Volumetric and Viscosity Studies of Oil and Gas from a San Joaquin Valley Field

Abstract

AbstractThe volumetric behavior of five mixtures of black oil and natural gas and oftwo mixtures of condensate and natural gas from a field in the San JoaquinValley was experimentally established. This work was carried out at 100?, 190?and 250?F in the pressure interval between 400 and 5000 psi. The viscosity ofthe liquid phase of four mixtures of black oil and natural gas wasexperimentally measured in the above-indicated temperature and pressureintervals. The effect of methane upon the precipitation of bitumen from theblack oil was studied at 230?F.IntroductionThe solution of a number of the economical and technological problems whicharise in connection with petroleum production is dependent upon theavailability of the necessary quantitative information covering the materialsinvolved. This requires data concerning physical properties of naturallyoccurring hydrocarbon mixtures at the pressures and temperatures characteristicof underground petroleum reservoirs. The experimental determination of thedesired data for each situation encountered is relatively time-consuming.However, it is considered to yield results sufficiently more reliable thanthose obtained from correlations to justify the effort. For these reasons therewas undertaken a laboratory investigation of the viscosity of the liquid phaseand the volumetric and phase behavior of mixtures of oil and gas samplesobtained from wells in a field located in the San Joaquin Valley.TerminologyThe nomenclature of petroleum engineering is not at present entirelystandardized. Many commonly used technical terms are not everywhere given thesame meanings. For the purposes of this paper the following definitions will beadopted:Black oil refers to the dark-colored, hydrocarbon liquid obtained when theproducing horizon of the well lies partly in the condensed hydrocarbon phase ofthe reservoir. Condensate is the term applied to the relatively volatile, paleyellow or amber-colored hydrocarbon liquid that is often obtained from thesurface separator system when the producing horizon of the well lies in the gascap of the reservoir. The gas obtained from the surface separator system iscalled natural gas regardless of whether the well is producing black oil orcondensate.As might be expected from the multicomponent character of naturallyoccurring hydrocarbon materials, the compositions of black oil, condensate andnatural gas are subject to considerable variation depending upon thetemperatures and pressures prevailing in the surface separator system as wellas upon the overall composition of the material produced from thereservoir.T.P. 2412