Page 195 - Introduction to Petroleum Engineering

182 WELL LOGGING
9.9 aCTIVITIES

9.9.1 Further Reading

For more information about well logging, see Selley and Sonnenberg (2015), Hyne
(2012), Johnston (2010), Raymond and Leffler (2006), Asquith and Krygowski
(2004), and Bassiouni (1994).

9.9.2 True/False
9.1 A log suite is a combination of well logging tools.

9.2 The Pickett cross‐plot is a plot of porosity versus impedance.
9.3 The gamma‐ray log detects shale from in situ radioactivity.
9.4 A well log and a porosity–permeability cross‐plot can be used to estimate the
Dykstra–Parsons coefficient.
9.5 A well log cross‐plot is a plot of one well log parameter against another.
9.6 The caliper log gives information about the shape of the borehole.
9.7 Electrode logs, induction logs, and acoustic logs are resistivity logs.
9.8 The sonic log measures the transit time of sound propagating in a porous
medium.
9.9 Gamma‐ray logs detect gamma rays from NORM.
9.10 Archie’s equation relates wetting‐phase saturation to resistivity.

9.9.3 Exercises
9.1 a. Typical reservoir values for rock, oil, water, and gas compress ibilities are

−6
−6
c =×310 / psia c =10 ×10 / psia
r
o
−6
−6
c =×310 / psia c = 500 ×10 / psia
g
w
Suppose oil saturation is 0.8 in an oil–water system. Calculate total
fluid compressibility using the aforementioned compressibilities. Hint:
First, calculate water and gas saturation, and then calculate total fluid
compressibility.
b. Calculate bulk modulus of fluid. Note that bulk modulus K = 1/c .
f f
9.2 Plot hydrostatic pressure versus depth for a column of drilling mud in a well
that is drilled to a depth of 5000 ft. The pressure gradient of drilling mud in the
well is 0.48 psi/ft.