FORTRAN algorithm for correcting normal resistivity logs for borehold diameter and mud resistivity

Technical Report · Sat Jan 01 00:00:00 EST 1983

DOI:https://doi.org/10.2172/6069986· OSTI ID:6069986

Scott, J H

The FORTRAN algorithm described was developed for applying corrections to normal resistivity logs of any electrode spacing for the effects of drilling mud of known resistivity in boreholes of variable diameter. The corrections are based on Schlumberger departure curves that are applicable to normal logs made with a standard Schlumberger electric logging probe with an electrode diameter of 8.5 cm (3.35 in). The FORTRAN algorithm has been generalized to accommodate logs made with other probes with different electrode diameters. Two simplifying assumptions used by Schlumberger in developing the departure curves also apply to the algorithm: (1) bed thickness is assumed to be infinite (at least 10 times larger than the electrode spacing), and (2) invasion of drilling mud into the formation is assumed to be negligible.

• Research Organization: US Geological Survey, Denver, CO (United States)
• OSTI ID: 6069986
• Report Number(s): USGS-OFR-78-669; ON: DE83902143
• Country of Publication: United States
• Language: English

Related Subjects

15 GEOTHERMAL ENERGY
RESISTIVITY LOGGING
DATA ANALYSIS
ALGORITHMS
BOREHOLES
DRILLING FLUIDS
FORTRAN
CAVITIES
ELECTRIC LOGGING
FLUIDS
MATHEMATICAL LOGIC
PROGRAMMING LANGUAGES
WELL LOGGING
Geothermal Legacy
150301* - Geothermal Exploration & Exploration Technology- Geophysical Techniques & Surveys