bluuebunny/crossref_metadata_2025_split huggingface dataset:
Selection of Routes For Sub-Mediterranean Pipelines
Authors: Serpas Luis B. , Belazoug Amar B. , Matteelli Rolando B. 
Published: October 2008

ABSTRACT
This paper deals with the planning, the execution and the data gathering operations ofa marine survey in the Strait of Sicily and the ultimate objective of determining a path or paths where it could be feasible to construct pipelines across the Mediterraneanbetween North Africa and Sicily establishes the scope and defines the principal tasks and their sequence to accomplish the objectives. A brief summary is given of the operations performed by the survey fleet and presents the techniques and general instrumentation used. A brief analysis is made CO of each one- of the investigative operations, including oceanography, hydrography, hydrology, geology soil mechanics and mefeorology. The description of operations includes the establishing and operating- of the horizontal control system and the photographic techniques employed for the study of the bottom morphology and nature of soils. The paper gives the type of results obtained and the subsequent plottings for use in the analysis of the crossing. The route analysis which was followed for the paths determination is given, together with the methods used to find and select the preferred corridors. Finally, the paper concludes on the results, the applicability and the reliability of the data and its usefulness to the project.

INTRODUCTION
The proposition of transporting natural gas or liquid petroleum from North Africa to Europe via pipelines across the Mediterranean Sea has been discussed, promoted, studied and experimented by many during the last fifteen years. Many energy entities and engineering companies have dealt with this project in various degrees of detail, including a series of full scale experiments intended to demonstrate the feasibility of installing the pipelines in the deep waters of the Western Mediterranean.
It was not until SONEMS, a study company formed by SONATRACH of Algeria, Ente Minerario Siciliano (EMS) and Ente Nazionali Idrocarburi (ENI) of Italy, decided to proceed with an intense techno economic study of feasibility, that such project assumed its imminent charactel' of today. Such project had the specific task of studying the transport of natural gas from Algeria to Italy by a pipeline traversing Algeria Tunisia, the Strait of Sicily, Sicily and the Strait of Messina. Not much was known of the Sicily, especially about the area in the known as the Tunisian Trench. The available charts and existing technical documentation even those as yet unpublished, showed a blank in this area in practically all respects. Among the decisions made by SONEMS, with Bechtel Incorporated as its engineer, was to proceed without delay on a two-phase program:A preliminary feasibility study to be based on a field reconnaissance of the Strait of Sicily.A final in-depth study to be based on a detailed marine survey of the Strait of- Sicily and the Strait of Messina.
Super Jack-Up Type Mobil Drill Rig Platform For Operation In 500 To 600-Ft.Water Depths
Authors: Giblon Robert P. , Minorsky Vladimir U. 
Published: October 2008

ABSTRACT
The developing energy crisis and the resulting need to discover oil and gas producing areas that are under 300 to 600- ft. of water has pointed to the need for a stable mobile drill rig platform that can be utilized for the drilling operation all year round.
This paper describes the basic features of a jackup type mobile drill rig platform for operation in a water depth of 500 ft. in the Gulf of Mexico during the hurricane season (about 550 ft. in the non-hurricane season). Included are drawings showing the general configuration of the unit and the method for jacking up and jacking down, as well as estimates of weight and cost.
The jack-up drill rig is compared with a semisubmersible as are presently required for drilling in water depths ranging from 450 to 600 ft. As part of this comparison, information is furnished relating to jack-up drill rigs callable of operating in water depths of 450 to 600 ft. in the Gulf of Mexico and the North Sea.

INTRODUCTION
The trend in offshore exploration clearly indicates that the oil industry has a need to search for oil and gas where water depths are 300 to 600 ft. and beyond the capability of the present jack-Up drill rig platforms. Further, for these water depths there is a need for a stable platform from which drilling can proceed under all types of weather conditions except for the most severe storm.
It is for this reason that the authors' company, George G. Sharp, Inc., developed the design for the jack-up type mobile drill rig platform described in this paper.

CONCEPT

General
The jack-up type mobile drill rig platform described herein for operation in a water depth of 500 ft. in the Gulf of Mexico during the hurricane season is based on calculations and drawings developed by the authors' company. The design has been developed to conform to the requirements of the American Bureau of Shipping"Rules For Building and Classing Offshore Mobile Drilling Units". Although the unit described is configured for operation in the Gulf in a water depth of 550 ft during the non-hurricane season, minor design changes will permit operating in greater water depths.
The materials selected will permit operation of the unit in the North Sea, but due to the more severe weather conditions in this area, the unit as presently configured would be confined to a water depth of around 460 ft. during the winter season and a somewhat greater depth when the weather conditions are not as severe.
Calculation of Long Term Values for Motions and structural Response of Mobile Drilling Rigs
Authors: Pedersen Bjørn , Egeland Olav , Langfeldt Jan N. 
Published: October 2008

ABSTRACT
A method is presented which is based on statistical evaluation of loads and corresponding stresses in irregular seas. Observed wave data in the potential areas of operation are used as a basis for simulating characteristic sea states on the computer, i.e. the time variation of the irregular wave pattern. On this basis the maximum stresses over the lifetime of the structure are predicted.

