SPWLA Twenty-Second Annual Logging Symposium, JUNE 23-26, 1981        PAPER DD

PAPER DD

 

MECHANICAL PROPERTIES PROGRAM USING BOREHOLE ANALYSIS AND MOHR’S CIRCLE

 

G.R. COATES and S.A. DENOO

Schlumberger Well Services, Houston, Texas

 

ABSTRACT

 

The prediction of sanding from the mechanical properties program has always been a bit of a localized art normally built in case histories and interpretation of G/Cb ratios. In this paper, a new method is presented to determine sand strength limits using tangential and radial stresses with Mohr’s Circle.

 

The availability of reliable shear velocities leads to a refinement of calculated elastic rock properties as well as an upgrade of the mechanical properties program. Within the text of this paper are presented the elastic moduli determination, the uniaxial strength calculations, individual borehole stress components, rock failure theories and predicted failure values.