Replacement of MEG with KHI for Hydrate Control in Subsea Flowline Offshore Myanmar

2021 ◽  
Author(s):  
Jonghyun Kim ◽  
Paolo Scalea ◽  
Chulhwan Hwang ◽  
Jeongmoon Kim
Keyword(s):  
Selection Process ◽  
Field Tests ◽  
Equilibrium Temperature ◽  
Field Application ◽  
Operating Conditions ◽  
Field Conditions ◽  
Gas Industry ◽  
Promising Alternative ◽  
Selection Of

Abstract Objectives/Scope This paper describes the successful replacement of Mono Ethylene Glycol (MEG) by Kinetic Hydrate Inhibitor (KHI) to guarantee flow assurance in the Shwe field subsea production system, offshore Myanmar. It covers the initial difficulties experienced with MEG, specific field conditions, the comprehensive KHI selection process and testing up to field application and operation. Methods, Procedures, Process MEG used for hydrate inhibition in the field's subsea flowline was originally regenerated in the topside facility, however contamination of the MEG with salts from formation water was causing process upsets. The option of installing a reclamation package presented many challenges and, after review of field conditions, the application of a KHI was considered as a promising alternative to MEG. With the engagement of specialist chemical suppliers a broad and challenging series of laboratory, as well as field tests, was carried out to select a suitable product. Finally a dedicated permanent injection skid was installed to guarantee stable KHI delivery and production. Results, Observations, Conclusions The difficulties caused by salt contamination of the MEG system, combined with the intricate field logistics at the remote site offshore Myanmar, entailed a speedy solution. This combined with suitable operating parameters of the field; i.e. low water content, high wellhead flowing temperatures, subcooling within known KHI operating range, ensured KHI was an economical solution. Nevertheless from desktop study to successful field application a series hurdles had to be crossed, including performance and compatibility tests, simulating all the expected Shwe Offshore Platform (SHP) operating conditions: Determination of Hydrate Equilibrium Temperature (HET); Induction Time Autoclave test for the required residence time in the presence of Corrosion Inhibitor (CI); Hot Injection ests at wellhead operating temperature; Thermal stability tests for topsides and condensate disposal system; Umbilical material compatibility tests; Compatibility of KHI with incumbent products (MEG and CI). Testing of a range of products, carried out by specialist chemical supplier, resulted in the selection of a qualified product, followed by a successful field application testing programme. Seven years after its introduction, KHI has helped achieve optimum field uptime and reduced operational costs as well as eased logistics constraints. Novel/Additive Information KHI is not new to the Oil & Gas industry, however information on its selection and application is not widely available. This paper sheds light on the steps to be considered when evaluating KHI as a suitable hydrate inhibitor, as well as the detailed laboratory tests for proper selection of a product. The intent is to help operators who are facing challenges with hydrate inhibition and could revert to KHI as an alternative.

Parametric Optimization of Structures Under Combined Base Motion Direct Forces and Static Loading

1998 ◽  
Vol 124 (1) ◽  
pp. 132-140 ◽  
Author(s):  
Izhak Bucher
Keyword(s):  
Degrees Of Freedom ◽  
Structural Parameters ◽  
Operating Conditions ◽  
Design Parameters ◽  
Power Spectral ◽  
Loading Patterns ◽  
The Cost ◽  
Selection Of ◽  
Eigenvectors And Eigenvalues

This paper deals with the optimization of vibrating structures as a mean for minimizing unwanted vibration. Presented in this work is a method for automatic determination of a set of preselected design parameters affecting the geometrical layout or shape of the structure. The parameters are selected to minimize the dynamic response to external forcing or base motion. The presented method adjusts the structural parameters by solving an optimization problem in which the constraints are dictated by engineering considerations. Several constraints are defined so that the static deflection, the stress levels and the total weight of the structure are kept within bounds. The dynamic loading acting upon the structure is described in this work by its power spectral density, with this representation the structure can be tailored to specific operating conditions. The uncertain nature of the excitation is overcome by combining all possible spectra into one PSD encompassing all possible loading patterns. An important feature of the presented method is its numerical efficiency. This feature is essential for any reasonably sized problem as such problems are usually described by thousands of degrees of freedom arising from a finite-element idealization of the structure. In this paper, efficient, closed form expressions, for the cost function and its gradients are derived. Those are computed with a partial set of eigenvectors and eigenvalues thus increasing the efficiency further. Several numerical examples are presented where both shape optimization and the selection of discrete components are illustrated.

