Development of a Novel Green Surfactant - Low Salinity Nanofluid for Enhanced Oil Recovery Application

Natural surfactants have been considered part of the EOR processes, given their non-toxic and environment-friendly nature. In this project, two novel natural surfactants have been extracted. Furthermore, the physical-chemical properties of novel saponins, foamability and foam stability, interfacial tension (IFT), and wettability between saponins and low salinity water (LSW) and nanoparticles have been investigated. On the other hand, the interactions of the particles (mechanisms) between saponins, salt, nanoparticles, crude oil, and formation rocks have been examined

Design and Synthesis of Low Molecular Weight and Polymeric Surfactants for Enhanced Oil Recovery

Surfactants are defined as molecules able to lower the surface (or interfacial)tension at the gas/liquid, liquid/liquid, and liquid/solid interfaces. Due totheir properties, they are typically employed as detergents, emulsifiers, dispersants,wetting and foaming agents. In chemical enhanced oil recovery (cEOR), surfactantsare used as flooding agents, alone or in combination with polymers, alkali, and morerecently nanoparticles, to increase the microscopic displacement efficiency. Froma chemical point of view, surfactants are amphiphiles, meaning that they bear intheir structure both hydrophilic and hydrophobic moieties. Some naturally occurringsurfactants exists, but the majority are synthetic. The availability of syntheticsurfactants, allows a big variety of structures and properties. In this chapter, the mainclasses of surfactants will be reviewed, with focus on those used or proposed foruse for chemical enhanced oil recovery. After a general introduction about surfactantsand their main structural and physico-chemical properties, specific aspects ofdesign and synthesis will be discussed. Particular emphasis will be given to the mostrecent developments, which includes zwitterionic, gemini and polymeric surfactants.Own work of the author of this chapter in the field of polymeric surfactants will behighlighted

Experimental investigation on coal fines migration through proppant packs: Assessing variation of formation damage and filtration coefficients

Coalbed methane reservoirs generate coal fines during production that cause irreversible damage to cleat conductivity. In severe scenarios, this can result in temporary closure of recovery operations from the gas well(s). In this work, we simulate the impact of coal fines on proppant conductivity. Four sets of experiments were conducted: effect of salinity – 0 to 3.5 NaCl wt.%, pH – 2 to 11, coal rank - anthracite, high volatile bituminous, and sub-bituminous; and 0.01 wt% additives – Sodium Dodecyl Benzene Sulfonate (SDBS) and Cetrimonium bromide (CTAB) and validated with established analytical models. Moreover, medical computed tomography of three extreme cases was conducted. Results showed that coal fines uniform distribution within a proppant pack does not cause greater conductivity decline than non-uniform distribution owing to clogging and straining. Additionally, results showed that anionic surfactants successfully dispersed coal fines. These research results can be applied to coalbed methane reservoirs, especially during the early water drainage phase, to optimise the impact of coal fines on proppant conductivity

Mineral Processing

The minerals and the metals are integrally associated with the development of human culture and growth of the society. Minerals are essential component of Nation's material and economic base. They contribute to indust-rialization and form an important infrastructure for the development of the country. However, conservation of these non-renewable assets is absolutely essential in view of the rapid industrialization and consumption of minerals. Attempts should be aimed to use the resour-ces wisely and efficiently for complete utilization of the components with no waste. Ignoring the awareness in respect of mineral resources, environmental issues have come into prominence and the aspect of conservation and safe guarding the environment can be managed by making proper use of the mined materials, wasting the least, reclamation, restoration, afforestation and creation of better environment for better habitat

Stable dispersion of coal fines during hydraulic fracturing flowback in coal seam gas reservoir: An experimental study

In subterranean coal seam gas (CSG) reservoirs, massive amounts of small-sized coal fines are released during the production and development stages, especially during hydraulic fracturing stimulation. These coal fines inevitably cause mechanical pump failure and permeability damage due to aggregation and subsequent pore-throat blockage. This aggregation behavior is thus of key importance in CSG production and needs to be minimized. Consequently, such coal fines dispersions need to be stabilized, which can be achieved by the formulation of improved fracturing fluids. Here, we thus systematically investigated the effectiveness of two additives (ethanol, 0.5 wt % and SDBS, 0.001 and 0.01 wt %) on dispersion stability for a wide range of conditions (pH 6–11; salinity of 0.1–0.6 M NaCl brine). Technically, the coal suspension flowed through a glass bead proppant pack, and fines retention was measured. We found that even trace amounts of sodium dodecyl benzene sulfonate (SDBS) (i.e., 0.001 wt %) drastically improved dispersion stability and reduced fines retention. The retention was further quantified by fractal dimensional analysis, which showed lower values for suspensions containing SDBS. This research advances current CSG applications and thus contributes to improved energy security

Gels for Oil and Gas Industry Applications

This Special Issue includes many advanced high-quality papers that focus on gel applications in the oil and gas industry. The papers in this Special Issue present the new development of gels that can be used as conformance control agents, drilling fluid additives, and hydraulic fracturing agents

