scholarly journals Evaluation and Utilization of Nano-Micron Polymer Plug for Heterogeneous Carbonate Reservoir with Thief Zones

2020 ◽  
Vol 2020 ◽  
pp. 1-7 ◽  
Author(s):  
Chenji Wei ◽  
Jie Zheng ◽  
Lihui Xiong ◽  
Zhengzhong Li ◽  
Jian Yang ◽  
...  
Keyword(s):  
Water Content ◽  
Flow Resistance ◽  
Polymer Concentration ◽  
Carbonate Reservoir ◽  
Water Flooding ◽  
High Concentration ◽  
Displacement Effect ◽  
Polymer Injection ◽  
Thief Zone ◽  
Good Agreement

Thief zones are highly permeable zones in oil reservoirs which affect the performance greatly during water flooding. The most effective way to prevent the invalid circle of thief layer is the injection of high-concentration polymer slugs. In this paper, the plugging effect of nano-micron polymer flooding on the thief zone is studied by experimental and theoretical analysis. The changes of water content and flow resistance were analyzed under different conditions. The result shows that the model presented here has good agreement with the experimental results. The displacement effect is the best when the thief zone is located on the upper part of the reservoir. And the water content will decrease with the increase of flow resistance after nano-micron polymer injection. Besides, the higher the polymer concentration, the more obvious the decrease of water content, and more effective the plugging. This study has provided a quick and reasonable guide in the later adjustment of water flooding development of carbonate reservoirs with thief layers.

Synthesis of High Concentration Cuprous Oxide Nanoparticles by Modified Polyol Process

2007 ◽  
Vol 124-126 ◽  
pp. 1185-1188 ◽  
Author(s):  
In Keun Shim ◽  
Young Il Lee ◽  
Kwi Jong Lee ◽  
Jae Woo Joung
Keyword(s):  
Cuprous Oxide ◽  
Polymer Concentration ◽  
Polyol Process ◽  
Oxide Nanoparticles ◽  
High Concentration ◽  
Cuprous Oxide Nanoparticles ◽  
Single Reaction

Cuprous oxide nanoparticles at high concentration (up to 0.3M) were successfully synthesized by modified polyol process. The redispersion stability could be controlled by optimizing various conditions like polymer concentration, temperature, reductant, and catalyst. Reductant and catalyst play a crucial rule in redispersion of cuprous nanoparticles. Under poor conditions, particles grow to larger sizes due to aggregation of nanoparticles. This modified polyol process allows monodispersed cuprous oxide to be obtained on gram scale in a single reaction and make possible a high synthetic yield of more than 80%.

scholarly journals Effects of Saline Solutions on the Desiccation Cracking and Shrinkage Behavior of Gaomiaozi Bentonite

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Long Tan ◽  
Penglin Zheng ◽  
Qingbing Liu
Keyword(s):  
Water Content ◽  
Saline Solution ◽  
Shrinkage Strain ◽  
Sample Surface ◽  
Water Evaporation ◽  
Gmz Bentonite ◽  
Residual Water ◽  
High Concentration ◽  
Desiccation Cracking ◽  
Saline Solutions

Bentonite, when used as buffer/backfill material in the deep disposal of high-level radioactive waste (HLW), could undergo desiccation shrinkage or even cracking due to the heat released from HLW, impairing the efficiency of the barrier system. Furthermore, in-service buffer materials are inevitably in contact with the groundwater, which sometimes contain high salt concentrations. The groundwater salinity may modify the properties of bentonite and hence affect the process of desiccation and its performance. To investigate this effect, in this study, a series of temperature-controlled desiccation tests was conducted on compacted specimens of Gaomiaozi (GMZ) bentonite preliminarily saturated with two different saline solutions (NaCl and CaCl2) at the concentration varying from 0.5 to 2.0 mol/L. The experimental results indicated that, as the concentration of saline solution increases, the initial saturated water content of bentonite decreases, whereas the residual water content at the completion of the desiccation test increases. The water evaporation rate is reduced for the specimens saturated with a high-concentration saline solution, and CaCl2 has a more significant influence on water evaporation than NaCl. The evolution of cracks on the sample surface during the desiccation process can be divided into four stages: crack growth, maintenance, closure, and stabilization; an increase in the salt concentration effectively inhibits crack development. It was shown that the infiltration of saline solutions alters the microstructure of bentonite by changing the arrangement of clay particles from a dispersed pattern to more aggregate state, which results in a decrease in shrinkage strain and shrinkage anisotropy.

