Abstract: An active downhole antenna located in a borehole receives electromagnetic (EM) telemetry transmissions from sources in adjacent boreholes. The antenna comprises a processor operable do decode and measure signal to noise ratio of received transmissions. Data received at the active antenna is transmitted to surface using a high-speed data communication network. The active antenna may handle data communications from multiple downhole EM telemetry transmitters.

Abstract: A gap joint for use with a gap sub for electromagnetic telemetry. The gap joint has a replaceable uphole shoulder on the male gap joint component, which may be composed of a sacrificial material, to extend gap joint useful life where there is electrolysis of the component outside diameter. The gap joint also has a thicker outside diameter seal to reduce the risk of underlying O-ring extrusion and failure, again extending gap joint useful life. The thicker seal may also be able to withstand higher pressures before collapsing or experiencing punctures in unsupported areas. The replaceable shoulder and outside diameter seal can be used separately or together in a gap joint.

Abstract: A gap joint for use with a gap sub for electromagnetic telemetry. The gap joint has a replaceable uphole shoulder on the male gap joint component, which may be composed of a sacrificial material, to extend gap joint useful life where there is electrolysis of the component outside diameter. The gap joint also has a thicker outside diameter seal to reduce the risk of underlying O-ring extrusion and failure, again extending gap joint useful life. The thicker seal may also be able to withstand higher pressures before collapsing or experiencing punctures in unsupported areas. The replaceable shoulder and outside diameter seal can be used separately or together in a gap joint.

Abstract: An active downhole antenna located in a borehole receives electromagnetic (EM) telemetry transmissions from sources in adjacent boreholes. The antenna comprises a processor operable do decode and measure signal to noise ratio of received transmissions. Data received at the active antenna is transmitted to surface using a high-speed data communication network. The active antenna may handle data communications from multiple downhole EM telemetry transmitters.

Abstract: A gap joint for use with a gap sub for electromagnetic telemetry. The gap joint has a replaceable uphole shoulder on the male gap joint component, which may be composed of a sacrificial material, to extend gap joint useful life where there is electrolysis of the component outside diameter. The gap joint also has a thicker outside diameter seal to reduce the risk of underlying O-ring extrusion and failure, again extending gap joint useful life. The thicker seal may also be able to withstand higher pressures before collapsing or experiencing punctures in unsupported areas. The replaceable shoulder and outside diameter seal can be used separately or together in a gap joint.

Abstract: A gap joint for use with a gap sub for electromagnetic telemetry. The gap joint has a replaceable uphole shoulder on the male gap joint component, which may be composed of a sacrificial material, to extend gap joint useful life where there is electrolysis of the component outside diameter. The gap joint also has a thicker outside diameter seal to reduce the risk of underlying O-ring extrusion and failure, again extending gap joint useful life. The thicker seal may also be able to withstand higher pressures before collapsing or experiencing punctures in unsupported areas. The replaceable shoulder and outside diameter seal can be used separately or together in a gap joint.