Measurement of Thermoelectric Potential Coupling Coefficient for Sandstone Rock Sample

2016 ◽  
Vol 819 ◽  
pp. 83-87
Author(s):  
Mohd Zaidi bin Jaafar ◽  
Abdul Razak Ismail ◽  
Mohamad Kamil bin Saharuddin ◽  
Siti Mardhiah binti Mohd Anuar ◽  
Siti Rahmah bte Suradi ◽  
...  
Keyword(s):  
Temperature Difference ◽  
Coupling Coefficient ◽  
Rock Sample ◽  
Water Injection ◽  
Control Valve ◽  
Water Production ◽  
Coupling Coefficients ◽  
Voltage Versus ◽  
Sandstone Rock ◽  
Excessive Water

Excessive water production is one of the main problems that occur during hydrocarbon production. During water injection, the less viscous water which has higher mobility than the reservoir fluid, tends to by-pass the oil. This phenomenon is normally called water fingering. Density difference between denser water and oil makes the water segregate to the bottom of layer, creating water tongue. Uncontrolled excessive water production will reduce oil production potential and increase the cost for water management and treatment. This phenomenon is economical unfavorable. Intelligent well integrated with monitoring systems and inflow control valve (ICV) has been applied in producing hydrocarbon. The excessive flow of water into well can be controlled using ICV. There are various methods and approaches been proposed to control water production. One of them is by measuring the spontaneous potential (SP) using permanent sensor outside the insulated casing. However, thermoelectric (TE) potential could also contribute to the measurement of the SP. The main objective of this experiment is to measure TE potential across sandstone rock sample at four different salinities which are 0.001M, 0.01M, 0.1M, and 1.0M of brine (NaCl). The core samples dimension is 7.62 cm in length and 3.81 cm in diameter. Temperature difference up to 80°C was applied to rock sample inducing different TE potentials at different salinities. Gradual heating technique was applied in creating temperature difference by using a temperature controller. Three different experiments were conducted for each salinity and real-time voltage (V) and temperature (T) were recorded using data acquisition system. Then the TE coupling coefficient can be determined by calculating the slope after plotting Voltage versus Temperature Difference. The result is as the salinity increases, TE coupling coefficient decrease and drop to zero around 0.1M. The result shows small but still measurable thermoelectric coupling coefficients.

New method of controlling excessive water production in wells using induced formation damage

2015 ◽  
Vol 55 (2) ◽  
pp. 485
Author(s):  
Abbas Zeinijahromi ◽  
Pavel Bedrikovetski
Keyword(s):  
Fresh Water ◽  
Large Scale ◽  
Produced Water ◽  
Water Injection ◽  
Cost Effective ◽  
Formation Damage ◽  
Water Production ◽  
Permeable Barrier ◽  
Water Influx ◽  
Excessive Water

Excessive water production is a major factor in reduced well productivity. This can result from water channelling from the water table to the well through natural fractures or faults, water breakthrough in high permeability zones, or water coning. The use of foams or gels for controlling water production through high-permeable layers has been tested successfully in several field cases. A large treatment volume, however, is required to block the water influx that generally involves high operational and material costs. This extended abstract proposes a new cost-effective method of creating a low-permeable barrier against the produced water with induced formation damage. The method includes applying induced formation damage to block the water influx without hindering the oil production. This can be achieved by injection of a small slug of fresh water into the water-producing layer. This results in release of in situ fines from the matrix, which can decrease permeability and create a local low-permeable barrier to the producing water. In large-scale approximation, water injection with induced fines migration is analogous to polymer flooding. This analogy is used to model the fresh water with induced formation damage. Sensitivity studies showed that the injection of 0.01 PVI of fresh water resulted in the blockage of the water-producing layer and an incremental recovery by 8% in field case A, with respect to the standard production scenario. The authors found that the incremental gas recovery with induced formation damage was sensitive to reservoir heterogeneity, permeability reduction and slug volume.

