Svetlana Nikolayevna Rudyk

Microbial Fluid-rock Interactions in Chalk Samples and Salinity Factor in Divalent Ca2+ Ions Release for Microbial Enhanced Oil Recovery Purposes

In this study core laboratory experiments were performed on chalk samples from Danish sector of the North Sea to study microbial fluid-rock interactions with carbonate rock and to evaluate the dissolution of rock matrix (CaCO3). The microbial media consisted of a strain of Clostridium tyrobutyricum with reinforced clostridia media and molasses as carbon and energy sources. Results showed that the average concentration of Ca ions after microbial fluid interactions with chalk samples in media of salinity 40-100g/l increased from initial average concentration of 203 mg/l at the start of the experiment to 1178 mg/l in 28 days. All the bacteria media irrespective of their salinity condition experienced a decrease in measured pH from average of 7.0 to 6.0 in the first week; this however started to increase again from second week with release of calcium ions indicating a correlation between the pH and calcium ions released. 3-D surface plot for the range of salinity measured revealed delineation of the measured salinity into two groups with a boundary between 70 80 g/l. The highest Ca ion concentration was measured at the highest salinities by the end of experiment which means that the dissolution rate of chalk increased with increase in salinity. This could be due to the lower values of pH as an indication of that higher salt concentration facilitates more acid production by bacteria.

3D Model of extraction of oil from north sea fields by supercritical carbon dioxide

The extraction of North Sea oil from the oil saturated chalk samples by supercritical carbon dioxide was investigated to determine the pressure value, at which the highest amount of oil can be extracted. The pressure of extraction was gradually increased at every next test to check out how the extraction of lighter hydrocarbon fractions at lower pressure affect the oil recovery rate at higher pressure. The first serial test was conducted with three core chalk samples of equal size and each of a weight of 9 g. The samples were naturally saturated with oil at three values of temperature of 50 o , 60 o and 70C. For comparison, the second serial test was conducted with three pure chalk samples of equal size and weight of 26 g saturated with the North Sea oil under vacuum in the laboratory at the same values of temperature. The results of experiments were represented as the surfaces in the coordinates of (Pressure, Amount of extracted oil, Temperature). 3D models revealed that the deviations in the graphs are not occasional. They form wavy surfaces where the folds of waves correspond to hydrocarbon fraction of certain compositions. The highest amounts of oil at all three temperature values in both tests were extracted at 18 MPa in average, where the graphs formed peaks, but the oil was very light, which means that the heavier hydrocarbon fractions were not extracted at such pressure value.

DETERMINATION OF MINIMUM MISCIBILITY PRESSURE IN SUPERCRITICAL EXTRACTOR USING OIL SATURATED SAMPLE

The main parameter for determination of the possibilities to enhance oil recovery by e.g. CO2 injection into a specific oil field is the measurement of Minimum Miscibility Pressure (MMP). This pressure is the lowest pressure for which a gas can obtain miscibility through a multi contact process with a given oil reservoir at the reservoir temperature. The oil formation to which the process is applied must be operated at or above the MMP. Before field trial this parameter is to be determined at the laboratory which traditionally is done by help of a slim tube or a raising bubble experiments. However, in order to investigate the MMP, we suggest another method by using a supercritical extractor. Spe-ed SFE equipment with oil saturated natural rock samples were used for the purpose. The clean chalk samples were saturated with oil from the Dan field under vacuum. The CO2 gas was injected into the extractor vessel containing the sample at different increasing pressure levels. The oil displaced in such a way was collected and measured. The volume of extracted oil was plotted against the increasing pressure. The form of the graph is similar to that typically obtained from a slim tube experiment. Following the breakover point criterion the MMP read from the plot was found equal to 20 MPa.

Laboratory investigation of Thermoanaerobacter brockii Subsp. Lactiethylicus Strain 9801T for Possible utilization in microbial enhanced oil recovery

Thermoanaerobacter brockiisubsp. lactiethylicus strain 9801T originally isolated from a deep reservoir environment was evaluated for potential use in microbial enhanced oil recovery (MEOR). Investigation was conducted for finding the optimum environmental parameters for growth (temperature, salinity and pH) and production of metabolites desired for microbial enhanced oil recovery. There was growth in the media with pH from 6-9.5 and salinity range of 0.5-3.5% (w/v) and temperature of 50-60oC. The optimum growth occurred at about pH of 7 and temperature of 55oC. The fermentable substrates included molasses, reinforced clostridia medium, thioglycolate and crude oil with major fermentation end products being lactic acid, volatile fatty acids and some amount of gas that included carbon dioxide. The concentration of lactic acid reached 11.7 g/l with a corrosive effect on core chalk samples that led to dissolution and release of calcium ions approximately 38 times greater than the background value. Additionally, this strain also produced biomass with a yield of between 0.0034-0.052 g/h per 100 ml of broth. Result of biosurfactant production assay indicated an oil displacement area of 3.5 cm2 and fermentation of crude oil indicated a significant reduction in concentration of long chain alkanes in both light and heavy oils. Finally this strain compared favorably well in terms of metabolites production with other known bacteria strains employed in MEOR thus confirming the potential of Thermoanerobacter brockii subsp lactiethylicus 9801T for utilization in microbial enhance oil recovery.

