A Computational Model for Wells’ Performance Analysis

The ability to identify underperforming wells and recover the remaining oil in place is a cornerstone for effective reservoir management and field development strategies. As advancement in computing programming capabilities continuous to grow, Python has become an attractive method to build complicated statistical models that predicts, diagnose or analyze well performance, efficiently and accurately. The aim of this study is to develop a computational model that will allows us to diagnose and analyze well performance using nodal analysis with the help of python. In this study, python was used to compute Nodal analysis method using Darcy and Vogel Equations. A case study was carried out using the data obtained from a field operating in the Niger Delta. Again, sensitivity of tubing size was conducted using python. The results obtained showed that a computational model with python has the ability to visualize, model and analyze wells performances. This technique will petroleum engineers to better monitor evaluate and enhance their production operation without the need for expensive softwares. This will reduce operating cost increases revenue.

Reducing Operating Cost With Anammox In Wastewater Treatment -- A Simulation Study

A simulation study is presented to investigate the use of the Anammox process for removing nitrogen compounds from wastewater to reduce operating cost. The literature review of technologies for removal of Total Nitrogen includes an overview of the biological nitrogen cycle, the discovery of Anammox, bioreactor design, operational strategies, and start-up of full-scale processes. A facility of 656 MLD with influent loading of 35 mg/L as NH3-N and 250 mg/L as BOD is used as a basis of the simulation study. Preliminary bioreactor sizing calculations are developed for six configurations. Subsequently, eight whole-plant simulation cases are compared to demonstrate operational savings for removal of Total Nitrogen. For the sample facility, this is shown to be on the order of $460 to $680K/year while attaining 66-70% Total Nitrogen removal and reduced greenhouse gas emissions by 2 kt CO2/year. The project concludes with ideas about future development of the Anammox process.

Reducing Operating Cost With Anammox In Wastewater Treatment -- A Simulation Study

A simulation study is presented to investigate the use of the Anammox process for removing nitrogen compounds from wastewater to reduce operating cost. The literature review of technologies for removal of Total Nitrogen includes an overview of the biological nitrogen cycle, the discovery of Anammox, bioreactor design, operational strategies, and start-up of full-scale processes. A facility of 656 MLD with influent loading of 35 mg/L as NH3-N and 250 mg/L as BOD is used as a basis of the simulation study. Preliminary bioreactor sizing calculations are developed for six configurations. Subsequently, eight whole-plant simulation cases are compared to demonstrate operational savings for removal of Total Nitrogen. For the sample facility, this is shown to be on the order of $460 to $680K/year while attaining 66-70% Total Nitrogen removal and reduced greenhouse gas emissions by 2 kt CO2/year. The project concludes with ideas about future development of the Anammox process.

Increased Recovery of Gold Thiosulfate Alkaline Solutions by Adding Thiol Groups in the Porous Structure of Activated Carbon

Thiosulfate leaching combined with ion-exchange resins is an innovative alternative for gold recovery. According to the properties of activated carbon, it could replace resins in the gold recovery process, improve efficiency, and reduce operating cost. In this research, the adsorption process of gold thiosulfate complex on thiol-modified activated carbon was studied. Thioglycolic acid (ATG) was impregnated in activated carbon, and its adsorption ability was tested with synthetic solutions of gold and sodium thiosulfate (Au 10 mg·L−1, Na2S2O3 0.1 mol·L−1, pH = 10.0). Carbon was characterized by infrared spectroscopy, SEM-EDS, PZC titration, hardness number measures, and proximal analysis. Synthetic solutions were also characterized by UV-vis spectroscopy and cyclic voltammetry. The percentage of volatile material increased from 10.0 to 13.9% due to the impregnation process of ATG. Infrared spectra show characteristic bands of C-H, S-H, and C-S bonds. In the adsorption tests, the ATG-impregnated carbon achieved 91% of gold recovery, while the same amount of ATG in the liquid phase stirred with unmodified activated carbon reached 90% of gold recovery. The 44.9% of gold recovered with activated carbon impregnated with ATG was eluted with sodium cyanide ([NaCN] = 0.2 mol·L−1; [NaOH] = 0.25 mol·L−1; [CH3CH2OH] = 30% V/V; pH = 12.0; t = 24 h). These results suggest the gold transferred from the thiosulfate complex to a new gold thiolate complex.

