Design of Experiment and Validation of Model for Offshore Buried Pipeline Thermal Analysis

2016 ◽  
Author(s):  
Suvra Chakraborty ◽  
Vandad Talimi ◽  
Yuri Muzychka ◽  
Rodney McAffee ◽  
Gerry Piercey
Keyword(s):  
Heat Loss ◽  
Oil And Gas ◽  
Surrounding Medium ◽  
Soil Surface ◽  
Oil And Gas Industry ◽  
Cfd Modeling ◽  
Soil Conditions ◽  
Actual Behavior ◽  
Buried Pipeline ◽  
Backfill Materials

Buried pipeline heat transfer modeling has become an important topic in the Oil and Gas industry. The viscosity of fluid i.e. crude oil travelling through the buried pipeline largely depends on the flow temperature and pressure. The aim of this paper is to give an overview of designing the experiment for heat loss from offshore buried pipelines and validation of the experimental model using analytical solution and CFD modeling. Several benchmark tests have been performed to ensure the validity of the test using theoretical shape factor models which depend on the amount of heat flow, thermal conductivity and geometry of the surrounding medium. This theoretical model has limitations such as the assumption of uniform soil properties around the buried pipeline, isothermal outer surface of the buried pipeline and soil surface. This paper illustrates several steady state and transient experiments to simulate the mechanism of heat loss from an offshore buried pipeline along with the experimental procedures. This paper also shows the transient response for shutdown tests performed in dry sand medium with numerical runs as well. With the progress of the research, several investigations will be made using different burial depths and diameters of the buried pipeline with backfill materials and trenching for different soil conditions, affecting the actual behavior of the model.

CFD Modeling of Moonpool Behavior

2014 ◽  
Author(s):  
Alessio Pistidda ◽  
Harald Ottens
Keyword(s):  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Cfd Modeling ◽  
Fixed Position ◽  
Gas Industry ◽  
Operational Conditions ◽  
Water Motion ◽  
Pumping Mode ◽  
Offshore Oil And Gas ◽  
Offshore Oil

Vessels equipped with a moonpool are frequently used in the offshore oil and gas industry. They are used to lay pipelines, risers, structures, cables, and for drilling. These operations are generally possible if the water motion inside the moonpool remains within workable limits. Water oscillations are generated by waves and forward speed. The water motion in the moonpool is characterized by two dominant modes, sloshing and pumping. Both modes are usually present during sailing, while during installation phase, where the vessel is kept in a fixed position, the pumping mode is dominant and sloshing is negligible. The behavior of the water column in the moonpool can either be predicted numerically (CFD and potential code) or by model tests. In this work we focus on modeling the behavior of the DCV Aegir moonpool in operational conditions via CFD. The work presented in this paper consist on the validation of the available experimental results. Results show that CFD is an adequate tool to predict the pumping mode of the water inside the moonpool and outperforms predictions of potential codes.

Optimization of perforation drilling for mitigating punch-through in multi-layered clays

2011 ◽  
Vol 48 (11) ◽  
pp. 1658-1673 ◽  
Author(s):  
M.S. Hossain ◽  
M.J. Cassidy ◽  
R. Baker ◽  
M.F. Randolph
Keyword(s):  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Soil Conditions ◽  
Gas Industry ◽  
Frequent Use ◽  
Layered Clays ◽  
Industry Practice ◽  
Offshore Oil And Gas ◽  
Drilling Rigs ◽  
Offshore Oil

“Spudcan” foundations for mobile drilling rigs continue to exhibit a high failure rate in the offshore oil and gas industry. The more frequent use of larger jack-ups in highly stratified regions, such as the Sunda Shelf in Southeast Asia, contributes to this concerning increase in “punch-through” incidents, which can lead to buckling of a leg or even toppling of the rig. An industry practice known as “perforation drilling” is sometimes used to mitigate the punch-through risk in layered clays, extracting soil from the upper strong layer before the jack-up is installed. This paper reports results from centrifuge model tests exploring the efficiency of perforation drilling. The soil conditions tested simulate offshore strength profiles that have reported punch-through failures. An experimental method for “drilling” sites in an enhanced gravity centrifuge environment was developed and the installation responses of model spudcan foundations penetrating through multi-layered clays with interbedded stiff layers were recorded. The experimental results show that the removal of soil inside the spudcan perimeter, with an area of 9% perforated, eliminated rapid leg run and severe punch-through on the two- and four-layer seabed profiles tested. This confirms the effectiveness of perforation drilling and indicates how the offshore drilling plan may be optimized.