Polymer Injection to Unlock Bypassed Oil in a Giant Carbonate Reservoir: Bridging the Gap Between Laboratory and Large Scale Polymer Project

2021 ◽  
Author(s):  
Clement Fabbri ◽  
Haitham Ali Al Saadi ◽  
Ke Wang ◽  
Flavien Maire ◽  
Carolina Romero ◽  
...  
Keyword(s):  
High Salinity ◽  
Water Injection ◽  
Cross Flow ◽  
Carbonate Reservoir ◽  
Carbonate Reservoirs ◽  
Laboratory Work ◽  
High Permeability ◽  
Polymer Injection ◽  
Single Well ◽  
Pilot Design

Abstract Polymer flooding has long been proposed to improve sweep efficiency in heterogeneous reservoirs where polymer enhances cross flow between layers and forces water into the low permeability layers, leading to more homogeneous saturation profile. Although this approach could unlock large volumes of by-passed oil in layered carbonate reservoirs, compatibility of polymer solutions with high salinity - high temperature carbonate reservoirs has been hindering polymer injection projects in such harsh conditions. The aim of this paper is to present the laboratory work, polymer injection field test results and pilot design aimed to unlock target tertiary oil recovery in a highly heterogeneous mixed to oil-wet giant carbonate reservoir. This paper focuses on a highly layered limestone reservoir with various levels of cyclicity in properties. This reservoir may be divided in two main bodies, i.e., an Upper zone and a Lower zone with permeability contrast of up to two orders of magnitude. The main part of the reservoir is currently under peripheral and mid-flank water injection. Field observations show that injected water tends to channel quickly through the Upper zone along the high permeability layers and bypass the oil in the Lower zone. Past studies have indicated that this water override phenomenon is caused by a combination of high permeability contrast and capillary forces which counteract gravity forces. In this setting, adequate polymer injection strategy to enhance cross-flow between these zones is investigated, building on laboratory and polymer injection test field results. A key prerequisite for defining such EOR development scenario is to have representative static and dynamic models that captures the geological heterogeneity of this kind of reservoirs. This is achieved by an improved and integrated reservoir characterization, modelling and water injection history matching procedure. The history matched model was used to investigate different polymer injection schemes and resulted in an optimum pilot design. The injection scheme is defined based on dynamic simulations to maximize value, building on results from single-well polymer injection test, laboratory work and on previous published work, which have demonstrated the potential of polymer flooding for this reservoir. Our study evidences the positive impact of polymer propagation at field scale, improving the water-front stability, which is a function of pressure gradient near producer wells. Sensitivities to the position and number of polymer injectors have been performed to identify the best injection configuration, depending on the existing water injection scheme and the operating constraints. The pilot design proposed builds on laboratory work and field monitoring data gathered during single-well polymer injection field test. Together, these elements represent building blocks to enable tertiary polymer recovery in giant heterogeneous carbonate reservoirs with high temperature - high salinity conditions.

scholarly journals Optimization of development mode of asphalt profile control based on numerical simulation and study of its mechanism

2020 ◽  
Vol 75 ◽  
pp. 30
Author(s):  
Fulin Wang ◽  
Tao Yang ◽  
Yunfei Zhao ◽  
Yanjun Fang ◽  
Fuli Wang ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Oil Recovery ◽  
Evaluation System ◽  
Injection Rate ◽  
Injection System ◽  
Injection Timing ◽  
High Concentration ◽  
Development Mode ◽  
Displacement Effect ◽  
Profile Control

Asphalt profile control is an effective method, which can further improve oil recovery of reservoir polymer flooded, it has a lot of advantages including high strength profile control, seal strata formation efficiency, low cost and no pollution, but there has not a perfect evaluation system for its development mode. The effect of different concentration, injection rate, radius of profile control, the timing of profile and segment combination way on the oil displacement effect of the asphalt profile control were researched using numerical simulation method on actual typical well area in Daqing oilfield, and the mechanism of asphalt profile control was studied in detail. According to the results of laboratory test, the largest Enhanced Oil Recovery (EOR) of asphalt was obtained at injection concentration 4000 mg/L, and the best combination was “high–low–high” concentration slug mode. According to the results of numerical simulation, the best concentration, injection rate, radius of profile control and injection timing were 4000 mg/L, 0.15 PV/a (Pore Volume [PV], m3), 1/2 of well spacing and 96% water cut in single slug of asphalt injection system, when the injection condition was multiple slug, the “high–low–high” slug combination mode was the best injection mode. These results could provide effective development basis for asphalt profile control after polymer flooding in thick oil layers.

