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Abstract Application of dendrimers and dendritic polymers in oil and gas field fluid formulation can revolutionise the fluid properties due to the unique physical, chemical and biological characteristics of these materials. The ability to synthesize tailor made dendrimer products with desirable functional behaviour also highlights the potential application of dendrimers in smart and intelligent fluid design for oil and gas field application. The large number of monomer units associated with dendrimer core has the potential to add several functional groups of same ionic nature or different ionic natures to fulfil certain technical tasks for a particular application. Custom made dendrimer-based additives that are insensitive to temperature, salinity, pH, solids concentration, cement and lime contamination may lead to the development of a multiple contaminant tolerant drilling mud system for trouble free drilling operation in variable borehole environments. Due to superior physical, chemical, electrical and mechanical properties of dendrimers and dendritic polymers, and also the synthesis of dendrimers that are capable to respond intelligently according to down hole conditions can provide instantaneous solution to various drilling problems. The internal cavities within the dendrimer structures can be used to store desirable chemicals, enzymes, surfactants, etc to trigger appropriate interactions on-demand at bottom hole condition to negate, neutralize or reduce the unwanted changes in drilling, drill-in, completion, cleaning, stimulation, fracturing, etc fluids. The three dimensional spherical configurations of nano-sized dendrimers with high specific surface area can also allow the attachment of multiple functional groups at the terminals to accomplish different functional tasks. Dendrimers with the ability to trigger on-demand interaction by releasing stored chemicals, enzymes or surfactant stored in the cavities can play a pivotal role in developing an intelligent drilling fluid system to provide instantaneous solution to down hole problems. Due to nano-scale dimension, dendrimers may provide effective external and internal inhibition to reactive shale surfaces leading to long-term stabilization of reactive shales. The tiny size and high surface area of dendritic materials will also provide superior fluid properties at a drastically reduced additive concentration. Dendrimers and dendritic polymers with high thermal stability and affinity to acid gases such as H2S and CO2 will help overcome the technical challenges of geothermal and sour gas drilling operations for a safe, risk-free and economic drilling operation. This paper describes some applications of emerging dendrimers and dendritic polymer-based additives in the development of high performance drilling and drill-in, completion, stimulation, etc fluids for trouble-free drilling, completion and production operations in challenging environments.
Abstract With the ever-growing demand for more environmentally friendly oilfield chemicals, classic oilfield chemistries are no longer acceptable and new chemical systems are required. Future oil production will still require efficient dehydration and desalting of crude oil. In addition, the protection of the affected environment will be of increased significance. The industrial availability of ethylene oxide in the 1940s firstly allowed the design of nonionic surfactants for emulsion breaking. With the development of ethylene oxide / propylene oxide block copolymers, the first highly efficient crude oil demulsifers were available. The addition of ethylene oxide / propylene oxide to alkylphenol formaldehyde resins and to oligoamines yielded emulsion breakers that performed sufficiently at low concentrations. To achieve the future requirements of environmentally acceptable oilfield chemicals, emulsion breakers with low toxicity and high biodegradability are needed. Due to the fact that nonionic alkoxylate based polymeric surfactants have in general a low toxicity, biodegradation was identified as the major bottle neck. Above described polyether type chemistries usually show low biodegradation due to their high molecular weights, especially in marine biodegradation tests (OECD 306) which are often required. Alkylphenol resins have an improved biodegradation profile in comparison to the polyether types, but some serious toxicity issues. Polyesters are well known as highly biodegradable polymers with low toxicity and a lot of effort was made to design polyester based demulsifers. This paper describes the development of biodegradable alkoxylated polyester dendrimers for breaking oil/water emulsions.