Assessment of the Effectiveness of Gas Path Diagnostic Schemes

2004 ◽  
Vol 128 (1) ◽  
pp. 57-63 ◽  
Author(s):  
K. Mathioudakis ◽  
Ph. Kamboukos
Keyword(s):  
Gas Turbines ◽  
Individual Component ◽  
Uncertainty Propagation ◽  
Data Retrieval ◽  
Operating Conditions ◽  
Small Deviations ◽  
Component Identification ◽  
Operating Points ◽  
Selection Of

A variety of methods can be used for the diagnosis of faults in gas path components of gas turbines. Problems that are common for diagnostic method implementation are the choice of measured quantities, choice of health parameters, and choice of operating conditions for data retrieval. The present paper introduces some general principles for evaluation of the effectiveness of different diagnostic schemes. They encompass criteria proposed in past publications, while they offer additional possibilities for assessment of diagnostic effectiveness in various situations. The method is based on the evaluation of the behavior of linear systems, which are a good approximation of the nonlinear ones for small deviations and employs the concept of system condition number to formulate criteria. The determination of limits for this number for establishing system condition criteria and quantification of observability is examined, on the basis of uncertainty propagation. Sample problems evaluated are: maximizing effectiveness of individual component identification from a multiplicity of available measurements, selection of individual operating points for multipoint applications.

Effect of Errors in Temperature Measurement on the Accuracy of Composition of the Liquid-Vapour Phases and Their Impact on the Calculated Number of Theoretical Stages of Rectification Columns

1992 ◽  
Vol 57 (9) ◽  
pp. 1867-1878
Author(s):  
Ján Dojčanský ◽  
Soňa Bafrncová ◽  
Július Surový
Keyword(s):  
Phase Composition ◽  
Binary Systems ◽  
Equilibrium Temperature ◽  
Systematic Errors ◽  
Operating Conditions ◽  
Rectification Column ◽  
Relative Volatility ◽  
The Impact ◽  
Calculated Number

The effect of random and systematic errors in the determination of the equilibrium temperature on the phase composition in isobaric L-G equilibria was simulated on five binary systems with different size and relative volatility. The impact of the inaccuracies on the calculated number of theoretical stages of a continuously operating rectification column is discussed with respect to the different operating conditions of the separatory process.

Risk-based Winterization for Vessels Operations in Arctic Environments

2013 ◽  
Vol 29 (04) ◽  
pp. 199-210 ◽  
Author(s):  
Ming Yang ◽  
Faisal I. Khan ◽  
Leonard Lye ◽  
Heri Sulistiyono ◽  
John Dolny ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Temperature Data ◽  
Operating Conditions ◽  
Hydrocarbon Exploration ◽  
The Arctic ◽  
Gas Industry ◽  
Arctic Regions ◽  
Exploration And Production

Because the oil and gas industry has an increasing interest in the hydrocarbon exploration and development in the Arctic regions, it becomes important to design exploration and production facilities that suit the cold and harsh operating conditions. In addition to well-established minimum class requirements for hull strengthening, winterization should be considered as a priority measure early in the design spiral for vessels operating in the Arctic environments. The development of winterization strategies is a challenging task, which requires a robust decision support approach. This article proposes a risk-based approach for the selection of winterization technologies and determination of winterization levels or requirements on a case-by-case basis. Temperature data are collected from climatology stations located in the Arctic regions. Loading scenarios are defined by statistical analysis of the temperature data to obtain probabilistic distributions for the loadings. Risk values are calculated under different loading scenarios. Based on the risk values, appropriate winterization strategies can be determined. A case study is used to demonstrate how the proposed approach can be applied to the identification of heating requirements for gangways.

Factors Associated with the Determination of Predominant Unit in Two Units Cord Blood Transplantation for Pediatric Acute Leukemia.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 5394-5394
Author(s):  
Hyoung Jin Kang ◽  
Sang Hyeok Koh ◽  
Mi Kyung Jang ◽  
Jeong Ah Park ◽  
Hee Young Shin ◽  
...  
Keyword(s):  
Body Weight ◽  
Acute Leukemia ◽  
Cord Blood ◽  
Cord Blood Transplantation ◽  
Median Number ◽  
Promising Alternative ◽  
Factors Associated ◽  
Blood Transplantation ◽  
Selection Of

