Release of CO2 as a by-product of industrial and domestic operations around the world is undesirable due to its negative impact on the environment climate. As an option for reduction many efforts are made to develop methods for the capture and storage of CO2. One potential option, the CO2 enhanced oil recovery (CO2-EOR) technique, is already in use for decades and widely accepted as a promising solution for mobilization and recovery of residual oil in water wet rock. It is also a mitigation prospect for CO2 reduction and an opportunity for permanent storage after the production stage. For better understanding of the mechanisms controlling the oil displacement and CO2 sequestration, the interaction between pore system, flow and phase equilibrium were conducted in a series of CO2 flooding experiments. As an improvement, we propose to inject CO2 as a 2nd stage EOR action after water flooding and accurately monitor and measure CO2 in the system. The experimental part involves brine injection into vertical positioned cylindrical Bentheimer sandstone (BS) cores at residual oil saturation, which mimic depleted oil reservoirs. Next, CO2 is injected at the bottom side of the column to recover oil and to trap CO2. The trapped and residual saturations are measured by mass balance and visualized by a CT - scanner during the experiment to discriminate different phases through time. The oil recovery and trapped saturations of oil and gas are determined as functions of initial oil and gas saturation. Different from previous experimental studies, a continuous CO2 injection technique was used for coupled CO2 sequestration and EOR. The experiments show for CO2 flooding experiments an increase in the back pressure between tests that result in higher CO2 storage and in higher oil recovery. The laboratory results are used for upgrading and building of a model for three phase flow in sandstone reservoir. This paper gives a better understanding of three phase trapping mechanisms and shows results on gas phase behavior with various injection flow rates. In addition, we assess whether the flow and pressure schemes are feasible and we show prospective recoveries and storage efficiency. The experimental results help to improve up-scaling conditions for recovery at field scale.
|Title of host publication||EUROPEC 2015|
|Publisher||Society of Petroleum Engineers|
|Number of pages||12|
|Publication status||Published - 2015|
|Event||EUROPEC 2015 - Madrid, Spain|
Duration: 1 Jun 2015 → 4 Jun 2015
|Period||1/06/15 → 4/06/15|