Analysis of the Electron Traps at the 4H-SiC/SiO2 Interface of a Gate Oxide Obtained by Wet Oxidation of a Nitrogen Pre-Implanted Layer

2009 ◽  
Vol 615-617 ◽  
pp. 533-536
Author(s):  
Ioana Pintilie ◽  
Francesco Moscatelli ◽  
Roberta Nipoti ◽  
Antonella Poggi ◽  
Sandro Solmi ◽  
...  
Keyword(s):  
Low Frequency ◽  
Gate Oxide ◽  
High Accuracy ◽  
Interface Trap Density ◽  
Interface Trap ◽  
High Concentration ◽  
Mos Capacitors ◽  
Order Of Magnitude ◽  
Good Agreement

This work is focusing on the effect of a high concentration of nitrogen (N) introduced by ion implantation at the SiO2/4H-SiC interface in MOS capacitors. The N implanted sample (Ninterface ~1x1019cm-3) is compared with a non-implanted one (Ninterface ~1x1016cm-3) by means of the electron interface trap density (Dit). The Dit is determined via High-Low frequency C-V method and Thermal Dielectric Relaxation Current (TDRC) technique. It is shown that the TDRC method, mainly used so far for determination of near interface oxide charges, can be exploited to gain information about the Dit too. The determined value of Dit in the N-implanted sample is nearly one order of magnitude lower than that in the sample without N implantation. Good agreement between the TDRC results and those obtained from High-Low frequency C-V measurements is obtained. Furthermore, the TDRC method shows a high accuracy and resolution of Dit evaluation in the region close to the majority carrier band edge and gives information about the traps located into the oxide.

Comparison of Turbulent Boundary Layer Profiles Modified With Injection or Uniform Concentration of Drag-Reducing Polymer Solution

2020 ◽  
Author(s):  
Brian R. Elbing
Keyword(s):  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
Drag Reduction ◽  
Polymer Concentration ◽  
Weissenberg Number ◽  
Polymer Injection ◽  
Von Karman ◽  
Polymer Properties ◽  
Polymer Drag Reduction ◽  
Von Kármán

Abstract The current study explores the influence of polymer drag reduction on the near-wall velocity distribution in a turbulent boundary layer. The classical view is that the polymers modify the intercept constant within the log-region without impacting the von Kármán coefficient, which results in the log-region being unaltered though shifted outward from the wall. However, it has been recently shown that this is not accurate, especially at high drag reduction (> 40%). Past work examining the von Kármán coefficient and intercept constant has shown that polymer properties must impact the deviations, but without any quantification of the dependence. This work reviews the literature to make estimates of the local polymer properties and then demonstrates that the scatter at HDR can be attributed to variations in the Weissenberg number. In addition, new polymer ocean results are incorporated and shown to be quite consistent with polymer injection results using the maximum polymer concentration to define the polymer properties.

New automated dye-binding method for serum albumin determination with bromcresol purple.

1978 ◽  
Vol 24 (1) ◽  
pp. 80-86 ◽  
Author(s):  
A E Pinnell ◽  
B E Northam
Keyword(s):  
Serum Albumin ◽  
Albumin Concentration ◽  
High Concentration ◽  
Serum Globulin ◽  
The Poor ◽  
Dye Binding ◽  
Free Serum ◽  
Very High ◽  
Continuous Flow Method ◽  
Good Agreement