Modeling the Atmospheric Boundary Layer Wind Response to Mesoscale Sea Surface Temperature Perturbations

2014 ◽  
Vol 142 (11) ◽  
pp. 4284-4307 ◽  
Author(s):  
Natalie Perlin ◽  
Simon P. de Szoeke ◽  
Dudley B. Chelton ◽  
Roger M. Samelson ◽  
Eric D. Skyllingstad ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Wind Speed ◽  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Coupling Coefficient ◽  
Eddy Viscosity ◽  
Sea Surface ◽  
Coupling Coefficients ◽  
Wind Response ◽  
Speed Response

Abstract The wind speed response to mesoscale SST variability is investigated over the Agulhas Return Current region of the Southern Ocean using the Weather Research and Forecasting (WRF) Model and the U.S. Navy Coupled Ocean–Atmosphere Mesoscale Prediction System (COAMPS) atmospheric model. The SST-induced wind response is assessed from eight simulations with different subgrid-scale vertical mixing parameterizations, validated using Quick Scatterometer (QuikSCAT) winds and satellite-based sea surface temperature (SST) observations on 0.25° grids. The satellite data produce a coupling coefficient of sU = 0.42 m s−1 °C−1 for wind to mesoscale SST perturbations. The eight model configurations produce coupling coefficients varying from 0.31 to 0.56 m s−1 °C−1. Most closely matching QuikSCAT are a WRF simulation with the Grenier–Bretherton–McCaa (GBM) boundary layer mixing scheme (sU = 0.40 m s−1 °C−1), and a COAMPS simulation with a form of Mellor–Yamada parameterization (sU = 0.38 m s−1 °C−1). Model rankings based on coupling coefficients for wind stress, or for curl and divergence of vector winds and wind stress, are similar to that based on sU. In all simulations, the atmospheric potential temperature response to local SST variations decreases gradually with height throughout the boundary layer (0–1.5 km). In contrast, the wind speed response to local SST perturbations decreases rapidly with height to near zero at 150–300 m. The simulated wind speed coupling coefficient is found to correlate well with the height-averaged turbulent eddy viscosity coefficient. The details of the vertical structure of the eddy viscosity depend on both the absolute magnitude of local SST perturbations, and the orientation of the surface wind to the SST gradient.

scholarly journals Differential Bi-Level Microstrip Directional Coupler with Equalized Coupling Coefficients for Directivity Improvement

Electronics ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 547
Author(s):  
Slawomir Gruszczynski ◽  
Robert Smolarz ◽  
Krzysztof Wincza
Keyword(s):  
Coupling Coefficient ◽  
Dielectric Layer ◽  
Directional Coupler ◽  
Capacitive Coupling ◽  
Coupling Coefficients ◽  
Coupled Line ◽  
Line Section ◽  
Measurement Results

In this paper, a bi-level microstrip differential directional coupler has been investigated. It has been shown that the equalization of coupling coefficients can be successfully made with the use of appropriate dielectric stack-up and conductor geometry. The application of additional top dielectric layer can ensure proper equalization of coupling coefficients by lowering the value of capacitive coupling coefficient to the value of the inductive one. The theoretically investigated coupled-line section has been used for the design of a 3-dB differential directional coupler. The measurement results are compared with the theoretical ones.

