Volumetric Behavior of Oil and Gas from Several San Joaquin Valley Fields

Abstract

Abstract The formation volume and volume of the liquid phase of oil and gas obtainedfrom four fields in the San Joaquin Valley have been investigated at pressures, temperature, and gas-oil ratios comparable to those encountered in underground?reservoirs. All the fields covered in this investigation yielded a product of agas-oil ratio in excess of 5000 cu ft per barrel and the gravity of the tankoil for the four fields in question varied between 52' and 63' API. The resultsof the investigation, together with analytical data concerning the compositionof the oil and gas, are submitted in tabular form. Rough correlations of theformation volume as a function of pressure, temperature, and gas-oil ratio andof the retrograde dew-point pressure as a function of gas-oil ratio, temperature, and gravity of tank oil are presented. It was not found feasibleto correlate simply the formation volume of the liquid phase as a function ofthe applicable variable. It is desired to emphasize that these correlations areconsidered applicable only to the range of conditions covered in thisinvestigation and for systems of similar nature and composition. Introduction Information concerning the physical properties of mixtures of oil and gas fromparticular fields have often been employed in predicting the situationsobtaining in underground reservoirs. One of the earlier studies of this naturewas the work of Beecher and Parkhurst, while a more recent study of theDominguez Field presented detailed volumetric data in the two-phase as well asin the single-phase regions. Although these studies were confined to individualfields, their results proved of value in application to other fields. It hasrecently been shown 3,4 that it is possible in the region of low gas-oilratios' to correlate the? volumetric behavior of naturally occurringhydrocarbon mixtures from a single geographical area with sufficient accuracyto be of industrial value. For this reason it is considered of interest tosubmit information concerning the volumetric behavior of oil and gas mixturesfrom four different fields in the San Joaquin Valley and, in combination withsimilar published data concerning mixtures of oil and gas from the Paloma fieldin the same area, to show rough correlations between the composition and thebehavior of materials from these fields. T.P. 2153