Abstract We describe a new automated dye-binding method for serum albumin determination with bromcresol purple (BCP) that has several advantages over an existing bromcresol green (BCG) method. The continuous-flow method is sensitive, linear, and precise, with negligible sample interaction at an analytical rate of 60 samples per hour. Unlike BCG, BCP did not react with an albumin-free serum globulin preparation or pure human transferrin solutions. Reaction with serum was instantaneous; in contrast, BCG exhibits a slow nonspecific reaction with some specimens. The specificity of BCP was demonstrated by good agreement with results of "rocket" immunoelectrophoresis (EIA) where y(BCP) = 0.95X(EIA) + 1.72. The BCG method overestimated serum albumin concentration where y(BCG) = 1.01X(EIA) + 6.77. Precipitation, which affects the BCG method, was not observed with BCP. Blank corrections were negligible, salicylate did not interfere, and bilirubin affected the method only if present in very high concentration. The method offers a solution to the poor accuracy of existing BCG methods while retaining many of their desirable features.

scholarly journals FLOW DYNAMICS OF WAVES PROPAGATING OVER DIFFERENT PERMEABLE BEDS

2017 ◽  
pp. 35
Author(s):  
Sara Corvaro ◽  
Alessandro Mancinelli ◽  
Maurizio Brocchini
Keyword(s):  
Shear Stress ◽  
Flow Resistance ◽  
Single Layer ◽  
Coastal Engineering ◽  
Flow Dynamics ◽  
Bottom Shear Stress ◽  
Natural Stones ◽  
Wave Height Attenuation ◽  
Rough Beds ◽  
Good Agreement

The analysis of the hydrodynamics over porous media is of interest for many coastal engineering applications as the wave propagation over permeable structures or gravel beaches. The study of a boundary layer evolving over permeable beds is important to a better understanding of the interactions between the flow over and inside the porous medium. An experimental study has been performed to analyze the dynamics produced when waves propagate over two kinds of permeable beds: spheres (regular permeability) and natural stones. For comparative purposes the same analysis has been extended to two rough beds made, respectively, by a single layer of spheres and natural stones. We here focus on the correlation between the wave energy reduction induced by a porous bed and the flow resistance. An experimental law for the prediction of the friction factor is found by using the log-fit method in analogy to that reported in Dixen et al. (2008) for rough beds. Moreover, inspection of the turbulent velocity components allows one to evaluate the bottom shear stress. The latter analysis has been performed for different permeable beds (regular and irregular beds). A good agreement between the bottom shear stress behavior and the wave height attenuation over rough and permeable beds (Corvaro et al. 2010 and Corvaro et al. 2014a) has been observed.

3-D Visual Experiments on Fluid Flow Behavior of Water Flooding and Gas Flooding in Fractured-Vuggy Carbonate Reservoir

2017 ◽  
Author(s):  
Ming Qu ◽  
Jirui Hou ◽  
Fenglan Zhao ◽  
Zhaojie Song ◽  
Shixi Ma ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Flow Behavior ◽  
Carbonate Reservoir ◽  
Water Flooding ◽  
Gas Flooding

The Parametric Modeling of Local Resistance and Pressure Drop in a Rotary Ball Valve

2017 ◽  
Vol 140 (3) ◽  
Author(s):  
Dan Wang ◽  
Changqing Bai
Keyword(s):  
Pressure Drop ◽  
Flow Resistance ◽  
Analytical Formula ◽  
Resistance Coefficient ◽  
Parametric Modeling ◽  
Equivalent Model ◽  
Local Resistance ◽  
Operating Process ◽  
Valve Opening ◽  
Good Agreement

In this paper, a theoretical study of ball valves is carried out for investigating the local resistance and pressure drop of ball valves in operating process. An equivalent model of ball valves is proposed based on the inherent mechanism of the resistance loss, which can be divided into three equivalent throttling components: a thick orifice, two variable-opening eccentric orifice plates, and a Z type elbow. Through analysis of the flow resistance of the three components, a general parametric modeling of ball valves is presented for the flow resistance analysis, and then an analytical formula of pressure drop is demonstrated. The results obtained from the presented model are compared with the prior test data to validate this model, and good agreement is observed. Indicate that the presented model has high accuracy in predicting the resistance and pressure loss in various openings. The results show that the influences of thin orifice plates play an important role in the total flow resistance coefficient and pressure drop, especially in the small opening. The effects of thick orifice plates and the Z type elbow gradually increased as the valve opening rises and becomes significant when the opening is more than 70%.

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