bluuebunny/crossref_metadata_2025_split huggingface dataset:
Design Correlation of Elastic Behavior and Static Strength of Zero Eccentricity T, Y, and K Tubular Joints
Authors: Graff William J. 
Published: October 2008

ABSTRACT
The stress state on the tube surface adjacent to the weld line in the chord member of a tubular joint is very complex. Over the past decade investigations have shown however that the most critical stress component is the circumferential stress directed around the chord. This stress is very high immediately next to the weld toe and decreases rapidly going away from this point about the circumference. The location of the origin for this stress axis depends on the kind of joint and the type of loading. This paper analyzes experimental data from several investigations to show the location of the circumferential axis for different loading arrangements and to present a method of estimating whether a proposed tubular joint Will be within or beyond the elastic limit stress at the critical point on this axis.

INTRODUCTION
This paper is an analysis of the experimental work contained in several investigations to combine and interpret the results in a form more usable for design purposes. Within the past five years there her e been several outstanding experimental studies of tubular joints (1, 2, 3). In the five year period before that there were many investigations, several (4, 5, 6) of which seemingly would combine with and support the more recent studies. However, the most perplexing aspect of attempting to correlate these data is the unending variability of various geometrical details and loading arrangements of the joints tested. In trying to reach generalizations, it is as if each individual test were a special case both in geometry and load.
The industrial community is fortunate in that from time to time certain investigators have such dedication and interest in their work that nothing is omitted from the completeness of their reporting. Such is true of References 2 and 3 and the preliminary reports (7, 8, 9) associated with them. Even a modest attempt at testing a tubular joint (10) is sufficient to point up the degree of expertise and care required to obtain meaningful information. The thorough and systematic nature of the data in the reports just mentioned permitted their use extensively in the analysis which follows.

THE TUBULAR JOINT
A welded tubular joint is that portion of a structure where circular cylindrical tubesare joined by fusion welding of the cross section of one or more tubes (called braces) to the undisturbed exterior surface of the other tube (called the chord). In structural applications the brace ordinarily does not penetrate the chord wall.
The stresses in tubular joints, as in most structural parts, are not simple stresses, such as tension, compression, bending or shear, but are combined stresses that act in more than one direction. Determination of the stress state in a tubular joint is quite complex and a satisfactory analysis for practical work has yet to be developed, although one method (11) recently published indicates a useful approach.
Flexible Pipe for Ultra-Deepwater Applications: The Roncador Experience
Authors: Neto E. , Maurício J. , Waclawek I. 
Published: October 2008

Abstract
The exploration and production (E&P) segment of the petroleum industry has progressively been led to act deeper. In Brazil, where the deep water (400 to 1,000m WD) and ultra-deep water (1,000 to 2,000m WD) have been the segments responsible for the major portion of the overall country petroleum production (approx. 1.3 MMBPD), one can find in Campos Basin the main arena for the pioneer deployment of new technologies. CSO has been working in this environment as a strong partner of Petrobras, helping them to reach their main objectives, from engineering to product manufacturing and supply, installation and commissioning.
This paper will describe:
The technical solutions incorporated in the design of flexible lines of up to 9.2" in 1,500m WD and 6" in 2,000m WD, well in excess of any previous design.
The installation procedures developed and the up to date installation experience in the field, the challenges encountered and lessons learned.
It will also mention the strategies that are being adopted by Petrobras and CSO to overcome the main technological ultradeepwater challenges, to go beyond the 2,000m WD mark.

Introduction
Petrobras history in Campos Basin is discerned by a permanent challenge to overcome deeper water depths. The discovery of giant fields, like Marlim, Albacora and more recently, Roncador, in water depths ranging from 1,500m up to 2,000m, has demanded the development of new technologies, mainly the optimization of subsea hardware, installation and operational procedures.
Flexible pipes have played an important role in the history of oil production in Brazil, gradually building an outstanding reputation of reliability and cost-effectiveness.
No other oil province worldwide has applied flexible pipes so intensively as Campos Basin, where up to the present date there are about 2223km of risers and flowlines installed. For Petrobras, flexibles is the best way to make feasible production of oil fields in a short time, even before the reservoir delimitation and subsea layout consolidation, as they can be easily recovered, inspected, repaired, re-laid and connected in new sites.
Flexible pipes are composed of unbonded layers of plastic and steel, each layer being designed to resist to a specific loading, such as: crushing loads, internal pressure, collapse pressure, axial loads, torsion and so on and may be designed both for dynamic (risers) and for static (flowlines) applications.
The recent advances on the application of flexible pipes in deeper waters associated with a significant CSO R&D effort on the improvement of current structure design has shown that the adoption of flexible will continue to have a large demand in Campos Basin.
The main goal of this paper is to describe how Petrobras has dealt with the necessity of starting oil and gas production on Roncador ultra-deep waters in a short period of time, and what has been done by CSO and Petrobras to overcome the main challenges of this field.
Conversion of Tankers into FPSOs and FSOs: Practical Design Experiences
Authors: Neto Tomazo Garzia , Lima Heitor Augusto de Souza 
Published: October 2008

