Organosilane has been explored previously as a kaolinite fixing agent, and surface modifier to enhance adsorption of scale inhibitors. Here, self-assembled organosilane films are investigated for their potential to prevent scale deposition directly, that is without the presence of scale inhibitors. Film formation on quartz crystals is analysed using a quartz crystal microbalance, which suggests that different film structures can be created using the same organosilane molecule. Brine tests using singlecrystal quartz coupons coated with organosilane indicate that calcium carbonate scale deposition can be reduced by 66%.
Keywords: adsorption, organosilane, inorganic scale precipitation, self-assembled monolayer, quartz
Field emission from carbon nanotube (CNT) bundles has been applied to develop new class of computational vacuum microelectronics for harsh environment applications. CNTs have demonstrated superior field emission performance because of their low emission threshold, high current density, and are conducive for monolithic integration with silicon structures to develop microelectronic/microsensor systems. In this paper we present high-temperature tolerant "digital" vacuum electronics using CNTs. This technology is applicable to in situ sensor electronics for down-hole applications where the operating environment is high temperature, high pressure, and has corrosive chemicals. The digital and analog electronic devices developed using CNT-vacuum microelectronic technology can be integrated with sensor systems to achieve prolonged stand-alone operation during E&P. NASA-JPL has developed high performance cold cathodes using arrays of carbon nanotube bundles that produce > 15 A/cm2 at applied fields of 5 to 8 V/µm. They have exhibited robust operation in poor vacuums of 10-6 to 10-4 Torr- a typically achievable range inside hermetically sealed microcavities. By monolithically integrating CNT cathodes with micromachined Si multi-gate structures we have demonstrated a new class of programmable "vacuum" logic gates. We have achieved switching operation at temperatures up to 700° C. The initial design, operation, and the potential performance in an improved design will be presented in this paper along with vacuum packaging techniques to make stand alone devices for circuit board integration. CNT-vacuum microelectronics opens up a new regime of in situ electronics for novel sensor/electronics systems because of their inherent high-temperature tolerance, and corrosion resistance. Unlike traditional vacuum tubes, these are low power, miniature, and potentially as fast as their solid-state counterparts while exhibiting superior reverse bias or leakage current characteristics. These devices offer potential to significantly enhance E&P operation.
We describe a water dispersed nano sensor cocktail based on InP/ZnS quantum dots (QDs) and atomic silver clusters with a bright and visible luminescence combined with optimized sensor functionalities for the water flooding process. The QDs and Ag nano sensors were tested in simulated reservoir conditions (high salinity, Ca2+, pH, high temperature, oil and solids). The nano sensors showed enhanced sensor functionalities towards pH, temperature, sub-terrain chemistry and reservoir solids like clay or calcium carbonate.
The success of drilling operations is heavily dependent on the drilling fluid. Drilling fluids cool down and lubricate the drill bit, remove cuttings, prevent formation damage, suspend cuttings and also cake off the permeable formation, thus retarding the passage of fluid into the formation. Typical micro or macro sized loss circulation materials (LCM) show limited success, especially in formations dominated by micropores, due to their relatively large sizes.
In the current work, a new class of nanoparticle (NP) loss circulation materials has been developed. Two different approaches of NP formation and addition to oil-based drilling fluid have been tested. All NPs were prepared in-house either within the oil-based drilling fluid (in-situ), or within an aqueous phase (ex-situ), which was eventually blended with the drilling fluid. Under low pressure low temperature API standard test, more than 70% reduction in fluid loss was achieved in the presence of NPs compared to only 9% reduction in the presence of typical LCMs. The filter cake developed during the NP-based drilling fluid filtration was thin, which implies high potential for reducing the differential pressure sticking problem and formation damage while drilling. Moreover, at the level of NPs added, there was no material impact on drilling fluid viscosity and the fluid maintained its stability for more than 6 weeks.
The cost of the drilling fluid loss often represents one of the single peak capital expenditure during drilling. Current experience, nevertheless, shows that it is often impossible to reduce fluid loss successfully with micro and macro type fluid loss additives due to the fact that their physio-chemical and mechanical characteristics still falls short of the best that can be conceived. This impacts the economy of drilling since it increases the non-productive drilling time (Fraser et al., 2003; Amanullah et al., 2011; Chenevert and Sharma, 2009).