I INTRODUCTION
The most commonly used method for evaluating wave loads on an offshore structure has until now been to base the calculations on one or more design waves. This was also the case in the shipbuilding industry some years ago. When ship size increased, however, it became obvious that the design wave method led to unreasonable results in many cases. It was realized that the random nature of the ocean waves, and consequently of the responses of a structure to these waves, could only be described by statistical methods.
Recent research had revealed that the irregular wave pattern could be described by linearly superimposing regular waves of different frequencies. In this way it was made possible to take into account all the wave components present in a realistic sea. The development of methods for calculating the response of a floating structure to the regular waves was also initiated in this period. Det norske Veritas has played its part in this development and a number of computer programs relating to ship problems have been the result, see for instance /1, 2/. Calculations for ships based on the principles indicated have proved successful and these methods are now commonly used.
It was a natural step to try to extend the same principles and methods to offshore structures like drilling platforms.
The following will give a description of these methods as applied to semisubmersibles. Fig. 1.1 illustrates the procedure in principle. A particular feature is that the wave load program is directly connected to the stress analysis programs.

2 HYDRODYNAMICS

2.1 Equations of motion
The following forces acting on the platform are accounted for in the present analysis:–Hydrodynamic forces due to the relative motion between platform and waves–Inertia forces due to platform Motion–Restoring forces set up by the Anchors–Hydrostatic forces and other static forces applied at any point and acting in. arbitrary direction, e.g. wind and current forces.
The static forces are included in the list for completeness only, of course they do not influence the dynamics of-the problem.
The set of equations used to solve the motion problem in six degrees of freedom may be written in matrix notation as:(Mathematical equation available in full paper)
where M, Band C are six by six symmetric matrices. M is associated with the platform mass and added mass, B with the damping, and C with restoring. The displacement matrix may be written more explicitly as:(Mathematical equation available in full paper)
The First Dual Lateral Well Successfully Drilled Underbalanced in Libya
Authors: Safar Hussein , Azhary Sadek , Hijazi Ahmad , Qutob Hani , Chopty James , Pham Chau 
Published: October 2008

Abstract
The B24 well in the Fidaa Field was the first dual lateral underbalanced horizontal well drilled in Libya and the second well of Zueitina Oil Company's (ZOC) underbalanced drilling campaign.
The targeted reservoir "Facha" is partly depleted after 23 years of production to a 7.2 ppg equivalent mud weight. Nitrified diesel, a two-phase drilling fluid, was used to drill the reservoir section of the B24 underbalanced to avoid circulation losses and formation damage. Real time LWD was crucial for geosteering the well path in a complex reservoir structure and real time annular pressure measurement was also necessary to ensure the underbalanced condition was maintained throughout the entire UBD drilling phase.
Two 6" horizontal drains were drilled successfully with 2053' and 1517' drain lengths. Integrated efforts of ZOC and service companies of various disciplines during planning and operation stages of the well led to the success of the project. No QHSE incidents were reported and the productivity of the well was enhanced significantly.
The B24 well's production alone contributes to over 30% of the total Fidaa field production.

Introduction
The Fidaa field in the north of Muelah Graben at the western edge of Sirt Basin was discovered in 1979. The structural map of the Facha reservoir (Figure 1) shows the structure to be northwest - southeast trending with approximately 9.5 by 2.5 km size and a pay zone thickness of 28 feet. A total of 23 vertical wells were drilled to date in the Fidaa field. Well B24 was the last one drilled horizontally with two lateral legs. It was completed in May 2005.
Facha reservoir "C" layer is dolomite with vuggy porosity of 23% on average and logs indicate extensive fracturing. The reservoir pressure of the upper Facha ranges between 1600 psi to 2330 psi and the average pressure along the planned drain hole in the Facha "C" was 1900 psi at 6085' TVD (6 ppg EMW). The Facha reservoir is an oil bearing pay zone with a stock tank oil gravity of 41.7° API, a gas oil ratio of 68 SCF/STB, and water cut ranging from 6% to 70%. Due to a partially depleted pressure of the Fidaa field, lost circulation and other drilling problems were encountered in the field.

Challenging Problems
To cover the un-drained areas of the field, drilling new wells with conventional drilling fluids was very difficult. Severe losses and differential sticking especially in the horizontal reservoir section(s) were experienced. The invasion of foreign fluids and cuttings into the reservoir led to formation damage that accounted for low flow rates after the wells were put into production. Therfore, another drilling methods or techniques were needed to be considered by Zueitina Oil Company to solve the problems of the Fidaa field.

