Rethinking Well Construction by Use of Drilling With Casing

We carried out a set of experiments to compare three particle number concentration standards (NCSs) by calibrating the same condensation particle counter (CPC) unit (Model 3772, TSI Inc., Shoreview, MN, USA). The standards were, in the order of operation size range, the primary NCS of the National Institute of Advanced Industrial Science and Technology (AIST, Japan), the Single Charged Aerosol Reference (SCAR) (Finland), and the Inkjet Aerosol Generator (IAG) of AIST. The results obtained with the 3 standards were found to agree at all overlapping particle sizes within the uncertainty limits. The relative expanded uncertainties varied between 0.6% and 2.6%, depending on the size and standard, while the overall agreement between the standards was within 0.5%. The observed consistency of the results is an important step toward establishing internationally coherent particle NCSs. As a result, the CPC 3772 was successfully calibrated in a particularly wide size range, approximately from 10 nm to 10 μm. The re...

8 - Particulate Formation and Control Technologies

We developed a Digital Holographic Microscope (DHM) working with a partial coherent source specifically adapted to perform high throughput recording of holograms of plankton organisms in-flow, in a size range of 3 µm-300 µm, which is of importance for this kind of applications. This wide size range is achieved with the same flow cell and with the same microscope magnification. The DHM configuration combines a high magnification with a large field of view and provides high-resolution intensity and quantitative phase images refocusing on high sample flow rate. Specific algorithms were developed to detect and extract automatically the particles and organisms present in the samples in order to build holograms of each one that are used for holographic refocusing and quantitative phase contrast imaging. Experimental results are shown and discussed.

Although technologies do exist for removing solids from waters, oils, drilling fluids and sludges in the oil and gas industry, the capital and operating costs related to solids removal and cleaning can be very high and greatly reduce the economics in offshore oil and gas processing drilling technologies and many other sludge cleaning operations. For the past four years Chevron UK Limited and Richard Mozley Limited UK have been developing hydrocyclone technology, based on the minerals industry, for applications in solids removal and clean-up in the oil and gas industry. The flexibility of hydrocyclone with respect to fluid rate, solid type, solid concentration pressure, temperature, etc. enables them to be used for many different process applications. In addition the size, weight, cost and absence of moving parts make the hydrocyclone attractive when compared with alternative technologies. This improves the economics of offshore developments particular for small field development and simple retrofitting to existing field. This paper discusses the results of:Laboratory and field trials for removal of solids from brine/produced water for injection into reservoirs.Laboratory trials for cleaning oil from solids.The applications of the technology for offshore oil, gas and drilling process.Application of the technology to reduce environmental pollution SURVEY OF APPLICATIONS In nearly all offshore oil and gas field developments, solids present a major problem in optimizing processes and make operations difficult for many unit operations. Hydrocyclone technology can replace present offshore technologies reducing the size, weight and cost of the operations. These include:-Replacement of coarse and fine filters for sea-water filtration. Sea-water can be taken from a lower water-depth, below the possible ‘ algae bloom’ depth. For low permeability reservoirs the hydrocyclone may have to be used in conjunction with other filtration methods.Re-injection of produced water reduces the sea-water filtration and deaeration capacity required for reservoir pressure maintenance. Also, this has a major impact on the environment by reducing oil and solids discharge into the sea.Solids removal from separators and reducing the oil level on the solids to the accepted environmental requirement.Removing sand from gas/condensate field fluids to reduce pipeline deposition and erosion.Removing oil from drilling cuttings.Cleaning reservoir rock, debris or cuttings from drilling operations.Recovery and cleaning of solids from oil and water based muds. In the offshore oil and gas industry, removing and cleaning solids from oil will significantly reduce environmental pollution. Solids can be returned to the natural environment in many instances. If the quantity of residue is sufficiently small it may be economic to transport to a land-fill site. HYDROCYCLONE TECHNOLOGY DEVELOPMENT The Mozley hydrocyclone used in the minerals industry have been developed since 1977 for removing a wide range of particle sizes. Figure 1 is a graphic example of efficiency curves (percentage recovery of the size fractions to underflow) for different sizes of hydrocyclone. Figure 2 shows the operation of a hydrocyclone.

