Combined simulation for improving operations in LNG logistics

Chemical engineering research & design, 2005

L iquefied natural gas (LNG) is a commodity that is increasing in importance. It is, however, complicated to produce, process, ship and distribute. Dynamic simulation provides a means of managing the risk of all stages of the LNG value chain. This paper describes the technical and research changes that had to be made to a general dynamic simulation program so that it could be used to contribute to the successful exploitation of natural gas resources in remote and difficult locations.

2017

Increased competition and low oil prices coupled with promising prospects for new oil and gas (O&G) reserves in the Arctic region has led to expansion of activities into the offshore Arctic. This brings along new challenges for the offshore logistics that need to be addressed. These challenges impose more stringent requirements for the logistics system setup, especially on the design and operation of vessels. Copying the logistics system and vessels designed for the North Sea operations is not a sustainable way forward. The few existing studies related to Arctic logistics mainly focus on ship technology solutions for cold and ice infested areas or solutions to the area-specific operational challenges for shipping companies. However, there is a need to understand how these solutions are connected and impact each other in a larger offshore supply logistics system, and thus address the challenges of Arctic logistics as a whole. A methodology for quick evaluation of the feasibility and costs of the logistics system in the early stages of offshore supply planning was developed and presented in previous research [1]. It allows for testing the effects of using alternative ship designs and the overall supply fleet composition on system's cost and performance while satisfying prospective campaign requirements. Safety standards and requirements for emergency preparedness and environmental performance are taken into account while cost effectiveness of the logistics system as a whole is the main quantifiable measure. Building on the new methodology a simulation tool for remote offshore operations has been developed and is presented in current work. Simulation models allow us to consider the dynamic and uncertain nature of variables, such as variation in weekly transport demand, weather impact on sailing times and fuel consumption, and schedule deviations. The evaluation of the performance of a logistic system is done by simulating the logistic operation over a large number of scenarios. Input parameters are weather data generated from historical observations and probability distributions for transport demand. Output from the tool are key performance indicators for: system costs, logistic robustness and emergency preparedness. The tool consists of three main components: simulation of a regular supply logistics operation, simulation of emergency situations, and visualization of the simulated operations. The proposed methodology and tool are tested on real-life cases for offshore supply planning of drilling campaigns in remote areas for one of the major international O&G operators.

2010

The purpose of this study was the development of a simulation model to verify the logistic feasibility of the construction of a new regazification offshore terminal feeding a power plant located in Africa, subjected to a possible future doubling. In particular the model was used to test the proper supply of LNG (Liquefied Natural Gas) in the power plant real operating conditions and with particular reference to certain sizing configurations of vessels involved (dimensional range for tank buffer, shuttle ship size range). The model, taking into account sea conditions data available on site, extensively characterized during the oceanographic studies made, and with reference to defense works type realization and preliminary sizing (and specifically the breakwater dam and the its effect on the perturbation conditions in the proximity of the ship's mooring points) has assessed the risk of the power plant supply failure and the consequent lack of production (Unavailability of LNG or s...

Resource scheduling is a critical step in the management of complex logistic networks. The paper proposes an integrated scheduling and simulation approach for dynamic resource allocation in complex transportation logistics. An example application, specific to the maritime logistics of the chemical supply chain, is discussed in the paper, along with preliminary testing of the system by industrial users.

Transportation Research Procedia, 2014

One of the most important objectives of a manufacturing company is the optimization of the distribution of the produced goods considering the whole value chain. Unfortunately, in many companies the performance of the supply chain depends on many uncertain factors that are difficult to predict. The only way to face them is to adopt innovative solutions and tools that allow a swift response to the market changes. This paper analyzes the distribution processes managed by the logistics department of a large company producing and distributing petroleum products through the following main steps: crude oil's transportation typically from many countries to a refinery; refining process; maritime transportation from the refinery to three costal depots; road transport from depots to gas stations. The analyzed process is the primary supply, consisting in the maritime transport from the refinery to the coastal depots, liable to stochastic activities and events as weather condition. Through simulating the primary supply, we study the effects that the ship traffic generates on the overall variance of inventory levels at the costal depots with respect to specific inventory level targets, and analyze the impact of different tactical decision choices on the variance reduction. Reducing inventory's variance, through a better control of the distribution, allows the company to reduce inventory target levels and hence to reduce inventory costs in term of capital stock, while keeping the same risk level of stock out. The project is made of many phases: map all relevant processes to have a complete vision of transport's structure; conduct a statistical analysis to identify specific statistical distributions of every ships' process (delay, mooring, loading, etc.); model and simulate the primary supply using simulation software; use the model to make a "what-if" analysis. Within this project, it has been possible to realize a model that presents stochastic elements. All these phases are supported by six-sigma methodology, which focalizes on defects' process reduction by the control of its mean square deviation and following the stages of the DMAIC (Define Measure Analyze Improve Control). One of the what-if analysis which has been done consists in simulating the opening refinery's jetties h24, because currently these are closed during the night. Opening the jetties, will increase the capacity of some of the bottleneck resources for the oil distribution process, and thanks to the simulation model we can estimate quickly the effects on the oil transport system.

