Description:
This paper presents the initial results of a survey of the
occurrence and characteristics of geopressured fluid
resources in California using the publicly-available database
involving more than 150,000 oil and gas wells drilled in the
State. Of the 975 documented on-shore oil and gas pools
studied, about 42 % were identified as potentially
geopressured. Geothermal gradients in California oil and
gas fields lie within the normal range of 1°F to 2 OF per
100 feet. Except for the Los Angeles Basin, there was no
evidence of higher temperatures or temperature gradients in
geopressured pools. The porosity of geopressured pools
shows the same normal distribution as for normal pressured
pools, with a mode in the range of 20 to 25 %. The salinity
distribution of both the geopressured and normal pressured
pools appear to be bimodal, each with two peak ranges of
o to 10,000 and 25,000 to 30,000 ppm. Compared to the
U. S. Gulf Coast region, geopressured pools in California
display much lower water salinity, and therefore, should
have a higher solubility for methane.