Development of Dual-Lifting Technique for Installation of Topside Mega-Modules

Author(s):  
Dong Woo Jung ◽  
Hyun Joe Kim ◽  
Hae Sung Ji ◽  
Hyoen Su Jeong ◽  
Mihee Nam ◽  
...  

As many deep-sea oil and gas fields are being developed, floating platforms becomes larger with more complicated topsides. However, the construction time is demanded to be shorter to meet the overall project schedule. The use of very large topside modules is one of the effective ways to reduce the integration time and decrease the possibility of fabrication defects. The Ichthys Project’s CPF (Central Process Facility) is currently being constructed at Samsung Heavy Industries (SHI). The CPF will be the world’s largest production semi-submersible platform. The hull is constructed on the Offshore Floating Dock and most of the topside modules are prepared at workshops and integrated by floating cranes on the hull. To maximize production efficiency in terms of reduced integration time and reworks, several topside modules are assembled into a larger module weighing up to 7,400 tonne spanning 150m long. Such large module cannot be handled by a single 8,000 tonne F/C, the largest crane that SHI owns. This fact initiated the idea of dual-lifting with a combination of the two F/Cs (8,000 tonne and 3,600 tonne) which enables lifting, transportation and integration of the mega-modules properly and safely without building a larger capacity F/C. Using different sized F/Cs increases the flexibility of the operation of the F/Cs. To ensure safety during the dual-lifting, the two F/Cs are synchronized to be controlled as a single crane unit. During hoisting, all the measured data such as loads and positions of the hooks, and rotation of the module, are monitored in real time basis and used to hoist the module automatically. All the systems are designed to be redundant. Additional engineering works are performed to check the safety such as 1) structural analysis to investigate the structural safety with out-of-phased motions at boom-tip 2) time-domain analysis and 3) model test in ocean basin with the operation scenarios in real environments to obtain the dynamic load factors and the guidance on the operation limits in terms of wave heights. The two crane barges are moored side-by-side using fenders and mooring lines, and tug operation conditions are planned not only to move but also to push the two barges from sideways to be moored tightly, which minimizes the possibility of relative motions between the two barges. The developed system had been applied to the integration of all the modules successfully weighing from 4600 to 7400 tonne. It is expected to be applied to many other offshore projects to keep the construction schedule on time. This paper will address and share the technical experiences obtained during the dual lifting of the mega-modules for the Ichthys Project’s CPF.

Author(s):  
Liping Sun ◽  
Xu Zhang ◽  
Youwei Kang ◽  
Shuhong Chai

Catenary anchor legs mooring (CALM) buoy offloading system is widely used in offshore oil and gas exploitation engineering. Proper prediction of the motion response of CALM systems is very important to the fatigue analysis of offloading pipelines and the design of mooring lines. Numerical models of a CALM system in survival and operation conditions will be established in this paper, and motion characteristics of the buoy and its sensibility to environmental factors, as well as performance of slender bodies are derived. More importantly, the shuttle tanker’s stability in plane and the risk of its collision with other floating bodies are focused on in this paper. All of the conclusions will provide recommendation for designing in practical engineering.


Author(s):  
Jorge Mendoza ◽  
Jacopo Paglia ◽  
Jo Eidsvik ◽  
Jochen Köhler

Mooring systems that are used to secure position keeping of floating offshore oil and gas facilities are subject to deterioration processes, such as pitting corrosion and fatigue crack growth. Past investigations show that pitting corrosion has a significant effect on reducing the fatigue resistance of mooring chain links. In situ inspections are essential to monitor the development of the corrosion condition of the components of mooring systems and ensure sufficient structural safety. Unfortunately, offshore inspection campaigns require large financial commitments. As a consequence, inspecting all structural components is unfeasible. This article proposes to use value of information analysis to rank identified inspection alternatives. A Bayesian Network is proposed to model the statistical dependence of the corrosion deterioration among chain links at different locations of the mooring system. This is used to efficiently update the estimation of the corrosion condition of the complete mooring system given evidence from local observations and to reassess the structural reliability of the system. A case study is presented to illustrate the application of the framework.


