Method and apparatus for fluid influx detection while drilling
AssigneeBaker Hughes Incorporated
InventorsPingjun Guo, Padmakar Deo
Life of this patent
Estimating the term…
Abstract
A C/O ratio is determined using measurements of inelastically scattered gamma rays with a pulsed neutron source. Combined with look-up tables, the C/O measurement is used as an indicator of formation fluid influx into wellbore such as gas kick.
Claims21
A method of detecting a presence of a second fluid from an earth formation into a borehole containing a first fluid, the method comprising:
- (a) conveying a logging tool into the borehole;
- (b) irradiating the earth formation with a source thereof on the logging tool;
- (c) measuring radiation resulting from interaction of the irradiation with nuclei in the borehole at least one detector;
- (d) determining from the measured radiation a change in an elemental composition of the first fluid;
- and
- (e) using the determined change in elemental composition as an indicator of the presence of the second fluid in the borehole.
An apparatus for detecting a presence of a second fluid from an earth formation into a borehole containing a first fluid, the apparatus comprising:
- (a) a logging tool configured to be conveyed into the borehole;
- (b) a source of the radiation on the logging tool configured to irradiate the earth formation;
- (c) at least one detector on the logging tool configured to measure radiation resulting from interaction of the irradiation with nuclei in the borehole;
- and
- (d) a processor configured to:
- (A) estimate a change in an elemental composition of the first fluid using the measured radiation, and
- (B) use the change in the elemental composition as an indicator of the presence of the second fluid in the borehole.
A computer-readable medium product accessible to at least one processor, the computer-readable medium including instructions which enable the at least one processor to:
- estimate a change in an elemental composition of a first fluid in a borehole using measured radiation resulting from interaction of radiation from a radiation source on a logging tool conveyed in the borehole to irradiate an earth formation with nuclei in the borehole, and
- use the estimated change in the elemental composition as an indicator of a presence of a second fluid in the borehole.
Dependencies are inferred from the claim text.