Filtering facepieces (FFP), mainly class FFP2 particle half masks (EN 149:2001#x02009;+ A1:2009), are commonly used in European mines to protect workers from respirable dust, especially from particulate matter (PM) with a diameter of 4 µm or less (PM4). The aerosol associated with diesel exhaust (DE) is dominated by submicrometer particles (with a diameter of less than 1 µm) and nanoparticles (size in the range between 10 and 500 nm). In the European Union (EU), the occupational exposure level (OEL) for DE has been defined in terms of elemental carbon (EC) concentration. Based on measurements in underground mines, on average, 60% of EC associated with PM4 was contained in PM with a diameter of 1 µm or less (PM1). Particle number size distribution (PNSD) of PM1 showed that the most numerous were particles in the size range of 20 to 300 nm. Four popular types of certified FFP2 half masks were tested for penetration. Brand new and thermally conditioned masks of each type were included in the study. NaCl aerosol in the particle size range of 7 to 270 nm was used for tests. Filtration efficiencies of 98.5% (median) or higher were achieved. Aerosol penetration was a function of particle size. Maximum penetration was observed between 20 and 60 nm, depending on the type of mask. During filtration, aerosol characteristics changed. Nanoparticles ranging in size from 7 to about 60 nm were removed to a very limited extent. The change was more noticeable for brand-new masks compared to the thermally conditioned ones. Usually, aerosol penetration through thermally conditioned masks was lower and more consistent. It was confirmed that the half masks of the FFP2 class are capable of filtering submicrometer aerosol in particle size range 7 to 270 nm with an efficiency exceeding 96% and can contribute to achieving compliance with the OEL for DE in the mining sector.

Particle size distribution measurements of twelve USEPA priority pollutant polycyclic aromatic hydrocarbons (PAHs)—collected in Riverside, California, down to 10 nm aerodynamic diameter (Dp)—observed on integrated nocturnal samples (7:00 p.m.-6:30 a.m.) revealed that between 46 and 100% of the mass of particles in the Aitken size range was found in the 10–18 nm size bin. Particles in this size range have high alveolar deposition efficiency.

In-situ transesterification process for biodiesel production using spent coffee grounds from the instant coffee industry

Venusian saltation

Landslide barrier structures are a useful mitigation tool for managing debris flow risks, working to slow their momentum or alter their course to avoid damage to downslope inhabitants or infrastructure. Their design is typically governed by the expected impact force, which is predicted using analytical models or numerical simulations. These methods only provide estimates of the peak force and require detailed information about the flow at impact that can be difficult to accurately predict. In this experimental study, we use the large Queen’s University Landslide Flume to explore the relative contributions of the fluid and solid phases of a multi-phase flow on the structural demand on a barrier. Impact forces following dam break experiments of up to 0.4 m3 of material, released from the top of a 6.5 m long slope inclined at 30 degrees are explored for material releases of pure water, dry granular particles (3 mm diameter), and fully saturated water-grain mixtures. Temporal impact behaviour captured using ultrahigh speed imaging (7500 fps) is correlated with the time series of impact load measured at the barrier. The addition of the fluid phase was found to significantly increase the impact force and the maximum run-up height along the barrier. Further tests are performed using single-graded particles ranging in diameter from 3-25 mm. Over this range, the dilatancy of the flow increased with increasing particle size, leading to reduced influence of the fluid phase on the flow dynamics and decreased impact force, despite similar flow velocities (4-5 m/s).To explore the performance of an alternate barrier type, impact tests were conducted using a single-slit barrier with varying slit size (30-240 mm) and grain diameter (3-25 mm), providing a wide range of relative slit sizes. A benefit of the slit barrier design is its ability to ‘self-clean,’ letting material slowly release through the slit following an impact event. This allows the barrier to remain effective in halting a secondary debris flow without maintenance clearing between impacts. To explore the dynamics of this subsequent event, secondary releases were performed for both solid and slit barrier designs. Barrier performance is investigated using load measurement, LiDAR imaging, and PIV analysis. The solid barrier experienced overtopping under the second release. The addition of the slit alters the deposit geometry, generating two slopes on either slide of the slit which act as redirection berms, altering the flow behaviour and reducing the runup height and force of the second impact. The results of this large-scale experimental study provide detailed data on the flow behaviour, impact mechanics, and barrier efficiency for a range of debris flow compositions, particle sizes, and slit sizes under single and sequential impacts, suitable for numerical model benchmark tests that may lead to improved barrier design.

The static recrystallization kinetics of four steels microalloyed with Nb, Ti and Nb–Ti have been investigated, covering conventional and hot direct rolling conditions. The influence of the grain size on the recrystallization time has been studied for a wide range of grain sizes (20–1000 μm). For the same deformation conditions it has been observed that the quadratic dependence on grain size works well in the range of finergrain sizes (<160 μm). In contrast, the recrystallization times measured at coarse grain sizes are significantly lower than those predicted by this dependence. However, when the whole grain size range analysed is considered, a linear dependence on grain size gives the best fit to experimental data. The effect of strain on the recrystallization kinetics has been also analysed for different initial grain sizes. It has been observed that the time to reach a 50% recrystallized fraction (t0.5) shows a dependence on strain of the type t0.5∝ε-p, the exponent being influenced by the initial grain size. A unique equation has been proposed to describe the static recrystallization kinetics of Nb, Ti and Nb–Ti microalloyed steels. The predictions of the equations have been compared to previously published data on similar steels.

