Abstract: A digitizing apparatus for transmitting electromagnetic telemetry signals to facilitate drilling operations comprises a local receiver and one or more remote transmitters. A method uses the remote transmitter to measure an electric potential between a pair of ground stakes that are positioned at some distance away from the local receiver. The local receiver is coupled to a surface receiver that is located at or near a drilling rig. The remote transmitter converts the electric potential into a digital signal and transmits the digital signal wirelessly to the local receiver. The local receiver then converts the digital signal into an analog signal that is provided to the surface receiver for processing. The remote transmitter and local receiver may comprise GPS clocks to synchronize the signals to maintain a constant phase shift.

Abstract: A digitizing apparatus for transmitting electromagnetic telemetry signals to facilitate drilling operations comprises a local receiver and one or more remote transmitters. A method uses the remote transmitter to measure an electric potential between a pair of ground stakes that are positioned at some distance away from the local receiver. The local receiver is coupled to a surface receiver that is located at or near a drilling rig. The remote transmitter converts the electric potential into a digital signal and transmits the digital signal wirelessly to the local receiver. The local receiver then converts the digital signal into an analog signal that is provided to the surface receiver for processing. The remote transmitter and local receiver may comprise GPS clocks to synchronize the signals to maintain a constant phase shift.

Abstract: A retrievable receiver for electromagnetic telemetry signals originating from a first wellbore is located in a second wellbore. The receiver uses a casing of the second wellbore as an antenna. A signal pickup unit is provided on a multi-conductor wireline in the second wellbore. The signal pickup provides sensors (e.g. electrodes) for detecting signals at plural locations along the second wellbore. Signal reception can be optimized by adjusting the position of the wireline in the second wellbore and/or selecting sensor(s) for use in receiving the telemetry signals. The receiver may lack any active electronics in the second wellbore.

Abstract: A retrievable receiver for electromagnetic telemetry signals originating from a first wellbore is located in a second wellbore. The receiver uses a casing of the second wellbore as an antenna. A signal pickup unit is provided on a multi-conductor wireline in the second wellbore. The signal pickup provides sensors (e.g. electrodes) for detecting signals at plural locations along the second wellbore. Signal reception can be optimized by adjusting the position of the wireline in the second wellbore and/or selecting sensor(s) for use in receiving the telemetry signals. The receiver may lack any active electronics in the second wellbore.

Abstract: A retrievable receiver for electromagnetic telemetry signals originating from a first wellbore is located in a second wellbore. The receiver uses a casing of the second wellbore as an antenna. A signal pickup unit is provided on a multi-conductor wireline in the second wellbore. The signal pickup provides sensors (e.g. electrodes) for detecting signals at plural locations along the second wellbore. Signal reception can be optimized by adjusting the position of the wireline in the second wellbore and/or selecting sensor(s) for use in receiving the telemetry signals. The receiver may lack any active electronics in the second wellbore.

Abstract: A retrievable receiver for electromagnetic telemetry signals originating from a first wellbore is located in a second wellbore. The receiver uses a casing of the second wellbore as an antenna. A signal pickup unit is provided on a multi-conductor wireline in the second wellbore. The signal pickup provides sensors (e.g. electrodes) for detecting signals at plural locations along the second wellbore. Signal reception can be optimized by adjusting the position of the wireline in the second wellbore and/or selecting sensor(s) for use in receiving the telemetry signals. The receiver may lack any active electronics in the second wellbore.