Housingless ESPs for Slim Completion Wells

This paper describes a new electrical submersible pump (ESP) design concept to overcome the challenges of applications in slim well completions or thru-tubing deployment. The housing of the conventional pump is removed, allowing the pump impellers to have a larger diameter. The impact of this design change on pump hydraulic performance is assessed in this paper. Downhole ESPs operate in environments where space is limited radially. This is especially the case for slim completions or for thru-tubing rigless deployment. To provide the required rate and total dynamic head, the current approach is to use permanent magnetic motors and operate the slim systems at rotational speed over the conventional speed of 3500-4000 RPM. High-speed operations require new pump stage designs to minimize erosion and vibration. This paper provides an alternative pump design, which removes the pump housing with the benefit of increasing the impeller tip diameter, and hence potentially reducing pump length and operational speed. To ensure the pump retains the well fluids, the diffusers are designed to be externally threaded with an O-ring feature. The centrifugal pump affinity laws are applied to evaluate the impact of removing the pump housing and increasing the impeller outside diameter. A typical ESP housing wall thickness is about 0.18-0.25 inch. With the housing removed, the incremental space available for the impeller tip to occupy is increased by 0.36-0.5 inch. Analysis shows that, for the same pump speed as a conventional pump with a housing, a housingless pump will increase the head generated by 23-32%, and the rate capacity about 36-51%, depending on the pump series. In general, the smaller the pump outer diameter, the greater the flow and head capacity increase. This is because the available space due to removing the housing becomes a considerable size of the impeller tip diameter for the smaller series pumps. The elimination of pump housing enables impellers with a larger diameter to be used to generate more head per stage. In comparison to a conventional pump of the same outside diameter, and providing the same amount of total dynamic head, the housingless pump can have fewer stages and a shorter length or operate at a reduced speed. The reduced length can help mitigating pump-bending stress for installation in deviated or horizontal wells. The reduction in required operating speeds will reduce pump wears, heat generation and vibration. The housingless ESPs have applications for slim well completions or thru-tubing deployments.

Double-objective optimization-based firefly algorithm of a stand-alone photovoltaic/water pumping system for water supply in rural and remote areas: a case study

A techno-economic study of a stand-alone PV water pumping system for water supply is done in this paper. An optimal design of the system is realized thanks to a double-objective optimization based on a proposed operational strategy of the system and on firefly algorithm (FA). The two objective functions simulated simultaneously using FA are: the function defining the cost of water (COW) and the function which defines the loss of water supply probability (LWSP). The system is designed to supply water to around 328 households in Cameroon, each composed by an average of six (06) persons. For different LWSP, the double-objective simulation determines the optimal configurations of the system with their related cost. The optimal and reliable (LWSP of 0%) system configuration obtained is composed by a number of 7 PV modules, a reservoir volume of 98.4 m3 with 2 days autonomy, a total dynamic head of 40 m, and a pump power of around 1 kW. The related COW corresponding to this configuration is 0.1185 $/m3, and the total investment cost is 27,506 $. The sensitivity analysis of the system revealed that the PV size, the volume of reservoir storage, and the efficiency of the pump influence the system both technically and economically, whereas the total dynamic head only influences the system economically. The validation of the optimized system has been done by comparison with manufacturer datasheets. It is demonstrated in this paper that the techno-economic analysis of energy systems based on multi-objective optimization using firefly algorithm is a powerful tool for decision-making.

HEAD Metamodel: Hierarchical, Extensible, Advanced, and Dynamic Access Control Metamodel for Dynamic and Heterogeneous Structures

The substantial advancements in information technologies have brought unprecedented concepts and challenges to provide solutions and integrate advanced and self-ruling systems in critical and heterogeneous structures. The new generation of networking environments (e.g., the Internet of Things (IoT), cloud computing, etc.) are dynamic and ever-evolving environments. They are composed of various private and public networks, where all resources are distributed and accessed from everywhere. Protecting resources by controlling access to them is a complicated task, especially with the presence of cybercriminals and cyberattacks. What makes this reality also challenging is the diversity and the heterogeneity of access control (AC) models, which are implemented and integrated with a countless number of information systems. The evolution of ubiquitous computing, especially the concept of Industry 4.0 and IoT applications, imposes the need to enhance AC methods since the traditional methods are not able to answer the increasing demand for privacy and security standards. To address this issue, we propose a Hierarchical, Extensible, Advanced, and Dynamic (HEAD) AC metamodel for dynamic and heterogeneous structures that is able to encompass the heterogeneity of the existing AC models. Various AC models can be derived, and different static and dynamic AC policies can be generated using its components. We use Eclipse (xtext) to define the grammar of our AC metamodel. We illustrate our approach with several successful instantiations for various models and hybrid models. Additionally, we provide some examples to show how some of the derived models can be implemented to generate AC policies.

Simulation of a downhole jet-vortex pump’s working process

The article is devoted to the theoretical study of the operation process of the borehole ejection system as part of the tubing string, jet pump and packer installed below; the system implements the hydrojet method of oil well operation. The improved design of the jet pump contains inclined guiding elements placed in its receiving chamber for swirling the injected flow, which results in an increase in the efficiency of the borehole ejection system. Based on the law of conservation of liquid momentum in the mixing chamber of the jet pump and taking into account the inertial pressure component caused by the swirling of the injected flow, there is obtained the relative form of the equation of the ejection system pressure characteristic, the structure of which contains a component that determines the value of the additional dynamic head. According to the results obtained, the additional dynamic head caused by swirling of the injected flow is determined by the ratio of the geometric dimensions of the flow path of the jet pump, the angle of inclination of the elements for creating vortex flows, and the ratio of the power and reservoir fluids. In the case of asymmetric swirling of the injected flow, an increase in the value of the relative displacement of the jet pump decreases the value of the additional dynamic pressure. In order to study the effect of flow swirling on the energy characteristic of the ejection system, the pressure characteristic of the jet pump was transformed into the dependence of its efficiency on the injection coefficient. Jet pump models with the ratio of the cross-sectional areas of the mixing chamber and the nozzle of 5.012 and 6.464, respectively, were used to check the adequacy of the theoretical pressure and energy characteristics obtained during the simulation of the performance process of the concentric ejection system. The average error in the theoretical determination of the pressure and efficiency of the vortex jet does not exceed 8.65% and 6.48%, respectively.

