scholarly journals Experimental Investigation of the Matching Relationship between Asphalt Particle and Reservoir Pore in Profile Control Process

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Chengfeng Ren ◽  
Junjian Li ◽  
Yiqiang Li ◽  
Jingshu Yuan ◽  
Yanqiang Xi ◽  
...  
Keyword(s):  
Low Cost ◽  
Water Injection ◽  
Control Process ◽  
Resistance Coefficient ◽  
Control Effect ◽  
Migration Ability ◽  
Reservoir Permeability ◽  
Profile Control ◽  
Alternative Water ◽  
Relative Change

Modified sulfonated asphalt particles have a bright application prospect of the profile control of thick reservoirs due to the low cost, extensive sources, and good compatibility with reservoir. Nevertheless, the matching relationship between asphalt particles and reservoir pore has seldom been investigated till now. Oversized particles always block the near-wellbore area, which causes high injection pressures, while undersized particles cannot plug large pores. We designed a core for this experiment which has a high permeability zone in front of it and many pressure measuring points. We could quantitatively assess the matching relationship by measuring the on-way resistance coefficient, residual resistance factor, and relative change of permeability of man-made cores after injecting asphalt. Experimental results indicate that asphalt particles with sizes of 0.02 mm, 0.02–0.06 mm, and 0.08–0.1 mm match with reservoir permeability of 500 mD, 1000 mD, and 2000 mD, respectively. Undersized or oversized particles can reduce the conformance control effect, and the concentration of asphalt particles in the injectant can limit their migration ability. When the concentration of asphalt particles increases to 3000 mg/L, accumulations of asphalt particles can be caused in the formation, in which a scheme with asphalt particles alternative water injection is proposed to avoid the accumulation.

A Practical Model for Water Injection Evaluation and Optimization in Typical Offshore Reservoirs Considering Formation Heterogeneity Based on Experimental Study

2021 ◽  
Author(s):  
Shijun Huang ◽  
Yuanrui Zhu ◽  
Shichao Chai ◽  
Guanyang Ding ◽  
Yicheng Xin ◽  
...  
Keyword(s):  
Horizontal Well ◽  
Superposition Principle ◽  
Water Injection ◽  
Injection Rate ◽  
Rate Curve ◽  
Control Effect ◽  
Injection Efficiency ◽  
Profile Control ◽  
Horizontal Wellbore ◽  
Heterogeneous Formation

Abstract A major concern with water injection in offshore oil reservoir is the water breakthrough. The formation heterogeneity is the main reason for it. In order to evaluate the water injection efficiency, a visualized 2-D experiment was carried out to obtain the distribution law of injected water and the variation of injection parameters in homogeneous and heterogeneous formation. In addition, a coupled wellbore/reservoir model was established by applying microelement method, superposition principle and imaging. This model considers the formation heterogeneity and pressure drop caused by wellbore friction. The visualized 2-D sand filling displacement experiment indicates that the injection rate at the horizontal well heel is greater than that at the toe and the injection front is more irregular in heterogeneous formation. The injection rate and injection pressure distribution along the horizontal well are obtained analytically based on the proposed model, the results show that the injection rate at the two sides of the wellbore is much higher than that in the middle when the formation is homogeneous and the wellbore is infinite-conductive. In this case, the injection rate curve along horizontal well shows a "U" shaped distribution. When a finite-conductive horizontal wellbore is considered, the injection rate at the heel of the wellbore is higher than that of the toe, although the injection rate curve along horizontal well also exhibits a deformed "U" shape distribution. For the formation heterogeneities along the horizontal wellbore, the injection rate distribution curve is not continuous anymore, but a deformed "U" shape is also observed for each wellbore segment. At last, the established model was applied to an ultra-heterogeneous offshore reservoir. It is concluded that the profile control effect of typical well is obvious. The results of this study are of great significance for the calculation of the injection rate profile and improving the water injection efficiency.

DEPOSITION OF SINGLE-PHASE CuInSe2 THIN FILMS UNDER LOW VACUUM LEVEL BY A TWO-STAGE GROWTH TECHNIQUE

2009 ◽  
Vol 16 (03) ◽  
pp. 381-386 ◽  
Author(s):  
J. B. CHU ◽  
H. B. ZHU ◽  
Z. A. WANG ◽  
Z. Q. BIAN ◽  
Z. SUN ◽  
...  
Keyword(s):  
Solar Cells ◽  
Single Phase ◽  
Low Cost ◽  
Control Process ◽  
Rf Magnetron Sputtering ◽  
Chalcopyrite Structure ◽  
Sputtering Deposition ◽  
Vacuum Level ◽  
X Ray ◽  
High Efficient

