PHASETREAT demulsifiers an eco-friendly solution for the separation of crude oil from water

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1 Innovation Spotlight PHASETREAT PHASETREAT demulsifiers an eco-friendly solution for the separation of crude oil from water Issue: Winter 2014 Demulsifiers from Clariant Oil Services also enable efficient and safe production of heavy oil It s an effect we re familiar with from salad dressing: vinegar and oil don t mix very well. But every amateur chef knows the trick to make it work: stir the two liquids with a fork or egg whisk until a viscous mixture is obtained and there s your vinaigrette. Water-in-oil emulsion is what chemists call this unstable mixture of innumerable tiny water droplets in a matrix of oil. Within a few minutes, the emulsion separates out again into its constituent phases a process that the chef can greatly slow down, however, by adding an emulsifier like mustard or egg yolk. Yet what s desirable in the salad bowl is problematic in crude oil production, because almost all of the world s oil wells produce an emulsion of oil and water. The source of water is either a naturally-occuring presence in the reservoir or it is introduced by pumping through injection wells to maintain the pressure needed to extract the oil. Theoretically, you could wait for the emulsion to separate into its constituents like vinaigrette left to stand for too long, and then skim off the lighter oil floating on the surface of the water. Unfortunately, this takes far too long for efficient oil production.»the solution is to use a demulsifier from the PHASETREAT family to speed up this lengthy process«, says Dr. Jonathan J. Wylde, Global Head of Application Development at Clariant Oil Services. CLARIANT INTERNATIONAL LTD OIL SERVICES 2750 Technology Forest Blvd. The Woodlands Texas, 77381, USA PHASETREAT Innovation Spotlight Page 1

2 Chemically speaking, PHASETREAT demulsifiers belong to the surfactant family elongated molecules with a carbon backbone that, despite differences in detail, have one feature in common: they possess a water-attracting (hydrophilic) and an oil-attracting (hydrophobic) end. In an emulsion, they act as mediators at the interface between water and oil the hydrophilic end projects into the water, the hydrophobic end into the oil. Depending on the molecular structure of the surfactant, this mediating activity can have completely contrary effects. Surfactants in cleaning agents act as emulsifiers, making the frying fat soluble, so to speak, and easy to wash off the plate. These emulsifiers are also used in foods like yogurt or in cosmetics to stabilize the emulsion of aqueous and fatty phases and maintain the desired creamy consistency. The opposite effect is achieved with special surfactants used as demulsifiers or emulsion splitters in oil production. They accelerate the coalescence of the tiny water droplets into increasingly larger droplets and thus the separation of oil and water, which is performed in a separator vessel. Demulsifiers have been used in oil production for almost 100 years. Clariant Oil Services can look back on more than 50 years of experience with PHASETREAT. This experience is critical to success, explains Clariant Oil Services expert Wylde:»The properties of the extracted oil and the requirements placed on the demulsifier differ from one oil well to the next. The PHASETREAT range comprising several hundred products is derived from different basic compounds we use to develop a tailored solution for each situation in cooperation with our customers. The know-how relates equally to the formulation of these mixtures and the development of the basic components.«the PHASETREAT MOLECULES attach at the interface between water and oil, facilitating the coalescence of all water droplets in the mixture and separating them from the oil. PHASETREAT Innovation Spotlight Page 2

3 A particular challenge is represented by the heavy oil reservoirs that are becoming increasingly important, but are especially challenging to dehydrate and extract the unwanted water (see Chemistry Explained). This is because the specific gravity of some heavy oils hardly differs from that of the water. The tendency of an emulsion to separate spontaneously into its oil and water components is correspondingly low. The newest generation of PHASETREAT demulsifiers is highly effective:»compared to the early era of the technology, we now need only approximately one-hundredth of the admixture quantity to achieve a greatly improved effect. As a result, when heating the emulsion, which in the case of heavy oil is often very viscous, the heating time, the amount of energy used and the residence time in the separator may be reduced. This not only saves energy and lowers costs for the user, but also actively contributes to environmental protection«, says John Dunne, Senior Vice President of Clariant Oil and Mining Services. One of the reasons for this is that the latest formulations of PHASETREAT demulsifiers are much more efficient at separating water from oil than conventional chemistry; not only this, they are highly biodegradable and result in a much cleaner produced water quality after separation.»day by day, around two million barrels of heavy oil are produced worldwide with the aid of Clariant Oil Services PHASETREAT demulsifiers. One example is our ability to solve the challenges encountered in producing particularly heavy offshore crude oil from around the world«, adds Dunne. Classic, easy-to-develop oil reservoirs are unlikely to meet future global energy demands. Many expert analysts see reservoirs of particularly heavy or impure oil long ignored because of either high extraction costs or a lack of innovative technology as the future of global liquid hydrocarbon supply. The enormous potential of these»unconventional«oil reserves, however, can only be developed with the aid of sophisticated technology and chemistry that also must support and protect environmental sustainability, explains Dunne.»The challenges confronting our customers in the oil industry are constantly changing. Our PHASETREAT demulsifiers meet and exceed the challenges.«gas WATER OIL IN THE SEPARATOR VESSEL, PHASETREAT is added to the fluid mixture to separate oil and water. Oil and gas are pumped into the pipeline system, while the produced water is injected back into the oil reservoir. PHASETREAT Innovation Spotlight Page 3