Analysis of oil-contaminated soil cleaning methods in emergencies at oil and gas facilities and in transport

2017 ◽  
pp. 23-31
Author(s):  
Diana Khalilova ◽  
Dina Yunusova
Keyword(s):  
Contaminated Soil ◽  
Contaminated Soils ◽  
Large Scale ◽  
Oil And Gas ◽  
Practical Importance ◽  
Soil Surface ◽  
Oil And Gas Industry ◽  
High Potential ◽  
Safety Level ◽  
Cleaning Methods

Objective: Environment contamination with oil and concomitant contaminants is a burning environmental issue in many parts of Russia. Oil contamination has an effect on the overall set of soil morphological, physical, physicochemical and biological characteristics that govern its fertile and ecological functions. To reach a higher environmental safety level in the Russian oil and gas industry and transport, a multiple factor assessment of the existing oil-contaminated soil cleaning methods has been performed. Methods: Comparison of the existing oil-contaminated soil cleaning methods: mechanical, physicochemical and biological ones. Based on the systems analysis methods, phytoremediation is found to have a high potential for cleaning soils and groundwater contaminated with hydrocarbons as the above method is as a rule cheaper than any alternative soil cleaning methods. Plants do not deteriorate soil or add any secondary pollution as compared with conventional methods. In addition, the public has a positive attitude towards phytoremediation regarding it as an eco-friendly approach to cleaning contaminated soils. Results: Basic physiological and biochemical processes in plants causing a lower hydrocarbon concentration in soil are discussed. Criteria for selection of plants for phytoremediation are identified. The primary limitations on use of phytoremediation include a long soil remediation period, a significant impact of local climatic and hydrological conditions on plant growth, a plant exposure area is limited to less than 0.9 m from the soil surface (root layer), by an impossibility of growing plants in heavily contaminated soils, and also probable ingress of contaminants into food chains. It is shown that large-scale implementation of the method is held back as the method mechanisms are not sufficiently investigated. Practical importance: Phytoremediation is found to have a high potential for cleaning oil-contaminated soils and groundwater.

Thermal Analysis of Offshore Buried Pipelines Through Experimental Investigations and Numerical Analysis

2016 ◽  
Author(s):  
Suvra Chakraborty ◽  
Vandad Talimi ◽  
Mohammad Haghighi ◽  
Yuri Muzychka ◽  
Rodney McAffee
Keyword(s):  
Numerical Analysis ◽  
Heat Loss ◽  
Transient Response ◽  
Oil And Gas ◽  
Burial Depth ◽  
Fluid Temperature ◽  
Buried Pipeline ◽  
Buried Pipelines ◽  
Arctic Regions ◽  
Backfill Soil

Modeling of heat loss from offshore buried pipelines is one of the prime concerns for Oil and Gas industries. Offshore Oil and Gas production and thermal modeling of buried pipelines in arctic regions are challenging tasks due to environmental conditions and hazards. Flow properties of Oil and Gas flowing through the pipelines in arctic regions are also affected due to freezing around pipelines. Solid formation in the production path can have serious implications on production. Heavy components of crude oil start to precipitate as wax crystal when the fluid temperature drops. Gas hydrates also form when natural gas combines with free water at high pressure and low temperature. Pipeline burial and trenching in some offshore developments are now one of the prime methods to avoid ice gouge, ice cover, icebergs, and other threats. Long pipelines require more thermal management to deliver production to the sea surface. Significant heat loss may occur from offshore buried pipelines in the forms of heat conduction and natural convection through the seabed. The later can become more prominent where the backfill soil is loose or sandy. The aim of this paper is to provide an insight of modeling and conducting the experiments using different parameters with numerical analysis results support to investigate the heat loss from offshore buried pipelines. This paper also provides validation of the outputs from benchmark tests with analytical models available for theoretical shape factor at constant temperature and constant heat flux boundary conditions. These theoretical models have limitations such as the assumption of uniform soil properties around the buried pipeline, isothermal outer surface of the buried pipeline and soil surface. Degree of saturation of surrounding medium can play a significant role in the thermal behavior of fluid travelling through the backfill soil. This paper presents several steady states and transient response analysis describing some influential geotechnical parameters along with test procedures and numerical simulations using CFD to model the heat loss for different parameters such as burial depth, backfill soil, trench geometries etc. This paper also shows the transient response for several shutdown (cooldown) tests performed in the saturated sand medium. The statistical and uncertainty analysis performed from the experimental outputs also ensure the legitimacy of the experimental model. The outcomes of this research will provide valuable experimental data and numerical predictions for offshore pipeline design, heat loss from buried pipelines in offshore conditions, and efficient model to mitigate the flow assurance issues e.g. wax and hydrates.