ABSTRACTThe use of polymer based chemical inhibitors has the advantage of utilizing chemical, macromolecular, and compositional (blends or block copolymers) towards chemical inhibitors whether it is for corrosion or scaling issues. It is important to understand the multi-phase condition of production fluids whether it is extraction or circulation (oil and gas vs geothermal brine). It is also important to understand the mechanism and the long-term action of inhibition from the fluid to the surface that is being protected. This talk will highlight the principles and work in investigating various corrosion and scaling inhibitors for the production and process industries. In particular, the use of block-copolymers and hyperbranched oligomeric design in inhibitors is of a high interest because of the multi-dentate and stability (or predictability) of their solubility in various phase conditions. While a number of these examples are highlighted in the design of new materials and dosing methods, it is important to stress the cost- performance ratio of chemical inhibitors and their long term viability for continuous dosing from upstream to downstream. The work of the author also involves a number of analytical methods and testing methods that can be used to augment circulation fluids under high pressure and temperatures.INTRODUCTIONMetals in their elemental state or as pure metals (reduced) are eventually oxidized under ambient conditions except for noble metals such as Au, Pt, etc. It is an electrochemical event, the result of which is the degradation of properties if not the formation of then films of metal oxides that we call rust. The economic cost on structures, machines, vehicles, is enormous based on studies by the National Association of Corrosion Engineers (NACE) to the total to US$ 276 billion or 3.1% of the country's Gross Domestic Product (GDP). Various mitigation techniques, about US$ 121 billion is spent, a majority of which is on the use of corrosion protective coatings. These are either alarming number for most industries or create a variety of business opportunities and scientific/technical challenges. In a March 2016 NACE report, “IMPACT – the International Measures of Prevention, Application, and Economics of Corrosion Technologies,” the global cost of corrosion was estimated to reach up to US$ 2.5 trillion or approximately 3.4% of the global GDP. The cost to process, production, and transport, industries is staggering. Various protocols have be used to significantly slow down the rate of corrosion. The most common of which includes the application of protective and barrier coatings, which can employ corrosion inhibiting additives onto metal surfaces.1
Abstract Asphaltene deposition is a major formation damage issue in production wells with asphaltene problematic oil. Asphaltene can precipitate within the reservoir or in production tubing, resulting in partial or total loss of well productivity. This is especially a large concern in reservoirs with high gas-oil ratio (GOR), as more gas can dissolve in the oil and strip out the asphaltene. This anticipated asphaltene precipitation mechanism might be responsible for several partially or totally damaged wells in Field-A with asphaltene precipitation. An extensive laboratory study including solubility tests, saturate aromatic resin asphaltene (SARA) analysis, compatibility tests and coreflood experiments was performed in this study. Solubility tests were conducted at reservoir temperature (220 °F) and elevated pressures using asphaltene obtained from a bailer sample to determine the effectiveness of different solvent systems. SARA analysis was performed to assess the stability of the reservoir oil of interest. Compatibility tests and coreflood experiments at reservoir conditions were also conducted to assure solvent system compatibility with formation fluids. In addition, other factors including the overall cost and environmental impact were taken into account in choosing the most suitable solvent system. Initial lab testing presented a number of candidate solvent systems with high asphaltene solvency power. Some solvent systems were ruled out because they were damaging to core permeability as indicated from the compatibility tests and coreflood experiments. A case study of two successful chemical treatments performed on Well-A with a time interval of more than two years is presented in the paper. The first treatment was successful in restoring productivity of Well-A while the second one was able to remove the partial organic deposition damage with a cost saving of 60%. Using the selected solvent system, a two-stage remediation procedure was implemented to dissolve the organic deposition in the horizontal open-hole section of this well. The first stage included bullheading the solvent, allowing it to soak for 24 hours to clean out the tubing. The second stage involved injecting the solvent in the open-hole section using coiled tubing (CT) with jetting/pulsing mechanism. Results showed an increase in the wellhead pressure by 40% and consequently well productivity, indicating the successful dissolving of the organic deposition. This paper presents a new methodology in incorporating all the mentioned analytical techniques into choosing the most proper and cost effective asphaltene treatment solution for a specific reservoir to have a successful field treatment.