LCM with diameters in the range of 0.1-100 µm may play an important role when the cause of fluid loss occurs in 0.1 µm-1 mm porous formation. In practice, however, the size of pore opening in shales that may cause fluid loss varies in the range of 10 nm-0.1 µm, where NPs as a loss circulation material could fulfill the specific requirements by virtue of their size domain, hydrodynamic properties and interaction potential with the formation (Abdo and Haneef, 2010; Amanullah et al., 2011; Srivatsa, 2010). NPs are defined as particulate dispersions or solid particles with a size in the range of 1-100 nm. Amanullah and Al-Tahini (2009) defined nano fluids as any fluids (drilling fluids, drill-in-fluids, etc) used in the exploitation of oil and gas that contain at least one additive with particle size in the range of 1-100 nm. These particles are smaller than micro particles, have a high surface to volume ratio and may provide superior fluid properties at low concentrations of the additives (Amanullah and Al-abdullatif, 2010). The main application of NPs would be to control the spurt and fluid loss into the formation and hence control formation damage. The presence of NPs can lead to better sealing at an earlier stage of filter cake formation and, subsequently, a thinner impermeable mud-cake. Due to its high surface to volume ratio the particles in the mud cake matrix can easily be removed by traditional cleaning systems during completion stages. Thus, the NPs can be used as rheology modifiers, fluid loss additives and shale inhibitors at low concentrations (Amanullah et al., 2011; Amanullah and Al-abdullatif, 2010; Zakaria et al., 2011) without the fear of particles lingering in the drilled well.
High water production greatly affects the economic life of producing wells and is a serious problem in the oil industry. Excessive water cut is also responsible for many oilfield-related damage mechanisms, such as scale deposition, fines migration, corrosion, etc. Nanomaterials, such as nanosilica, in combination with chelating agents, could be used for plugging and sealing water- or gas-producing zones (bottom-water coning, gas coning, natural fractures, etc.), thus improving oil recovery.
The nanosilica used in design of water shutoff is an inorganic material with properties of no dissolution or aggregation in a liquid environment. Moreover, the entire system, including the chelating agent, is compatible with reservoir fluids and is environmentally acceptable. The particle size of nanosilica greatly influences the structural properties of the material. These aspects, in turn, exhibit a strong effect on chemical reactivity. The smaller particle size of nanosilica than previously used silica products generates increased surface area and interface atoms, which in turn increases the surface free energy and associated structural perturbations.
This paper presents the development of a novel, environmentally acceptable conformance sealant that incorporates nanosilica and an activator. Different chelating agents, which are also non-toxic and biodegradable, are used as activators in this conformance evaluation. The newly developed system can effectively prevent water and gas flow in BHSTs up to 300°F. The static gelation times were evaluated at different temperatures up to 300°F. An increase in temperature caused an increase in the particle collision, which led to lower gelation times. The effects of pH and concentration of activators on gelation times of the new conformance system were also studied. The gelation time could be controlled by adjusting the concentration of the activator, which is advantageous because it allows the sealant to remain pumpable over predictable periods of time.
Enhancing the life of scale inhibitor squeeze treatments in the oil and gas industry is a major means of increasing productivity. Having an understanding of the route by which inhibitors such as PPCA can adsorb to the rock surface is important in designing new squeeze methodologies. Nanotechnology is emerging as an enabling technology in many fields including medicine, transport and pharmaceutical. Thus far there has been research activity in novel uses of nanotechnology in the oil and gas sector but there is still enormous potential for it to be further exploited. In the squeeze process, where fluids are pushed through the rock pore space, there is potential for nanotechnology to enhance the delivery of species (i.e. placement) and/or to assist in the "binding" of active species to the rock surfaces. It is in this area the current work is focused. In this paper we investigate the adsorption of PPCA (a common scale inhibitor) onto a C-based nanoparticle (CBN). The adsorption of PPCA on the CBN is quantified as a function of time and the concentration of the CBN. Experimental data from Inductively Coupled Plasma (ICP) illustrates a substantial adsorption of PPCA on CBNs comparing to the adsorption of PPCA on the rock. Various concentration ratios of CBNs and PPCA have been tested in dynamic adsorption tests to understand the effects of absorbent and absorbate concentration. The mass of adsorbent was assumed to be key factor in adsorption of PPCA on CBNs; indicative of the number of active sites on the nanoparticle.
Keywords: Nanotechnology, squeeze, PPCA, adsorption
Neutron porosity logging is one of the most fundamental techniques used to perform the estimation of reservoir hydrocarbon reserves. Together with resistivity and gamma-gamma density measurements, these three constitute the "triple combo?? well logging suite that is used to log almost all wells. In the case of classical neutron porosity measurement, two neutron detectors are used to measure the flux of thermal neutrons created by the fast neutrons emitted by a chemical neutron source in the process of their interaction with the formation. The obtained flux ratio depends on the hydrogen concentration and enables the determination of porosity.
