A ranging system and method to determine a relative distance and direction of a target borehole relative to a second borehole using a ranging tool that can make ranging measurements while the ranging tool is not rotating. An array of button electrodes included in the ranging tool can be fired in a sequential fashion so as to simulate rotation of one or more button electrodes, without the ranging tool rotating. The array of button electrodes can also be fired in a sequential fashion so as to simulate rotational and/or longitudinal movement of the ranging tool.

A ranging system and method to determine a relative distance and direction of a target borehole relative to a second borehole using a ranging tool that can make ranging measurements while the ranging tool is not rotating. An array of button electrodes included in the ranging tool can be fired in a sequential fashion so as to simulate rotation of one or more button electrodes, without the ranging tool rotating. The array of button electrodes can also be fired in a sequential fashion so as to simulate rotational and/or longitudinal movement of the ranging tool.

Fiber optic sensors are described for detecting the operational position of a downhole moveable device. In one example, an electric or magnetic field is emitted into the wellbore and interacts with the moveable assembly, thereby producing a secondary electric or magnetic field. The secondary field is detected by a fiber optic sensor which produces a corresponding response signal. The response signal is then processed in a variety of ways to determine the operational position of the moveable device. In another example, the operational position is determined using fiber optic temperature or acoustic sensors. A temperature or acoustic vibration reading is acquired before and after actuation of the moveable device. The two readings are then compared to determine the operation position of the moveable device.

Fiber optic sensors are described for detecting the operational position of a downhole moveable device. In one example, an electric or magnetic field is emitted into the wellbore and interacts with the moveable assembly, thereby producing a secondary electric or magnetic field. The secondary field is detected by a fiber optic sensor which produces a corresponding response signal. The response signal is then processed in a variety of ways to determine the operational position of the moveable device. In another example, the operational position is determined using fiber optic temperature or acoustic sensors. A temperature or acoustic vibration reading is acquired before and after actuation of the moveable device. The two readings are then compared to determine the operation position of the moveable device.

The present invention is aimed to reduce power consumption of a measuring apparatus. A measuring apparatus according to the present invention is to be disposed in an excavation section of an underground excavator. The measuring apparatus according to the present invention includes a first measurement module, a second measurement module, and an information processor. The first measurement module includes a triaxial first accelerometer and a triaxial first magnetometer for performing highly-accurate measurement. The second measurement module includes a triaxial second accelerometer and a triaxial second magnetometer for performing measurement during excavation. The information processor controls the first measurement module and the second measurement module and obtains a position and an attitude of the excavation section based on output data of the first measurement module or the second measurement module. Further, the second accelerometer and the second magnetometer are MEMS sensors.

The present invention is aimed to reduce power consumption of a measuring apparatus. A measuring apparatus according to the present invention is to be disposed in an excavation section of an underground excavator. The measuring apparatus according to the present invention includes a first measurement module, a second measurement module, and an information processor. The first measurement module includes a triaxial first accelerometer and a triaxial first magnetometer for performing highly-accurate measurement. The second measurement module includes a triaxial second accelerometer and a triaxial second magnetometer for performing measurement during excavation. The information processor controls the first measurement module and the second measurement module and obtains a position and an attitude of the excavation section based on output data of the first measurement module or the second measurement module. Further, the second accelerometer and the second magnetometer are MEMS sensors.

A drilling system, comprising a drill string; and a ranging tool mounted on the drill string, the ranging tool comprising a magnetic sensor pair comprising a first magnetic sensor and a second magnetic sensor mounted radially opposite one another on the ranging tool, wherein each of the magnetic sensors is structured and configured to detect at least a radial component and a tangential component of a magnetic field; a rotatable assembly, comprising a motor structured and arranged to actuate rotation of the magnetic sensor pair around the drill string; and an electronics package connected to at least one of the magnetic sensor pair, and the motor, wherein the electronics package comprises a controller and a wireless telemetry device.

A drilling system, comprising a drill string; and a ranging tool mounted on the drill string, the ranging tool comprising a magnetic sensor pair comprising a first magnetic sensor and a second magnetic sensor mounted radially opposite one another on the ranging tool, wherein each of the magnetic sensors is structured and configured to detect at least a radial component and a tangential component of a magnetic field; a rotatable assembly, comprising a motor structured and arranged to actuate rotation of the magnetic sensor pair around the drill string; and an electronics package connected to at least one of the magnetic sensor pair, and the motor, wherein the electronics package comprises a controller and a wireless telemetry device.

A system for analysis of isolated and connected porosities of a porous formation using permittivity is disclosed. An electrical subsystem can provide electrical signals for one or more of the porous formation or a representation of the porous formation; and the system can determine one or more of a rate of permittivity change (RPC) or permittivity ratio (PR) from a first estimation model that relates permittivity measurements and frequencies that are associated with the electrical signals, so that the system can generate a second estimation model using one or more of the RPC or the PR, associated with the isolated and connected porosities, where the second estimation model can be used with a total porosity of the porous formation to estimate or predict an isolated porosity and a connected porosity of a production porous formation.

A system for analysis of isolated and connected porosities of a porous formation using permittivity is disclosed. An electrical subsystem can provide electrical signals for one or more of the porous formation or a representation of the porous formation; and the system can determine one or more of a rate of permittivity change (RPC) or permittivity ratio (PR) from a first estimation model that relates permittivity measurements and frequencies that are associated with the electrical signals, so that the system can generate a second estimation model using one or more of the RPC or the PR, associated with the isolated and connected porosities, where the second estimation model can be used with a total porosity of the porous formation to estimate or predict an isolated porosity and a connected porosity of a production porous formation.