The Development of a Pressure Actuated Isolation Nozzle Assembly and its Application as Flow Control Device in Extended Reach Water-Alternating-Gas Pilot Wells

The re-development of a giant offshore field in the United Arab Emirates (UAE) consists predominantly of four artificial islands requiring in most cases extremely long horizontal laterals to reach the reservoir targets. Earlier SPE technical papers (1,2) have introduced the development, testing, qualification, and deployment of the plugged liner technology using the dissolvable plugged nozzles (DPNs). The use of DPN plugged liner technology has resulted in CAPEX savings and enhanced production performance. The benefits of DPN technology are its simplicity along with its cost effectiveness. However, the dissolvable material has some limitations, such as pressure rating and dissolution time, which are fluid chemistry dependent. To overcome these limits, a new Pressure Actuated Isolation Nozzle Assembly (PAINA) was developed as an alternative to the plugged liner tool for applications where a higher pressure rating is required, as well as on demand opening. Furthermore, the new PAINA also functions as a flow control device during injection and production, enhancing acid jetting effects during bullhead stimulation and reducing brine losses during liner installation. Liners with PAINAs can be run to TD similar to blank pipe: fluids can be circulated through the inside of the liner without the need for a wash pipe. Once on bottom, non-aqueous drilling fluid is displaced to brine without actuating the isolation mechanism. When the well is ready for production or injection, pressure is applied and the isolation mechanism is activated to establish communication between well and reservoir. These tools were successfully run as flow control devices in water-alternating-gas (WAG) pilot wells. The planning and execution of the initial application will be discussed, along with the tool development, qualification testing, and lessons learned. The key advantage of this technology is in extending plugged liner applications to cases where other pressure-operated tools are included as part of the liner lower completion. Pressure can be applied to the well multiple times without activating the isolation mechanism as long as the applied pressure is below the actuation pressure.

A Dual-Directional Flow Control Device for Cyclic Steam Stimulation Applications

Summary Cyclic steam stimulation (CSS) is one the most effective thermal recovery methods. It is widely used as the primary thermal recovery method to recover heavy oil fields in the Middle East, the Asia-Pacific region, and North and South America. In this paper, a novel dual-directional flow control device (FCD) will be introduced. This FCD technology can allocate accurate steam outflow into the reservoir formation and improve steam quality during the steam injection period and can mitigate steam breakthrough from the neighboring wells during the production period. In the first section, we give a brief introduction on CSS and the main issues encountered in the field operation. A multidirectional flow control nozzle specifically designed for CSS application will be presented. Design philosophy in thermodynamics and hydrodynamics of the nozzle will be discussed in detail. Field performance results, computational fluid dynamics (CFD), and flow loop testing data will be shown to evaluate the performance of the technology. The application of the technology in steam-assisted thermal applications will be introduced. Well-known issues such as erosion and scaling on the FCD tools will be studied in the end.

CNN-Based Flow Control Device Modelling On Aerodynamic Airfoils

Wind energy has become an important source of electricity generation, with the aim of achieving a cleaner and more sustainable energy model. However, wind turbine performance improvement is required to compete with conventional energy resources. To achieve this improvement, flow control devices are implemented on airfoils. Computational Fluid Dynamics (CFD) simulations are the most popular method for analyzing this kind of devices, but in recent years, with the growth of Artificial Intelligence, predicting flow characteristics using neural networks is becoming increasingly popular. In this work, 158 different CFD simulations of a DU91W(2)250 airfoil are conducted, with two different flow control devices, rotating microtabs and Gurney flaps, added on its Trailing Edge (TE). These flow control devices are implemented by using the cell-set meshing technique. These simulations are used to train and test a Convolutional Neural Network (CNN) for velocity and pressure field prediction and another CNN for aerodynamic coefficient prediction. The results show that the proposed CNN for field prediction is able to accurately predict the main characteristics of the flow around the flow control device, showing very slight errors. Regarding the aerodynamic coefficients, the proposed CNN is also capable to predict them reliably, being able to properly predict both the trend and the values. In comparison with CFD simulations, the use of the CNNs reduces the computational time in four orders of magnitude.

Heat and mass transfer in a metal hydride reactor: combining experiments and mathematical modelling

Heat transfer in porous metal hydride (MH) beds determines efficiency of MH devices. We present a COMSOL Multiphysics numerical model and experimental investigation of heat and mass transfer in a MH reactor filled with 4.69 kg of AB5 type alloy (Mm0.8La0.2Ni4.1Fe0.8Al0.1). To achieve an agreement between the model and experiments it is necessary to include a flow control device (inlet valve or flow regulator) into the model. We propose a simplified and easy-to-calculate boundary condition based on a porous domain with variable permeability at reactor inlet. The permeability of the domain is connected with hydrogen mass flow by a PID controller. Thus, boundary conditions for the inlet pressure and mass flow are coupled and heat transfer inside the reactor could be calculated without additional assumptions applied to heat and mass transfer in the MH bed.

