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Abstract This paper investigates the applicability of Low Salinity (LoSal) EOR for a Kuwaiti reservoir. Many reservoirs in the Middle East are not producing satisfied results after depletion methods for a long time of production. Therefore, new management and production strategies must be determined in order to meet the global market demand for oil, which can be done using Enhanced Oil Recovery (EOR) techniques. In Kuwait, one of the EOR methods that could be applied is the use of Low-Salinity (LoSal) Water Flood. Results from previous research have clearly shown that LoSal water injection has a significant impact on oil recovery. Although there are many LoSal experimental results reported in the literature, the process mechanisms and the prediction modeling are yet to be fully investigated and understood. As a result, further experimental work is needed in order to be able to develop reliable prediction tools. The research in this paper is an integrated study combining laboratory work to assess the performance of LoSal water flood using live crude, reservoir brine and native core with wettability conditions restored. The core flooding phase will conduct series of low salinity water flood experiments, design of Salt type and concentration. The performance of LoSal will be compared to different salinities water flood based on reservoir water salinity.
Abstract Extensive experimental work has indicated that low-salinity waterflooding is an enhanced oil recovery technique that improves oil recovery by lowering and optimizing the salinity of the injected water. Most of the low-salinity waterflooding studies focused on the injection brine salinity and composition. The question remains, how does the salinity and composition of the reservoir connate water affect the low-salinity waterflooding performance? Therefore, in this work different connate water compositions were used to investigate the role of reservoir connate water on the performance of low-salinity waterflooding. In this paper, nine spontaneous imbibitions experiments were performed. Two sandstone types (Bandera and Buff Berea) with different clay contents were used. The mineralogy of the rock samples was assessed by X-ray powder diffraction, scanning electron microscopy, and X-ray fluorescence. This work describes the experimental studies of the spontaneous imbibition of oil by low-salinity and high-salinity brines using 20 in. length outcrop samples. The main objectives of the spontaneous imbibition study was to investigate the role of the composition of the reservoir connate water (Na, Ca, and Mg), the effect of rock permeability, and test the effect of temperature (77 and 150°F) on the performance of the low-salinity waterflooding recovery. The volume of the produced oil was monitored and recorded against time on a daily basis. Imbibition brine samples were analyzed at the end of each experiment. Results demonstrate that the spontaneous imbibition oil recovery ranged from 38 to 69% OOIP for high permeability Buff Berea cores (164-207.7 md), while oil recovery of the low permeability Bandera cores (31.1-39.2 md) ranged from 20 to 51.5% OOIP at 77°F and 14.7 psia. The oil recovery decreased when the average pore-throat radius decreased. The reservoir connate water composition has a dominant influence on the oil recovery rate. The changes in the ion composition of reservoir connate water (Ca, Mg, and Na) showed a measurable change in the oil production trend. Reservoir cores saturated with connate water containing divalent cations of Ca and Mg showed higher oil recovery than for cores saturated with monovalent cations Na. In all cases, a measurable ion exchange was observed, while there was no significant change in the pH of the imbibition brine during the experiment. The ions exchange effect was more pronounced than the pH effect in the low-salinity waterflooding performance for Buff Berea and Bandera sandstone. As the temperature increased from 77 to 150°F, an additional oil recovery up to 15.4% of OOIP was observed by spontaneous imbibition for Buff Berea cores.
Abstract In many parts of the world, the redevelopment of older fields presents unique problems that will require innovative solutions. With the rising costs of finding and developing new oil fields, oil companies are turning more attention to revitalizing existing fields. Because of historical practices, these fields often have significant potential for enhanced recovery. These older fields have many different problems to deal with than the more modern fields that traditionally drive petroleum technology. Advances in computer hardware and software technology have made it possible to analyze reservoirs at a level of detail unimagined only a few years ago. With all of this power on our desktops, it is easy to lose sight of a major problem in dealing with older fields - the historical data. In many cases, there may be a large amount of historical data, but much of it is either inaccurate or critical types of data have not been gathered. Several field examples are discussed in this paper. Each field has redevelopment potential using modern techniques, but each project has great uncertainty due to data constraints. The conclusions and recommendations of the paper include suggestions for ways to solve these problems. Since we cannot go back in time to gather critical missing data (e.g., early production and injection data, initial fluid properties, produced compositions, etc.), special techniques will be needed to determine the value of these projects. Introduction We will soon mark the 150 anniversary of the discovery of commercial quantities of oil in Pennsylvania and the start of the modern petroleum industry. Since that time, oil has truly been the driver of industrialization around the world. The twentieth century was rightly called the Oil Century. The real oil production history of the planet actually dates back to 3000 B.C., but nobody then cared much about accurately measuring the volumes as it seeped out of the ground in various parts of the Middle East, Europe and elsewhere . More than 100 billion metric tons (800 billion stock tank barrels) have been produced in the last 150 years . According to recent estimates (see Table 1), this represents less than half of the estimated total world recoverable oil reserves. There are also estimates that another 40 to 140 billion tons are yet to be discovered . In any case, with a steadily increasing demand projected, it is now expected that worldwide oil production will start to decline in the next 5–20 years, depending on how optimistic the forecast is. Oil field technology has changed dramatically in recent time. Since the 1970's, modern computer technology has helped to improve our understanding of reservoir geology and fluid flow. Field measurement techniques have also greatly improved. Much of this coincided with the needs of the harsher operating environments of the North Sea and Alaskan North Slope, which started development at that time. Today, technology enables us to develop, operate and understand difficult fields and produce them more economically than would have been possible in the past. Modern measuring and analysis tools reduce the uncertainties in field development and allow operators to control costs effectively. Old Fields - Of the remaining already discovered oil (148 billion tons), 80% of it is contained in the Middle East, the Former Soviet Union (FSU), and South America where many fields can be classified as "old" fields. For example, the supergiant Ghawar field in Saudi Arabia and the Burgan field in Kuwait were found in the late 1930's. Major fields in Iran and Iraq were found even earlier. The Siberian oilfields in Russia were found in the 1950's. The Maricaibo basin fields in Venezuela started in the 1920's. Old Fields - Of the remaining already discovered oil (148 billion tons), 80% of it is contained in the Middle East, the Former Soviet Union (FSU), and South America where many fields can be classified as "old" fields. For example, the supergiant Ghawar field in Saudi Arabia and the Burgan field in Kuwait were found in the late 1930's. Major fields in Iran and Iraq were found even earlier. The Siberian oilfields in Russia were found in the 1950's. The Maricaibo basin fields in Venezuela started in the 1920's.