Abstract: A rotary steerable drilling tool with an electromagnetic steering system can include a drill collar, a bit shaft, an orientation control module, a mud tube, a mud tube coupler, a universal joint, a mud sealing device, and a drill bit. The bit shaft can be mechanically coupled to the drill collar through the universal joint and the orientation control module and rotate about the universal joint. The orientation and the inclination angle of the bit shaft against the drill collar can be controlled by the orientation control module with the electromagnetic steering system. The orientation control module can include a guide track mounted on the inside wall of the drill collar, arrays of electromagnets mounted on the guide track, a positioning frame, a permanent magnet mounted on the positioning frame, a coupling tube, and at least two bearing wheels. A corresponding electromagnetic steering method is also provided.

Abstract: A rotary steerable drilling tool with an electromagnetic steering system can include a drill collar, a bit shaft, an orientation control module, a mud tube, a mud tube coupler, a universal joint, a mud sealing device, and a drill bit. The bit shaft can be mechanically coupled to the drill collar through the universal joint and the orientation control module and rotate about the universal joint. The orientation and the inclination angle of the bit shaft against the drill collar can be controlled by the orientation control module with the electromagnetic steering system. The orientation control module can include a guide track mounted on the inside wall of the drill collar, arrays of electromagnets mounted on the guide track, a positioning frame, a permanent magnet mounted on the positioning frame, a coupling tube, and at least two bearing wheels. A corresponding electromagnetic steering method is also provided.

Abstract: An apparatus for making resistivity measurements near a drill bit includes a tool body, a transmitter deployed on the tool body, a receiver deployed on the tool body and at an axial distance from the transmitter, and a transmitting signal coupler coupled to the transmitter antenna and the receiver. The transmitter generates electrical signals and converts the electrical signals into electromagnetic signals to be transmitted. The receiver measures the amplitudes and phases of the electromagnetic signals received from the transmitter. The transmitting signal coupler couples a portion of the electrical signals from the transmitter antenna and measures the amplitudes and phases of the coupled electrical signals. Amplitude attenuation and phase shift between the electromagnetic signals received at the receiver and the electrical signals coupled at the transmitting signal coupler are computed for calculating resistivity.

Abstract: An apparatus for making formation resistivity measurements near a drill bit includes a tool body, a toroidal antenna deployed on the tool body near the drill bit, a coupler coupled to the toroidal antenna, a transmitter circuit coupled with the toroidal antenna via the coupler to provide voltage signals to energize the toroidal antenna, a receiver circuit coupled with the toroidal antenna via the coupler to couple electrical current signals flowing in the toroidal antenna to the receiver circuit, and a controller and processor module coupled to the transmitter circuit and the receiver circuit to control the measurement operation and calculate formation resistivity. Formation resistivity is computed based on the voltage signals to energize the toroidal antenna and the measured electrical current signals flowing in the toroidal antenna. A corresponding method for making formation resistivity measurements near a drill bit is also provided.

Abstract: A rotary steerable drilling tool with an electromagnetic steering system can include a drill collar, a bit shaft, an orientation control module, a mud tube, a mud tube coupler, a universal joint, a mud sealing device, and a drill bit. The bit shaft can be mechanically coupled to the drill collar through the universal joint and the orientation control module and rotate about the universal joint. The orientation and the inclination angle of the bit shaft against the drill collar can be controlled by the orientation control module with the electromagnetic steering system. The orientation control module can include a guide track mounted on the inside wall of the drill collar, arrays of electromagnets mounted on the guide track, a positioning frame, a permanent magnet mounted on the positioning frame, a coupling tube, and at least two bearing wheels. A corresponding electromagnetic steering method is also provided.