Abstract Cord blood transplantation (CBT) is a promising alternative means of allogeneic stem cell transplantation. However, limited cell doses may compromise outcome. To enhance engraftment, CBT has been conducted using two units with promising results. Our preliminary results showed the dominance of one unit which occurred early after CBT (Bone Marrow Transplant. 38:197). However, little is known about the mechanism of engraftment and factors influencing the dominancy. To improve the outcomes, CBT was performed with 2 partially HLA-matched units in pediatric acute leukemia with the analysis of factors that affect the determination of dominancy. The median age and body weight of patients (M:11, F:4) were 13 years (3–17) and 45.0 kg (10.5–62.9), respectively. Patients received various conditioning regimens according to the disease status. The median number of the infused nucleated cells by the sum of 2 units after thawing was 5.28×107/kg (0.72–15.09×107/kg). Engraftment achieved in 14/15 Patients. The median number of days required for ANC of more than 0.5×109 or 1.0×109/l were 18 days (13–31 days) and 21 days (14–34 days), respectively. Spontaneous platelet recovery to more than 20×109/l required a median 50 days (19–93 days). The early engraftment kinetics reveals that dominancy of one of two units determined from the day of engraftment (ANC > 0.5×109/l). The numbers of total nucleated cells, CD34+ cells, CD3+ cells, CFU-GM, order of infusion, and donor-recipient HLA disparities of the UCB units were viewed as factors that potentially influence dominancy. Among them infused CFU-GM per patient body weight was associated with the dominancy (P = 0.017). Interestingly, CFU-GM could not be found from each cord blood units in patient failed engraftment. Multiple factors associated with outcomes of CBT could influence the determination of dominancy, such as those factors that affect the recipient environment (underlying disease, previous treatment, conditioning regimen, use of ATG and the method of GVHD prophylaxis), the characteristics of each UCB unit and HLA disparity. For this reason, the selection of the two units requires consideration of the above factors. However optimal selection guidelines that take into account influencing factors are unavailable. CFU-GM was associated with the dominancy in our preliminary result but this kind of data is hard to get before CBT practically. Introducing the analysis of new parameters such as CFU-GM before freezing could help the selection of optimal cord blood unit and improve the outcomes with the consideration of cost-benefit.

scholarly journals Analysis of the exhaust emissions from hybrid vehicle during RDE test

2019 ◽  
Vol 294 ◽  
pp. 02002
Author(s):  
Andrzej Ziolkowski ◽  
Pawel Daszkiewicz ◽  
Lukasz Rymaniak ◽  
Paweł Fuc ◽  
Pawel Ukleja
Keyword(s):  
Exhaust Emissions ◽  
Operating Conditions ◽  
Drive System ◽  
Heavy Vehicles ◽  
Hybrid Drive ◽  
Emission Norm ◽  
Urban Rural ◽  
Test Route ◽  
Selection Of

The introduction of the Euro 6c emission norm in 2017 resulted in a change of the type approval procedures. The most important of these was the replacement of the NEDC test with WLTC test with different procedures. In addition, the research was extended to include emission tests in real operating conditions (RDE). Such tests are enforced for heavy vehicles since 2014. PEMS apparatus was used for the measurements, which has been used by many research and development centers to carry out exhaust emissions measurements long before the applicable procedures were introduced. The article presents the methodology of conducting RDE measurements in accordance with the requirements defined by the Euro 6c norm. The focus in this case was primarily on the selection of the test route in the Poznań agglomeration. After determining its course, RDE measurements were made for a vehicle with a hybrid drive. The test route parameters have complied with the applicable requirements. All requirements were met and it was possible to analyze the exhaust emissions. The main focus being the determination of exhaust emissions from the entire test and in accordance with the EMROAD method. The CF (Comformity Factor) coefficients were also determined for both methods and compared with the applicable legal values. An analysis of the hybrid drive system operation was carried out, defining the degree of hybridization, which is the portion of the vehicle travel using only the electric motor of the drive system throughout the whole test. All analyzes were carried out in individual sections of the test: urban, rural and motorway.

scholarly journals Determination of the importance of evaluation criteria during the process of recruitment and selection of personnel based on the application of the SWARA method

Ekonomika ◽  
2021 ◽  
Vol 67 (4) ◽  
pp. 1-9
Author(s):  
Milica Popović ◽  
Gabrijela Popović ◽  
Darjan Karabašević
Keyword(s):  
Personnel Selection ◽  
Selection Process ◽  
Evaluation Criteria ◽  
Domain Experts ◽  
Recruitment And Selection ◽  
Weighting Coefficients ◽  
Final Selection ◽  
Selection Of

Personnel selection for an organization is an extremely important process. Modern organizations strive to improve the process of recruitment and selection of personnel as much as possible, in order to provide the organization with quality personnel and thus long-term competitiveness. In addition, the evaluation criteria on which the recruitment and selection process is based is also important, as it has a large impact on the final selection of candidates. Therefore, the aim of this paper is to propose the application of multi-criteria decision-making methods for the process of determining the weighting coefficients of evaluation criteria. Accordingly, the SWARA (Step-Wise Weight Assessment Ratio Analysis) method for determining weights was applied in the paper. The SWARA method proved to be extremely reliable when it comes to defining the weights of evaluation criteria, primarily due to its simplicity and the fact that respondents and domain experts could easily express their views on the issue.

