Experimental and Numerical Simulation of Combined Enhanced Oil Recovery with In Situ Upgrading in a Naturally Fractured Reservoir

Abstract

The purpose of this research work is to show laboratory experiments conducted at 1500 psi and 350°C, experimentally simulating a reservoir located in the Gulf of Mexico. The experiments conducted used a novel process that involved a hot fluid to be injected with an ultra-dispersed nano catalyst. The results obtained showed that API gravity can be improved permanently as well as its viscosity, with the advantage of no coke or solid deposits formation. Laboratory analyses showed that by using this new process it is possible to enter into the matrix zone, expelling at least partially the oil confined inside. As a consequence of the temperature increase, matrix rock may expand and expel its oil; while temperatures decrease, the pores in the matrix could be contracted, generating additional oil expulsion from this area. As a consequence of this expansion-contraction in the reservoir the reserves could be increased. Also, a change in the permeability appears due to the temperature increases. The present study was focused in oil matrix extraction and in situ oil upgrading from a naturally fractured reservoir of heavy oil as a result of a hot fluid injection with nano catalyst. Moreover, the effects of capillary pressure, mobility, viscous effects, wettability, and gravitational drainage on the process were analyzed. Another aspect that was studied is how the thermal expansion generated as a consequence of the process that could expel the oil confined in the matrix.

In‐situ upgrading of heavy oil using nano‐catalysts: A computational fluid dynamics study of hydrogen and vacuum residue injection

“…Bench scale experiments suggest that a volumetric hydrogen‐to‐vacuum residue ratio of 120, at standard conditions, offers the best balance between conversion and yield on one side and stability on the other side . Hovsepian et al pointed out that severe conversions yield unstable synthetic oils that have high potential for asphaltene precipitation as an adverse outcome.…”

“…Also, this method has an inherent advantage over the practiced methods for oil production and recovery, such as steam assisted gravity drainage (SAGD), in that it produces a transportable crude oil with pipeline specification that does not need a diluent. As well, the exothermic nature of the reactions provides a platform for the self‐sustainability of the catalytic reactions and also leads to temperature alteration that helps expel the confined oil via permanent expansion‐contraction . In addition, the produced gases act like a solvent and they also apply a mechanical push for further oil recovery, enhancing the oil recovery factor by 36 %, as compared to SAGD …”

Heavy Oil Catalytic In Situ Upgrading in Fractured Carbonate Reservoirs. Fluid Distributions and Occurring Reactions Monitored with Marker Hydrocarbons

“…The ISUT process was initially designed for sand reservoirs but has been explored for use in fractured carbonate reservoirs. − It leverages the reservoir as a reactor, anchoring metallic ultradispersed catalysts onto minerals for in situ upgrading. Vacuum residue (VR) serves as the carrier fluid, containing heat, catalysts (100–700 ppm metals), and hydrogen (50–300 std cm 3 per std cm 3 of VR) .…”