Mobility of Gas-in-Oil Dispersions in Enhanced Solution Gas Drive (Foamy Oil) Exploitation of Heavy Oil Reservoirs

摘要

In cold production of foamy heavy oil under solutionrngas drive, the oil and the released solution gas arernbelieved to flow in the form of a gas-in-oil dispersion.rnThe mobility of such a dispersion is an important issue inrnmathematical modelling of the cold production process.rnHowever, very little factual information is available inrnthe literature on mobility of gas-in-heavy oil dispersions.rnThe objective of this work was to fill this gap in ourrnknowledge of the foamy oil flow behaviour by measuringrnthe mobility of the gas-in-heavy oil dispersion underrnvarying conditions.rnA new apparatus was developed for measuring therngas-in-oil dispersion mobility as a function of therndispersed gas fraction and the pressure gradient. It usesrna sand-pack holder with three sections of differentrndiameter to produce three different pressure gradients inrnthe same flow test. An in-line mixer was used to generaternlive oil for producing the foamy dispersions. Severalrnvalidation tests were conducted to check the equipmentrnand procedures. Tests were carried out with a viscousrnmineral oil as well as with a heavy crude oil.rnAt a low gas fraction, as would exist immediatelyrnbelow the bubble point pressure in the reservoir, thernapparent viscosity of gas-in-oil dispersion was higher