Bypassed Oil Detection Using Spectroscopy and Nano Technology

Abstract

Detection of the bypassed oil zones during any matured waterflood or EOR process is a critical step in planning the further applications of these processes on a field. While technically deciding whether to continue to waterflood or plug thief zones as a remedy to high water cuts, it is of utmost importance to take into consideration that the overall economics of the project governs most of the decisions not only the technical applicability. The 'Bypassed Zone Detection Tool' described and proposed in this article will detect the bypassed zones and thief zones located in a reservoir precisely, by using Raman Spectroscopy. The number of such zones detected and the depth of their location can be used in planning of further waterflood or EOR process. The same tool has been described in the author's previous paper with respect to microbial detection by Raman Spectroscopy in order to detect bypassed oil zones. However, since MEOR reservoirs are very few and none commercially proven yet, this paper is aimed at direct oil detection with the same tool as also the assistance of the tool in planning an enhanced recovery process economically. This aspect has not been analyzed in the previous paper. The tool promises applicability in a wide variety of situations and downhole areas thus proving itself as a strong candidate for commercial use in near future. Introduction After having spent much time and money on a reservoir and after a successful application of a waterflood or a polymer flood the reservoir starts giving out the injected fluid in large amounts and not the desired one. This means that the water cuts/ polymer recovery in matured fields is more than 80–90% while the desired fluid is crude which is supposed to have high cuts. The reason is thief zones. What should be done in these situations? A crude oil crisis is 'haunting' the world and every bit of crude remaining in that reservoir is absolutely critical with growing technical advancements and thus the need for energy and hydrocarbons. An operator cares only for the economics involved in the project inspite of all this and rightly so! Hence, the aim here is to assist in planning the recovery of this crude remaining in the bypassed zones effectively and economically. This will be done first, by detecting the depth of the thief zones and bypassed zones precisely using the 'Bypassed Zone Detection Tool'. Also, for doing this, the tool uses 'Raman Spectroscopy' which has been the unexplored territory by the oil industry so far and 'Laser light'. Need For New Technology Fig. 1 gives us an idea of how important it is to think of new technologies and new means of recovering oil. As per the example in the figure it is seen that the original oil in place in US is 649 Billion Barrels. The discovered but unrecovered by current technology is a huge 45% of the whole sum while a huge sum is also under the undiscovered and unrecoverable by current technology section. This shows that great amount of crude oil exists and is known to us but our existing technology does not permit its production, so adding new efficient technologies which target this unrecoverable oil, is the best we can do than waiting for more hydrocarbons to be found which are easily recoverable or waiting for nature to make more of those. Also, since the crude oil prices have been sky rocketing with highest till now US $145, it is the best time for oil companies to invest in new technologies.