New Hybrid Steam-Solvent Processes for the Recovery of Heavy Oil and Bitumen

Abstract

TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractCanada has declining reserves of conventional oil, but vast reserves of heavy oil and bitumen. Over 90% of the world's heavy oil and bitumen trapped in sandstones and carbonates are deposited in Canada and Venezuela. Up to 80% of estimated reserves could be recovered by in-situ thermal operation. The current in-situ thermal technologies such as cyclic steam stimulation (CSS), steam flooding and steamassisted gravity drainage (SAGD) are energy intensive and use large quantities of fresh water. Increasing pressure of environmental concerns and the threat of a carbon tax will make it imperative to find new oil extraction technologies that are less energy intensive and that use less water. Combining technologies in the form of hybrid steam-solvent processes offer the potential of higher oil rates and recoveries, but at less energy and water consumption than processes such as SAGD.At the Alberta Research Council, new hybrid steam-solvent processes have been undergoing development in recent years. The Expanding Solvent-SAGD (ES-SAGD) (1-2) , is aimed at improving and extending SAGD performance by solvent addition to steam. The improvements include higher and faster drainage rates, lower energy and water requirements and reduced green house gas (GHG) emissions. The Thermal Solvent Hydrid process focuses on combining solvent with a small amount of steam in a VAPEX (vapour extraction) process (3)(4) . This process offers the potential of higher rates than cold solvent VAPEX at less energy consumption than SAGD.Hybrid steam-solvent processes, when fully developed, will extract oil at lower cost than SAGD and will also open currently marginal resources for exploitation, increasing oil reserves. This paper presents and discusses the principal concepts and key parameters for the new hybrid steam-solvent processes and compares expected performance to SAGD.

Analysis of steam–solvent–bitumen phase behavior and solvent mass transfer for improving the performance of the ES-SAGD process

“…However, the co-injection of butane was found to reduce bitumen production (Orr, 2009). A project managed by Suncor with naphtha co-injection in SAGD in the Firebag area found that naphtha addition has no effect on bitumen production (Nasr and Ayodele, 2006).To achieve a better understanding of ES-SAGD, reservoir simulation was employed to examine the profiles of different reservoir properties, including temperature, gas phase composition, oil phase composition, oil and water saturations, oil viscosity, and oil flow rate in regions near the boundary of the steam chamber. Figures are presented to show important phenomena occurring in those regions and their consequences on oil flow.…”

Beneficiation of Bitumen Deposit at Selenice (Albania)

“…The minimum specific energy seems to be around 150 kJ/kg, making the process economically affordable. With regard to the separation techniques, both flotation and gravity separation can contribute in providing an appropriate solution to the problem of bitumen concentration, although the performance of flotation seems better for the finest size class (<0.5 mm) of the HERA disintegration product, while gravity concentration can be suggested for the coarser one (0.5-1 mm) according to the indication of the technical literature confirmed by the results of some tentative tests on the Selenice tar sands [4,5,6]. The assessment of the technical and economic feasibility of the concept needs further research including tests of industrial significance extended to samples representative of the local variations of the deposit and of its features as a function of climatic conditions.…”

An Investigation of Hybrid Steam-Solvent Injection for Increasing Economy and Reducing CO2Emission

“…A good solvent should be condensed at the same condition with water phase. Hexane is a solvent which has the closest vaporization temperature to steam, which is 215 • C at pressure of 2200 kPa (Nasr et al, 2003;Nasr and Ayodele, 2006). On the other hand, Shu (1984) investigated that mixing of solvents and bitumen will reduce the viscosity drastically at small concentrations of solvents.…”