Schlumberger Technology Corporation

Timothy Tristam Jervis

Benjamin Peter Jeffryes

Stuart I Jardine

Methods and apparatus are described for recognizing wellbore telemetry signals, wherein a received analog telemetry signal is compared to a number of possible analog signals. The probability of representing the received signal is determined for each of the possible analog signals. By selecting the signal with the highest probability, the received signal is demodulated. For calculating the probability, Bayes' method or any equivalent thereof is used. In variants, this probabilistic method is used to determine the synchronization point of the telemetry signal and for controlling the noise removal therefrom. The method and apparatus show increased accuracy in recognizing and demodulating the received signals.

Signal recognition system for wellbore telemetry

This invention describes methods and apparatus for identifying potentially hazardous events during the drilling or production of hydrocarbon reservoirs where such events include kick detection in a well, fluid influx from a drilled formation, sticking pipe in a borehole, pipe washouts or formation fracture generation, according to measurements made by instruments such as flowmeter paddles, electro-chemical transducers or MWD parameter sensors. Measured signals are compared to a number of possible signals and the probability for said measured signals representing such an event are determined.

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Waterbeach, United Kingdom

Timothy Tristam Jervis