Tensile Response of a Flexible Pipe With an Incomplete Tensile Armor Layer

2021 ◽  
Vol 143 (5) ◽  
Author(s):  
Xiaohua Zhu ◽  
Qinglong Lei ◽  
Yu Meng ◽  
Xiaoxuan Cui
Keyword(s):  
Oil And Gas ◽  
Production Systems ◽  
Element Model ◽  
Flexible Pipe ◽  
Flexible Pipes ◽  
Safety And Reliability ◽  
Oil And Gas Resources ◽  
Offshore Oil And Gas ◽  
Unbonded Flexible Pipes ◽  
Offshore Oil

Abstract Unbonded flexible pipes are widely utilized in the exploitation of offshore oil and gas resources. They are connected to two of the most critical types of system: floating production platforms and underwater production systems. However, if some tensile armor wires are substituted by cables or broken, the tensile armor layer will be incomplete, which seriously reduces the safety and reliability of the flexible pipe. In the present study, models of a flexible pipe with a complete tensile layer and with the tensile layer partially missing were established. The error for the tensile stiffness obtained by the finite element model of an intact flexible pipe was only 1% compared with experimental results. Because the load borne by the inner tensile armor layer is larger under tension than that borne by the outer tensile armor layer, the loss of inner tensile armor wires has a greater impact on the tensile properties. The maximum axial elongation of the flexible pipe increases with the number of missing inner tensile armor wires as a cubic polynomial. If the distribution of the missing armor wires is too dense, a stress concentration and local bending may occur, which will reduce the tensile strength of the flexible pipe.

scholarly journals A New Pricing Model for Crude Oil Pre-Sale Units via SPFO (Standard Parallel Forward with Options) in Iran

2018 ◽  
Vol 7 (1) ◽  
pp. 32
Author(s):  
Ghasem Nikjou ◽  
Hamed Najafi ◽  
Kamran Salmani
Keyword(s):  
Oil And Gas ◽  
Development Program ◽  
Oil Industry ◽  
Pricing Model ◽  
Forward Security ◽  
Option Pricing Model ◽  
Oil And Gas Resources ◽  
Offshore Oil And Gas ◽  
Offshore Oil ◽  
Legal Barriers

Nowadays energy has an important role as a driving sector of economy. Forecasting 150 billion dollars investment in energy sector during the fifth development program in Iran, the banking and financial system require a dynamic and modern economy and financial instruments. Obviously, this approach needs to remove legal barriers and modification of contracts. Financing in the oil industry has faced with serious challenges in recent years. In addition, investing in common offshore oil and gas resources is indispensable. Accordingly we are going to design a new contract which is called Oil SPFO (Standard Parallel Forward security with two Options under betting condition), in order to raise funds needed. In this article we would investigate the SPFO for Iran Ministry of Petroleum (MOP)’s finance and present a model for pricing the oil SPFO based on Black and Scholes option pricing model. Finally, we have some recommendations to develop the oil SPFO and suggest that other researchers work on pricing the oil parallel forward securities according to this model.

Technical and Economic Considerations in Developing Offshore Oil and Gas Prospects Using Floating Production Systems

1986 ◽  
Vol 23 (03) ◽  
pp. 253-270
Author(s):  
W. J. Drawe ◽  
Anil Raj ◽  
P. J. Rawstron
Keyword(s):  
Decision Tree ◽  
Oil And Gas ◽  
Production Systems ◽  
State Of The Art ◽  
Related System ◽  
Offshore Oil And Gas ◽  
Offshore Oil ◽  
Economic Considerations

This paper discusses the use of floating production systems (FPS) in developing offshore fields and includes consideration of related system and subsystem options. The system options are discussed from their relative technical and economic merits. Proven conventional and state-of-the-art technology as well as technical limitations are included. A decision tree matrix has been developed for use in the early planning stages to assist in determining preferred baseline options for selecting an approach. Systems from the mud-line upwards to the floating hull, and on-board systems, are included.

SUBSEA PRODUCTION FOR WELLS DRILLED FROM JACKUP DRILLING UNITS

1987 ◽  
Vol 27 (1) ◽  
pp. 357
Author(s):  
M. Thatcher ◽  
D.B. Marietta
Keyword(s):  
Oil And Gas ◽  
Production Systems ◽  
Oil And Gas Fields ◽  
Offshore Oil And Gas ◽  
The Cost ◽  
Gas Fields ◽  
Offshore Oil

Subsea production systems have been an accepted method of developing offshore oil and gas fields since the installation of the first subsea trees in the early 1960s offshore California. Generally subsea completions have been done from floating drilling vessels on wells with subsea wellhead equipment. A number of wells have been completed subsea by bottom supported jackup rigs on wells drilled using mudline suspension equipment. The subsea completion equipment and methods utilised to adapt mudline suspension wells for a subsea production tree are described. This method of completion offers important benefits as it allows completion of wildcat or delineation wells, it can be used in areas of small, scattered reservoirs, and it can be used in conjunction with floating production systems. The cost associated with these subsea completions is roughly equivalent to those of standard subsea completions from floating vessels. An overview of a typical completion system is presented and compared.