Author(s):  
Morten Lovstad ◽  
Tor G. Syvertsen

Abstract Huge steel or reinforced concrete structures in deep waters support the installations for oil and gas production in the North Sea. Steady operations in a hostile environment require that structural safety and integrity is maintained. For rapid evaluation and assessment of structural integrity in case of modifications or urgency situations, Structural Integrity Systems are established, comprising computational models and structural analysis programs. A major problem for structural assessment at short notice is to keep the analysis models updated and consistent with the actual state of the physical structure and the loadings. This paper proposes a layered approach for model integration, which enable maintenance of the models at a high level, from which detailed analysis models are derived in a consistent manner.


2021 ◽  
Author(s):  
Andrey Alexandrovich Rebrikov ◽  
Anton Anatolyevich Koschenkov ◽  
Anastasiya Gennadievna Rakina ◽  
Igor Dmitrievich Kortunov ◽  
Nikita Vladimirovich Koshelev ◽  
...  

Abstract Currently, production and exploration drilling has entered a stage of development where one of the highest priority goals is to reduce the time for well construction with new technologies and innovations. One of the key components in this aspect is the utilizing of the latest achievements in the design and manufacture of rock cutting tools – drill bits. This article presents some new ideas on methods for identifying different types of vibrations when drilling with PDC bits using a system of sensors installed directly into the bit itself. In the oil and gas fields of Eastern Siberia, one of the main reasons for ineffective drilling with PDC bits are vibrations, which lead to premature wear of the cutting structure of the bit and the achievement of low ROPs in the dolomite and dolerite intervals. For efficient drilling of wells of various trajectories with a bottom hole assembly (BHA), including a downhole motor (PDM) and a PDC bit, special attention is paid to control of the bit by limiting the depth of cut, as well as the level of vibrations that occur during drilling process. Often, the existing complex of surface and BHA equipment fails to identify vibrations that occur directly on the bit, as well as to establish the true cause of their occurrence. Therefore, as an innovative solution to this problem, a system of sensors installed directly into the bit itself is proposed. The use of such a system makes it possible to determine the drilling parameters, differentiated depending on the lithological properties of rocks, leading to an increase in vibration impact. Together with the Operators, tests have been successfully carried out, which have proven the effectiveness of the application of this technology. The data obtained during the field tests made it possible to determine the type and source of vibration very accurately during drilling. In turn, this made it possible to precisely adjust the drilling parameters according to the drilled rocks, to draw up a detailed road map of effective drilling in a specific interval. Correction of drilling parameters based on the analysis of data obtained from sensors installed in the bit made it possible to reduce the resulting wear of the PDC bit cutting structure and, if necessary, make changes to the bit design to improve the technical and economic indicators. Thus, the use of a system of sensors for measuring the drilling parameters in a bit ensured the dynamic stability of the entire BHA at the bottomhole when drilling in rocks of different hardness, significantly reduced the wear of the drilling tools and qualitatively improved the drilling performance.


Author(s):  
Mo Fan ◽  
Da Li ◽  
Tuanjie Liu ◽  
Alex Ran ◽  
Wei Ye

An octagonal FPSO has been proposed for marginal oil and gas development in shallow waters. A shuttle tanker will be deployed near the FPSO during offloading operations. This new concept simplifies the design and manufacturing processes, yet maintains full production, storage, and offloading functions of a conventional ship-shaped FPSO. However, design of the mooring system for this floating unit imposes technical challenges due to: 1) high environmental loads expected on this unit, 2) large dynamic offsets of the unit in shallow waters, and 3) inadequate performance of catenary mooring systems in shallow waters. Thus, development of a viable station keeping solution becomes a key issue to the new concept FPSO design. In this paper, an innovative mooring system is designed to meet the challenges. The FPSO mooring system consists of pile anchors, bridle chains, anchorage buoys, and polyester ropes. Nine mooring lines are grouped into three bundles which evenly spread around the FPSO. The shuttle tanker is attached to the FPSO with a nylon rope hawser at the bow and secured to pre-installed anchorage buoys at the stern with two other nylon ropes. Analyses have been performed for the FPSO mooring system. It is concluded that the proposed mooring system is fully functional and effective.