Frosting Phenomenon and Frost-Free Technology of Outdoor Air Heat Exchanger for an Air-Source Heat Pump System in China: An Analysis and Review

Frost layer on the outdoor air heat exchanger surface in an air-source heat pump (ASHP) can decrease the system coefficient of performance (COP). Although the common defrosting and anti-frosting methods can improve the COP, the periodic defrosting not only reduces the system energy efficiency but also deteriorates the indoor environment. To solve these problems, it is necessary to clearly understand the frosting phenomenon and to achieve the system frost-free operation. This paper focused firstly on the analyses of frosting pathways and frosting maps. Followed by summarizing the characteristics of frost-free technologies. And then the performances of two types of frost-free ASHP (FFASHP) systems were reviewed, and the exergy and economic analysis of a FFASHP heating system were carried out. Finally, the existing problems related to the FFASHP technologies were proposed. Results show that the existing frosting maps need to be further improved. The FFASHP systems can not only achieve continuous frost-free operation but reduce operating cost. And the total COP of the FFASHP heating system is approximately 30–64% higher than that of the conventional ASHP system under the same frosting conditions. However, the investment cost of the FFASHP system increases, and its reliability also needs further field test in a wider frosting environment. In the future, combined with a new frosting map, the control strategy for the FFASHP system should be optimized.

Conceptual Design of Flapping Wing Using Shape Memory Alloy Actuator for Micro Unmanned Aerial Vehicle

Micro Air Vehicle (MAV) has the capability to fly autonomously in complex environments which enables human to conduct surveillance in areas which are deemed too dangerous or in confined spaces that does not allow human entry. Research and development of MAVs aim to reduce their size further, thus novel techniques need to be explored in order to achieve this objective while still maintaining the MAVs’ current performance. In this paper, a conceptual design of an MAV with a main drive system using shape memory alloy (SMA) actuator to provide the flapping motion is proposed. SMA is considered superior to other smart materials due to its efficiency and large energy storage capacity. By incorporating SMA in the flapping wing MAV, it will provide users the flexibility to add more payloads by reducing bulky cables or reduce operating cost by using less fuel. However, there are some drawbacks in using SMAs such as nonlinear response of the strain to input current and hysteresis characteristic as a result of which their control is inaccurate and complicated.

Accessibility Evaluation of Guangzhou Subway Network Based on Space Syntax Model and GIS

Based on the current condition of Guangzhou subway network, the authors used GIS methods and extended the space syntax theory to analyze the accessibility of the subway network, and compared with actual passenger flow. The results show: 1)Space syntax is practicable to measure the accessibility of subway system; 2)Among all sections by division, the accessibility of Tiyuxilu-Chen Clan Academy is the highest, the accessibility of Yantang-Panyu Square is the second highest, while the accessibilities of Jiaokou–Xicun and Dongchong–Jinzhou are the lowest, the accessibility of Xilang -Chen Clan Academy is the second lowest; 3)The accessibility level of subway and actual passenger flow have a positive correlation, the higher the accessibility, the larger the passenger flow; 4)As a whole, line 1 has the highest accessibility and the largest passenger flow, followed closely by line 3. Their departure frequency and number of carriages should be properly increased to relieve passenger flow pressure. Line 4 has relatively low accessibility and less passenger flow, so it should appropriately decrease train frequency or extend departure interval to reduce operating cost at present. Certainly, space syntax inevitably has its limitations, but after proper extension, the space syntax method can be used to instruct traffic reconstructing and urban planning etc.

Supersonic Ejectors for Hydrocarbon Emissions Capture

Supersonic ejectors can be applied to capture low-pressure leakage gas from the gas seal vents of a centrifugal compressor. This captured gas can be re-injected into the fuel gas line of the gas turbine driver or the captured gas can be used as a fuel for gas fired utility heaters. By capturing the gas that is normally emitted to the atmosphere the operator can reduce operating cost and enjoy a reduction in hydrocarbon foot print. Because the supersonic ejector does not have moving parts, the system operating and maintenance costs are lower than functionally comparable traditional systems. In this study, a prototype of a supersonic ejector system was developed and tested at a pipeline compressor station. The obtained test data were used for developing and tuning a mean-line aerodynamic analysis tool, which predicts the ejector’s operating map. A family of three ejectors was designed to cover a range of operating conditions associated with gas turbine driven pipeline compressors. These ejectors were built, installed on a specially designed panel, described as the ejector system, and tested on inert gas at the original equipment manufacturer’s (OEM’s) facility. A comparison of predicted and as-tested supersonic ejector performance maps is discussed and conclusions are made about the system operating range.