Estimate formation strength using log data

Journal Article · Sun Nov 01 04:00:00 EST 1987 · World Oil; (United States)

OSTI ID:5571615

Stein, N

Density and sonic well log data may be used to calculate in-situ strength plots for sands adjoining a wellbore. This article focuses on the basic approach. Some variables incorporated in this approach will be discussed in articles in future issues; at present, information may be found in a short course available to the industry. Transposing density and sonic log data into strength plots is accomplished by using the log data to calculate modulus values for the sands under vertical grain pressure conditions, finding a reasonable relation between modulus and strength values for sands, and taking the straight line plot of shear modulus versus vertical grain pressure values to be proportional to the Mohr-Coulomb straight-line strength plot of shear strength versus vertical grain pressure values. A shear modulus value may be defined as the ratio of shear stress to lateral deformation when the sand is in an elastic state.

• Research Organization: S.A.N.S. Co., Dallas, TX
• OSTI ID: 5571615
• Journal Information: World Oil; (United States), Journal Name: World Oil; (United States) Vol. 205:5; ISSN WOOIA
• 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
DENSITY
FORMATION DAMAGE
GEOPHYSICS
IN-SITU PROCESSING
MECHANICAL PROPERTIES
MECHANICS
NATURAL GAS WELLS
OIL WELLS
PHYSICAL PROPERTIES
PROCESSING
ROCKS
SANDSTONES
SEDIMENTARY ROCKS
SHEAR
SOIL MECHANICS
SONIC LOGGING
STRESSES
WELL LOGGING
WELLS