2021 ◽  
Author(s):  
Jonathan Kent Longridge ◽  
Johnny Shield ◽  
Sarah Finn ◽  
Tom Fulton

Objectives/Scope As the offshore oil and gas industry has changed, deep water Mobile Offshore Drilling Units (MODU) are commonly outfitted with dynamic positioning (DP) systems and on-vessel mooring equipment to facilitate drilling operations at ultra-deep and shallow water well locations. However, since many shallow water locations can experience harsh conditions and may require moorings for station-keeping performance, it is beneficial to enable a DP rig to quickly disconnect from its mooring system and avoid hazardous conditions without support vessel assistance. Providing this capability, acoustically releasable subsea mooring connectors allow a rig's mooring lines to be released remotely and almost immediately. Additionally, the ability to disconnect without Anchor Handler Vessel (AHV) assistance for mooring operations and rig transit support offers reduced risk and cost savings. Methods, Procedures, Process A brief review of existing quick-disconnect mooring devices will be presented. It will highlight how the technology has evolved and is being used, particularly in recent years. Successes, problems, and lessons learned from past InterMoor and SRP product development will be summarized and focused attention will be given to a significant number of more recent improvements to increase the product's reliability, availability, serviceability, and robustness. Improvements to ensure reliable long-term battery life and power supply, enhance on-vessel accessibility and user-friendliness for rig personnel, and employ advanced acoustic signal transmission, reception, and device status analytics will be discussed. External modifications to reinforce its robustness during deployment and internal electromechanical changes to facilitate its serviceability will also be described. Results, Observations, Conclusions A substantially lighter and smaller acoustically releasable mooring connector was developed two years ago, tested thereafter, recently deployed on several offshore mooring campaigns, and has now been upgraded to incorporate high-fidelity electronics with the ability to release under tension loads as high as 900 tonnes. As such, this second-generation device's reliability, accessibility, and serviceability are significantly enhanced. Results from offshore deployments from recent MODU and barge mooring operations will be summarized. This technology provides a safer way to quickly disconnect mooring lines and offers cost efficiency by allowing faster rig moves from one location to the next with reduced risk. Novel/Additive Information The paper will cover the work, challenges, trials, and tribulations required to bring a new product to market with cutting edge capabilities. Novel highlights will include the integration of a networked data transmission and communication system, the system's fundamental change from pneumatic to electromechanical actuation, and additional enhancements and improvements that are unique to mooring quick-disconnect devices and at the forefront of subsea technology.


2019 ◽  
Vol 11 (6) ◽  
pp. 1613
Author(s):  
Daekyoung Yi ◽  
Eul-Bum Lee ◽  
Junyong Ahn

Korean oil and gas contractors have recently incurred significant losses due to improper engineering performance on EPC (engineering procurement and construction) projects in overseas markets. Several previous studies have verified the significant impact engineering has on EPC construction cost and project lifecycle. However, no literature has studied the time impact engineering has on EPC projects, representing a gap in the existing body of knowledge. To fill this gap, a Monte Carlo simulation was performed with the Pertmaster, Primavera risk analysis software for three sample onshore oil and gas projects. From said simulation of all major EPC critical activities, the authors found that the engineering phase is up to 10 times as impactful as the procurement and construction phases on the overall schedule duration. In assessing the engineering activities, the authors found the piping design activities to have the greatest impact on the overall schedule performance. Using these findings, the authors present a design schedule management process which minimizes the delays of project completion in EPC projects. Said process includes the following six steps: (1) Milestone management, (2) drawing status management, (3) productivity management of engineering, (4) interface management, (5) management of major vendor documents, and (6) work front management. The findings of this paper add to the body of knowledge by confirming the design phase to be the most impactful on the overall project schedule success. Furthermore, the presented design schedule management will aid industry with successfully executing the design phase in a timely manner, including examples from case study projects for a greater understanding.