Multifunctional foams and emulsions for subsurface applications

Foams and emulsions hold immense potential in assisting in the different stages of oil recovery processes such as enhanced oil recovery, drilling, and completion. This work is focused on developing robust, multifunctional foams or emulsions for subsurface applications, which offer unique advantages over conventional methods. The first half of the dissertation is focused on investigating novel foams stabilized using nanoparticles and/or surfactants to improve the gas enhanced oil recovery process. Gas flooding often has poor volumetric sweep efficiency due to viscous fingering, channeling, and gravity override. Foam is a promising tool to improve sweep efficiency in gas floods. It can reduce the mobility of gas by several orders of magnitude by increasing its apparent viscosity while keeping the liquid phase mobility unchanged. For sandstone reservoirs, which are typically water-wet in nature, two different approaches of foam stabilization using nanoparticles were developed. In the first approach, synergistic stabilization of foams with a mixture of hydrophilic nanoparticles and an anionic surfactant was investigated. Foam stability experiments in bulk and porous media tests showed that adding hydrophilic nanoparticles to surfactant formulations increases the foam stability. Microscopy revealed that nanoparticles are trapped in lamellae as well as at the Gibbs-Plateau borders. These nanoparticles act as physical barriers and retard the liquid drainage and the Ostwald ripening process. To fundamentally understand the role of nanoparticles in altering the foam dynamics in porous media, a high-pressure visualization experiment was performed in a 2D layered, heterogeneous porous media. This experiment showed that immiscible foams can result in significant incremental oil recovery of 25% to 34% OOIP (over waterflood). In the second approach, foam stabilized using in-situ surface-activated nanoparticles without any surfactant was explored as an EOR agent. The surface chemistry of the hydrophilic nanoparticles was tailored by adsorption of a small amount of short-chain surface modifiers to obtain surface-modified nanoparticles (SM-NP). Foam stabilization using these SM-NP was compared with that using a conventional surfactant to evaluate the potential of these SM-NP to act as an effective foaming agent. Carbonate reservoirs, which are typically highly heterogeneous and oil-wet in nature, pose additional challenges for an effective foam EOR process. Crude oils are typically detrimental to foam stability. An oil-wet carbonate will have a thin oil film on the surface and thus foam lamellae stabilization is challenging. Therefore, wettability-alteration of rock matrix toward water-wet condition using a surfactant is required to favor the in-situ foam stability. This work demonstrated for the first time a synergistic approach of using foams with wettability-altering capabilities for oil-wet systems. It was shown that optimal surfactant formulations can not only alter the wettability of a carbonate core from oil-wet to water-wet conditions, but also can significantly increase the in-situ foam stability even in presence of crude oil. The second half of the dissertation is focused on developing novel microencapsulation techniques using the concept of water-in-air powders for subsurface applications. A facile, one-step method was reported to encapsulate micro- or nano-sized hydrophilic particles using silica nanoparticles. The encapsulated particles can be released based on an external stimulus, such as a change in pH of the external continuous phase. The use of this novel carrier system was demonstrated for the delayed release of PPG particles for conformance control. The application of this technology was then explored for microencapsulating highly concentrated acids (~10 wt.% HCl) for acid treatment of shales. The advantages of these novel acid-in-air powders over conventional acid-in-oil emulsions (which are typically used for shale acidization processes) were illustrated in terms of the thermal stability, corrosion inhibition efficiency, and shale surface reactivity.Petroleum and Geosystems Engineerin

Wettability Alteration and Adsorption of Methyl Ester Sulphonate / Polystyrene Nanofluid to Enhance Oil Recovery from Sandstone Reservoir

Chemical Enhance Oil Recovery method is a tertiary recovery technique to recover residual oil from reservoirs by injecting various chemical materials. The major drawbacks such as excessive surfactant losses and oil-wet rock, causing oil recovery reduction. This research investigates the low salinity water/Methyl Ester Sulphonate/nanoparticles synergy to enhance oil recovery from sandstone reservoirs. Experimental works were conducted to ascertain the effect of the synergy solution on wettability alteration, surfactant adsorption reduction, and oil recovery enhancement

Adsorption Of Anionic Surfactants From Synthetic Produced Water On CrudeSorb And Kaolin

Conventional treatment process cannot meet the need for treatment of produced water from surfactant flooding of Enhanced Oil Recovery (EOR) field. In this study, adsorption of surfactants using commercialised adsorbent, CrudeSorb and natural adsorbent, kaolin were investigated to assess the removal of surfactants from synthetic produced water. Adsorbents were first sent for XRD to verify theirs mineralogical and SEM to determine their external morphology texture. In the adsorption test, the adsorbents were exposed to anionic surfactants in produced water and final surfactant concentration of produced water is measures using titration method. The amount of surfactant that was adsorbed was quantified by subtracting the concentration of surfactants after adsorption from the initial concentrations. The surfactant removed was optimized at pH value of 2 for kaolin, and pH12 for CrudeSorb. An increase in of contact time also increases the percentage removal of surfactants from produced water on both CrudeSorb and kaolin. The adsorption activities for both CrudeSorb and kaolin fitted the Langmuir Isotherm with correlation coefficients of 1.00 and 0.9962. The adsorption activities also found to be fitted the pseudo second-order reaction kinetic model at correlations coefficients value of 0.9993 and 0.9923 respectively