Study of Numerical Modeling of Moonpool as Minimization Device of Monocolumn Hull

2004 ◽  
Author(s):  
Fernando G. S. Torres ◽  
Marcos Cueva ◽  
Edgard Borges Malta ◽  
Kazuo Nishimoto ◽  
Marcos Donato Ferreira
Keyword(s):  
Wave Spectrum ◽  
Oil Field ◽  
Oil Fields ◽  
Natural Period ◽  
Section Area ◽  
New Type ◽  
Steel Catenary Risers ◽  
Heave Motion ◽  
Bilge Keel ◽  
Geographical Characteristics

The steel catenary risers (SCR) have been studied to be used in ultra-deep oil fields. In Brazil, the oil field is going to deeper water. The geographical characteristics impose this type of production risers, and the necessity of these risers is real. However, in order to avoid risers fatigue problems, some premises related to low vertical motions have to be respected. To reach the necessary good seakeeping responses, new type of hull shape has been proposed, the monocolumn hull, to which some motion minimization devices have been developed. There are several conceptions of monocolumn type hull, but the concept presented in this paper is different from the existing monocolumn hull. To have good seakeeping capability, three main minimization devices were proposed: the structural skirt, the inclined wall, and the moonpool. The inclined wall, a variation of a section area near the water-plane, works together with the skirt, an enlarged bilge keel at the bottom of the platform, modifying the effect of damping, added mass and inertia. The moonpool is the old tank usually found in drilling units, properly modified to work as a motion minimization system. It works as a passive heave motion reduction system, shifting the natural period far from the wave spectrum. Some numerical analyses were made to present the effects obtained from these devices. These numerical results from WAMIT® were compared to experimental showing to be according to them.

scholarly journals A New Semisubmersible Design for Improved Heave Motion, Vortex-Induced Motion and Quayside Stability

2011 ◽  
Author(s):  
Qi Xu
Keyword(s):  
Floating Platform ◽  
Natural Period ◽  
Suppression Effect ◽  
Structural Rigidity ◽  
Hull Design ◽  
Induced Motion ◽  
Steel Catenary Risers ◽  
The Difference ◽  
Touchdown Point ◽  
Heave Motion

Recently the semisubmersible has become a favorable choice as a wet-tree floating platform supporting steel catenary risers (SCRs), mainly due to its capability of quayside topside integration and cost-effectiveness. However, it is still a challenge for a conventional semisubmersible to support SCRs, particularly large ones, in harsh environment and relatively shallow water due to its large heave motion. To answer this challenge, a new semisubmersible design has been developed at Technip as a wet-tree floater which achieves significantly improved heave motion and vortex-induced-motion (VIM) performance through hull form optimization while maintaining the simplicity of a conventional semisubmersible design. The difference between the NexGen semi-submersible design and a conventional semi-submersible design is in the blisters attached to the columns, distribution of pontoon volume, and pontoon cross section shape. In the NexGen semi-submersible design, the pontoon volume is re-distributed to minimize heave loading while maintaining sufficient structural rigidity, a long heave natural period and adequate quayside buoyancy. The blisters attached to the columns effectively break the vortex shedding coherence along the column length and therefore suppresses VIM. The blisters also provide much needed stability at quayside and during the hull deployment process, making the hull design less sensitive to topside weight increase. In the present paper the hydrodynamic aspects of this new design are discussed in detail. A benchmark case is presented in which the new design is compared against a more conventional design with the same principal dimensions. It is shown that the heave response in extreme sea states (100-yr hurricane) at the platform center of gravity is reduced by about 30–40%, and at the SCR hang-off locations by about 25–30%. Due to the reduced heave motion, SCRs experience about one third less stress at the touchdown point. A qualitative VIM analytical model is used to predict the VIM suppression effect of the new design. A highlight of a VIM model test for the proposed design is also presented. The reduced heave and VIM significantly improve the riser stress and fatigue near the touchdown point. This new design makes the semisubmersible a more robust wet-tree floater concept, and even a potentially good candidate as a dry-tree host concept in relatively benign environment.

Flow Assurance in Buzios Field: Key Challenges and Implemented Solutions

2021 ◽  
Author(s):  
Ivan Noville ◽  
Milena da Silva Maciel ◽  
Anna Luiza de Moraes y blanco de Mattos ◽  
João Gabriel Carvalho de Siqueira
Keyword(s):  
Liquid Flow Rate ◽  
Hydrate Formation ◽  
Oil Field ◽  
Oil Fields ◽  
Injection System ◽  
Flow Assurance ◽  
Water Alternating Gas ◽  
Early Design Stages ◽  
Scale Deposition ◽  
Full Operation

Abstract This article's goal is to present some of the main flow assurance challenges faced by PETROBRAS in the Buzios oil field, from its early design stages to full operation, up to this day. These challenges include: hydrate formation in WAG (Water Alternating Gas) operations; reliability of the chemical injection system to prevent scale deposition; increasing GLR (Gas Liquid Ratio) management and operations with extremely high flowrates. Flow assurance experience amassed in Buzios and in other pre-salt oil fields, regarding all these presented issues, is particularly relevant for the development of future projects with similar characteristics, such as high liquid flow rate, high CO2 content and high scaling potential.