Currently, almost all available neutron porosity logging-while-drilling (LWD) tools use He-3 detectors to detect neutrons downhole due to their mechanical robustness and the absence of the limitations to operate at high temperatures. Unfortunately, the lack of sufficient quantities of the He-3 isotope caused by the depletion of its stockpile accumulated during the Cold War makes this material unavailable to well logging industry for the next 3 to 5 years. Among all other available neutron detection technologies, only Li-6 scintillation detectors do not have limitations on neutron detection efficiency that would prevent them from consideration for LWD applications.
The key component of Li-6 scintillation detector is the scintillation material containing Li-6 isotope. To be used as detectors for neutron porosity LWD tools based on pulsed neutron generators (PNG), such material should be able to operate at high temperature and enable large neutron detector constructions. In this paper we present new Li-6 scintillation nanostructured glass-ceramics that perform substantially better than all available Li-6 scintillation materials. It is this performance improvement provided by nanostructured nature of obtained material which enables its use in the neutron detectors of PNG-based neutron porosity LWD tools.
Javadpour and Nicot (2011) presented a novel idea of adding nanoparticles (NPs) to injected CO2 (aka. nano-CO2) to expedite convective mixing and decrease the potential of buoyancy flow of CO2. In this paper we implement that idea through the use of compositional numerical simulations.
Numerical simulation scheme is divided into two scenarios. The first scenario represents a saline aquifer of 20 m thickness, and extending 100 m laterally from the wellbore. This scenario is modeled to show the effect of nano-CO2 injection on field scale for 200 years. The second scenario represents a small part of the field scale model with dimension of 7.5 cm x 7.5 cm. These small scale models show density contrast effect on convective fingers at the brine/nano-CO2 interface.
Comparison of results between injection of nano-CO2 and normal CO2 clearly show that nano-CO2 exhibits the capability of improved mixing and reduced buoyancy driven flow in both scenarios. In scenario 1, nano-CO2 plume is able to dissolve deeper and move less laterally forward than the normal CO2 plume. In scenario 2, the CO2 dissolves and forms fingers due to gravity driven flow in a heterogeneous medium. The difference in length of convective fingers between nano-CO2 and CO2 increases with time.
Adding nanoparticles with the injected CO2 presents a great potential in quick mixing with the in-situ brine which will reduce the chances of leakage through the sealing. Injection of nano-CO2 can obviate the use of some of the monitoring techniques post injection. Waste materials such as depleted Uranium can be used as nanoparticles which favor economic feasibility of the proposed idea.
Nanotechnology has already contributed significantly to advances in several industries, e.g. electronics, biomedical, aerospace, and more recently the energy industries. In particular, nanotechnology has the potential to pioneer changes in several areas of the oil and gas industry, such as exploration, drilling, production, enhanced-oil-recovery (EOR), and refining. For example, superparamagnetic nanoparticles that could act as contrast agents could be used to accurately determine the oil saturation distribution in a reservoir and help determine bypassed oils. Moreover, by correctly functionalizing the surface of the magnetic nanoparticles, colloidal suspensions of these nanoparticles that are stable at high temperatures and high salinities (oil-well conditions) can be prepared and could be co-injected with sweep and/or fracture fluids and their location determined and tracked over time by electromagnetic measurements. With this in mind, a study of the magnetic properties of ferrite nanoparticles with varying compositions (MFe2O4; M = Fe, Al) has been conducted to determine the magnetic responses of the various particles in order to evaluate the likelihood of using them as magnetic contrast agents in the oil and gas industry.
Copyright 2012, Society of Petroleum Engineers This paper was prepared for presentation at the SPE International Oilfield Nanotechnology Conference held in Noordwijk, The Netherlands, 12-14 June 2012. This paper was selected for presentation by an SPE program committee following review of information contained in an abstract submitted by the author(s). Contents of the paper have not been reviewed by the Society of Petroleum Engineers and are subject to correction by the author(s). The material does not necessarily reflect any position of the Society of Petroleum Engineers, its officers, or members. Electronic reproduction, distribution, or storage of any part of this paper without the written consent of the Society of Petroleum Engineers is prohi bited. Permission to reproduce in print is restricted to an abstract of not more than 300 words; illustrations may not be copied. The abstract must contain conspicuous acknowledgment of SPE copyright.