Method and apparatus for spectroscopic analysis of a geological formation

Patent · Tue Aug 07 04:00:00 EDT 1984

OSTI ID:6423051

Flaum, Ch

Earth formations surrounding a well borehole are analyzed by obtaining a series of capture gamma ray spectra representative of the interaction of thermal neutrons with various chemical elements in the formation surrounding a borehole. The capture gamma ray spectra are used to determine spectral elemental yields quantitatively indicative of the relative abundance of various chemical elements present in the formation. These yields are recorded as a function of depth in said borehole to produce a plurality of traces. The relative sensitivities of the logging tool to a number of the formation components, such as sandstone and limestone, are predetermined either from tool responses in the borehole plus core measurements or from tool responses in a laboratory formation plus the known makeup of the laboratory formation. The volume fractions of the formation components surrounding the well borehole are then determined from the spectral elemental yeilds and the predetermined relative sensitivities and are recorded as a function of depth to generate a tangible record which graphically illustrates the formation lithology.

• Assignee: Schlumberger Technology Corp.
• Patent Number(s): US 4464569
• OSTI ID: 6423051
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200* -- Petroleum-- Reserves
Geology
& Exploration
03 NATURAL GAS
030200 -- Natural Gas-- Reserves
Geology
& Exploration
BARYONS
CAPTURE
CHEMICAL ANALYSIS
CONTROL
DESIGN
ELECTRON CAPTURE
ELEMENTARY PARTICLES
EQUIPMENT
FERMIONS
GAMMA LOGGING
GAMMA SPECTRA
GAMMA SPECTROMETERS
HADRONS
INTERACTIONS
MEASURING INSTRUMENTS
NATURAL GAS WELLS
NEUTRONS
NUCLEONS
OIL WELLS
PARTICLE INTERACTIONS
PROCESS CONTROL
QUANTITATIVE CHEMICAL ANALYSIS
RADIOACTIVITY LOGGING
RESERVOIR ROCK
SPECTRA
SPECTROMETERS
THERMAL NEUTRONS
WELL LOGGING
WELL LOGGING EQUIPMENT
WELLS