Abstract: Apparatus and methods for operating an electronics assembly of a downhole tool. A method comprises disposing a temperature-sensitive electronic component within an insulated chamber contained within a downhole tool. The temperature of the temperature-sensitive electronic component is monitored and a temperature control system is selectively activated to regulate the temperature of the temperature-sensitive electronic component. A downhole electronic assembly comprises a temperature-sensitive electronic component and a temperature-tolerant electronic component in electrical communication with the temperature-sensitive electronic component. An insulating chamber provides a thermal barrier between the temperature-sensitive electronic component and the temperature-tolerant electronic component. A temperature control apparatus in thermal communication with the temperature-sensitive component.

Abstract: Embodiments of methods and apparatus for high temperature operation of electronics according to the invention are disclosed. One embodiment of the invention generally includes an integrated circuit package having a substrate. A plurality of integrated circuits are coupled to a surface of the substrate. A lid is positioned above the substrate facing the surface. One or more pieces of compliant and thermally conductive material are compressed between at least one of the integrated circuits and the lid. The lid defines in part an enclosed volume containing the compliant and thermally conductive material.

Abstract: A compression scheme for reducing the amount of data that must be transmitted uplink from a formation test while drilling apparatus. Periodic samples are taken within the formation test apparatus and prior to transmitting data uplink, the samples are analyzed to generate curve fit parameters that define a curve that most closely fits the sampled data. A minimal set a data points, time variables, and curve fit parameters are transmitted to the surface where the transmitted data is used to reconstruct the formation pressure test curve. A quality of fit value is also transmitted with the minimal data set as an indication of the quality of the fit between the reconstructed data and the actually sampled data points.

Abstract: A method and related apparatus for telemetry between downhole devices and surface devices. In particular, the methods and related apparatus may send a first datum of a first parameter in an uncompressed form, and send a second datum of the first parameter in compressed form.

Abstract: A resistivity tool includes receiver electronics near each receiver antenna loop. Placement of the electronics in this position such as at the circuit card between the terminal ends of the receiver antenna loop improves signal to noise ratio by reducing or eliminating interference, noise, and cross-talk of transmissions from the receiver to a remote microprocessor. By using material such as silicon-on-sapphire, electronics can be miniaturized and operate reliably at when exposed to high temperatures, even for long periods.

Abstract: In at least some embodiments, electronic devices suitable for use at temperatures in excess of 200 C. may comprise an integrated circuit fabricated on a silicon carbide substrate, and a thick passivation layer. In other embodiments, electronic devices suitable for use at temperatures in excess of 200 C. may comprise an integrated circuit formed from silicon located on a sapphire substrate, and a thick passivation layer. The electronic devices may be implemented in the context of hydrocarbon drilling and production operations.

Abstract: A method and system of operating an electromagnetic resistivity tool wherein at least one transmitting antenna of the tool is selectively operable at three or more resonant frequencies for better resistivity profiling of a formation.

Abstract: A method and related apparatus for telemetry between downhole devices and surface devices. In particular, the methods and related apparatus may send a first datum of a first parameter in an uncompressed form, and send a second datum of the first parameter in compressed form.

Abstract: A compression scheme for reducing the amount of data that must be transmitted uplink from a formation test while drilling apparatus. Periodic samples are taken within the formation test apparatus and prior to transmitting data uplink, the samples are analyzed to generate curve fit parameters that define a curve that most closely fits the sampled data. A minimal set a data points, time variables, and curve fit parameters are transmitted to the surface where the transmitted data is used to reconstruct the formation pressure test curve. A quality of fit value is also transmitted with the minimal data set as an indication of the quality of the fit between the reconstructed data and the actually sampled data points.