scholarly journals FORMALIZATION OF THE PROBLEM OF SELECTION OF AUTOMATED SYSTEM

2018 ◽  
pp. 16-20
Author(s):  
A. V. Petukhov
Keyword(s):  
Economic Effect ◽  
Operating Conditions ◽  
Automated System ◽  
Qualitative Assessment ◽  
Automated Systems ◽  
Customer Requirements ◽  
Qualitative And Quantitative ◽  
Complete Restoration ◽  
Selection Of

The results of many years of research in the field of formalizing the task of selecting automated systems for various areas of design and office activities are given. The purpose of the study is the development of methods for qualitative and quantitative evaluation when choosing an automated system, taking into accounts the operating conditions and customer requirements. Qualitative assessment is based on the theory of choice and decision making, which examines the mathematical models of this type of activity. In view of the fact that in the problem under consideration, many alternatives, which are automated systems, are known, it can be related to the choice problem. The peculiarity of this approach is that it does not require a complete restoration of the principle of optimality, but allows us to confine ourselves to information sufficient to identify the optimal variant. The quantitative assessment is based on the determination of the projected annual economic effect from the introduction of an automated system. The described technique can be used by enterprises and organizations in the evaluation of automated systems at the stage preceding the tender for their purchase.

scholarly journals Acidic Gases Separation from Gas Mixtures on the SILMs Providing the Facilitated and Solution-Diffusion Transport Mechanisms

2018 ◽  
Author(s):  
Alsu I. Akhmetshina ◽  
Alla Mochalova ◽  
Maxim M. Trubyanov ◽  
Artem A. Atlaskin ◽  
Nail R. Yanbikov ◽  
...  
Keyword(s):  
Operating Conditions ◽  
Separation Performance ◽  
Factors Affecting ◽  
Acidic Gases ◽  
Membrane Performance ◽  
Ideal Selectivity ◽  
Counter Ions ◽  
Supported Ionic Liquid Membranes ◽  
Selection Of

Nowadays, the imidazolium-based ionic liquids containing acetate counter-ions are attracting much attention as both highly selective absorbents of the acidic gases and CO2 carriers in the supported ionic liquid membranes. In this regard, the investigation of the gas transport properties of such membranes may be appropriate for better understanding of various factors affecting the separation performance and the selection of the optimal operating conditions. In this work, we have tested CH4, CO2 and H2S permeability across the SILM impregnated by 1-butyl-3-methylimidazolium acetate (bmim[ace]) with the following determination of the ideal selectivity in order to compare the facilitated transport membrane performance with the SILM that dissolves acidic gases physically, namely, containing 1-butyl-3-methylimidazolium tetrafluoroborate (bmim[BF4]). Both SILMs have showed modest individual gases permeability and ideal selectivity of CO2/CH4 and H2S/CH4 separation that achieves values up to 15 and 32, respectively. The effect of the feed gas mixture composition on the permeability of acidic gases and permeselectivity of the gas pair was investigated. It turned out that the permeation behavior for the bmim[ace]-based SILM toward the binary CO2/CH4, H2S/CH4 and ternary CO2/H2S/CH4 mixtures was featured with high acidic gases selectivity due to the relatively low methane penetration through the liquid phase saturated by acidic gases.

scholarly journals Sistem Pendukung Keputusan Penentuan Penerima Beasiswa pada SMK Madyatama dengan Metode TOPSIS

2017 ◽  
Author(s):  
Ani Sunalia ◽  
Leon Andretti Abdillah
Keyword(s):  
Decision Making ◽  
Decision Support ◽  
Selection Process ◽  
Topsis Method ◽  
Scholarship Recipients ◽  
Decision Making System ◽  
The Right ◽  
Computerized System ◽  
Selection Of

Data processing in the determination of scholarships in SMK Madyatama to date still use a system that is still manual. Where the absence of a well-computerized system in determining the acceptance of scholarship which then led to the emergence of some problems in this manual system. The problem that often arises is not exactly the distribution of scholarships to students. Problems like this are triggered by the lack of scrutiny of the scholarship selectors in conducting the selection process of the scholarship recipients, which is basically the selection process conducted by teachers from the school itself. The decision-making system at SMK Madyatama will be made using TOPSIS method to determine the right scholarship recipient in accordance with the scholarship recipient criteria. With the decision support system of awarding scholarship recipients at SMK Madyatama Palembang based on this website can help and facilitate the school in evaluating the selection of scholarship receipt.

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