Solution
The Drilling Engineering Department of Zueitina Oil Company investigated many possible alternatives to solve the problems encountered which could also be applied economically and effectively in the field.
Ormen Lange-Challenges in Offshore Project Execution
Authors: Nordvik Birgitte , Kilde Einar 
Published: October 2008

Abstract
Ormen Lange is the second-largest Norwegian gas field and was discovered by Hydro in 1997. The Ormen Lange field comprises an offshore subsea solution approximately 125 km off the west coast of Norway, an onshore gas processing and export facility at Nyhamna, a gas export transportation system between Norway and the UK, and the Easington gas reception terminal in the UK. The Ormen Lange development is divided into three main sub-projects: Onshore, Offshore, and Langeled.
This paper gives a summary of the Ormen Lange Offshore development, including descriptions of project execution and contract strategy, and how Hydro's competence and systematic work processes have been utilized in order to secure efficient progress. The Offshore project will be further described - including the technical challenges of the project -in three OTC 2007 papers:OTC 18965 Ormen Lange subsea production systemOTC 18967 Ormen Lange pipelines installation and seabed preparationOTC 18969 Ormen Lange subsea compression pilot as a supplement to the summary provided here.

Introduction
Ormen Lange is Norway's second largest gas field, with expected gas export equivalent to the total energy demand in Norway.
The Ormen Lange gas field was proven by drilling in 1997, and Hydro was selected as operator for the development of the field in December 1999.
After an intensive period of studies, Hydro decided in 2003 to develop the field without any platforms. The subsea solutions on Ormen Lange will take the technological developments on the Norwegian continental shelf a significant step forward.

Project Description
The Ormen Lange development is an innovative subsea to shore concept, comprising 24 large bore wells drilled from four subsea templates, with the following key challenges:Extreme seabed topographyMain production area located in an avalanche / slide areaLow temperatures, minus 1°C at seabedStrong currents, waves and winds850 -1,000 m water depthHigh flow production wells 10MSm3/d
The two first subsea production stations will be located 120km from shore, at a water depth of 850 m. Each of the subsea production stations weighs more than one thousand tonnes, and will produce 80 MSm3/day from large bore wells. The stations will be remotely controlled from the shore.
From the subsea production stations, two 30? pipelines will transport the well stream to the onshore plant for processing. The pipelines are laid across an extremely irregular seabed, with boulders and slide blocks up to 60 m tall in the Storegga slide area. Furthermore, the pipelines cross the slide at an inclination of up to 40 degrees. The Storegga slide created a tsunami 8100 years ago which hit the west coast of Norway and the coasts of the UK. NOK 700 million has been spent to make sure that the slide area is stable, and that development and gas production will not change its stability. In order to make the pipeline concept feasible we have drawn on all relevant expertise worldwide, and stretched the technology to its limits.
On Fatigue Design Rules For Welded Structures
Authors: Gurney T.R. , Hicks J.G. 
Published: October 2008

ABSTRACT
A comparison between the design rules in use in various countries has shown that there is a wide difference between them on such questions as design stresses, the treatment of high tensile steel vis-a-vis mild steel, the question of whether or not a cumulative damage approach should be used in design and on what factors of safety should be adopted. However, published test data exist for many types of detail and the paper quotes the results of a statistical analysis of these data which could form the basis for a universal set of ‘master rules’. It is suggested that all design standards should be related to the same basic data. In the context of offshore structures much additional data are required, particularly reliable information about the fatigue strength of tubular joints and about corrosion fatigue.

INTRODUCTION
Offshore structures, whether they be floating or fixed platforms, are subjected to loading of an extremely complex nature arising from a variety of sources, but particularly from wave action. The severity, both in terms of magnitude and frequency of application, of these loads varies considerably from one part of the world to another, but in some places at least it can be such that the fatigue strength of these structures has to be treated as a most important design criterion. Thus, in the North Sea several structures are known to have suffered fatigue cracking, sometimes of major proportions and after only a relatively short period in service. In contrast, there is reputed to be no fatigue problem in the Gulf of Mexico.(1) The difference stems from the much more, severe fatigue loading spectrum in the North Sea.
In view of the current, and future, large investment in offshore structures and equipment, and the potential cost in terms of lost production, environmental pollution and new capital requirements, which could result from major structural failures, it is pertinent to consider what steps can be taken to reduce the risk of fatigue failure to acceptable levels. Clearly, there is a need for a realistic set of design rules which can readily be interpreted by designers.
In the context of offshore structures, fatigue can be taken to mean high cycle fatigue. It is the purpose of this paper to review the current situation regarding high cycle fatigue design rules for welded structures, to suggest ways in which improvements could be made and to point out regions where further research seems to be necessary.