Management of Mid-Atlantic Offshore Development Risks

1977 ◽  
Vol 14 (04) ◽  
pp. 331-350
Author(s):  
W. D. Snider ◽  
G. J. Buffleben ◽  
J. R. Harrald ◽  
K. F. Bishop ◽  
J. C. Card
Keyword(s):  
Oil And Gas ◽  
Environmental Damage ◽  
System Safety ◽  
Oil And Gas Resources ◽  
Development Plans ◽  
Offshore Oil And Gas ◽  
Development Risks ◽  
Offshore Development ◽  
Offshore Oil ◽  
Central Management

Careful attention must be given to identification, evaluation, and control of risks associated with development of mid-Atlantic offshore oil and gas if environmental damage and development delays are to be avoided. A number of approaches to safety, or risk management, are possible, but all seek to answer the central management, are possible, but all seek to answer the central management question, "Am I safe enough?" System safety methods are now available which can assist us in making intelligent decisions on safety measures to be incorporated in offshore development plans. Development of offshore oil and gas resources has brought new risks to exploratory and development drilling, production, and transportation operations. Concern over these risks has prompted a number of studies. After a brief review of these studies, the authors describe investigations in two areas: oil discharges in the Gulf of Mexico and worldwide accidents involving mobile offshore drilling units. A number of measures to reduce risks are being considered or have already been taken by government and industry. Greater application of system safety procedures offers new potential for reducing the risks in offshore development.

Size Effects in Winding Roll Formed Profiles: A Study of Carcass Production for Flexible Pipes in Offshore Industry

2013 ◽  
Vol 549 ◽  
pp. 117-124 ◽  
Author(s):  
Peter Søe Nielsen ◽  
Morten Storgaard Nielsen ◽  
Nils Bay
Keyword(s):  
Degrees Of Freedom ◽  
Oil And Gas ◽  
Target Location ◽  
Roll Forming ◽  
Fe Model ◽  
Element Analysis ◽  
Flexible Pipes ◽  
Offshore Industry ◽  
Offshore Oil And Gas ◽  
Offshore Oil

Carcass production of flexible offshore oil and gas pipes implies winding and interlocking of a roll formed stainless steel profile around a mandrel in a spiral shape. The location of the dividing point between the left and right half of the s-shaped profile in the finished carcass is very important as it directly influences carcass flexibility. The target location of the dividing point can be difficult to achieve since undesired degrees of freedom in the winding stage allows the profile to change geometry. The present work investigates this issue by performing production tests of a single carcass profile size on three mandrel sizes showing a size effect to be evident; smaller mandrel size increases a shift of the dividing point during initial mandrel contact in the winding stage. The cause is high strains in the open profile, which are minimized by the material moving closer to profile neutral plane. Other parameters such as profile entry angle on the mandrel and spiral pitch are likely to have significant importance. Proper dividing point position is shown to be obtainable by adjusting the profile in the roll forming stage. The profile rolling is successfully modeled by Finite Element Analysis (FEA), whereas a simplified FE-model of the subsequent winding operation shows that full interlock modeling is required for proper prediction of profile deformation.

Helical Wire Behavior of Unbonded Flexible Pipes Under Bending

2015 ◽  
Author(s):  
Yutian Lu ◽  
Huibin Yan ◽  
Yong Bai ◽  
Peng Cheng
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Axial Strain ◽  
Bending Moment ◽  
Element Model ◽  
Flexible Pipe ◽  
Slip Mechanism ◽  
Flexible Pipes ◽  
Bending Behavior ◽  
Unbonded Flexible Pipes

The bending behavior of unbonded flexible pipe is governed by the response of the helical wires in the tensile armor to bending. The behavior of the helical wire, especially the axial strain, is influenced by the slip mechanism as a result of an increasing curvature under bending. In the present paper, two limit curves are considered with a certain curvature. A 3-D finite element model using ABAQUS is developed to simulate the practical behavior of the helical wires under bending. By comparing the FEA and theoretical results, a basic conclusion about the real slip path of the helical wire between two limit curves is introduced. A hysteretic bending moment-curvature relationship induced by the slip mechanism is obtained from the finite element model as well.

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