Constants value unit g 10.0 m/s² ρSeaWater 1.0 g/cc ρSeaFloor 1.7 g/cc ρPoreFluid 1.0 g/cc ρMatrix 2.7 g/cc Part 1: Compute the ove rburde n stress a nd ove rbu rd a. Plot density vs. depth for each dataset. It is con venti approximate g, acceleration due to gravity. Notice that reasonable density for sediments at the Earth’s surface since the well is offshore, use a dens ity of 1.0 g /cc fro sediments. Again extrapolate from this point to the firs b. Divide the density profiles into 5 blocks . By c onsideri approximately constant density. Compute the average c. Calculate the overburden stress. Calculate and plot t profiles. On the same plots, show the hydrostatic pore d. Calculate the overburden gradient (overburden stres both the continuous and blocked density profiles. Part 2: Compute porosity from density logs a. Compute porosity assuming complete saturation an ρlog = (1-ϕ) ρmatrix + ϕρ fluid where ρlog is the log density, ϕ is the porosity, ρmatr i pore fluid (use 1.0 g/cc). b. Plot porosity vs. depthfor each da taset. Calculate an
Transcript
Part 1: Compute the overburden stress and overburd
a. Plot density vs. depth for each dataset . It is
conventi
approximate g, acceleration due to gravity. Notice that
reasonable density for sediments at the Earth’s surface
since the well is offshore, use a density of 1.0 g/cc fro
sediments. Again extrapolate from this point to the firs
b. Divide the density profiles into 5 blocks. By consideri
approximately constant density. Compute the average
c. Calculate the overburden stress. Calculate and plot t
profiles. On the same plots, show the hydrostatic pore
d. Calculate the overburden gradient (overburden stres
both the continuous and blocked density profiles.
Part 2: Compute porosity from density logs
a. Compute porosity assuming complete saturation an
ρlog = (1-) ρmatrix + ρ fluid
where ρlog is the log density, is the
porosity, ρmatri
pore fluid (use 1.0 g/cc).
en gradients
onal to put depth on an inverted y-axis and density on the x-axis.
Use 10.0 m/s2 to
the density measurements are not continuous to the surface. For the
Barnett data, assume a
and extrapolate by whichever method to the first measurement point.
For the GOM data,
the surface to the sea floor (1000 ft) and a density of 1.7 g/cc
for the shallowest seafloor
t point in the data set.
ng the variations of density in each profile, designate 5 blocks
representing sections of
density in each block and plot blocked density vs. depth for each
data set.
e overburden stress for each data set using both the continuous and
blocked density
pressure for each case.
s normalized by depth). Calculate and plot the overburden gradient
for each data set using
hydrostatic pore pressure.
is the density of the sedimentary reservoir rock (use 2.7 g/cc),
and ρ fluid is density of the