Gas Liquid Separation Using a GLCC in a Sodium Bicarbonate Solution Mining Operation

2001 ◽  
Author(s):  
Robbie M. Lansangan ◽  
Mike Huffman
Keyword(s):  
Liquid Phase ◽  
Sodium Bicarbonate ◽  
Water Injection ◽  
Sodium Bicarbonate Solution ◽  
Field Tests ◽  
Control Valve ◽  
Mining Operation ◽  
Liquid Density ◽  
Field Development ◽  
Solution Mining

Abstract Nahcolite is a naturally occurring sodium bicarbonate mineral found in subsurface formations. American Soda LLP conducted field tests to prove that nahcolite can be deep mined using low-cost conventional solution mining method. The process involved the injection of hot, high pressure water down wells into a nahcolite deposit about 2,600 feet below the surface where the mineral is dissolved and brought to the surface for recovery. The monitoring and optimization of recovery efficiency based on scores of upstream process parameters, such as water injection rate, required the monitoring of produced liquid density. This was done initially with a mass meter located immediately downstream of the well head. Co-production of small amounts of gas, mainly methane and carbon dioxide, entrained in the liquid phase prevented the accurate measurement of the solution density using a Coriolis meter technology. Premier Instruments provided a remedy with a gas liquid cylindrical cyclone (GLCC© 1) separator properly sized and engineered for the process requirements. A gas control valve with liquid level feedback was used to eliminate the entrained gas in the liquid phase. This strategy proved to be functional which allowed American Soda to proceed with the field development. Today, 26 production wells employ the GLCC separator at each production well.

Microstructure and Electrical Properties of Lead-Free (Na0.5K0.5)NbO3 - Bi0.5(Na0.97K0.03)0.5TiO3 Ceramics

2013 ◽  
Vol 368-370 ◽  
pp. 760-763
Author(s):  
Chun Huy Wang ◽  
Ming Qiu Wei
Keyword(s):  
Electrical Properties ◽  
Coupling Coefficient ◽  
Electromechanical Coupling ◽  
Piezoelectric Properties ◽  
Coupling Coefficients ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dense Microstructure ◽  
Dielectric And Piezoelectric Properties ◽  
Thickness Mode

(Na0.5K0.5)NbO3 with Bi0.5(Na0.97K0.03)0.5TiO3 with x≤0.05 has been prepared by the conventional mixed oxide process. X-ray diffraction analysis revealed that, during sintering, all the Bi(Na0.97K0.03)TiO3 diffuses into the lattice of (Na0.5K0.5)NbO3 to form a solid solution with a perovskite structure. A morphotropic phase boundary (MPB) between orthorhombic (O) and rhombohedral (R) was found at the composition 0.98(Na0.5K0.5)NbO3-0.02Bi0.5(Na0.97K0.03)0.5TiO3 [abbreviated as 0.98NKN-0.02BNKT] with correspondingly enhanced dielectric and piezoelectric properties. For 0.98NKN-0.02BNKT ceramics, the electromechanical coupling coefficients of the planar mode kp and the thickness mode kt reach 0.33 and 0.49, respectively, after sintering at 1100 oC for 3 h. The ratio of the thickness coupling coefficient to the planar coupling coefficient is 1.48. With suitable Bi0.5(Na0.97K0.03)0.5TiO3 concentration, a dense microstructure and good electrical properties are obtained.

Investigation of Steam Desuperheater Waterhammer

2004 ◽  
Author(s):  
Gregory Zysk
Keyword(s):  
Analytical Methods ◽  
Distribution Network ◽  
Water Injection ◽  
Root Cause ◽  
Water Interaction ◽  
Design Changes ◽  
High Level ◽  
Steam System ◽  
Excessive Water

Steam supplied to an underground piping distribution network from a fossil fired boiler is desuperheated using water injection valves. Waterhammers occurred in the system, failing a valve on two separate occasions. Operations personnel also experience excessive high-level alarms at drain stations local to the valves. An investigation was conducted to determine the root cause of the valve failures and the cause of the excessive water in the steam system. Mitigating design changes were also proposed to solve these problems. Available analytical methods were shown to be effective in predicting waterhammer occurrence and magnitude. These methods can be used to evaluate the potential for waterhammer in similar systems with potential steam/water interaction.

