophysical parameters in drill hole formations. The tool uses a transmitter coil and receiver coil to transmit and receive signals, and an electronic circuit processes the signals to provide a drill hole formation signal. The circuit also generates a synthetic null signal to eliminate direct mutual coupling, without the need for a bucking coil. GlobalData’s report on Imdex gives a 360-degree view of the company including its patenting strategy. Buy the report here.
According to GlobalData’s company profile on Imdex, was a key innovation area identified from patents. Imdex's grant share as of September 2023 was 42%. Grant share is based on the ratio of number of grants to total number of patents.
A patent granted for a drill hole logging tool
A recently granted patent (Publication Number: US11754739B2) describes a drill hole logging tool that can measure the combined geophysical parameters of magnetic susceptibility and conductivity of a blast hole formation. The tool includes a magnetic susceptibility and conductivity measuring device that consists of a transmit circuit for sending a signal into the formation, a receive circuit for receiving the signal after it has interacted with the formation, and an electronic circuit for processing the signals to provide a drill hole formation signal.
One notable feature of the tool is that it does not require a bucking coil to eliminate the direct mutual coupling from the receiver signal. Instead, the electronic circuit generates a synthetic null from the transmitter signal, which is used to buck out the direct mutual coupling. This eliminates the need for a bucking coil, simplifying the design of the tool.
The tool also includes a transmitter coil that is energized with a time-varying current, which induces a data signal that includes a primary mutual coupling signal and a formation coupling signal. The receiver circuit consists of one or more receiver coils spaced apart from the transmitter coil, which output a receiver coil voltage induced by the data signal.
The electronic circuit includes a synthetic null circuit that multiplies a digital coil current voltage signal with a predetermined constant for the amplitude of a base primary mutual coupling signal and shifts the phase with a predetermined phase offset. This synthetic null signal is then subtracted from the receiver coil voltage to provide a process signal. The process signal is further conditioned, digitized, and processed by a synchronous demodulator circuit to obtain conductivity and magnetic susceptibility signals.
In addition to the drill hole logging tool, the patent also describes a magnetic susceptibility and conductivity module that can be used in the tool. The module includes a transmitter coil, one or more receiver coils, a transmitter coil current sense circuit, a synthetic null circuit, a subtraction circuit, a signal precondition circuit, an analog to digital converter, and a synchronous demodulator circuit.
Overall, this patented technology offers a novel approach to measuring the magnetic susceptibility and conductivity of blast hole formations without the need for a bucking coil. The simplified design of the tool and module could potentially lead to more efficient and cost-effective drilling operations in various industries.