4 Chemistry EXPLAINED Conventional and not quite so conventional Crude oil and how to bring it to the surface ANIMATION WITH SOUND AVAILABLE AT: More than 90 percent of the crude oil produced today comes from conventional reservoirs oil resources that are more or less easy to produce and contain high-quality oil with low viscosity; therefore, they have good flow properties. However, no two crude oils are exactly identical, even if they are considered to be»conventional«. Every deposit contains a mixture of different hydrocarbons from volatile gas to oils of differing viscosity to more-or-less solid constituents like bitumen or wax. The demands already placed by conventional oil production are also correspondingly variable. While the first 10 to 15 percent of a deposit in the so-called primary phase flow naturally to the surface due to the pressure exerted by the overlying rock formations, the effort required increases as oil production continues. In the secondary phase, water can be pumped into the reservoir to maintain the necessary pressure in the reservoir. In this way, depending on the reservoir, 30 to 50 percent of the oil it contains can be brought to the surface. The final tertiary phase (or Enhanced Oil Recovery EOR) extracts oil from the rock strata using special techniques such as injecting steam. Also widespread is the use of special chemicals that, for example, enhance the efficacy of the injected water by making it more viscous and therefore better at displacing the oil. Surfactants can also be added that further enhance oil production by favorably altering the interfacial tension between the oil and water phase so as to allow preferential oil flow. These EOR chemical and oil-water mixtures are easier to bring to the surface, but then have to be separated again using demulsifiers. Depending on the geological conditions and the properties of the oil deposit, altogether up to 70 percent of the hydrocarbons it contains can be extracted. Unconventional oil deposits are those which are so challenging to produce that they only gradually become profitable as the price of oil on the world market increases or the technology improves such that the production of oil becomes more efficient. This may be conventional oil in unconventional locations that are difficult to access, such as the estimated reserves in the polar regions or deepwater zones. The»pre-salt«reservoirs of the South Atlantic, like the Tupi oilfield off the coast of Brazil, only discovered as recently as 2006, belong in this category. Up to eight billion barrels of good quality, extractable crude oil are present at this location but under a four-kilometer-thick layer of salt and rock that, moreover, is located below 2,000 meters of water. Unconventional crude oil in the narrower sense is the term used for deposits of the soughtafter hydrocarbons that require great effort to extract and convert into usable oil. Three main types are involved: oil sands, found in vast amounts in Canada and Venezuela, are mixtures of bitumen, water, sand and clay. Almost just as viscous as the bitumen obtained from them are the heavy and ultra heavy oils of Venezuela. Finally, oil shale is a sedimentary rock rich in hydrocarbons, the largest deposits of which are in the USA. PHASETREAT Innovation Spotlight Page 4

5 CHEMISTRY EXPLAINED Common to all three is that the oil contained can only be extracted and converted into usable crude oil with the aid of heat and special chemicals such as PHASETREAT demulsifiers. Although this has not yet been worthwhile for many of the known deposits, the potential of unconventional crude oil deposits is nevertheless enormous; they represent by far the greatest proportion of global resources of fossil fuel. As conventional reservoirs are increasingly exhausted, it is only a matter of time that their extraction will become commercially interesting. What was unconventional yesterday could be quite normal tomorrow. ANIMATION WITH SOUND AVAILABLE AT: PHASETREAT CHEMISTRIES contribute to safe oil production while minimizing impact on the environment onshore and offshore. INFORMATIVE LINKS PHASETREAT Innovation Spotlight Page 5