Experimental study of the Effect of the Blades of Number on Characteristics Pico Bulb Turbine on Horizontal Flow

This study discusses the effect of the number of blades on a horizontal flow propeller turbine performance on a small scale experimentally. The development of small-scale water turbines has made many advances, including water turbines with the horizontal flow. Water turbines in horizontal flow can be applied to irrigation systems, piping systems, the wastewater treatment channel, and other closed channels. Pengukuran dynamic head pada aliran horisontal berdasarkan nilai pressure drop atau perbedaan tekanan sebelum dan sesudah turbin. Dynamic head measurement on the horizontal flow is based on pressure drop values or pressure before and after the turbine. Static bulbs placed before the turbine aim to increase the speed of water flow and potentially improve turbine performance. This study aims to determine the effect of the number of blades on the performance and efficiency of propeller turbines. The blade angle used is 200 with a bulb ratio of 0.6 to the pipe diameter. The variations in the number of blades used were 4, 5, 6, and 7, with each tested at 7 L / s, 9 L / s, 11 L / s, and 13 L / s. The results of this study indicate the number of blades 5 with a discharge of 13 L / s shows the best turbine performance compared to the number of other blades, besides that the number of blades 5 with a flow rate of 13 L / s shows the best efficiency value of around 40%.

Investigating age differences in the influence of joint attention on working memory: a preregistered online study.

Previous research has demonstrated that older adults make limited use of social cues as compared to younger adults. This has been investigated by testing the influence of gaze cues on attentional processes, with findings showing significantly smaller gaze cuing effects for older than younger adults. Here we aimed to investigate whether this would also result in age related differences in the influence of gaze cues on working memory. We therefore tested the effects of gaze cues from realistic human avatars on working memory across two experiments using dynamic head turns and more subtle eye gaze movements. Results demonstrated that for both older and younger adults, gaze cues influenced working memory processes, though there were some important differences related to the nature of the cue. Overall, we provide important evidence that sharing attention benefits cognition across the lifespan.

Regulation of Dishevelled DEP domain swapping by conserved phosphorylation sites

Wnt signals bind to Frizzled receptors to trigger canonical and noncanonical signaling responses that control cell fates during animal development and tissue homeostasis. All Wnt signals are relayed by the hub protein Dishevelled. During canonical (β-catenin–dependent) signaling, Dishevelled assembles signalosomes via dynamic head-to-tail polymerization of its Dishevelled and Axin (DIX) domain, which are cross-linked by its Dishevelled, Egl-10, and Pleckstrin (DEP) domain through a conformational switch from monomer to domain-swapped dimer. The domain-swapped conformation of DEP masks the site through which Dishevelled binds to Frizzled, implying that DEP domain swapping results in the detachment of Dishevelled from Frizzled. This would be incompatible with noncanonical Wnt signaling, which relies on long-term association between Dishevelled and Frizzled. It is therefore likely that DEP domain swapping is differentially regulated during canonical and noncanonical Wnt signaling. Here, we use NMR spectroscopy and cell-based assays to uncover intermolecular contacts in the DEP dimer that are essential for its stability and for Dishevelled function in relaying canonical Wnt signals. These contacts are mediated by an intrinsically structured sequence spanning a conserved phosphorylation site upstream of the DEP domain that serves to clamp down the swapped N-terminal α-helix onto the structural core of a reciprocal DEP molecule in the domain-swapped configuration. Mutations of this phosphorylation site and its cognate surface on the reciprocal DEP core attenuate DEP-dependent dimerization of Dishevelled and its canonical signaling activity in cells without impeding its binding to Frizzled. We propose that phosphorylation of this crucial residue could be employed to switch off canonical Wnt signaling.

Study on custom centrifugal pump performance in supplying food based high viscos liquid

Viscosity is one of the factors affecting the performance of the centrifugal pump. A centrifugal pump is a device that used driven motor called impeller to move fluid by rotational energy. This thesis is about the analysis of the performance of the centrifugal pump when transferring viscous liquids. For this project, the objective is to design and fabricate a device that can pump liquid with various viscosity using centrifugal pump. The liquids used in the experiment are comprised of a mixture of detergent and water with different ratio to alter the viscosity. The viscosity is being identified by the usage of Zahn Cup Method with the temperature kept constant at 26 °C throughout the experiment. The performance of the centrifugal pump is being investigated by four parameters which is the flowrate, Total Dynamic Head (TDH), power and efficiency. The performance of the centrifugal pump can be accessed by altering the pump shaft speed in order to get various reading for the flow rate. In order to alter the pump shaft speed, the usage of motor with Variable Frequency Drive (VFD) is implemented. The values for the flowrate and pump shaft power are measured by flowmeter and Variable Frequency Drive (VFD). The Total Dynamic Head (TDH), hydraulic power and pump efficiency is calculated based on the reading of the flowmeter and pump shaft power displayed at Variable Frequency Drive (VFD). At the end of this project, the pump performance while pumping different viscous liquids at different flowrates is being identified.