To produce an optimized matrix for the in situ crystallization of zeolite Y, a commercial kaolin chemically treated with NaOH solution at 97°C for 24 h and thermally transformed from 750 to 1100°C was studied. The kaolin calcined at 750°C has 20% more reactive tetrahedral aluminium species for the synthesis of zeolite Y than kaolin calcined at 865°C. The kaolin calcined at 1000°C has amorphous silica zones that may be extracted using caustic solution; this increases the surface area by a factor of 16 and generates mesopores ~5 nm in diameter. These structural changes in the calcined and treated kaolins were combined to prepare microspheres of the mesoporous matrix, upon which well-dispersed crystals of zeolite Y crystallized.

An efficient way to increase oil production in heavy oil reservoirs is by the In Situ Combustion (ISC) process implementation. Part of the oil in place is oxidized, generating heat that increases mobility by reducing oil viscosity. The increase in oil production is associated with displacement mechanisms such as flue gas flooding, steam drive, viscosity reduction by oil swelling and temperature increase, among others. However, not all reservoirs are suitable for an ISC process. Therefore, prior to the implementation of an ISC project, the reservoir properties and reactive characteristics of oil should be evaluated. The isoconversional principle is a technique to obtain information about oil oxidation characteristics, using the kinetic of the oil oxidation/combustion reactions. The isoconversional methods obtain the kinetic from different Ramped Temperature Oxidation (RTO) tests, usually three to five; this technique provides direct information of the effective activation energy. In addition, the technique can be used as a screening tool to identify good candidates to an ISC process and allow recognition of the number of dominant reactions to model the process in numerical simulators. This paper presents the results obtained after applying the isoconversional principle in a Colombian heavy oil. Furthermore, a reaction scheme to model the process in a commercial numerical simulator is proposed. The reaction scheme was validated by matching the experimental results in a numerical thermal simulator.

No abstract

In Situ Combustion (ISC) is a gas injection oil recovery process, the injection gas could be oxygen, air or enriched air. In the ISC process, heat is used as an adjuvant to improve the recovery. The heat is generated within the reservoir by burning a portion of the oil, the burning front is sustained by air injection (Sarathi 1999). The main displacement mechanisms are steam drive, miscible flue gas flooding and, viscosity reduction by oil swelling, temperature increase, among others. The ISC pherhaps is the most efficient enhanced oil recovery method and, possibly the best alternative to produce heavy oil reservoirs. However, despite the economic and technical success of field experiences, the oil industry has been reluctant to its implementation. Mainly, because is difficult to perform the scaling of the process from laboratory to field; any of the methodologies developed is completely reliable. An important point to understand the characteristics of oxidation/combustion of oil is the kinetic, this is usually obtained from Ramped Temperature Oxidation (RTO) tests and using the Arrhenius equation. However, in the last years have been introduced a new methodology named isoconversional principle. The technique provides direct information of effective activation energy and, it can be used as a screening tool to identify good candidates to ISC. In this paper are presented the results after applying the isoconversional principle in a Colombian heavy oil for the understanding of the oil oxidation/combustion characteristics.

No abstract