Drill-bit seismic with downhole sensors
AssigneeBaker Hughes Incorporated
InventorsRadu Coman, Sunil Kumar
Life of this patent
Estimating the term…
Abstract
A drill-bit seismic method where the seismic receivers are located in the BHA. The data detected by these receivers is processed by a downhole processing unit in order to estimate the interval velocity of the seismic wave between the sensors and between the bit and a sensor. Additionally, the processed data might provide the distance to a seismic reflector close to the borehole and the average seismic velocity between the well and this reflector. The processed data can be transmitted to surface location by mud-pulse telemetry. The pilot signal can be also used to process seismic data recorded by receivers located at the earth surface (or close to it).
Claims20
A method of evaluating an earth formation, the method comprising:
- conveying a bottom hole assembly (BHA) into a borehole and using a drillbit for generating an unknown seismic signal into the formation;
- receiving signals at at least two spaced apart sensors on the BHA responsive to the generated seismic signal;
- and
- using at least one processor for:
- processing the received signals at the at least two spaced apart sensors and estimating the generated seismic signal.
An apparatus configured to evaluate earth formation, the apparatus comprising:
- a bottom hole assembly (BHA) configured to be conveyed into a borehole;
- a drillbit configured to generate an unknown seismic signal into the formation;
- at least two spaced apart sensors on the BHA responsive to the generated seismic signal;
- and
- at least one processor configured to process the received signals at the at least two spaced apart sensors and estimate the generated seismic signal.
A non-transitory computer-readable medium product having thereon instructions that when read by at least one processor cause the at least one processor to execute a method, the method comprising:
- receiving signals at at least two spaced apart sensors on a bottomhole assembly (BHA) responsive to an unknown seismic signal generated by a drillbit on the BHA;
- and
- processing the received signals at the at least two spaced sensors using an estimate of the generated seismic signal and estimating a property of the earth formation.
Dependencies are inferred from the claim text.