Devolatilisation behaviour of shredded tyre chips in combusting environment

We developed an inverted, co-flow, methane∕air∕nitrogen burner that generates a wide range of soot particles sizes and concentrations. By adjusting the flow rates of air, methane, and nitrogen in the fuel, the mean electric mobility diameter and number concentration are varied. Additional dilution downstream of the flame allows us to generate particle concentrations spanning those produced by spark-ignited and diesel engines: particles with mean diameters between 50 and 250nm and number concentrations from 4.7∙104to107cm−3. The range of achievable number concentrations, and therefore volume concentrations, can be increased by a factor of 30 by reducing the dilution ratio. These operating conditions make this burner valuable for developing and calibrating diagnostics as well as for other studies involving soot particles.

In many applications of geotechnical analysis and design, correct determination of the coefficient of earth pressure at rest, K0, is essential. The K0 in soils is typically estimated using empirical equations that depend on the soil’s friction angle and stress history in terms of the overconsolidation ratio (OCR). However, this estimation ignores any effects of particle morphology in granular soils, potentially leading to unrealistically large hysteresis upon loading–unloading cycles. Existing experimental and numerical studies only reported K0 of granular soils with limited ranges of particle morphology during loading. This study conducted a comprehensive experimental campaign to systematically study K0 of soils with controlled morphology along loading and unloading paths. An oedometer equipped with flexible tactile sensors to precisely measure horizontal and vertical stresses during loading–unloading cycles was developed to obtain K0 in five granular soils with a wide range of particle shapes but similar particle size and initial density. Results showed that K0 during loading and unloading were strongly associated with particle morphology. Soils with a lower particle regularity (REG, i.e., average of roundness and sphericity) or overall regularity (OR, i.e., average of aspect ratio, convexity, and sphericity) mobilized more friction angles during loading, returning smaller K0 values. They also hold most of the locked-in stresses developed upon loading at different unloading stages, causing greater hysteresis. When employing REG and OR, equations were obtained for K0 during loading that are identical to Jaky’s equation, even though these overall descriptors have different definitions and ranges of value. New empirical equations that incorporate REG and OR into the K0–OCR relationship were developed to markedly improve the estimation of hysteretic K0 after validating against high-quality laboratory data of 10 sand types from the literature.

Collisions between spheres are a common ingredient in a variety of scientific problems, and the coefficient of restitution (COR) is a key parameter to describe their outcome. We present a new collision model that treats adhesion and viscoelasticity self-consistently, while energy losses arising from plastic deformation are assumed to be additive. Results show that viscoelasticity can significantly increase the energy that is dissipated in a collision, enhancing the sticking velocity. Furthermore, collisions well above the sticking velocity remain dissipative. We systemically compare the model to a large and unbiased set of published laboratory experiments to show its general applicability. The model is well capable of reproducing the important relation between impact velocity and COR as measured in the experiments, covering a wide range of materials, particle sizes, and collision velocities. Furthermore, the fitting parameters from those curves provide physical parameters such as the surface energy, yield strength, and characteristic viscous relaxation time. Our results show that all three aspects—adhesion, viscoelastic dissipation and plastic deformation—are required for a proper description of the kinetic energy losses in sphere collisions.

Enzyme engineering by immobilization techniques has proven to be well compatible with the other chemical or biological approaches aiming to improve enzyme's functions and stability. Zeolites are porous alumino-silicates with a wide range of porosity and particle size along with the other remarkable properties such as high surface area, high stability against a wide range temperatures, pHs, as well as organic solvents. Nano-zeolites are a class of advanced materials that have special properties that has made them ideal candidate for a wide range of applications. In this study, a nano-zeolite which has been synthesized and characterized in our previous work, was used to immobilize α-amylase and activated with glutaraldehyde as a bi-functional agent to improve enzyme properties. Studies have shown an increased stability of the immobilized enzyme compared to the free enzyme against a range of temperature change and pHs as well. Also the stability of the immobilized enzyme was increased with respect to storage. The calculated binding efficiency shows that the immobilized α-amylase conserved 58.44 % of its native activity. Using nano pore zeolite for covalent attachment of the α-amylase resulted in an increased resistance of this enzyme against denaturation. The immobilized enzyme demonstrated higher stability compared to the free enzyme at higher temperatures and pH variations. Immobilization also caused an increase in the enzyme stability during storage.