Logistics networks are complex systems since they are made up by many elements interconnected by a great variety of non linear relationships. This property makes it impossible to study such systems with traditional analytical approaches. Therefore, computer simulation is a valuable tool to virtually replicate the structure of a logistics network, the relationships among its components, and the rules governing its functioning. The output of this process, the simulation model, can be run in order to reproduce the evolution of the real system over a specific time interval, and analyze its patterns of behavior. This work focuses on simulation approaches for managing the performance of logistics networks in manufacturing supply chains. With the aim of providing a reference framework for choosing the best tool, five approaches are reviewed and compared: Neural Networks, Petri Nets, Agent Based Modeling, Discrete Event Simulation, and System Dynamics. The results show that the complexity o...

Zeszyty Naukowe Politechniki Częstochowskiej Zarządzanie, 2019

The article presents the concept of modern simulation systems applicable in the analysis of the logistics chain configuration. The main goal of the article is to present advanced possibilities of using various methods of simulation of a logistic system, or to determine the appropriateness of introducing changes in the configuration of a logistics chain or the assessment of already prepared solutions for given logistics processes. The article contains a description of information technologies that can be used in simulation, including specialized simulation programs, spreadsheets, languages and simulation interfaces etc. The article presents the basic issues related to the creation of a logistics project simulation, as well as the possibilities of the FlexSim 3D Simulation software, which easily allows to map complex logistic processes. The simulation, including the data generated during its implementation on individual logistic processes, allows the selection of the most advantageous and optimization of the solutions used so far in a given process. The article presents an example of simulation of logistics issues in the production process and examples are presented to explain the cognitive appeal of this method based on the use of computer technology and FlexSim 3D Simulation software.

Eastern-European Journal of Enterprise Technologies, 2021

The main link in the logistics supply chain is the cargo customs complex. It provides customs and logistics services to cargo owners during the export and import of goods, complex services, placement of goods in a customs warehouse and a temporary storage warehouse. To substantiate the choice of the optimal logistics supply chain and optimize the work of the cargo customs complex, it is proposed to use simulation modeling. The model of operation of the logistics chain and the cargo customs complex is presented in a general form. The proposed model is implemented in the GPSS World simulation automation package. Testing the simulation model involved checking its adequacy. Checking the adequacy of the simulation model, which showed the maximum value of the t-statistic of 1.424 with a critical value of 1.85, proved its compliance with the work of a real object. After completing the adequacy check, the simulation error was estimated, which was 3 % with an allowable 5 %, due to the presen...

2012

The paper proposes a stochastic, dynamic discrete-event micro-simulation model to analyse the operation of a logistic platform in order to determine its performance in different system configurations by using appropriate efficiency indicators. The issues connected to the management and optimization of operational functions are studied at a global level in order to obtain a technical/economic analysis through aggregate evaluations, which provide information useful to a tactical/strategic planning. The model implementation consists of four sequential steps: survey and statistical analysis, specification, calibration and validation model. The micro-simulation model has been implemented by using Witness software. The paper proposes an application of the micro-simulation model on the Kuehne+Nagel logistic platform in order to analyse its operativity.

Multidisciplinary Aspects of Production Engineering

Optimization of production logistics processes through the use of simulation tools brings a lot of benefits to a production company, and thus significantly reduces production costs. Increasing competition resulting from the use of production automation to increase productivity has increased the complexity of production systems that can only be analysed by simulation. Production logistics performs management functions such as planning, motivating, organising and controlling. It does not deal with technological processes, but the organisation of physical delivery and displacement of components and information in the system. An important feature of production logistics is combining supply logistics with distribution logistics. If the production logistics is properly organised, it provides access to all materials and components of a given product during the implementation of a specific order. Simulation tools ensure continuity and rhythm of production after it is started, as well as con...