A Dual-Directional Flow Control Device for Cyclic Steam Stimulation CSS Applications

Cyclic steam stimulation (CSS) is one the most effective thermal recovery methods. It is widely used as the primary thermal recovery method to recovery heavy oil fields in Middle East, Asia Pacific, North and South America. In this paper, a novel dual-directional flow control device (FCD) will be introduced. This FCD technology can allocate accurate steam outflow into the reservoir formation and improve steam quality during steam injection period and can mitigate steam breakthrough from the neighboring wells during production period. In the first section, we will give a brief introduction on CSS and the main issues encountered in the field operation. A multi-directional flow control nozzle specifically designed for CSS application will be presented. Design philosophy in thermodynamics and hydrodynamics of the nozzle will be discussed in detail. Field performance results, Computational Fluid Dynamics (CFD) and flow loop testing data will be shown to evaluate the performance of the technology. The application of the technology in steam assisted thermal applications will be introduced. Well-known issues such as erosion and scaling on the FCD tools will be studied in the end.

Design, Development, and Characterization of a Flow Control Device for Dynamic Cooling of Liquid-Cooled Servers

Transistor density trends till recently have been following Moore's law, doubling every generation resulting in increased power density. The computational performance gains with the breakdown of Moore's law were achieved by using multi-core processors, leading to non-uniform power distribution and localized high temperatures making thermal management even more challenging. Cold plate-based liquid cooling has proven to be one of the most efficient technologies in overcoming these thermal management issues. Traditional liquid-cooled data center deployments provide a constant flow rate to servers irrespective of the workload, leading to excessive consumption of coolant pumping power. Therefore, a further enhancement in the efficiency of implementation of liquid cooling in data centers is possible. The present investigation proposes the implementation of dynamic cooling using an active flow control device to regulate the coolant flow rates at the server level. This device can aid in pumping power savings by controlling the flow rates based on server utilization. The FCD design contains a V-cut ball valve connected to a micro servo motor used for varying the device valve angle. The valve position was varied to change the flow rate through the valve by servo motor actuation based on pre-decided rotational angles. The device operation was characterized by quantifying the flow rates and pressure drop across the device by changing the valve position using both CFD and experiments. The proposed FCD was able to vary the flow rate between 0.09 lpm to 4 lpm at different valve positions.

Rotating Microtab Implementation on a DU91W250 Airfoil Based on the Cell-Set Model

Flow control device modeling is an engaging research field for wind turbine optimization, since in recent years wind turbines have grown in proportions and weight. The purpose of the present work was to study the performance and effects generated by a rotating microtab (MT) implemented on the trailing edge of a DU91W250 airfoil through the novel cell-set (CS) model for the first time via CFD techniques. The CS method is based on the reutilization of an already calculated mesh for the addition of new geometries on it. To accomplish that objective, the required region is split from the main domain, and new boundaries are assigned to the mentioned construction. Three different MT lengths were considered: h = 1%, 1.5% and 2% of the airfoil chord length, as well as seven MT orientations (β): from 0° to −90° regarding the horizontal axis, for five angles of attack: 0°, 2°, 4°, 6° and 9°. The numerical results showed that the increases of the β rotating angle and the MT length (h) led to higher aerodynamic performance of the airfoil, CL/CD = 164.10 being the maximum ratio obtained. All the performance curves showed an asymptotic trend as the β angle reduced. Qualitatively, the model behaved as expected, proving the relationship between velocity and pressure. Taking into consideration resulting data, the cell-set method is appropriate for computational testing of trailing edge rotating microtab geometry.

Investigation of a Passive Flow Control Device in an S-Duct Inlet at High Subsonic Flow

This paper reports the investigation of a flow control strategy for an S-duct diffusers. The method incorporates stream-wise tubercles, and aims to enhance the performance of S-duct inlets by reducing the size and intensity of separated flow. These devices, bioinspired from humpback whale flippers’ leading edge protuberances, have been shown to be effective in increasing post-stall coefficients of lift of airfoils. In S-duct diffusers, the presence of convex curvature next to the separated region provides an ideal location for the installation of a tubercle-like device. The flow control effectiveness was evaluated by test-rig measurements and computational fluid dynamics (CFD) simulations of the flow in an S-duct at high subsonic flow conditions (Ma = 0.80). The S-ducts were rapid prototyped in plastic using 3D printing. Static surface pressure along the length and total pressure at the exit revealed pressure recovery, total pressure loss, swirl, and the nature of flow distortion at the S-duct exit. CFD simulations used ANSYS FLUENT with a RANS solver closed with the RKE turbulence model. The CFD simulation compared well with the test-rig data and provided useful information on flow mechanism and for understanding flow features. The performance of the baseline and variant with the flow control device was compared and flow control strategy was evaluated.