Author(s):  
Philipp R. Thies ◽  
Lars Johanning ◽  
Tessa Gordelier ◽  
Andrew Vickers ◽  
Sam Weller

The reliability and integrity of components used in the marine offshore environment is paramount for the safety and viability of offshore installations. The engineering challenge is to design components that are robust enough to meet reliability targets whilst lean enough to minimise cost. This is particularly the case for offshore marine renewable installations which operate in the same, possibly harsher, environment as offshore oil and gas installations, and are subjected to highly cyclic and dynamic wave, wind and operational load conditions. The cost of electricity produced has to compete with other means of electricity generation and does thus not offer the same profit margins available as oil and gas commodities. As a result, components for marine renewable installations have to meet the target reliability, without the application of costly safety factors to account for load and environmental uncertainties. Industries with similar design tasks such as the aviation or automotive industry have successfully used a service simulation test approach to develop robust yet lean designs. This paper builds on an approach to establish and validate the reliability of floating renewable energy devices in which dedicated component testing using the purpose built Dynamic Marine Component test rig (DMaC) plays a pivotal role to assess, validate and predict the reliability of components in the marine environment. This paper presents a test rig for both static and fatigue tests of marine components such as mooring lines and mooring shackles under simulated or measured load conditions and provides two case studies from recently conducted mooring component tests. This includes an investigation into the load behaviour of synthetic mooring ropes and the ageing of mooring shackles.


2019 ◽  
Vol 4 (1) ◽  
pp. 115-122
Author(s):  
Ernest Oria Ihendeson ◽  
Awajiogak A Ujile ◽  
Anthony K. Leol

This study aim to proffer solution to the factors causing delay is pipeline construction project deliverables, it compared deterministic model (variable with certainty) and stochastic model (variable with uncertainty), with Six (6) planned project schedules of Brownfield Energy Service Limited for pipeline construction. Time assigned to critical activities, identified from a network analysis, with the aid of the Critical Path Method, expected mean time, both deterministic and stochastic duration was calculated. Program Evaluation Review Techniques (PERT), the variance and standard deviation of the critical activities were also calculated. The probability of completion of a project within a given period was gotten with PERT. Comparing the results for deterministic duration 60 days to 79 days, which is 50% compared to 64%. It was concluded that stochastic model is preferable when scheduling and executing pipeline construction projects, because uncertainties are factored into the planning and scheduling process including delays. Delays during execution stage, occurs mainly due to community related issues, equipment failures, change in job scope and work- men antics but not limited to these. This study advocates elimination of causes of delay, especially before and during project execution phase. It also suggested that every project schedule should follow an order of precedents, prerequisite, and management involvement and cooperation at all stages of the project


Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 5016
Author(s):  
Mikhail Konstantinovich Rogachev ◽  
Thang Nguyen Van ◽  
Aleksandr Nikolaevich Aleksandrov

Within the past few decades, the production of high-wax oils at offshore fields in Vietnam has been fraught with severe problems due to the intense formation of asphalt-resin-paraffin deposits (ARPD) in the downhole oil and gas equipment. The formation of organic wax deposits in the tubing string led to a significant decrease in gas-lift wells production, efficiency of compressor units, transport capacity of the piping systems, along with an increase in equipment failure. Subsequently, the efficiency of gas-lift wells dramatically decreased to less than 40% as a whole. The existing methods and technologies for combating organic wax deposit formation in downhole equipment have many advantages. However, their use in producing high-wax anomalous oil does not entirely prevent the wax formation in the tubing string and leads to a significant reduction in oil production, transport capacity, and treatment intervals. The results of theoretical and experimental studies presented in this article demonstrate that a promising approach to improve the efficiency of gas-lift wells during the production of high-wax oil is to use the technology of periodic injection of hot associated petroleum gas (APG) into the annulus of an oil-producing well. The effectiveness of the proposed method of combating wax formation in gas-lift wells highly depends on the combination of a few factors: the determination of wax deposit formation intensity in the well and the implementation of a set of preparatory measures to determine the optimal injection mode of hot APG (flow rate and injection depth) into the annulus between tubing strings and technological pipes. The injection depth of the hot APG should not be less than the depth of wax formation in the tubing string. The optimal injection rate of hot APG is determined by analyzing and mathematically modeling the APG injection system based on well-known thermodynamic laws.


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