Abstract
The fleet of FPSOs and FSOs has been growing in the last years and is expected to grow more quickly in the coming years. The reason for fleet growth are the deep-water production, the increasing number of offshore fields that are being discovered and the need for fast-track development. The present fleet of FPSOs is composed by more than 65% of converted units and the fleet of FSOs is almost 100% of converted units. The conversion of an existing tanker into an FPSO or FSO is, in most cases, more economical and takes less time than a newbuilding. There are several factors that should be considered in a FPSO or FSO conversion to have a successful project. Based in the experience gained in the successful conversion of four FPSOs and FSOs for the deepwaters of Campos Basin - Brazil, several aspects that should be considered in the design for a conversion of a tanker into an FPSO or FSO are described. Critical issues like the selection of the vessel to be converted, project start up structural design installation of large capacity production processing facilities will be addressed.

Introduction
The fleet of FPSOs and FSOs has been growing in the past years and is expected to grow more quickly in the coming years. The reasons for the fleet growth are the deep-water production, the increasing number of offshore fields being discovered and the need for fast-track development. The main advantages of FPSO utilization includes:Integration of several functions in one vessel;Large deck area;Small variations of draft due to weight of production processing facilities;Flexibility in the vessel selection;Simple construction;Reduced investment cost;Short time schedule;Easy decommissioning after completed field production.
The conversion of an existing tanker into a FPSO is, in most cases, more economical and takes less time than a newbuilding FPSO.
Nevertheless a FPSO cannot be considered as a tanker with a different payload, that is the production processing facilities. The function of a FPSO is totally different from the function of a tanker in many aspects of design, conversion/construction and operation. The proper understanding of the function of FPSO is an essential element for the successful design and conversion/construction.
The FSO is less complex than an FPSO but, except for small vessels in shallow waters, cannot, also, be considered as a tanker. In deep waters and harsh environments the mooring and offloading systems and the need to stay on site for periods as long as 20 years are responsible for significant modifications in the vessel.
The intent of this paper is to discuss some aspects of FPSO and FSO conversion design for installation in deep waters and mainly related to the vessel.

The FPSO Fleet
The present FPSO fleet is composed of about 80 vessels, with about 66 vessels in operation and about 14 vessels in conversion or construction, and the FSO fleet is composed of about 80 vessels with about 77 vessels in operation and 3 vessels in conversion.
Nile - Design and Qualification of Reeled Pipe in Pipe for Deepwater
Authors: Tough Gordon , Denniel Sylvain , Al Sharif Majid , Hutchison John 
Published: October 2008

Abstract
The design requirements for the BP Nile pipe in pipe system required the employment of several high performance pipeline components. Of these components, the insulation system, buckle arrestors and water stops were being installed on a pipeline for the first time.
This paper presents the design sequence for these components and a summary of the qualification programme performed.

Introduction
The Nile field is located approximately 85 miles SE of New Orleans, Louisiana and is located in two blocks: Viosca Knoll (VK) 913 and 914. This field is expected to produce primarily gas condensate. The Nile field will be developed as a sub-sea tieback to the Marlin TLP, located in VK 915 at a water depth of 3245 feet (989 m). The Nile tieback comprises a 7.5 km long 6" × 10" pipe-in-pipe connected to a 6" steel catenary riser. The Overall Heat Transfer Coefficient (OHTC) requirement for the pipe in pipe is 0.21 BTU/°F.ft2.hr (1.2 W/m2K). The design temperature is specified as 95°C. This paper will outline the design process and summarise the qualification programme performed for insulation material, pipeline centralisers, buckle arrestors and reelable water stops.

