Abstract: The present invention is a method of transmitting one or more acoustic signals in a drill string using PSK, ASK, FSK or MSFK. The method includes determining one or more stopbands and one or more passbands by testing or modeling the drill string. Two modulating frequencies are selected that are equidistant about a carrier frequency, and which are located within at least one passband. Data representative of downhole measurements or calculations are converted to signals to be transmitted at the modulating frequencies.

Abstract: A drilling control system provides, in one aspect, advisory actions for optimal drilling. Such a system or model utilizes downhole dynamics data and surface drilling parameters, to produce drilling models used to provide to a human operator with recommended drilling parameters for optimized performance. In another aspect, the output of the drilling control system is directly linked with rig instrumentation systems so as to provide a closed-loop automated drilling control system that optimizes drilling while taking into account the downhole dynamic behavior and surface parameters. The drilling models can be either static or dynamic. In one embodiment, the simulation of the drilling process uses neural networks to estimate some nonlinear function using the examples of input-output relations produced by the drilling process.

Abstract: The present invention provides a drilling system that utilizes a neural network for predictive control of drilling operations. A downhole processor controls the operation of the various devices in a bottom hole assembly to effect changes to drilling parameters and drilling direction to autonomously optimize the drilling effectiveness. The neural network iteratively updates a prediction model of the drilling operations and provides recommendations for drilling corrections to a drilling operator.

Abstract: The present invention is a method of transmitting one or more acoustic signals in a drill string using PSK, ASK, FSK or MSFK. The method includes determining one or more stopbands and one or more passbands by testing or modeling the drill string. Two modulating frequencies are selected that are equidistant about a carrier frequency, and which are located within at least one passband. Data representative of downhole measurements or calculations are converted to signals to be transmitted at the modulating frequencies.

Abstract: Torsional oscillations of the drillstring will lead to frequency modulation (FM) of the signal from a vibratory source (e.g., the bit). This results, in the frequency domain, in sidebands being present around a detected excitation frequency. In accordance with the present invention, it has been discovered that these sidebands may be used in advantageous methods for optimizing drillstring and drilling performance. In a first embodiment of this invention, these sidebands are used to discriminate between downhole and surface vibrational sources. Once the location of the drillstring vibration is determined, appropriate action may be taken to optimize drilling and drillstring performance. In a second embodiment of this invention, the sidebands are used to determine the rotary speed of BHA (bottom hole assembly) components.