Numerical Simulation of Gas Lift Optimization Using Artificial Intelligence for a Middle Eastern Oil Field

2021 ◽  
Author(s):  
Mohammed Ahmed Al-Janabi ◽  
Omar F. Al-Fatlawi ◽  
Dhifaf J. Sadiq ◽  
Haider Abdulmuhsin Mahmood ◽  
Mustafa Alaulddin Al-Juboori
Keyword(s):  
Genetic Algorithm ◽  
Sensitivity Analysis ◽  
Middle Eastern ◽  
Optimization Technique ◽  
Injection Rate ◽  
Oil Field ◽  
Oil Fields ◽  
Reservoir Pressure ◽  
Artificial Lift ◽  
Gas Lift

Abstract Artificial lift techniques are a highly effective solution to aid the deterioration of the production especially for mature oil fields, gas lift is one of the oldest and most applied artificial lift methods especially for large oil fields, the gas that is required for injection is quite scarce and expensive resource, optimally allocating the injection rate in each well is a high importance task and not easily applicable. Conventional methods faced some major problems in solving this problem in a network with large number of wells, multi-constrains, multi-objectives, and limited amount of gas. This paper focuses on utilizing the Genetic Algorithm (GA) as a gas lift optimization algorithm to tackle the challenging task of optimally allocating the gas lift injection rate through numerical modeling and simulation studies to maximize the oil production of a Middle Eastern oil field with 20 production wells with limited amount of gas to be injected. The key objective of this study is to assess the performance of the wells of the field after applying gas lift as an artificial lift method and applying the genetic algorithm as an optimization algorithm while comparing the results of the network to the case of artificially lifted wells by utilizing ESP pumps to the network and to have a more accurate view on the practicability of applying the gas lift optimization technique. The comparison is based on different measures and sensitivity studies, reservoir pressure, and water cut sensitivity analysis are applied to allow the assessment of the performance of the wells in the network throughout the life of the field. To have a full and insight view an economic study and comparison was applied in this study to estimate the benefits of applying the gas lift method and the GA optimization technique while comparing the results to the case of the ESP pumps and the case of naturally flowing wells. The gas lift technique proved to have the ability to enhance the production of the oil field and the optimization process showed quite an enhancement in the task of maximizing the oil production rate while using the same amount of gas to be injected in the each well, the sensitivity analysis showed that the gas lift method is comparable to the other artificial lift method and it have an upper hand in handling the reservoir pressure reduction, and economically CAPEX of the gas lift were calculated to be able to assess the time to reach a profitable income by comparing the results of OPEX of gas lift the technique showed a profitable income higher than the cases of naturally flowing wells and the ESP pumps lifted wells. Additionally, the paper illustrated the genetic algorithm (GA) optimization model in a way that allowed it to be followed as a guide for the task of optimizing the gas injection rate for a network with a large number of wells and limited amount of gas to be injected.

scholarly journals The use of the method of controlling the electrochemical parameters of aqueous solutions to combat complications in the operation of oil field pipelines

2021 ◽  
Vol 225 ◽  
pp. 01008
Author(s):  
Oleg Latypov ◽  
Sergey Cherepashkin ◽  
Dina Latypova
Keyword(s):  
Aqueous Solutions ◽  
Oil And Gas ◽  
High Efficiency ◽  
Oil Field ◽  
Oil Fields ◽  
Control Methods ◽  
Test Results ◽  
Chemical Reagents ◽  
Electrochemical Parameters ◽  
Very High

Corrosion of equipment in the oil and gas complex is a global problem, as it contributes to huge material costs and global disasters that violate the environment. Corrosion control methods used to protect equipment do not always ensure the absolute safety of the operation of oil and gas facilities. Moreover, they are quite expensive. The developed method for controlling the electrochemical parameters of aqueous solutions to combat complications during the operation of oil-field pipelines provides the necessary protection against corrosion. The method is economical and environmentally friendly, since it does not require the use of chemical reagents. The test results have shown a very high efficiency in dealing with complications in oil fields.

scholarly journals Metallic Composition Analysis of Crude Petroleum from Some Oil Fields in Ghana

