Identifying and Evaluating Potential Inhibitors to Treat Downhole Asphaltene Precipitation using UV-Visible Spectrometer

The objectives of this study are to compare potential inhibitors in treating asphaltene precipitation and to evaluate the effectiveness in terms of amount of n-heptane required for precipitation to take place. Asphaltene can cause severe problem when it started to precipitate upon surplus presence of paraffin solvent that can plug wellbore, safety valves, flow line and so on. In addition, asphaltene can aggregate oil/water interfaces as it stabilize water-oil emulsion or at oil/solid interfaces. It is unfortunate for engineers since major part of reservoir fluid contains paraffin which precipitation will occur over time. Therefore, preventive or remedial solutions are required to cater this problem. The study covers the fundamental understanding of asphaltene precipitation mechanism, identifying potential inhibitors and evaluating the effectiveness through laboratory experiments. The study is organized into two stages which mainly cover a depth study of the subject and validating early inferences through experiments. The method used in the study is based on observing light absorbance using Shimadzu UV-visible double beam spectromter. Interpretation is done by observing light intensity difference between test cell and reference cell inside UV-visible spectrometer. Throughout early study in literature reviews, aromatic solvents and sulphonic acid derivative shows a great result in inhibiting asphaltene precipitation. Therefore, xylene and 1,3 benzenedisulfonic acid were chosen as main inhibitors with toluene as backup inhibitor to be studied. The effectiveness between these three inhibitors in inhibiting asphaltene precipitation was compared in this study.