An alcohol dimerization process known as the Guerbet reaction is used to create large alcohol structures for the production of the corresponding alkoxy sulfate surfactants. In the alcohol industry, Guerbet (dimer) alcohols are considered the "gold" standard for large, branched alcohols. These Guerbet alcohols tend to be more expensive than other alcohols when produced in high purity for various industrial applications. The high cost is mainly due to driving the reaction to completion and/or stripping-off of the unreacted monomer alcohol to produce high purity. However, inexpensive Guerbet alcohols (GA) can be prepared by aiming for less than quantitative conversion during the alcohol dimerization process. The resultant blend of 85-95% GA and 5-15% monomer alcohol is subsequently used in the alkoxylation process to add propylene oxide and/or ethylene oxide, followed by sulfation. Through the use of this new Guerbet process, these surfactants can be manufactured at low cost when made as sulfates as opposed to sulfonates. For example, a C32 GA can be produced from a C16 alcohol. These and other sulfate surfactants can be stabilized at high temperature with alkali. This is a surprising discovery that greatly increases the availability of low-cost, high performance surfactants for high temperature reservoirs. Guerbet Alkoxy Sulfate SurfactantsWhen the equivalent alkane carbon number (EACN) of a crude oil is higher than about 12 surfactants with very large hydrophobes and branched structures are required to obtain ultra-low interfacial tensions and low microemulsion viscosities (Liu et al., 2007) and this is even more difficult to achieve at high temperature and/or high salinity and hardness. However, the cost of these very large hydrophobe surfactants can be prohibitive. However, inexpensive Guerbet alcohols (GA) can be prepared by aiming for less than quantitative conversion during the alcohol dimerization process.The Guerbet reaction dimerizes a linear alcohol using base catalysis at high temperatures (for example 230 °C) to produce near mid-point branching. (O'Lenick Jr., 2001) The Guerbet alcohols (GA) are considered the "gold" standard for large, branched alcohols which are low melting point liquids. Very large hydrophobe structures can be produced from smaller linear alcohols using the Guerbet reaction. For example, a C32 GA can be produced from a C16 alcohol. These Guerbet alcohols (GA) can then be used in the production of corresponding alkoxy sulfate surfactants. Guerbet alkoxy sulfate surfactants have previously been studied at the air-water (Varadaraj et al., 1991) and oil-water interfaces (Aoudia et al., 1995). These anionic surfactants can be produced by adding propylene oxide (PO) and ethylene oxide (EO) units to the GA, followed by sulfation (O'Lenick Jr. and Parkinson, 1996). By varying the amount of PO and EO in the Guerbet surfactants, they can be tailored to fit specific EOR needs.Guerbet alcohols tend to be more expensive than other alcohols when produced in high purity for various industrial appli...

The ability to select low-cost, high-performance surfactants for a wide range of crude oils under a wide range of reservoir conditions has improved dramatically in recent years. We have developed surfactant formulations (surfactant, co-surfactant, co-solvent, alkali, polymer, electrolyte) using a refined phase behavior approach. Such formulations nearly always result in more than 90% oil recovery in both outcrop and reservoir cores when good surfactants with good mobility control are used. Chemical flood residual oil saturations are typically less than 0.04 and surfactant retention between 0.01 and 0.1 mg/g with these formulations using as little as 0.2% surfactant concentration and 30% pore volume ASP slugs. We describe some of the advances that have improved the performance, reduced the cost, increased the robustness, and extended the range of reservoir conditions for these formulations. There are thousands of possible combinations of the chemicals that could be tested for each oil and each chemical combination requires many observations over a long time period at reservoir temperature for proper evaluation, so it would take too long, cost too much and in many cases not even be feasible to test all combinations. In practice we use our scientific understanding of how to match up the surfactant/co-surfactant/co-solvent characteristics with the oil characteristics, temperature, salinity, hardness and so forth. We have synthesized and tested new surfactants with much larger hydrophobes and more branching than previously available. We have tested new classes of co-solvents and cosurfactants with superior performance. These new developments have enabled us to develop good formulations for both oils that react with alkali to make soap and oils that do not. We have significantly lowered the chemical cost needed for waxy crudes with very high equivalent alkane carbon numbers. We have good results for oils with API gravities as low as 17, high temperature, high salinity, and high hardness brines. Many of these developments are synergistic and taken together represent a breakthrough in reducing the cost of chemical flooding and thus its commercial potential in both sandstone and carbonate reservoirs. SPE 129978ordered arrays such as gels or liquid crystals and decreases the reliance on alcohols or other co-solvents for rapid equilibration of microemulsions. Branched co-surfactants with different structures than the primary surfactant can be added to disrupt the orderly arrangement of surfactant molecules at interfaces (

Currently, there are several mind models developed as cognitive architectures and their main focus is to explain mind functions. However, few architectures explain the neural basis of the mind. Also, neuroscience explains the neural basis of the brain and is directly related to the mind. The study objective was to identify a mind model with a neural basis established in the model. Therefore, the study uses a systematic review of existing literature to find a mental model with a neural basis. There are 300 articles identified in searching databases of PUBMED and Google Scholar. After duplicated removal, initial screening was done using an independent reviewer and remaining full-text articles were submitted to eligibility assessment. From the assessed full-text articles, 9 full-text articles were selected for synthesis. From those selected architectures, considering the richness of mental functions and richness of neurological assemblies, features of the architectures op of ACT-R (Adaptive control of thoughts – Rational) cognitive architecture, Leabra cognitive architecture and an embodied cognitive-affective architecture select for inclusion in the final model. The central structure of the mind is the amygdala. It gets sensory inputs through the sensory cortex and external stimuli through the thalamus. It processes those inputs using working memory as mPFC and dLPFC. After processing, the amygdala provides output as behavior. Also, brain structures of the partial cortex, cortex, para hippo cortex, perirhinal cortex, entorhinal cortex, subiculum, dentate gyrus, CA1 and CA3 areas of the hippocampus are used for memory encoding, memory retrieval, and critical learning. Overall, the posterior cortex processes the sensory and semantic information. The hippocampus works as episodic memory. The frontal cortex works as active maintenance of the thinking process. The basal ganglia works as action selection and the main part of the thinking process. This reveals the mind model with neurological circuit assemblies to it. The final model will limit to features of the currently existing literature.