Removal of Grease from Wind Turbine Bearings by Supercritical Carbon Dioxide

This work aims to test the ability of liquid carbon dioxide to remove grease from bearings in wind turbines. Currently, the removal of grease from wind turbines offshore in the North Sea is done by dismantling the bearing covers and scraping off the grease. This procedure is long, labour intensive and raises maintenance cost. Another issue is the environmental policy, the approval for newly introduced chemicals for flushing purposes are procedurally long. If the problems with grease removal could be solved in a different way other than manual removal or using chemicals, it will open many new market opportunities and would carved out a niche for the wind turbine maintenance industry. The solution of flushing grease could lower cost, time and reduce environmental impact by applying Supercritical Carbon Dioxide. The oil based grease SKF LGWM 1 was designed to handle extreme pressure and low temperature conditions. The grease covered the main bearing for 4 - 5 y in a wind turbine at Horns Rev 1 Offshore Wind Farm in the North Sea, 14 km from the west coast of Denmark. The series of experiments focused on higher pressures and temperatures as well as the use of some co-solvents. The highest recovery by pure carbon dioxide is 26 % and was achieved at 60 MPa and 80 ˚C while the addition of Kirasol-318SC improved the recovery by 8 % at the same conditions. Outgassing losses increase with the addition of kirasol. The low recoveries and high pressures obtained by the experiment do not provide an applicable method for grease removal; however it can be implemented for the removal of the contaminants from grease wastes.

The bitumen extraction from Nigerian tar sand using dense carbon dioxide

The need for alternative sources of energy has become even more acute in light of the recognition of the dwindling conventional world oil reserves. The interest in exploring other avenues of complimenting and/or eventually replacing this resource is growing quite rapidly. A ready alternative to conventional crude oil is oil sands which are abundant and vastly unexplored. The huge deposits of tar sand found in SouthWestern Nigeria remain untapped due to concerns about the environmental impact. The consequences of the methods in processing tar sand, ranging from water pollution to emission of greenhouse gases, especially in Canada bring in to sharp focus the urgent need for an alternative means of extracting oil from tar sand. A more effective and less environmentally damaging procedure could be the break through needed to open a new chapter in the exploitation of oil sands. The alternative recovery procedure is supercritical carbon dioxide extraction. Recent supercritical extractions use high temperatures and pressures. The upgrade in this research involves using high pressures and lower temperatures which saves energy and improves the process. The experimental study of the bitumen extraction from Nigerian tar sand by dense CO2 was carried out by high pressure extractor. The samples of tar sand were first heated in an oven at 120 °C to melt. A 50 g sample of melted tar sand with addition of 3 g of ethanol was placed into an extractor and heated to 80 °C to initiate the experiment. Carbon dioxide was injected in to the extractor to create 50 MPa of pressure in static mode for 20 min after which the extract was collected. In the presence of ethanol, the extract had a lighter colour than the usual black. Nigerian tar sand is known to be composed of 84 % sand, 17 % bitumen, 4 % water and 2 % mineral clay. Using this data, an extract of 19.47 % was calculated which makes the recovery achieved very encouraging. The experiment shows that recovery of bitumen from tar sand is possible under relatively low temperatures and can be possibly economically profitable.

