In a drill bit which has hard-faced cutting or gauge protection elements positioned to be in direct contact with subterranean formation as the bit is rotated, at least one of these elements includes a window positioned to be in direct contact with the formation or cuttings from the formation as the bit rotates and moves forward to drill into the formation. Electromagnetic radiation with wavelength in the range from 100 nm to 2600 nm is transmitted through the window to the formation in contact with the window. Electromagnetic radiation such as fluorescence that returns through the same window is received by a spectrometer. The source and receiver of electromagnetic radiation are both accommodated within the downhole drilling equipment but spaced from the windowed element. The electromagnetic radiation travels along light guides from the source to the window and from the window to the receiver.

In a drill bit which has hard-faced cutting or gauge protection elements positioned to be in direct contact with subterranean formation as the bit is rotated, at least one of these elements includes a window positioned to be in direct contact with the formation or cuttings from the formation as the bit rotates and moves forward to drill into the formation. Electromagnetic radiation with wavelength in the range from 100 nm to 2600 nm is transmitted through the window to the formation in contact with the window. Electromagnetic radiation such as fluorescence that returns through the same window is received by a spectrometer. The source and receiver of electromagnetic radiation are both accommodated within the downhole drilling equipment but spaced from the windowed element. The electromagnetic radiation travels along light guides from the source to the window and from the window to the receiver.

Systems and methods are discussed to image lithological data within the strata beneath the earth surface, including a subterranean object detection system. The system may further comprise a pipeline operable to conduct a working fluid and an instrumented pig operable to travel within the pipeline and operable to image lithological strata and voids within the strata beneath and around the pipeline. The instrumented pig may comprise an outer case, a battery coupled to the outer case, a ground imaging unit operable to send a signal to image the lithological strata and voids within the strata beneath and around the pipeline and may be operable to receive a reflected signal indicating lithology data, wherein the ground imaging unit may be operably coupled to the battery.

A method for assessing and/or removing one or more motion effects from logging while drilling (LWD) measurement data may include disposing a borehole logging tool into a borehole, wherein the borehole logging tool is disposed on a bottom hole assembly (BHA), taking one or more measurements at one or more depth in the borehole with the borehole logging tool to form a measurement data set, and identifying one or more pipe breaks and one or more stations in the measurement data set. The method extracts measurement data at one or more pipe breaks and one or more stations to form a non-motion measurement data set, providing answer products from the non-motion measurement data set. The method may further include removing the one or more pipe breaks and one or more stations from the measurement data set to form a corrected measurement data set and providing one or more answer products.

A method that includes deploying a casing with a multi-electrode configuration over a dielectric layer in a downhole environment. The method also includes collecting electromagnetic (EM) measurements using the multi-electrode configuration, and processing the EM measurements to obtain a characterization of fluids in an annulus between the casing and a borehole wall. A related system includes a casing deployed downhole, the casing having a multi-electrode configuration and a dielectric layer between the casing and the multi-electrode configuration. The system also includes a controller for directing collection of EM measurements using the multi-electrode configuration, and a processor that processes the EM measurements to obtain a characterization of fluids in an annulus between the casing and a borehole wall.

A method that includes deploying a casing with a multi-electrode configuration over a dielectric layer in a downhole environment. The method also includes collecting electromagnetic (EM) measurements using the multi-electrode configuration, and processing the EM measurements to obtain a characterization of fluids in an annulus between the casing and a borehole wall. A related system includes a casing deployed downhole, the casing having a multi-electrode configuration and a dielectric layer between the casing and the multi-electrode configuration. The system also includes a controller for directing collection of EM measurements using the multi-electrode configuration, and a processor that processes the EM measurements to obtain a characterization of fluids in an annulus between the casing and a borehole wall.

An electromagnetic tool using slotted dipole antennas is presented. The dipoles may be placed in slots on a drill collar. A receiver or transmitter antenna consists of one or more slots. A dipole consists of a ferrite rod with electric wires placed above and below the ferrite. Wires may be connected such that wire current forms a loop around the ferrite rod. When a group of slots are used for an antenna, wire holes are constructed between slots. Effectively a single wire may be used to go above all ferrite rods in the group and then turn to go below all the rods. Two wire segments are in a wire hole connecting two adjacent slots. Currents in the two segments are the same in magnitudes and flow in opposite directions. There is no net current in wires in a wire hole.

An electromagnetic tool using slotted dipole antennas is presented. The dipoles may be placed in slots on a drill collar. A receiver or transmitter antenna consists of one or more slots. A dipole consists of a ferrite rod with electric wires placed above and below the ferrite. Wires may be connected such that wire current forms a loop around the ferrite rod. When a group of slots are used for an antenna, wire holes are constructed between slots. Effectively a single wire may be used to go above all ferrite rods in the group and then turn to go below all the rods. Two wire segments are in a wire hole connecting two adjacent slots. Currents in the two segments are the same in magnitudes and flow in opposite directions. There is no net current in wires in a wire hole.

The disclosure presents processes to generate look ahead data to guide borehole operations, such as drilling operations. The processes can array collected resistivity data around a representation of an active borehole. The array can be in various patterns, such as an interleaved helix pattern. Each slice of data from the collected resistivity data can be positioned and oriented corresponding to the central point depth parameter for each slice of data. A selection of one or more card views can be enabled to display details of the collected resistivity data corresponding to the selected slice of data. An analysis of the resistivity data can generate an identification of a boundary, such as an object or a subterranean formation change, in the subterranean formation look ahead portion of the active borehole. The boundary identification can be used as inputs to a borehole operation plan or to a geo-steering system.

The disclosure presents processes to generate look ahead data to guide borehole operations, such as drilling operations. The processes can array collected resistivity data around a representation of an active borehole. The array can be in various patterns, such as an interleaved helix pattern. Each slice of data from the collected resistivity data can be positioned and oriented corresponding to the central point depth parameter for each slice of data. A selection of one or more card views can be enabled to display details of the collected resistivity data corresponding to the selected slice of data. An analysis of the resistivity data can generate an identification of a boundary, such as an object or a subterranean formation change, in the subterranean formation look ahead portion of the active borehole. The boundary identification can be used as inputs to a borehole operation plan or to a geo-steering system.