Enhanced Oil Recovery (EOR) by Miscible CO2 and Water Flooding of Asphaltenic and Non-Asphaltenic Oils

Abstract

An EOR study has been performed applying miscible CO 2 flooding and compared with that for water flooding. Three different oils are used, reference oil (n-decane), model oil (n-C10, SA, toluene and 0.35 wt % asphaltene) and crude oil (10 wt % asphaltene) obtained from the Middle East. Stearic acid (SA) is added representing a natural surfactant in oil. For the non-asphaltenic oil, miscible CO 2 flooding is shown to be more favourable than that by water. However, it is interesting to see that for first years after the start of the injection (< 3 years) it is shown that there is almost no difference between the recovered oils by water and CO 2 , after which (> 3 years) oil recovery by gas injection showed a significant increase. This may be due to the enhanced performance at the increased reservoir pressure during the first period. Maximum oil recovery is shown by miscible CO 2 flooding of asphaltenic oil at combined temperatures and pressures of 50 °C/90 bar and 70 °C/120 bar (no significant difference between the two cases, about 1%) compared to 80 °C/140 bar. This may support the positive influence of the high combined temperatures and pressures for the miscible CO 2 flooding; however beyond a certain limit the oil recovery declined due to increased asphaltene deposition. Another interesting finding in this work is that for single phase oil, an almost linear relationship is observed between the pressure drop and the asphaltene deposition regardless of the flowing fluid pressure. OPEN ACCESSEnergies 2009, 2 715

Application of Nanoparticles in Enhanced Oil Recovery: A Critical Review of Recent Progress

“…Gas injection techniques have been used commercially worldwide for more than 40 years [131]. However, improvement in sweep efficiency is one of the most pressing technical challenges to enable wider application of these techniques.…”

Investigation of CO2 Enhanced Oil Recovery Using Dimensionless Groups in Wettability Modified Chalk and Sandstone Rocks

“…In the past five decades, there have been extensive laboratory studies, numerical simulations, and field applications of CO 2 EOR processes [1,[3][4][5][6]. The mechanisms affecting the displacement of oil by CO 2 injection include oil swelling, IFT (interfacial tension), and viscosity reduction as well as increasing the injectivity index due to solubility of CO 2 in water and subsequent reaction of carbonic acid with the minerals [7][8][9].…”

Screening and PVT Analysis on Explored-Not-Productive Southern Iranian Oilfields

“…So, extensive researches have been conducted to develop various EOR methods, evaluate their applicability and optimize operation conditions [5] [6]. But, since EOR projects are generally more expensive and involve higher front end costs than conventional secondary projects, one of the principal areas is to develop an effective tool for selection of a suitable EOR method according to oil field characteristics [7].…”