Single-phase CuInSe 2 films were grown by high vapor selenization of CuIn alloy precursors within a partially closed graphite box. The CuIn precursors were prepared using Cu x In y alloy targets with different composition rates under low vacuum level by a homemade sputtering system. The Cu and In composition rates of the used targets are 11:9, 10:10, and 9:11, respectively. The metallic precursor films were selenized using a two-step temperature profile, i.e. at 250°C and 400–500°C, respectively. The influence of the temperature at the second selenization step on the quality of the CIS absorbing layers was investigated. The CIS films were characterized by X-ray diffractometry, scanning electron microscopy, energy dispersive X-ray analysis, and Raman spectroscopy. The deposited CIS absorbers selenized at a high temperature of 500°C for 30 min exhibited a single-phase chalcopyrite structure with a preferential orientation in the (112) direction. These layers display uniform, large, and densely packed crystals with a grain size of about 3–5 μm. Cadmium sulfide buffer layer was manufactured by chemical bath deposition method. Bilayers ZnO / ZnO : Al were prepared by RF magnetron sputtering deposition. CIS solar cells with an efficiency of about 6.5% were produced without antireflective films. The method to fabricate CIS solar cells by a combination of the low vacuum sputtering deposition and the graphite box selenization process has provided a simple control process and shown a promising potential for developing high efficient and low-cost CuInSe 2 solar cells.

Manufacturability Study for Etching High-Density BST/Pt Capacitors

2000 ◽  
Vol 655 ◽  
Author(s):  
Jay Hwang
Keyword(s):  
High Temperature ◽  
Etch Rate ◽  
Control Process ◽  
High Density ◽  
Wafer Surface ◽  
Plasma Chamber ◽  
Reactive Plasma ◽  
Pt Electrodes ◽  
Profile Control

AbstractProfile control, process repeatability and productivity concerns in etching Pt electrodes are reviewed specifically for application in fabricating high-density BST/Pt capacitors. The approach of using a high temperature cathode in a high-density reactive plasma chamber has produced a repeatable >85° Pt profile, stable etch rate and low particle results over a 500-wafer marathon test. A “corrosion-like” BST defect can be prevented by adding a post etch treatment to remove any corrosive residue from the wafer surface. A feasible manufacturing solution for etching BST/Pt capacitors for future high-density DRAM application is demonstrated.

The Research and Evaluation of Finely Layered Water Injection Standard in Low-Permeability Reservoirs - A Case from Block A in one Low-Permeability Reservoir

2014 ◽  
Vol 1073-1076 ◽  
pp. 2310-2315 ◽  
Author(s):  
Ming Xian Wang ◽  
Wan Jing Luo ◽  
Jie Ding
Keyword(s):  
Oil Recovery ◽  
Water Injection ◽  
Injection Pressure ◽  
Injection Rate ◽  
Low Permeability ◽  
Reservoir Permeability ◽  
Engineering Parameters ◽  
The Common ◽  
Common Problems ◽  
Low Permeability Reservoirs

Due to the common problems of waterflood in low-permeability reservoirs, the reasearch of finely layered water injection is carried out. This paper established the finely layered water injection standard in low-permeability reservoirs and analysed the sensitivity of engineering parameters as well as evaluated the effect of the finely layered water injection standard in Block A with the semi-quantitative to quantitative method. The results show that: according to the finely layered water injection standard, it can be divided into three types: layered water injection between the layers, layered water injection in inner layer, layered water injection between fracture segment and no-fracture segment. Under the guidance of the standard, it sloved the problem of uneven absorption profile in Block A in some degree and could improve the oil recovery by 3.5%. The sensitivity analysis shows that good performance of finely layered water injection in Block A requires the reservoir permeability ratio should be less than 10, the perforation thickness should not exceed 10 m, the amount of layered injection layers should be less than 3, the surface injection pressure should be below 14 MPa and the injection rate shuold be controlled at about 35 m3/d.

scholarly journals Automatic Roadway Backfilling of Caving Gangue for Cutting Roofs by Combined Support on Gob-Side Entry Retaining with No-Pillars: A Case Study

2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Shengrong Xie ◽  
Xiaoyu Wu ◽  
Dongdong Chen ◽  
Yaohui Sun ◽  
Junchao Zeng ◽  
...  
Keyword(s):  
Longwall Mining ◽  
Control Process ◽  
Coal Pillar ◽  
Main Roof ◽  
Control Effect ◽  
Mining Technology ◽  
Thick Coal Seam ◽  
Immediate Roof ◽  
Seam Mining ◽  
And Control

Automatic roadways on gob-side entry retaining with no-pillars are used for longwall mining technology. The mining technology with no-pillars can recover coal pillar resources and reduce the amount and cost of roadway excavations. Automatic roadway technology for cutting roofs by combined support on gob-side entry retaining with no-pillars is adopted for the condition of thick immediate roof and medium-thick coal seam mining, cutting off the immediate roof and the main roof on the gob by combined support. The fractured roof forms gangue blocks to fill the gob and loads the overlying strata. The gangue control system is placed on the roadside, which controls the caving gangue to form a gangue rib. In this paper, the viewpoints and key technologies (the roof-cutting technology, the reinforcement and support technology, the gangue rib control technology, and the auxiliary support technology) of automatic roadway technology for cutting roofs by combined support on the gob-side entry retaining with no-pillars are introduced. Furthermore, the formation and control process are explained. The numerical simulation is used to simulate and analyze the roof hanging and the roof cutting structures. In addition, a field engineering test is performed. The field test shows that automatic roadway technology for cutting roofs by combined support on gob-side entry retaining with no-pillars is feasible. This process uses construction techniques and technologies to meet on-site production needs. The combined support has high resistance strength and is shrinkable. In engineering applications, the combined support has a low damage rate. The deformation of the automatic roadway with gob-side entry retaining is small, and the control effect is significant.

