At 09:53 PM 8/24/98 +0100, Vernon Jenkins wrote of arguments for a young
earth.
>However, in case not,
>here are some: oil gushers,
I replied:
The pressure in oil wells is kept in by capillary pressure not in the way
that Young-earthers calculate it. They use permeability and ignore
capillary pressure.
"Petroleum and natural gas are held at high pressures in underground
reservoirs of porous rock and sand. These fluids are retained in their
reservoirs by relatively impermeable cap rock. However, in many cases the
pressurs are exceedingly high. Calculations based on the measured
permeability of the cap rock show that the oil or gas pressure could not be
maintained for much longer than 10,000 years or perhaps a maximum of
100,000 years (permeability is a measure of how easily fluids under
pressure will seep through the rock.) If these fossil fuel deposits were
actually millions or hundreds of millions of years old, they would long ago
have leaked out through their cap rock to the surface." ~ Robert E. Kofahl,
Handy Dandy Evolution Refuter, (San Diego: Beta Books, 1977), p. 122-123
He cites as source Melvin A. Cook Prehistory and Earth Models, (London: Max
Parish, 1966), p. 254-262 and P. Dickey, et al Science, May 10, 1968, p. 609
who says nothing about rapid leakage.
I brought home from work an excel spreadsheet that I use in calculating
whether or not a trap could hold natural gas. It is based upon the article
R.R. Berg, "Capillary Pressures in Stratigraphic Traps AAPG June
1975:939-956, in Traps and Seals II Treatise of Petroleum Geology Reprint
Series No. 7, p. 36-37 especially equatiosn 16 and 20
The height of an oil column which can be held by capillary pressure is:
zc = pc/g/(pw-po)
where pc= 16.3 gamma/D
where D is the grain diameter
where gamma is the surface tension 35 in the case of oil and approximately
72 in the case of gas (see Revil et al, "Capillary Sealing in Sedimentary
Basins, Geophysical Research letters 25:3 (1998), pp 389-392, esp. p. 391)
where pw is water density
where po is the density of the hydrocarbons (.9 in the case of oil and .05
in the case of gas.
Using a smectite grain diameter .0007 cm and a density difference of .1 for
oil, we find that capillary pressure can hold a 560 foot column of oil
without leaking. Salt can hold about a 4000 foot column if need be and
many of the oil fields in the Gulf of Mexico are associated with salt.
Young earth creationists are wrong to ignore capillary pressure when
dealing with oil fields (of course very few of them actually work in the
oil industry).
glenn
Adam, Apes and Anthropology
Foundation, Fall and Flood
& lots of creation/evolution information
http://www.isource.net/~grmorton/dmd.htm