Shaly gas-sand analysis using hand-carried calculators

Journal Article · Tue May 01 04:00:00 EDT 1979 · Log Anal.; (United States)

OSTI ID:6364480

Wu, C H ^[1]; Krug, J

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1. Colorado School of Mines, Golden

A well log evaluation program is presented in this article for shaly-sand cross-plot analysis using either the Hewlett Parkard HP-97 or HP-67 calculator. This program uses analytic methods to compute the effective porosity and shale content from a density (rho/sub b/) and a neutron log porosity (phiN) cross-plot. When hydrocarbon effect is significant, the gamma ray log or spontaneous potential log response is used to compute a shale-corrected, and consequently, hydrocarbon-corrected porosity. First the porosity and shale content are computed, then the water saturation is calculated using the total shale formula. The program has been tested on low permeability (tight) gas-sand analysis and the results are comparable with SARABRAND sand-shale analysis. The accuracy and versatility of the program allows the user to: (1) evaluate shaly formations accurately and quickly in the field and to assist on-site decisions for formation tests and completion; and (2) determine the effect of log parameters on the porosity and saturation calculations or to spot-check SARABRAND results quickly for hydrocarbon-in-place estimates. Furthermore, the program should relieve the user from tedious shaly-sand calculations and allow more time for log quality control and interpretation.

• OSTI ID: 6364480
• Journal Information: Log Anal.; (United States), Journal Name: Log Anal.; (United States) Vol. 20:3; ISSN LGALA
• Country of Publication: United States
• Language: English

Related Subjects

03 NATURAL GAS
030200* -- Natural Gas-- Reserves
Geology
& Exploration
440400 -- Well Logging Instrumentation
47 OTHER INSTRUMENTATION
CALCULATORS
DATA ANALYSIS
GEOLOGIC DEPOSITS
METAMORPHIC ROCKS
NATURAL GAS DEPOSITS
POROSITY
PROGRAMMING
RESERVOIR ROCK
RESOURCES
ROCKS
SANDSTONES
SEDIMENTARY ROCKS
SHALES
WELL LOGGING