2021 ◽  
pp. 19-29
Author(s):  
Robert Wilson ◽  
Calvin Kwesi Gafrey ◽  
George Amoako ◽  
Benjamin Anderson
Keyword(s):  
Chemical Elements ◽  
Earth Metal ◽  
Oil Field ◽  
Oil Fields ◽  
Composition Analysis ◽  
Crude Petroleum ◽  
Reservoir Properties ◽  
Exciting Field ◽  
Nuclear Research Institute ◽  
X Ray

Qualitative and quantitative analyses of chemical elements in crude petroleum using energy-dispersive X-ray fluorescence spectroscopic technique has attracted the attention of scientific world because it is fast, cheap, non-destructive and assurance in quality compared to other methods. Metallic element characterisation of crude petroleum is important in the petrochemical industry because it determines rock reservoir properties, the technology needed for extraction and refinery process, hence an exciting field that calls for research. X-ray fluorescence method was used for metallic composition analysis of four rundown crude petroleum samples (SB-2, SB-4, TB-2 and TB-1) from three oil fields (Saltpond, TEN and Jubilee). It was conducted at the National Nuclear Research Institute of Ghana. Analysis of the four samples concluded that oil field maturity decreases orderly from Saltpond, Jubilee and TEN. Vanadium-nickel ratios for each crude petroleum sample was less than 0.5, indicating that both Saltpond and Tano sedimentary rocks are of marine organic origin. Higher concentration levels of rare earth metal elements (scandium and yttrium) in the Saltpond sedimentary basin compared to Tano sedimentary rock suggest seismic effect of McCarthy Hills on Saltpond Basin. The strong negative correlation between the vanadium-nickel ratio (predictor) and scandium concentration (dependent) among the three oil fields implies that scandium concentration can equally be used to characterise the oil fields just as the vanadium-nickel ratios.

scholarly journals Naturally occurring radioactive materials and related hazard indices in Ahdeb oil field

2019 ◽  
Vol 13 (27) ◽  
pp. 164-173
Author(s):  
Zainab Mohammed Hassan
Keyword(s):  
Crude Oil ◽  
Activity Concentration ◽  
International Comparisons ◽  
Oil Field ◽  
Oil Fields ◽  
Hazard Indices ◽  
Radioactive Materials ◽  
Naturally Occurring ◽  
Naturally Occurring Radioactive Materials ◽  
Crude Oil Sludge

In this work, measurements of activity concentration of naturally occurring radioactive materials (NORM) isotopes and their related hazard indices for several materials such as crude oil, sludge and water in Ahdeb oil fields in Waste governorate using high pure germanium coaxial detection technique. The average values for crude oil samples were174.72Bq/l, 43.46Bq/l, 355.07Bq/l, 264.21Bq/l, 122.52nGy/h, 0.7138, 1.1861, 0.601 mSv/y, 0.1503mSv/y and 1.8361 for Ra-226, Ac-228, K-40, Ra eq, D, H-external and H-internal respectively. According to the results; the ratio between 238U to 232Th was 4, which represents the natural ratio in the crust earth; therefore, one can be strongly suggested that the geo-stricture of the Ahdeb oil fields dose not contents any kind of rocks. Although the results indicate the rising in the activity concentration of NORM isotopes, the national and international comparisons proved that it is still in the world range limits.

Laboratory studies of oil-washing characteristics of surfactants in the pore space of reservoir rocks

2021 ◽  
pp. 86-98
Author(s):  
V. Yu. Ogoreltsev ◽  
S. A. Leontiev ◽  
A. S. Drozdov
Keyword(s):  
Oil Recovery ◽  
Pore Space ◽  
Oil Field ◽  
Oil Fields ◽  
Molecular Surface ◽  
Laboratory Studies ◽  
Reservoir Rocks ◽  
Technological Efficiency ◽  
Chemical Eor ◽  
Physical And Chemical

When developing hard-to-recover reserves of oil fields, methods of enhanced oil recovery, used from chemical ones, are massively used. To establish the actual oil-washing characteristics of surfactant grades accepted for testing in the pore space of oil-containing reservoir rocks, a set of laboratory studies was carried out, including the study of molecular-surface properties upon contact of oil from the BS10 formation of the West Surgutskoye field and model water types with the addition of surfactants of various concentrations, as well as filtration tests of surfactant technology compositions on core models of the VK1 reservoir of the Rogozhnikovskoye oil field. On the basis of the performed laboratory studies of rocks, it has been established that conducting pilot operations with the use of Neonol RHP-20 will lead to higher technological efficiency than from the currently used at the company's fields in the compositions of the technologies of physical and chemical EOR Neonol BS-1 and proposed for application of Neftenol VKS, Aldinol-50 and Betanol.

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