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This paper sets out to demonstrate, at lab scale, the feasibility of the twomain phases of the process, namely the emulsification of a heavy Venezuelanacidic crude oil (ZUATA), and the subsequent breaking of the oil-in-wateremulsion. The heavy ZUATA crude can be emulsified directly by making use of thesurfactants naturally present in this rich acid oil. These potentialsurfactants, mainly represented by naphthenic acids, become effectiveemulsifiers when salified into naphthenate anions by the addition of bases(soda, ammonia). Stable oil-in-water emulsions, typically with 60 to 65% oil, are obtained byusing these two bases. There are a number of advantages to be gained in usingammonia to form the oil-in-water emulsions as opposed to other bases (soda forexample) for emulsion breaking and phase separation. The paper demonstrates that it suffices to heat the emulsion to break it. Itdescribes the conditions required for ammonia removal and recovery, and theresulting emulsion breaking. An industrial process for achieving the separation is then proposed. Introduction Extra heavy oils (viscosity >10,000 cP, 7<°API<12) can betransported1–3 by heated pipelines, or regular heating of the crude, or dilution with a lighter crude or a naphtha. Of all these different transportmeans, dilution is the most economical and currently the most widely used. The dilution ratio varies between 30 and 40% depending on the transportationspecifications of the pipelines (19°API and crude viscosity<350 cP forCanada, 400 cP for Venezuela). Using the diluent affects the capacity of thepipeline, which is reduced from 30 to 40% and this entails the necessity ofeither having a second pipeline for diluent return, or purchasing more diluenton the production site. Moreover, as the diluent is extracted from the crudeduring atmospheric distillation in the upgrader unit or in the customer'srefinery, the crude desalting, heating and atmospheric distillation units areover-sized by 30 to 40%. The transportation of heavy crude oil by emulsification in water4can be made economically attractive, in comparison with other means such asdilution, provided the surfactant stabilizing the emulsion can be recovered.The lower viscosity of the oil-in-water emulsion significantly increases thetransportation capability. Using water instead of diluent simplifies the crudetreatment process. This paper sets out to demonstrate, at lab scale, the feasibility of the twomain phases of the process, firstly, emulsification of a heavy Venezuelanacidic crude oil (ZUATA) and, secondly, the subsequent breaking of theoil-in-water emulsion. Emulsification of heavy ZUATA oil The ZUATA oil can be emulsified directly, without any added externalsurfactant, owing to the surfactants naturally present in this rich acid heavyoil (°API: 7.8, Total Acidity: 4.3 mg KOH/g). The relevant "potential"surfactants are chiefly represented by naphthenic acids, which become"effective" surfactants when transformed into naphthenate anions by addition ofa base (NaOH, NH4OH)5.These naphthenate salts assume therole of "effective" surfactants, enabling oil-in-water emulsions to be obtainedat various oil-to-water ratios.

Polymer flooding is a mature EOR technique successfully applied commercially in sandstone reservoirs and at the pilot stage in carbonate reservoirs. However, all previous pilots in carbonates reservoirs were implemented in relatively low temperature and low salinity conditions. No field application of polymer in carbonate was implemented in the last 25 years. In recent EOR screening studies for carbonate reservoirs in Abu Dhabi, polymer based EOR techniques were identified to target by-passed oil in heterogeneous/layered reservoirs The main challenges for polymer based EOR processes in ADNOC reservoirs is to find a stable polymer under the extreme conditions of high temperature/high salinity/high content of divalent cations which can be injected in carbonate reservoirs. An extensive laboratory program initiated 10 years ago led to the development of a polymer rich in Sodium Acrylamido tertiobutyl Sulfonate (ATBS). Thermal stability, bulk and in-situ rheology, adsorption and injectivity performed and the polymer was found suitable for the harsh conditions of ADNOC reservoirs. A de-risking strategy was designed in which a polymer injectivity test (PIT) followed by a multi well pilot are performed before the full field implementation of polymer based EOR for a number of ADNOC reservoirs. This paper describes in details the main steps of the successful PIT recently carried out including: the selection of the candidate well and the injection skid, the test design, its execution, the polymer solution quality management and the operational challenges faced during the pilot. The polymer Injectivity Test was conducted for 4 months and concluded by February 2020. A total of 150,000 barrels of viscous solution was successfully injected into the reservoir. This paper also details the real time surveillance and injection monitoring plans implemented during the test period for real time assessment of the skid delivery and the well response. This Injectivity test achieved the designed Key Performance Indicators related to polymer solution quality, viscosity, concentration, injection rate and skid running time. The dedicated surveillance and injection monitoring plan designed and implemented during this pilot, enables to confirm the good performance of the polymer during PIT period. Furthermore, PIT results showed good performance of Polymer in terms of viscosity, Injectivity at target rate and concentration. This paper also addresses the impact of water quality on polymer viscosity and skid operation. This paper presents field results for a new polymer developed for carbonate reservoirs at HT/HS. This successful Polymer Injectivity test qualified the new polymer for field application at harsh carbonate reservoir conditions. Results from this world first Injectivity test opens a new area of possibilities to improve recovery in giant heterogeneous carbonate reservoirs in ADNOC and in the Middle East.

In this work, methane conversion was carried out over a group VIII metal in a Pd−Ag membrane reactor to produce hydrogen and higher hydrocarbons in a nonoxidative atmosphere. A two-step reaction sequence operated at two different temperatures was adopted to pass around the thermodynamic barrier of low-temperature methane conversion. Methane was first activated as a result of the dissociative deposition over a Ru catalyst, followed by rehydrogenation to form higher hydrocarbons. The use of the Pd−Ag membrane reactor significantly enhanced the methane conversion into hydrogen and carbonaceous species in the first step and the yield of higher hydrocarbons upon rehydrogenation in the second step. The repartition of different carbonaceous species was monitored by temperature-programed surface reaction (TPSR). The effective methane conversion at low temperatures in the membrane reactor favored the formation of Cα species which were selective to produce higher hydrocarbons. A C2+ yield of about 16% was obtained by conducting methane decomposition at 300 °C and rehydrogenation at 100−120 °C in the Pd−Ag membrane reactor.