The Optimization of Gas/ Steam Injection Using Numerical Simulation

Abstract

TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractSimultaneous injection of heated exhaust gas (mainly CO2 and N2) and steam is one of EOR methods used in Russia for heavy oil recovery. In this case the energy released by gassteam generator is used more efficiently compared to pure steam injection. Another benefit of using this EOR method is an additional reduction of the oil viscosity caused by exhaust gases solution in oil. This technology is particularly efficient when used for the small reservoirs being developed by a single well. Practical implementation of this technology is not always successful. One of the main reasons of failure is that parameters of the injected gas-steam mixture are far from being optimal. This study presents results of numerical simulation of the gassteam injection process, so called huff-and-puff injection. The aim of the modeling was to estimate an influence of reservoir geometry and heterogeneity as well as huff-and-puff injection parameters on oil recovery factor. The reservoir's and oil properties were typical for Volga-Ural oil province of Russia. The radial geometry was used in numerical simulation with model radius equal to 400 meters. The main results of this study can be summarized as follows:• heavy oil reservoir development based on primary depletion is not profitable; EOR methods are needed; • efficiency of the huff-and-puff gas-steam injection increases with oil column thickness increase • there is optimal time for well being shut-in after gassteam injection, this time is dependant on volume of injected energy; • the reservoir heterogeneity plays significant role in thermal oil recovery process.

Combining Steam and Flue Gas as a Strategy to Support Energy Efficiency: A Comprehensive Review of the Associated Mechanisms

“…In particular, the emphasis in this work is on evaluating experiences and phenomena associated with the use of flue gas to optimize steam injection processes. In this sense, Flue Gas (a mixture of compounds, where CO 2 is found in a major proportion , between 10 and 15% and 80–85% of N 2 , there are other associated components such as water, oxygen, carbon monoxide, nitrogen oxides, and sulfur oxides, among others; these are called impurities, and their presence will depend on the fuel used for its generation and the type of generator used. , …”