The Extraction of Hydrocarbons from Crude Oil by High Pressure CO2

Abstract

This paper presents the results of a laboratory study invest igating the mpacity of COZto extract hydrocarbons frdn cmde oils, The etlkzts of pressure, temperature and oil composition on the extraction G~pacityof C02 were studicd, Extract ion experiments using C02 with Sulimar Queen stock tank oil and Spraberry scpmtor oil samples at pressures bctwccn 1000 and 1900 psig were performed each at 95 "F and 138"F. The experiments were performd by continuously inject iug C02 through 5(X)-CC of oil placed in a 1.15 liter extraction vessel while cent inuously producing the upWr or C02 phase which contains the ext met ion products.C02 extraction capacity was found to bc a strong fhnction of pressure and temperature. The extraction capacity increases with increasing pressure and decremcs with increasing tcnlpcrature. For the oils used in this study, thc presence of solut ion gas in the oil does not affect the C02 extraction capacity, A CO#Minlar Queen oil extraction experiment at constant pressure and temperature of 1200 psig and 95 "F, respectively, was performed for m extended period oft imc to determine the numinnnn oil recovery that can be achicvcd by C02 extraction. It was found from the experiment that COZcould recover at Icmt 70 vol % or 64 wt ?4. of the original oil in place. The COZ cxt ract ion capacity decreased from mound 0,3 g oil/g C02 injeetcd at the beginning of the extraction to 0.005 g oiVg C02 injected at the time of termination.Comparison of the extraction and slim tube tests results shows that the slim tube minimum miscibility pressures (MMPs) m near the pressure range at which a drast ic increase in COz-oil extraction rate occurs, which implies that C02 cxtmction is a major factor in C02-oil miscibility development. The comparison also shows that the cxt raction experiment appears to have promise as a good COz-oil MMP estimation method.

Quantification of Methane-Induced Asphaltene Precipitation in a Multiple Contact Process

“…It indicates that the extraction caused by methane contact is not strong. Compared to CO 2 injection-caused composition change, , the composition change-related asphaltene precipitation is not the primary mechanism of the crude oil used in this work. Moradi et al proved that methane shows stronger ability to induce asphaltene precipitation in crude oil than N 2 at the same mole fraction.…”

Mini Review of Miscible Condition Evaluation and Experimental Methods of Gas Miscible Injection in Conventional and Fractured Reservoirs

“…In other words, over the years, the design of this device has been completed and fabricated in its current form. In this case, there are no perfectly standard dimensions for the slim tube apparatus. − …”

Experimental Investigation on Microscopic Residual Oil Distribution During CO2 Huff-and-Puff Process in Tight Oil Reservoirs

“…When the equilibrium pressure was higher than 9.51 MPa, the crude oil expanded by 28% and the oil swelling factor began to decrease. As the pressure continued to increase, the escaping rate of the light component molecules began to be greater than the rate of CO2 dissolved in the liquid phase [30]. When the equilibrium pressure reached 14.83 MPa, the oil swelling factor was only 0.61.…”