EXISTING RULES AND THEIR BASIS
Historically, the majority of the design standards relating to high cycle fatigue have been concerned primarily with bridges, and particularly railway bridges.
Characterization of Near Seabed Surface Sediment
Authors: Low Han Eng , Randolph Mark Felton , Rutherford Cassandra , Bernard Bernie B. , Brooks James M. 
Published: October 2008

Abstract
Accurate measurement of the shear strength profile in the upper 1 m of soft sediments is crucial for pipeline and riser design, particularly for deep water developments. In this paper, some existing approaches for the strength characterization of seabed surficial sediments are reviewed and the conclusion reached that performing in-situ strength tests within box core samples is the most reliable means of characterizing the shear strength of soft surficial sediments. A box corer for recovering high quality undisturbed sample of the very soft seabed surficial sediments (upper 0.5 m of the seabed) and a new manually operated penetrometer (DMS) for measuring profiles of undisturbed and remoulded undrained shear strength within the box core sample are described. Field data for DMS tests in box cores recovered from a site in the Gulf of Mexico are presented and compared with the strength data measured by motorized miniature vane tests to evaluate the potential of the DMS in characterizing the shear strength of seabed surficial sediments. These data showed that performing DMS tests in box core sample can provide a reliable and time effective means of obtaining strength profiles (undisturbed and remoulded) of soft seabed surficial sediments.

Introduction
Accurate characterization of seabed surficial sediments has became increasingly important due to escalating hydrocarbon field developments in water depths that are now approaching 3000 m, for which the cost of in-field flowlines and pipelines for exporting hydrocarbon products to shore forms a significant portion of the overall field development cost. However, the low strength of the surficial sediments, in the upper 0.5 to 1 m of the seabed, has rendered soil sampling and strength testing extremely difficult and has posed a major challenge in measuring the shear strength profile accurately, particularly in deep water. Typically, the shear strength of the seabed surficial sediments lies in the range 0 to 5 kPa, although in some deposits such as off the West African coast, a crust with strength of 10 to 15 kPa may be found (Borel et al. 2005; Ehler et al. 2005).
In this paper, some existing approaches for measuring the strength profile of seabed surficial sediment will first be reviewed. Subsequently, a box corer that is able to recover high quality undisturbed samples of the surficial sediments and a new manually operated penetrometer (DMS) for measuring undisturbed and remoulded undrained shear strength within the box cores will be described. Data from a field trial in the Gulf of Mexico will be presented, and compared with the strength data measured by motorized miniature vane shear tests, to evaluate the potential of the box corer and the DMS in the characterization of soft surficial sediments from deepwater sites.
Evaluation of PhaseWatcher Multiphase Flow Meter (MPFM) Performance in Sour Environments
Authors: Al-Khamis Mohammed Najim , Al Bassam: Abdulaziz Fahad , Bakhteyar Zaki , Aftab Muhammad Nadeem 
Published: October 2008

Abstract
Accurate oil, water and gas flow rate measurements from individual wells are essential in order to properly manage both the wells and reservoirs, as well as to obtain reliable data for production performance monitoring, optimization, allocation and simulation models1, 2, 3, 4, 5. Over the past three decades, there has been great advancement in the multiphase metering technology. These advancements have resulted in a significant improvement in measurement accuracy as well as in reducing the physical size of these meters which is a crucial element in limited-space environments as in offshore platforms.
The intent of this paper is to present results of a compact Multiphase Flow Meter (MPFM) " PhaseWatcher?? based on information gathered from Saudi Arabia, where more than one hundred meters have been installed so far in several fields covering wide ranges of fluid properties and operating conditions. Moreover, the paper will discuss in detail the effect of crude sourness (H2S concentration) and pressure on the meter's measurement accuracy.

Multiphase Flow Meter (MPFM) Design
The PhaseWatcher is designed to measure the total volumetric flow rates of oil, water and gas at line conditions. These flow rates are converted to standard onditions via a pressure-volume-temperature (PVT) package, which can be either the default Black Oil Model or a specific model derived using a client supplied PVT data.
The meter comprises of five basic components, Fig. 1:A Venturi meter with pressure transducers across it to measure the differential pressure between the inlet and throat of the Venturi.A nuclear dual energy fraction meter consisting of a Smart Detector and Barium Source, measures the count range of photons transmitted from the source to the detector at two different photon energy levels (the high energy level is used to measure the density of the mixture, while the low energy level is used to calculate the water-oil ratio).Process fluid temperature transducers, which measure the fluid temperature upstream of the Venturi section and the ambient temperature.A Blind Tee Static Mixer, used to homogenize the flow stream ahead of the Venturi meter.A process flow computer used to manipulate the measured data.