Emulsion Formation for EOR Applications

In this study, the oil recovery potential of Smart Water in the Danish sector of the North Sea chalk reservoirs was investigated. A series of flooding experiments were conducted at reservoir conditions, and a spontaneous imbibition test was carried out at reservoir temperature. Reservoir cores were used along with crude oil samples from the North Sea and representative synthetic formation water. The effect of changing the salinity, concentration of potential determining ions and temperature was studied as potential Smart Water effects. Of the investigated fluids, injection of low salinity seawater gave the highest additional oil recovery. Modular maintenance instructions Systematically increasing quality and consistency of maintenance instructions Niels Henrik Mortensen, Professor, DTU Mechanical Engineering Andreas Proschowsky, Research Assistant, DTU Mechanical Engineering Kim Bo Kristiansen, Research Assistant, DTU Mechanical Engineering Giacomo Montagner, Research Assistant, DTU Mechanical Engineering Kristoffer Vandrup Sigsgaard, Research Assistant, DTU Mechanical Engineering Saleh Zouelm, Research Assistant, DTU Mechanical Engineering Daniel Vorting, Student Assistant, DTU Mechanical Engineering A pilot study has found that preventive maintenance instructions for ESDVs and BDVs in DBU are inconsistent, of varying quality and are poorly aligned to the maintenance strategy. To overcome these problems, principles from modular product development have been applied in the developing of modular maintenance instructions. The study has shown that it is possible to identify a stable core of ESDV and BDV maintenance instructions, which can be reused for all valves, as well as a small number of add-on modules, which can customize the instructions to different valves. This have potential to decrease the magnitude of the instructions, ease implementation of changes, increase transparency and increase the quality of the instructions. This presentation will explain and visualize the modular instructions for ESDV and BDV maintenance, the bottom up approach for developing the instructions and discuss implementation opportunities. Fact based optimization of maintenance Utilizing operational data to optimize planning and execution of maintenance Niels Henrik Mortensen, Professor, DTU Mechanical Engineering Andreas Proschowsky, Research Assistant, DTU Mechanical Engineering Kim Bo Kristiansen, Research Assistant, DTU Mechanical Engineering Giacomo Montagner, Research Assistant, DTU Mechanical Engineering Kristoffer Vandrup Sigsgaard, Research Assistant, DTU Mechanical Engineering Saleh Zouelm, Research Assistant, DTU Mechanical Engineering Daniel Vorting, Student Assistant, DTU Mechanical Engineering Throughout time, large quantities of operational data have been gathered for maintenance of topside facilities in DBU. The reporting and structuring of the data has however varied significantly over time and between assets and systems. This has complicated the use of the data to support planning and optimization of maintenance. This study has investigated how different maintenance activities can be compared and how data can be cleaned and restructured to support planning and optimization. The result is a data model developed in QlikView that quickly enables comprehensive analyses of cost and time consumption of maintenance of topside systems and equipment types. This presentation will present the challenges of using historical maintenance data, the development of the data model and discuss its application areas. Experimental investigation on the effect of seawater ingress on the corrosion behavior of production tubings Riccardo Rizzo; Ajit Murli Rao; Rajan Ambat Corrosion and scale have a very important impact on the petroleum industry. On one side, they constitute a significant part of the capital and operational expenditures (CAPEX and OPEX), whereas on the other side they compromise the health and safety of the field personnel as well as the environment. It has been estimated that corrosion and scale formation account for 25% of the operational safety incidents, 8.5% increase on CAPEX and 11.5% increase to the lifting costs. CO2 corrosion occurs when water is present in the system and it wets the steel surface. A certain amount of water, formation water, is always present in the reservoir and enters the production tubing when the well starts to produce. In addition, it is normal practice to pump sea water from an adjacent injector well in order to maintain the reservoir pressure and drive oil out of the formation. This technique is known as waterflooding. As the field ages, the water/oil ratio can increase and reach level of 95% or higher leading to more significant corrosion problems. Another downside of producing water from an oil field is the precipitation