Method for interpretation of seismic records to yield indicating of the lithology of gas-bearing and capping strata

Patent · Tue Dec 31 00:00:00 EST 1985

OSTI ID:5909394

Ostrander, W J

The present invention indicates that gas-containing strata of an earth formation have low Poisson's ratios and that the acoustic contrast (with the overburden rock) has a surprising effect as a function of the angle of incidence on a seismic wave associated with an array of sources and detectors: viz., a significant-and progressive-change in P-wave reflection coefficient as a function of the angle of incidence (within a gather of data) indicates the lithology of the reflecting horizon and the capping strata. Thus, lithologic determination of high-intensity anomalies of gas-containing media is simplified: progressive increases in amplitude intensity of resulting traces generated by the field array as a function of offset between respective source-detector pairs, can be associated with high porosity sandstones; underlying impervious shales; and progressive decreases in amplitudes of likewise commonly gathered traces, is associated with medium-to-low porosity lime-stones underlying a similar type of shale.

• Assignee: Chevron Research Co.
• Patent Number(s): US 4562558
• OSTI ID: 5909394
• Resource Relation: Patent File Date: Filed date 28 Oct 1981; Other Information: PAT-APPL-316013
• Country of Publication: United States
• Language: English

Related Subjects

03 NATURAL GAS
NATURAL GAS DEPOSITS
SEISMIC SURVEYS
AMPLITUDES
EXPLORATION
GEOLOGIC STRATA
HETEROGENEOUS EFFECTS
LIMESTONE
LITHOLOGY
POISSON RATIO
REFLECTIVITY
RESERVOIR ROCK
SANDSTONES
SEISMIC ARRAYS
SEISMIC P WAVES
SHALES
CARBONATE ROCKS
GEOLOGIC DEPOSITS
GEOLOGIC STRUCTURES
GEOPHYSICAL SURVEYS
MEASURING INSTRUMENTS
MECHANICAL PROPERTIES
MINERAL RESOURCES
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
RESOURCES
ROCKS
SEDIMENTARY ROCKS
SEISMIC WAVES
SURFACE PROPERTIES
SURVEYS
030200* - Natural Gas- Reserves
Geology
& Exploration