Early kick detection in an oil and gas well
AssigneeBaker Hughes Incorporated
InventorsRocco DiFoggio, Douglas J. Patterson, Eric B. Molz, Volker Krueger
Life of this patent
Estimating the term…
Abstract
A stepped reflector on the outside of a bottomhole assembly produces two reflections in response to excitation of a transducer. The velocity of the fluid in the borehole is estimated using the two reflections. Alternatively, a change in the gas content of the borehole fluid is estimated from changes in the electrical impedance of a transducer in contact with the borehole fluid.
Claims9
An apparatus configured to detect a gas influx in a borehole fluid during drilling operations, the apparatus comprising:
- a bottomhole assembly (BHA) configured to be conveyed in the borehole filled with the borehole fluid;
- a transducer assembly on the outside of the BHA including a transducer configured to be in contact with the borehole fluid in an annulus between the BHA and a wall of the borehole while the BHA is submerged in the borehole fluid and configured to generate an acoustic pulse in the borehole fluid;
- a stepped reflector on the transducer assembly configured to be positioned in the annulus in contact with the borehole fluid while the BHA is submerged in the borehole fluid and configured to produce at least two reflections of the acoustic pulse;
- and
- a processor configured to use a response of the transducer to the at least two reflections to provide an indication of the gas influx;
- wherein the response of the transducer comprises a signal including a first signal arrival and a second signal arrival corresponding to the at least two reflections, and
- wherein the processor is further configured to:
- (i) estimate from the signal an acoustic velocity of borehole fluid, and
- (ii) use the estimated acoustic velocity to provide an indication of the gas influx.
A method of detecting a gas influx in a borehole fluid during drilling operations, the method comprising:
- conveying a bottomhole assembly (BHA) into the borehole;
- using a transducer assembly on the outside of the BHA including a transducer in contact with the borehole fluid in an annulus between the BHA and a wall of the borehole to generate an acoustic pulse in the borehole fluid;
- using a stepped reflector on the transducer assembly positioned in the annulus in contact with the borehole fluid to produce at least two reflections of the acoustic pulse;
- and
- using a response of the transducer to the at least two reflections comprising a signal including a first signal arrival and a second signal arrival corresponding to the at least two reflections to provide an indication of the gas influx by;
- (i) estimating from the signal an acoustic velocity of borehole fluid, and
- (ii) using the estimated acoustic velocity to provide an indication of the gas influx.
Dependencies are inferred from the claim text.