Evaluation of Produced Volumes of Carbon Dioxide from the Concentration of the Gas Absorbed in the Media during Microbial Fermentation for Enhanced Oil Recovery Purposes

Carbon dioxide produced by microbes during microbial enhanced oil recovery process (MEOR) promotes oil displacement and productivity through re-pressurization of the oil field and dissolution of the rock matrix. In the laboratory studies conducted using an adapted strain of Clostridium tyrobutyricum (DSMZ 663) in fermentation media of 500 mL, the volume of the produced gas, the concentration of the dissolved gas determined using titrimetric method and pH of the media as a result of microbial metabolic activities at different salt concentrations (0, 30, 60, 90 and 100 g/L) were measured after 24, 72 and 120 h. The volume of produced gas decreased from about 3000 mL at 0 g/L to 250 mL at 100 g/L. The rate of absorption, volumetric mass transfer coefficient and partial pressurewere then related quantitatively as a function of salinity and were compared. The result shows that the rate of absorption decreases exponentially with salinity suggesting a strong correlation with R2 value of 0.75-0.98 at constant coefficient of 0.0002. The volumetric mass transfer coefficient for carbon dioxideat 0 g/L is approximately 6 times greater than at 100 g/L suggesting the influence of the salinity of the media. The correlation of the gas concentration in the solution with the gas bulk volumes produced at different salinities after 120 h (R2 = 0.97) suggests an accurate tool for the estimation of the amount ofgas produced by microbes.

How Specific Microbial Communities Benefit the Oil Industry: Microbial-Enhanced Oil Recovery (MEOR)

Microbial-enhanced oil recovery (MEOR) involves injecting into the oil-saturated layer microbes and/nutrients to create the in situ production of metabolic products or nutrients to stimulate indigenous microbes. The purposes of MEOR are to increase oil production, decrease the water cut and prolong the productive life of the oilfield. The most probable targets of MEOR are reservoirs that have reached the limits of oil production by injection of water to displace oil (Donaldson and Obeida, 1991). MEOR is the cheapest approach of oil recovery after water flooding. MEOR investigations have been conducted all over the world and resulted in many successful field applications in the USA, UK, China, Russia, Malaysia, Germany, Romania, Poland and others.

Application of consistency test to the analysis of supercritical carbon dioxide extraction of crude oil

