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Title: Solubility of methane in water under natural conditions: a laboratory study. Final report, April 1, 1978-June 30, 1982

The solubility of methane in aqueous solutions has been determined over a broad range of temperature, pressure and salinities. The effect of dissolved carbon dioxide and ethane on methane solubility has been determined at 302{sup 0}F. Also the solubility of crude oil and water in methane has been determined over a broad range of temperatures and pressures. The solubility of methane is raised by increasing pressure and temperature (above about 170{sup 0}F). There is a solubility minimum near 170{sup 0}F at constant pressure and salinity. Ionic salts effectively salt methane out of solution at all concentrations investigated. The effect of the addition of small amounts of carbon dioxide or ethane to the gas dissolved in aqueous solutions is to enhance methane solubility compared to solutions without other gases. Higher concentrations of dissolved gases, depending upon the salinity and the gas involved, decrease aqueous methane solubility. The addition of carbon dioxide always increased total gas content even when reducing the concentration of methane. With increasing concentration of ethane in the dissolved gases the total gas content reaches a maximum and then both methane and total gas content decrease. Comparison of experimental methane solubilities with gas/water ratios, salinities, bottom hole temperatures andmore » pressures of geopressure test wells suggests that some formation fluids may be near saturation, while many others seem to be undersaturated. Petroleum is soluble in methane. Increasing pressure increases the solubility of crude oil in methane gas. At an elevated pressure, which depends upon the temperature, oil and gas form a single fluid phase.« less
Authors:
;
Publication Date:
OSTI Identifier:
5281520
Report Number(s):
DOE/ET/12145-1
ON: DE82017680
DOE Contract Number:
AS08-78ET12145
Resource Type:
Technical Report
Resource Relation:
Other Information: Portions of document are illegible
Research Org:
Idaho State Univ., Pocatello (USA). Dept. of Geology
Country of Publication:
United States
Language:
English
Subject:
15 GEOTHERMAL ENERGY; 03 NATURAL GAS; METHANE; SOLUBILITY; AQUEOUS SOLUTIONS; BRINES; CARBON DIOXIDE; ETHANE; PETROLEUM; SALINITY; SODIUM CHLORIDES; ALKALI METAL COMPOUNDS; ALKANES; CARBON COMPOUNDS; CARBON OXIDES; CHALCOGENIDES; CHLORIDES; CHLORINE COMPOUNDS; DISPERSIONS; ENERGY SOURCES; FOSSIL FUELS; FUELS; HALIDES; HALOGEN COMPOUNDS; HYDROCARBONS; MIXTURES; ORGANIC COMPOUNDS; OXIDES; OXYGEN COMPOUNDS; SODIUM COMPOUNDS; SOLUTIONS Geothermal Legacy