Abstract:
A device and method for securing a sleeve (for sacrificial wear and/or electrical isolation) inside a conduit. In one embodiment, the retention device sits adjacent one end of the sleeve and comprises a ring having a protuberance or lip extending parallel to and against the end of the sleeve, thus pressing the end of the sleeve against the inner surface of the conduit. This has the advantage, in situations where fluids are flowing through the conduit, of reducing the risk of fluids moving behind the sleeve and collapsing it inwardly.
Abstract:
Method and apparatus for transmitting data to or from a downhole tool while the tool is at or near the surface using a wireless data link. A downhole tool comprising a gap sub having a tubular section with first and second longitudinally spaced-apart electrically-conducting parts that are electrically isolated from each other. An electromagnetic telemetry transmitter is connected to apply a potential difference between the first and second electrically conductive parts. A single-wire bus provides a data connection between one of the first and second electrically conductive parts and a data processor.
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 wireless communications system for a downhole drilling operation comprises a drill string, surface communications equipment, and a downhole telemetry tool. The surface communications equipment comprises a surface EM communications module with an EM downlink transmitter configured to transmit through at least a portion of the drill string an EM downlink transmission at a frequency between 0.5 Hz and 180 kHz. The downhole telemetry tool is mountable to a drill string and has a downhole electromagnetic (EM) communications unit with an EM downlink receiver configured to receive the EM downlink transmission. The downhole EM communications unit can further comprise an EM uplink transmitter configured to transmit an EM uplink transmission at a frequency between 0.5 Hz and 180 kHz, in which case the surface EM communications module further comprises an EM uplink receiver configured to receive the EM uplink transmission.
Abstract:
An assembly for securing a probe retention member at a desired location within a tubular interior such as in a drill string collar, using one or more securing members external to the retention member or isolating most of the stresses from the probe retention structures of the retention member.