摘要:
An apparatus for measuring one or more earth formation properties during applications including formation evaluation and geosteering applications is provided. The apparatus includes: an elongated body; at least one recessed portion on a periphery of the elongated body; an electrically conductive coil forming a closed loop, at least a portion of the coil extending through the at least one recessed portion; and a u-shaped magnetically permeable and non-conductive material disposed between the coil and the at least one recessed portion, the u-shaped material partially surrounding the coil in the at least one recessed portion. A system for measuring one or more properties of an earth formation is also provided.
摘要:
An apparatus for measuring one or more earth formation properties during applications including formation evaluation and geosteering applications is provided. The apparatus includes: an elongated body; at least one recessed portion on a periphery of the elongated body; an electrically conductive coil forming a closed loop, at least a portion of the coil extending through the at least one recessed portion; and a u-shaped magnetically permeable and non-conductive material disposed between the coil and the at least one recessed portion, the u-shaped material partially surrounding the coil in the at least one recessed portion. A system for measuring one or more properties of an earth formation is also provided.
摘要:
The disclosure provides a resistivity tool for use in a wellbore, wherein at least two orthogonal antennas are located at the same or substantially the same location of the tool. A single set of vertically aligned grooves is provided for the at least two orthogonal antennas. Each antenna may be configured to operate as a transmitter or receiver. A tool with collocated antennas may be used to provide azimuthally sensitive measurements even if the tool is non-rotating.
摘要:
The disclosure provides a resistivity tool for use in a wellbore, wherein at least two orthogonal antennas are located at the same or substantially the same location of the tool. A single set of vertically aligned grooves is provided for the at least two orthogonal antennas. Each antenna may be configured to operate as a transmitter or receiver. A tool with collocated antennas may be used to provide azimuthally sensitive measurements even if the tool is non-rotating.
摘要:
An apparatus for estimating a property of an earth formation penetrated by a borehole, apparatus including: a carrier configured to be conveyed through the borehole; a transducer disposed at the carrier and configured to transmit and/or receive electromagnetic energy into and/or from the earth formation to estimate the property; wherein the transducer includes a plurality of inductively coupled elements in a series, each element configured to transmit and/or receive electromagnetic energy and at least a first connection to a first element in the plurality and a second connection to a second element in the plurality with at least one of the first element and the second element being disposed between end transducer elements in the series.
摘要:
An apparatus for estimating a property of an earth formation penetrated by a borehole, the apparatus having: a carrier configured to be conveyed through the borehole; a transmitter disposed at the carrier and configured to transmit electromagnetic energy at a first frequency into the formation; a first antenna disposed at the carrier and configured to receive electromagnetic signals from the formation as a result of the transmitted electromagnetic energy interacting with the formation; and an active filter coupled to the antenna and configured to filter electromagnetic signals received by the antenna to let the electromagnetic signals at the first frequency pass for processing to estimate the property.
摘要:
An apparatus for estimating a property of an earth formation penetrated by a borehole, apparatus including: a carrier configured to be conveyed through the borehole; a transducer disposed at the carrier and configured to transmit and/or receive electromagnetic energy into and/or from the earth formation to estimate the property; wherein the transducer includes a plurality of inductively coupled elements in a series, each element configured to transmit and/or receive electromagnetic energy and at least a first connection to a first element in the plurality and a second connection to a second element in the plurality with at least one of the first element and the second element being disposed between end transducer elements in the series.
摘要:
An apparatus for estimating a property of an earth formation penetrated by a borehole, the apparatus having: a carrier configured to be conveyed through the borehole; a transmitter disposed at the carrier and configured to transmit electromagnetic energy at a first frequency into the formation; a first antenna disposed at the carrier and configured to receive electromagnetic signals from the formation as a result of the transmitted electromagnetic energy interacting with the formation; and an active filter coupled to the antenna and configured to filter electromagnetic signals received by the antenna to let the electromagnetic signals at the first frequency pass for processing to estimate the property.
摘要:
An apparatus and method for estimating a resistivity property of an earth formation involving electric current induced in an earth formation. The method may include reducing an error in a voltage received by a receiver coil due to excitation of a transmitter coil due to temperature effects. The voltage may include amplitude and/or phase errors. The method may modify the measured voltage by multiplying/dividing the voltage by a reduction factor. The reduction factor may be determined using polynomic curve fitting. The apparatus may be configured to perform the method. The apparatus may include at least one transmitter coil, at least one receiver coil, and at least one processes configured to perform the error reduction.
摘要:
A unified circuit without using a relay is proposed to resonate an antenna at more than two frequencies. The use of such analog IC switches are common place for transceiver applications in high RF frequencies (500 MHz and above). However, the use of selectively tuned antennas has for the most part been accomplished by the use of latching relays or fixed value components. The IC switch allows for not only the functionality of a single antenna to be either a transmitter and/or a receiver, but also allows, by adding additional switches to select any number of frequencies to resonate the antenna. This frequency resonation could be at fixed frequency points or sweep in either linear or logarithmic steps. The component selection of capacitors for either method would be controlled by a DSP or other microcontroller device. In one embodiment, an antenna for a downhole measurement tool is provided with a tuning circuit couple by a transformer to at least one antenna. The tuning circuit is disposed entirely within and protected by the hollow body of the tool and selectively tunes the antenna to at least three discrete frequencies. Advantageously, no structural modification is made on the outer surface of the tool to accommodate the tuning circuit. In one embodiment, a switching circuit enables a single antenna to function as both a transmitter and a receiver.