Abstract: A method and a system for tuning a pad. The method may comprise disposing a downhole tool into a borehole, configuring the pad in a first configuration, taking a first measurement of the formation in the first configuration, configuring the pad in a second configuration, taking a second measurement of the formation in the second configuration, determining a tuning coefficient to reduce a tool body effect in the first measurement and the second measurement, computing a first weighted measurement from the tuning coefficient and the first measurement, computing a second weighted measurement from the tuning coefficient and the second measurement, and computing a tuned impedance from a ratio of the first weighted measurement and the second weighted measurement. A system for determining a formation boundary may comprise a downhole tool, an arm, and a pad. The system may further comprise a conveyance and an information handling system.

Abstract: A method and system for estimating a resistivity of a formation. A method for estimating a resistivity of a formation may comprise disposing a downhole tool into a borehole, wherein the downhole tool comprises a pad, an injector electrode, and a return electrode, injecting a current signal into the formation from the injector electrode, measuring a voltage signal between the injector electrode and the return electrode; and determining a formation resistivity and a formation dielectric constant from at least one of the voltage signal, at least one property of the downhole tool, and at least one property of the borehole. A system for estimating a resistivity of a formation may comprise a downhole tool. The downhole tool may comprise a pad, wherein the pad comprises an injector electrode and a return electrode. The system may further comprise a conveyance for disposing the downhole tool in a borehole and an information handling system.

Abstract: A downhole tool, comprising: a tool mandrel; a pad comprising a transmitter operable to transmit an electric current into a formation and a receiver operable to receive at least a portion of the electric current from transmitter; an extension from the tool mandrel that couples pad to tool mandrel; and a signal filter positioned in the downhole tool to suppress passage of mandrel leakage current that passes through tool mandrel to pad. A method of resistivity imaging, comprising: disposing a downhole tool into borehole; transmitting a current into formation surrounding the borehole with a transmitter that is extended from tool mandrel of the downhole tool towards borehole wall; and recording at least a portion of the current that returns to receiver of downhole tool, wherein a signal filter suppress passages of mandrel leakage current that passes through the tool mandrel to a pad on which the transmitter is disposed.

Abstract: This disclosure relates generally to downhole tools and, more particularly, embodiments related to incorporation of a pumpdown relief valve into a downhole tool that is responsive to changes in differential fluid pressure along a downhole tool. Disclosed is a system for pumpdown regulation in a wellbore. The system may include a downhole tool having a tool body with a tool head that is attachable to a line, the line being attached to a point at a surface of the wellbore. The system may further include a pumpdown relief valve coupled to the tool body that is operable to allow fluid to bypass the downhole tool in direct response to a differential fluid pressure across a length of the downhole tool.

Abstract: A method and a system for tuning a pad. The method may comprise disposing a downhole tool into a borehole, configuring the pad in a first configuration, taking a first measurement of the formation in the first configuration, configuring the pad in a second configuration, taking a second measurement of the formation in the second configuration, determining a tuning coefficient to reduce a tool body effect in the first measurement and the second measurement, computing a first weighted measurement from the tuning coefficient and the first measurement, computing a second weighted measurement from the tuning coefficient and the second measurement, and computing a tuned impedance from a ratio of the first weighted measurement and the second weighted measurement. A system for determining a formation boundary may comprise a downhole tool, an arm, and a pad. The system may further comprise a conveyance and an information handling system.

Abstract: This disclosure relates generally to downhole tools and, more particularly, embodiments related to incorporation of a pumpdown relief valve into a downhole tool that is responsive to changes in differential fluid pressure along a downhole tool. Disclosed is a system for pumpdown regulation in a wellbore. The system may include a downhole tool having a tool body with a tool head that is attachable to a line, the line being attached to a point at a surface of the wellbore. The system may further include a pumpdown relief valve coupled to the tool body that is operable to allow fluid to bypass the downhole tool in direct response to a differential fluid pressure across a length of the downhole tool.

Abstract: A downhole tool, comprising: a tool mandrel; a pad comprising a transmitter operable to transmit an electric current into a formation and a receiver operable to receive at least a portion of the electric current from transmitter; an extension from the tool mandrel that couples pad to tool mandrel; and a signal filter positioned in the downhole tool to suppress passage of mandrel leakage current that passes through tool mandrel to pad. A method of resistivity imaging, comprising: disposing a downhole tool into borehole; transmitting a current into formation surrounding the borehole with a transmitter that is extended from tool mandrel of the downhole tool towards borehole wall; and recording at least a portion of the current that returns to receiver of downhole tool, wherein a signal filter suppress passages of mandrel leakage current that passes through the tool mandrel to a pad on which the transmitter is disposed.

Abstract: A method and system for estimating a resistivity of a formation. A method for estimating a resistivity of a formation may comprise disposing a downhole tool into a borehole, wherein the downhole tool comprises a pad, an injector electrode, and a return electrode, injecting a current signal into the formation from the injector electrode, measuring a voltage signal between the injector electrode and the return electrode; and determining a formation resistivity and a formation dielectric constant from at least one of the voltage signal, at least one property of the downhole tool, and at least one property of the borehole. A system for estimating a resistivity of a formation may comprise a downhole tool. The downhole tool may comprise a pad, wherein the pad comprises an injector electrode and a return electrode. The system may further comprise a conveyance for disposing the downhole tool in a borehole and an information handling system.

Abstract: A nuclear magnetic resonance logging tool is provided. The tool includes a flexible or semi-flexible circuit board, at least one capacitor mounted on board, and a controller programmed to apply sequential pulses to the at least one capacitor of the tool with a spacing of less than 600 ?s between adjacent pulses. Ring down time induced by the at least one capacitor in response to pulses is less than about 200 ?s.

Abstract: A nuclear magnetic resonance logging tool is provided. The tool includes a flexible or semi-flexible circuit board, at least one capacitor mounted on board, and a controller programmed to apply sequential pulses to the at least one capacitor of the tool with a spacing of less than 600 ?s between adjacent pulses. Ring down time induced by the at least one capacitor in response to pulses is less than about 200 ?s.