Method for determining oil and water saturation in earth formation surrounding a borehole

Patent · Tue Oct 08 04:00:00 EDT 1991

OSTI ID:5605753

Roscoe, B A; Stoller, C

This paper describes a method for determining the hydrocarbon saturation S{sub 0} in an earth formation surrounding a borehole. It comprises: irradiating the formation with a source of neutrons of sufficient energy to interact with atoms of the formation in the borehole, according to inelastic neutron reactions; detecting and counting the gamma rays resulting from the reactions at least one location longitudinally spaced from the source; forming gamma ray spectrum signals from the gamma rays and deriving from the signals the carbon and oxygen yields; expressing the measured carbon (C) and oxygen (O) yields respectively as a first and second/linear function of S{sub 0} S{sub w} the water saturation in the formation, C{sub b} the hydrocarbon saturation in the borehole, and/or C{sub 0} the water saturation in the borehole; combining the respective measured carbon and oxygen yields (C, O) so as to form the difference C-O; and solving for the unknown S{sub o} from the difference C-O.

• Assignee: Schlumberger Technology Corp., Houston, TX (United States)
• Patent Number(s): US 5055676; A
• Application Number: PPN: US 7-521804
• OSTI ID: 5605753
• Country of Publication: United States
• Language: English

Related Subjects

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47 OTHER INSTRUMENTATION
BOREHOLES
CAVITIES
EQUIPMENT
GAMMA SPECTRA
INELASTIC SCATTERING
NEUTRON LOGGING
NEUTRON SPECTRA
OIL SATURATION
OIL WELLS
RADIOACTIVITY LOGGING
SATURATION
SCATTERING
SPECTRA
WATER SATURATION
WELL LOGGING
WELL LOGGING EQUIPMENT
WELLS