INVESTIGATION OF THE EFFECTS OF WAX CONTENT ON MINIMUM MISCIBILITY PRESSURE OF CARBON DIOXIDE IN WAXY OIL

• Main Author: Mohamed Nasir, Maerzad Mohamed Nazmi
• Format: Final Year Project
• Language: English
• Published: Universiti Teknologi PETRONAS 2011
• Subjects: T Technology (General)
• Online Access: http://utpedia.utp.edu.my/10525/1/2011%20-%20Investigation%20of%20the%20effectsof%20wax%20content%20on%20minimum%20miscibility%20pressure%20of%20co2%20in%20waxy%20.pdf; http://utpedia.utp.edu.my/10525/

The reservoir engineer's objective is to produce from oil and gas reservoirs with the highest economical recovery factor. For this reason, Enhanced Oil Recovery (EOR) methods were developed. EOR methods can increase field recovery factor and prolong field life, thus improving its economic value (E.Manrique and !.Wright, 2005). One of EOR methods that is becoming favourable is miscible displacement. For this method, there are a range of gasses suitable for miscible displacement (e.g. Propane and Methane), however, Carbon Dioxide (C02) is most commonly used due to availability and less expensive than Liquefied Petroleum Gas (LPG). C02 can also reduce the oil's viscosity. In miscible displacement, one of the most important parameters that need to be investigated is minimum miscibility pressure (MMP). This is the pressure where the crude oil and C02 gas will become miscible. MMP can be affected by wax content, however to an unknown degree. Waxy oil constitutes that the oil has paraffin content in it. After weighing the options, experimental work was chosen to determine MMP of oil samples and the effects of wax content on C02 MMP; and a technique called the Vanishing Interfacial Tension (VIT) will be employed. The basic principal of this technique is that when MMP is achieved, the IFT between C02 and oil will become zero. Several oil samples with varying wax content have been experimented to obtain the pressure at which the IFT approaches zero, also known as MMP. 5 samples were concocted for the experiment. However, the experiment failed to obtain one of the sample's MMP due to technical difficulties. MMP for the following samples were obtained; 3446 psi, 3706 psi, 3391 psi and 3332 psi for 5%, 15%, 20% and 25% wax content respectively. As noted from 5% and 15%, the MMP increases, however from 15% to 25%, it suddenly decreases. The theory is that there may be insufficient points to extrapolate because of equipment safety limitations. From the experiments, it is concluded that with increasing wax content, the MMP will also increase.