of scale. Scale can deposit on the wall of production tubing deceasing the inner diameter of the pipe reducing the production rate. In order to investigate the effect of the Seawater (SW) fraction as a fraction of the produced water a conventional three -electrode electrochemical cell setup was used. The atmosphere constituted of gas mixtures of pure CO2 and 100ppm H2S in CO2. The sample investigated were equivalent grade of L80-1Cr and L80-13Cr. The composition of the seawater and formation water were taken from Halfdan and they were mixed in the following ratio: 0% SW, 50% SW and 100% SW. Three different temperatures have been tested, namely: 40 ̊C, 60 ̊C and 80 ̊C. Experiments were conducted under initial pH of 6.1 and 3.9. The corrosion products and precipitates were analyzed using Grazing Incidence XRD, SEM-EDS and FIB. Systematic investigation of scales and corrosion on production tubings Abhijeet Yadav, Yan Yang, Goutham Ramachandran, Zhifeng Hao, and Rajan Ambat Section of Materials and Surface Engineering, Department of Mechanical Engineering, Technical University of Denmark, DK 2800Kgs. Lyngby, Denmark Internal corrosion of pipelines occurs extensively in the oil and gas production. The corrosive environment is composed of formation water, injection water, the dissolved acidic gases, such as CO2, volatile organic acids, and the hydrocarbons. Being the most commonly used construction materials for pipelines, carbon steels are prone to corrosion in such corrosive environments. In particular, localized corrosion i.e. pitting corrosion and mesa attack occurs in conjunction with the formation and removal of corrosion scale in the SO4 and CO2 containing produced water. Localized corrosion or underdeposit corrosion attack usually occurs due to porous nature of the scale or once the protective scale is damaged locally, and constitutes a principle cause resulting in the failure of the pipelines. Therefore, scale formation affects the corrosion behavior of the pipeline materials by changing the morphology and the physiochemical properties of the surface layer. Scale precipitation not only causes corrosion damage to the pipelines, but can also cause formation damage in the reservoir, flow loss or blockage on flow lines and equipment’s energy leak and severe accidents, which can influence the safety of production and the economic benefit of petroleum industry. Scale deposit precipitate out as a mixture of different elements, which may occur when solution becomes saturated due to the change in temperature, pressure, pH or due to mixing of two incompatible fluids. Severe scaling occurs when formation water rich in various compounds such as Ca, Sr, Ba, Mg ions etc mix with the SO4 rich sea water, causing super saturation. Scale deposition products in oil and gas field are mainly consisted of calcium carbonate, calcium sulfate, barium and strontium sulfate and carbonates, iron, silicon sediments and other insoluble solids. This paper focus on detailed systematic investigation of the scales and corroded internal surface of the tubes with scales to understand the nature of corrosion and scales formed under various well conditions. The experimental work include visual observation and digital photography of the interior surface of the tube and scales which is horizontally split, high resolution scanning electron microscopy, cross-section analysis using metallographic preparation and focused ion beam (FIB) cutting, EDX and X-ray mapping, Transmission electron microscopy, and X-ray diffraction for phase analysis. Corroded tubes and scales from three different fields were analysed namely Halfdan, Dan, and Gorm. From each field and well, tubes were selected based on the depth to provide systematic evaluation starting from shallow depth to high depth levels. Tubes from shallow depth showed high amount of penetration and localized attack compared to low uniform corrosion observed in tubes from higher depth. The scales showed a layered structure showing different compounds explaining the corrosion and scaling, based on the history of the well. Analysis of scale formed in tubes at shallow depth comprised predominantly of iron and calcium carbonate with high amount of chlorine present within the scale. The scale initially start to grow as iron sulfate/sulfite porous layer, attributing to higher localized corrosion attack observed in these tubes from shallow depth. The scale formed in Gorm and Dan at higher depth were very thick and dense and comprised of barium and strontium sulfate with high amount of calcium and chlorine present within the scale. The morphology and structure of the scale becomes porous with the presence of chlorine and may cause localized or underdeposit corrosion attack, if present in the scale closer to the pipe surface. Kinetics of Scale Formation in Oil and Gas production