This study produces an attempt to estimate the cost of future global energy supplies. The approach chosen to address this concern relies on a comparative static exercise of estimating the cost of three energy scenarios representing different energy futures. The first scenario, the business as usual scenario, predicts the future energy-mix based on the energy plans held by major countries. The second scenario is the renewable energy scenario, where as much of the primary energy supply as possible is replaced by renewable energy by 2050. The cost of the renewable energy generating technologies and their theoretical potential are taken into account in order to create a plausible scenario. The third scenario, the nuclear case, is based on the use of nuclear and renewable energy to replace fossil-fuels by 2050. Endogenous learning rates for each technology are modeled using an innovative approach where learning rates are diminishing overtime. It results from the analysis that going fully renewable would cost between -0.4 and 1.5% of the global cumulated GDP over the period 2009-2050 compared to a business as usual strategy. An extensive use of nuclear power can greatly reduce this gap in costs.The Miocene alkali basaltic rocks cover the northeastern part of Jordan, within Harrat Al-Shaam plateau. The volcanic concentrated along the Dead Sea boundary and spread around the north east of Jordan area, and was considered as interplat volcanic field in Jordan. The volcanic basalt is associated with xenoliths fragmental rocks or xenocryst minerals. Nine samples were collected from the study area and analyzed for XRD, XRF and SEM. These samples presented the xenoliths rocks and minerals existing in the study area. This study is focused on the garnet and pyroxene xenoliths minerals in Tulayl Al-Hasna area within Ufayhim Formation. Hand samples are characterized by coarse aggregates of garnets up to (2 cm in diameter) with dark brown to red color, and highly fresh fractures. Also, the pyroxene (<1.5 cm) with gray to dark green color, and the olivine (range 3 4 mm) are pale green to dark green and pale yellowish color. In thin sections, plagioclase phenocryst in the garnet presented corona texture. In addition, garnet surrounded by orthopyroxene refers to kelyphite texture. There are two types of kelyphite texture fibers and radial as shown in Scanning Electron Microscope photomicrograph. The mineralogical analyses of garnet for X-Ray Diffraction are composed of almandine, pyrope and majorite. The existence of minerals reflects the high pressure and temperature of the upper mantle origin. The chemical analysis showed the average composition of garnet as follow (Alm 42.78, Pyro 41.04, Gross 16.18), pyroxene (Wo 16.90, Fs 20.37, En 62.73). This referred to presentation of the following elements Mg, Fe and Ca in the garnet. As a result, the basaltic garnet xenoliths were from shallow lithosphere mantle origin.Context and objectives Fast Sodium Reactor (FSR) is one of the most promis ing nuclear reactor concept (“Generation IV systems”) to be issued in the next decades [1]. Thi s technology is intended to be much safer, to have a significantly better yield and to produce less wa stes with a lower nocivity. Liquid sodium is used as the thermal fluid in direct contact with the nuc lear core. Ideally, the heat extracted should be transferred between sodium and water in steam gener ators. BUT when sodium is brought in contact with liquid water, a highly exothermal chemical rea ction ensues which is believed to be explosive in certain situations [2]. Such a contact may happen i n a number of instances (repairs, decommissioning,..) and not only during major accid ents. This is thus a significant safety issue which may significantly handicap the development of this technology. Unfortunately the reasons for which the mixing of s dium with water may lead to an explosion, generating blast waves like an explosive material, do not seem to have been clarified so far not even deeply studied. The primary objective of this PhD w ork is thus to identify the details of the phenomenology, to isolate the leading mechanisms an d to propose a modelling approach.W examine the implications of increased unconventional crude oil production in North America. This production increase has been made possible by the existence of alternative oil-recovery technologies and persistently elevated oil prices that make these technologies commercially viable. We first discuss the factors that have enabled the United States to expand production so rapidly and the glut of oil inventory that has accumulated in the Midwest as a result of logistical challenges and export restrictions. Next, we assess the extent to which the increase in U.S. domestic production will affect global supply conditions and whether the U.S. experience can be repeated in other countries with unconventional oil sources. The evidence suggests that even in the bestcase scenario, the increase in U.S. oil production is unlikely to have a large effect on the global oil market’s demand–supply balance, so its effect on the price of oil is expected to be limited. Furthermore, the United States enjoys unique infrastructural and technological advantages that make it unlikely that rapid increases in unconventional production can be achieved elsewhere.T reactions of sunflower, rapeseed, corn and cameline oils in supercritical (sc) methanol were studied in a flow tubular reactor over a wide range of methanol (ether)/oil ratio, pressure, temperature, and residence time. Special attention was focused on the studies of the product distribution and how it varies upon variation of the above reaction parameters. Reaction conditions to enable high selectivity and conversion of vegetable oils transesterification were determined. Advantages of the reaction in supercritical alcohols and ethers over similar reaction in the presence homogeneous catalysts were demonstrated. It was found that the oil type produced insignificant effect on the product composition (fatty acid esters) and oil conversion value. The reaction conditions provided the selectivity and high conversion of the oils were selected.ID-215 INFLUENCE OF SILICA NANOPARTICLES ON THE TOUGHNESS OF FUSION BONDED EPOXY Patrícia Saliba, Herman Mansur UFMG, Brazil patalvessaliba@gmail.com, hmansur@demet.ufmg.brT Niger Delta is the hub of oil and gas production in Nigeria, and is one of the world’s most severely oil spill impacted areas. The exploration and exploitation of oil interfere with ecological and biodiversity integrity of ecosystems arising from flaring of associated gases, oil spills, use of drilling chemicals, etc. These processes can release heavy metals into coastal waters. Heavy metals are associated with crude oil in variable concentrations depending on the geologic background. Nigeria’s dominant and internationally preferred crude petroleum, Bonny Light, has associated with it metals, the main metals occurring in the order nickel>vanadium>cadmium>copper, lead. Recent pollution studies have revealed elevated levels of Zn, Cu, Pb, Cr, Ni, and V, in Niger Delta water, sediments and food species, thereby, compromising safety of the user population. Oil spills in the Niger Delta impact tremendously on the region’s flora and fauna which serve as the main livelihood support structures of the inhabitants. A recent UNEP study on a section of the Niger Delta revealed widespread oil contamination of land, groundwater and surface waters. Drinking water from wells in one community had benzene, a known carcinogen, 900 times above WHO permissible limit. The UNEP study concludes that restoration of the investigated area would take minimum of 30 years. This paper discusses the incidents of oil pollution, and prospect and challenges of ecosystem restoration of Niger Delta oil degraded environments.

Reservoir Evaluation and Saturation Monitoring Using RST Fluid Analysis for Improve Oil Recovery

To manage existing fields as effectively and efficiently as possible, there is a need to monitor movement of formation fluids within the reservoir as well as production from individual wells. Result from the case study of an unnamed well in Nigeria using the data acquired with reservoir saturation tool (RST) and interpreted with GeoFrame petrophysical software was able to identified formation fluid contacts, define saturation of those fluids, and locate potential cased-off, bypassed oil. From the sigma mode interpretation there is no gas within the zone of interest. The cross plot of the near and far carbon oxygen ratio statistically plot in the lower left corner of the quadrilateral indicated the annulus hold up value of zero. The final C/O interpretation shows that the original oil water contact in the zone of interest has risen to 2302m and the flushed zone is between 2302-2308m. The section above this depth (2294-2298 m) is possibly at initial water saturation and offers a choice for future re-drill.