Surface Facilities Development for Steam Flue Gas Injection in a Colombian Heavy Oil Reservoir

Abstract

Abstract Steam injection in heavy oil recovery often reaches the economical limit. Factors such as steam-oil ratio, generation costs, formation injectivity, reservoir pressure and heat losses are critical for the viability of these projects. This works presents a workflow to develop a scheme of surface facilities for different field conditions, that allows the capture, storage and usage of flue gas generated by steam generators and use it in a steam-flue gas injection process, which is going to mitigate the CO2 emissions, increase oil production and improve the results of steam injection alone in terms of energy efficiency. The proposed workflow has 4 phases: 1) material balance to estimate the composition of flue gas generated based in generator parameters as gas feed, energy capacity and air excess; 2) numerical simulation of the involved processes as combustion, compression and heat exchange to study thermodynamic properties of the flue gas generated; 3) integrity analysis for equipment selection; and 4) determination of the most adequate scheme for flue gas managing according to field requirements. Different case studies for surface facilities development are presented. High initial flue gas temperatures (400°F) and corrosion rates mainly by the presence of CO2 and O2 were identified as critical operation parameters. Since above 140°F corrosion rate gets higher compromising the integrity of the equipment, optimal relation between the gas feed used and an excess of air (15%) might allow a full combustion process decreasing the CO and hydrocarbons fraction in flue gas stream. Cooler units are required after the gas is compressed since the temperature raises, H2O separation has to be done after the first cooling process in order to mitigate the possible formation of carbonic acid on the stream; facilities dimensions are related to the capacity of steam generators and availability of flue gas volumes. The development of an adequate scheme of surface facilities requires an analysis of the conditions described before. Considering that each field has its own characteristics, the current workflow allows to develop optimal facilities for different projects using numerical simulation of multiple processes. The methodology presented allows to determine the adequate facilities for different field conditions, in order to implement a steam flue gas enhanced oil recovery project that increases production and mitigates environmental impacts.