scholarly journals An Effective Dynamic Immune Optimization Control for the Wastewater Treatment Process

2021 ◽  
Author(s):  
Fei Li ◽  
Zhong Su ◽  
Gongming Wang
Keyword(s):  
Wastewater Treatment ◽  
Dynamic Optimization ◽  
Performance Indicators ◽  
Treatment Process ◽  
Control Process ◽  
Control Effect ◽  
Wastewater Treatment Process ◽  
Immune Optimization ◽  
Effective Dynamic ◽  
Optimization Control

Abstract Aiming at the conflict of multiple performance indicators in the complex wastewater treatment process (WWTPs), an effective optimization control based on dynamic multi-objective immune (DMOIA-OC) is designed. This method first designs a dynamic optimization control scheme. It also divides the control process into a dynamic optimization layer and a tracking control layer. Secondly, based on analyzing the performance of WWTPs, the optimization layer establishes energy consumption and effluent quality models that adapt to the environment. Thirdly, an adaptive dynamic immune optimization algorithm is proposed to optimize complex and conflicting performance indicators. Besides, a suitable preference solution is selected from many Pareto solutions. It is to obtain the best set values of dissolved oxygen and nitrate nitrogen. Finally, the solution will be tested on the benchmark simulation platform (BSM1). The results show that the DMOIA-OC method can solve the complex optimization problem of multiple performance indicators in WWTPs. And it has a competitive advantage in the control effect.

An Experimental Research on Enhanced Oil Recovery Using Local Polymers

2021 ◽  
Author(s):  
Abiola Oyatobo ◽  
Amalachukwu Muoghalu ◽  
Chinaza Ikeokwu ◽  
Wilson Ekpotu
Keyword(s):  
Enhanced Oil Recovery ◽  
Experimental Research ◽  
Oil Recovery ◽  
Capital Investment ◽  
Oil And Gas ◽  
Produced Water ◽  
Water Injection ◽  
Gum Arabic ◽  
Oil And Gas Industry ◽  
Profile Control

Abstract Ineffective methods of increasing oil recovery have been one of the challenges, whose solutions are constantly sought after in the oil and gas industry as the number of under-produced reservoirs increases daily. Water injection is the most extended technology to increase oil recovery, although excessive water production can pose huge damage ranging from the loss of the well to an increase in cost and capital investment requirement of surface facilities to handle the produced water. To mitigate these challenges and encourage the utilization of local contents, locally produced polymers were used in polymer flooding as an Enhanced Oil Recovery approach to increase the viscosity of the injected fluids for better profile control and reduce cost when compared with foreign polymers as floppan. Hence this experimental research was geared towards increasing the efficiency of oil displacement in sandstone reservoirs using locally sourced polymers in Nigeria and also compared the various polymers for optimum efficiency. Starch, Ewedu, and Gum Arabic were used in flooding an already obtained core samples and comparative analysis of this shows that starch yielded the highest recovery due to higher viscosity value as compared to Ewedu with the lowest mobility ratio to Gum Arabic. Finally, the concentration of Starch or Gum Arabic should be increased for optimum recovery.

Design, Modeling and Simulation of CMOS-MEMS Piezoresistive Cantilever Based Carbon Dioxide Gas Sensor for Capnometry

2011 ◽  
Vol 403-408 ◽  
pp. 3769-3774 ◽  
Author(s):  
Asif Mirza ◽  
Nor Hisham Hamid ◽  
Mohd Haris Md Khir ◽  
Khalid Ashraf ◽  
M.T. Jan ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Modeling And Simulation ◽  
Low Cost ◽  
Cmos Technology ◽  
Simulation Software ◽  
Dynamic Mode ◽  
Fully Differential ◽  
Carbon Dioxide Gas ◽  
Carbon Dioxide Co2 ◽  
Relative Change

This paper reports design, modeling and simulation of MEMS based sensor working in dynamic mode with fully differential piezoresistive sensing for monitoring the concentration of exhaled carbon dioxide (CO2) gas in human breath called capnometer. CO2 being a very important biomarker, it is desirable to extend the scope of its monitoring beyond clinical use to home and ambulatory services. Currently the scope of capnometers and its adaption is limited by high cost, large size and high power consumption of conventional capnometers . In recent years, MEMS based micro resonant sensors have received considerable attention due to their potential as a platform for the development of many novel physical, chemical, and biological sensors with small size, low cost and low power requirements. The sensor is designed using 0.35 micron CMOS technology. CoventorWare and MATLAB have been used as simulation software. According to the developed model and simulation results the resonator has resonant frequency 57393 Hz and mass sensitivity of 3.2 Hz/ng. The results show that the longitudinal relative change of resistance is 0.24%/µm while the transverse relative change of resistance is -0.03%/µm.

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