Effect of Bi2O3 Addition on the Electrical and Physical Properties of Lead-Free 0.98(Na0.5K0.5)NbO3-0.02 Ba(Zr0.04Ti0.96)O3 Piezoelectric Ceramics

2010 ◽  
Vol 434-435 ◽  
pp. 413-416 ◽  
Author(s):  
Chun Huy Wang
Keyword(s):  
Coupling Coefficient ◽  
Electromechanical Coupling ◽  
Orthorhombic Phase ◽  
Lead Free ◽  
Coupling Coefficients ◽  
X Ray Diffraction ◽  
Sintering Aid ◽  
X Ray ◽  
Thickness Mode ◽  
Planar Mode

The 0.98(Na0.5K0.5)NbO3–0.02Ba(Zr0.04Ti0.96)O3 ceramics have been prepared following the conventional mixed oxide process. X-ray diffraction analysis revealed that, during sintering, all of the Ba(Zr0.04Ti0.96)O3 diffuses into the lattice of (Na0.5K0.5)NbO3 to form a solid solution, in which a orthorhombic phase with a perovskite structure was found In order to improve the sinterability of the ceramics, Bi2O3 additions were used as a sintering aid. The electromechanical coupling coefficients of the planar mode kp and the thickness mode kt reach 0.3 and 0.55, respectively, at the sintering of 1100oC for 5 h. For 0.98NKN-0.02BZT ceramics by doping 0.5 wt.% Bi2O3, the electromechanical coupling coefficients of the planar mode kp and the thickness mode kt reach 0.21 and 0.57, respectively. The ratio of thickness coupling coefficient to planar coupling coefficient is 2.7.

scholarly journals Polymer flooding – Does Microscopic Displacement Efficiency Matter?

2018 ◽  
Vol 16 (2) ◽  
pp. 83-89 ◽  
Author(s):  
Guangyuan Sun ◽  
Bernd Crouse ◽  
David M. Freed ◽  
Rui Xu ◽  
Juan Bautista ◽  
...  
Keyword(s):  
Rock Sample ◽  
Polymer Flooding ◽  
Phase Flow ◽  
Pore Scale ◽  
Displacement Efficiency ◽  
Sweep Efficiency ◽  
Sandstone Rock ◽  
Polymer Flood ◽  
Wet Condition ◽  
The Impact

Polymer flooding is an enhanced oil recovery (EOR) technique that aims to enhance the stability of the flood front in order to increase sweep efficiency and thereby increase hydrocarbon recovery. Polymer flooding studies often focus on large-scale sweep efficiency and neglect the impact of the pore-scale displacement efficiency of the multi-phase flow. This work explores the pore-scale behavior of water vs polymer flooding, and examines the impact of rock surface wettability on the microscopic displacement efficiency using digital rock physics. In this study, a micro-CT image of a sandstone rock sample was numerically simulated for both water and polymer flooding under oil-wet and water-wet conditions. All simulations were performed at a capillary number of 1E-5, corresponding to a capillary dominated flow regime. Results of the four two-phase flow imbibition simulations are analyzed with respect to displacement character, water phase break-through, viscous/capillary fingering, and trapped oil. In the water-wet scenario, differences between water flood and polymer flood are small, with the flood front giving a piston-like displacement and breakthrough occurring at about 0.4 pore volume (PV) for both types of injected fluid. On the other hand, for the oil-wet scenario, water flood and polymer flood show significant differences. In the water flood, fingering occurs and much of the oil is bypassed early on, whereas the polymer flood displaces more oil and thereby provides better microscopic sweep efficiency throughout the flood and especially around breakthrough. Overall the results for this rock sample indicate that water flood and polymer flood provide similar recovery for a water-wet condition, while the reduced mobility ratio of polymer flood gives significantly improved recovery for an oil-wet condition by avoiding the onset of microscopic (pore-scale) fingering that occurs in the water flood. This study suggests that depending on the rock-fluid conditions, the use of polymer can impact microscopic sweep efficiency, in addition to the well-known effect on macroscopic sweep behavior

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