Real-time velocity and pore-pressure prediction ahead of drill bit

Techniques for estimating velocity ahead of a drill bit include generating seismic waves at a surface from at least two different source positions in the vicinity of a borehole, receiving seismic waves reflected from a reflector ahead of the drill bit at one or more locations in the borehole, determ...

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Bibliographic Details
Main Authors CENGIZ ESMERSOY, BRIAN CLARK
Format Patent
LanguageEnglish
Published 12.09.2007
Subjects
DETECTING MASSES OR OBJECTS
EARTH DRILLING
EARTH DRILLING, e.g. DEEP DRILLING
FIXED CONSTRUCTIONS
GEOPHYSICS
GRAVITATIONAL MEASUREMENTS
MEASURING
MINING
OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR ASLURRY OF MINERALS FROM WELLS
PHYSICS
TESTING
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Summary:Techniques for estimating velocity ahead of a drill bit include generating seismic waves at a surface from at least two different source positions in the vicinity of a borehole, receiving seismic waves reflected from a reflector ahead of the drill bit at one or more locations in the borehole, determining travel times of the seismic waves received at the one or more locations in the borehole, and inverting the travel times to determine a velocity of a formation ahead of the drill bit. One embodiment includes transforming the velocity into pore pressure of the formation.
Bibliography:Application Number: GB20040015930