Wet Gas Measurement with Slotted Orifice Meter--Effect of Geometry of Slots and Pressure

2011 ◽  
Vol 6 (1) ◽  
Author(s):  
Perumal Kumar ◽  
Boon Foo Chai ◽  
Michael Wong Ming Bing
Keyword(s):  
Gas Flow ◽  
Oil And Gas ◽  
Homogeneous Model ◽  
Oil And Gas Industry ◽  
Differential Pressure ◽  
Pressure Recovery ◽  
Cfd Modeling ◽  
Flow Profile ◽  
Wet Gas ◽  
Gas Measurement

Wet gas metering by differential pressure flow meters is gaining prominence in the oil and gas industry, owing to their simple construction. Slotted orifice, a modified version of the standard orifice meter has been found promising by many researchers. This novel flow meter is shown to be insensitive to the upstream flow profile with lower head loss and faster pressure recovery compared to the standard orifice. In the present work, the effect of geometry of slots and pressure on the performance of the slotted orifice has been studied by CFD modeling of the wet gas flow. The performance of slotted orifice with rectangular perforations (1.5 ≤ l/w ≤ 3.0) and circular perforations has been compared with that of the standard orifice having same β-ratio of 0.40. Simulation results reveal that the shape of perforation of the slotted orifice has no effect on the differential pressure. However, the pressure recovery with the rectangular slots is found to increase with increasing aspect ratio. Moreover, at low pressure, slotted orifice is found to be more sensitive to liquid presence than the standard orifice. The relatively higher over reading values obtained in this work is consistent with the results of Geng et al (2006) that for slotted orifice, a low beta ratio is more sensitive to the liquid presence in the stream and hence is preferable for wet gas metering. Homogeneous model, Steven’s and De Leeuw’s correlations, are found to be better than orifice correlations for wet gas mass flow prediction.

Deployment of Digital NDT Solutions in the Oil and Gas Industry

2020 ◽  
Vol 78 (7) ◽  
pp. 861-868
Author(s):  
Casper Wassink ◽  
Marc Grenier ◽  
Oliver Roy ◽  
Neil Pearson
Keyword(s):  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Gas Industry

What Does Rent Give to Federal Budget (on the Russia's Budget Dependence upon "Oil Dollars")

2004 ◽  
pp. 51-69 ◽  
Author(s):  
E. Sharipova ◽  
I. Tcherkashin
Keyword(s):  
Oil And Gas ◽  
Strong Dependence ◽  
Oil Prices ◽  
Federal Budget ◽  
Oil And Gas Industry ◽  
Gas Industry ◽  
Resource Rent ◽  
Tax Legislation ◽  
Russian Economy ◽  
The Government

Federal tax revenues from the main sectors of the Russian economy after the 1998 crisis are examined in the article. Authors present the structure of revenues from these sectors by main taxes for 1999-2003 and prospects for 2004. Emphasis is given to an increasing dependence of budget on revenues from oil and gas industries. The share of proceeds from these sectors has reached 1/3 of total federal revenues. To explain this fact world oil prices dynamics and changes in tax legislation in Russia are considered. Empirical results show strong dependence of budget revenues on oil prices. The analysis of changes in tax legislation in oil and gas industry shows that the government has managed to redistribute resource rent in favor of the state.

The Political Economy of Power: Approaches to the Analysis of Relationships between the State and Business in Russia

2011 ◽  
pp. 19-33
Author(s):  
A. Oleinik
Keyword(s):  
Oil And Gas ◽  
Road Construction ◽  
Oil And Gas Industry ◽  
Retail Trade ◽  
Business Community ◽  
The Political ◽  
Economic Power ◽  
Gas Industry ◽  
The Road ◽  
Ruling Elites

The article deals with the issues of political and economic power as well as their constellation on the market. The theory of public choice and the theory of public contract are confronted with an approach centered on the power triad. If structured in the power triad, interactions among states representatives, businesses with structural advantages and businesses without structural advantages allow capturing administrative rents. The political power of the ruling elites coexists with economic power of certain members of the business community. The situation in the oil and gas industry, the retail trade and the road construction and operation industry in Russia illustrates key moments in the proposed analysis.

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