Design: Insulation & Centralisers
An insulation requirement of an OHTC of 1.2 W/m2K is particularly challenging, however, when combined with a water depth of approximately 1000 m and the high design temperature, there is a limited selection of suitable insulation materials. The design parameters dictated that a pipe in pipe solution was required and it was on this basis that the project was specified.

Insulation Material Selection.
There are three pipe in pipe insulation materials which were considered for selection to meet these performance requirements; polyurethane foam (PUF), mineral wool and microporous insulation. Each material has specific advantages in terms of insulation performance, operating temperature range and relative cost. A comparison of the thermal conductivity of each material is presented in Figure 1.
In the course of previous CSO development work each of these materials had undergone both simulated installation and thermal evaluation to assess their suitability. Furthermore a detailed heat transfer model had been developed by CSO which allowed the required thickness of each insulation material to be determined. A first assessment of required thickness of the above materials is presented in Table 1. From a first review of the results it was clear that the thickness of mineral wool required is too great for a 10" carrier pipe and a 12" pipe would be required. To use a larger diameter carrier pipe would increase procurement cost, and significantly increase pipe lay top tension. This option was not considered further.
Two densities of PUF were considered in the design process. The higher density PUF (85 kg/m3) would require that almost the entire annulus was filled with insulation. This has an impact on the fabrication procedure.
Roncador Field Development with Subsea Completions
Authors: Juiniti Ricardo 
Published: October 2008

Abstract
The development of the offshore industry introduced subsea completions as a means to produce hydrocarbons under the water in an economic way. Since the first subsea completion in the beginning of the 60's, an increasing number of installations occurred around the world during the incoming decades and particularly offshore Brazil after 1979, when the first installation was made at 189 meters of water. Different needs led Petrobras to use subsea completions in increasing water depths what called for different projects which surpassed important milestones, like the installation in water depths deeper than the diving limit and over 1,000 meters. Nowadays the deepest installations of subsea trees in the world are being performed in Roncador field where up to date 5 subsea trees, including the well 7 RO 8 RJS at 1,877 meters, were made in the range of 1,850 meters of water. The technical solutions developed in house for subsea completions in ultra deep water showed to be reliable and became a standard operation. Moreover, improvements in the overall time spent for these completions were also made.
As other subsea trees will be installed in Roncador field, the analysis of the efficiency of the installations performed so far will improve future results.
This paper will show the evolution of the subsea completions offshore Brazil in order to explain the solutions used in ultra deep waters field and then show a comparison of the time spent in different subsea completions in Roncador field. It will also anticipate proposed solutions for even deeper waters.
As ultra deep water exploration is surpassing the 2,000 meters barrier, reliable and efficient subsea completions hardware and techniques are a must in order to economically develop future discoveries.

A Brief History of Subsea Completions
Subsea completions were introduced in the beginning of the 60's in the Gulf of Mexico as a means to produce hydrocarbons under the water in locations far from the existing platforms and as a test for production in deeper waters, since at that time offshore production was only achieved with the use of fixed platforms. Soon later subsea completions were also introduced offshore California to produce gas directly to shore.
During the 60's all subsea trees installations were done in the USA, and the Through Flowline Concept (TFL) was widely used as it allowed tools like a pressure gauge, to be pumped downhole and recovered after the job was accomplished. Other features of these subsea trees were the diverassisted flowlines pull in and direct hydraulic operated subsea valves.
By the end of the 60's, the number of installed subsea trees was 68, at a maximum water depth (WD) of 130 meters, all of them in the USA.
With the discovery of hydrocarbons in the North Sea, subsea trees were also used as a means to accelerate production, to acquire more reservoirs information as well as to get an earlier cash flow.
Using the singularity analysis of seismic traces for improving resolution
Authors: Cao Yuming 
Published: October 2008

Abstract
By the convolutional model of the seismic trace, the convolution of a seismic wavelet, which has a starting point, with the reflection series, a series of spikes, brings about the singularity features of the seismic traces. The detected singularity of seismic traces can improve resolution of seismic data visibly. As a result, it should expose more geological phenomena on seismic section and benefit sequence stratigraphic studies, accurate correlation of reservoir tops and bottoms and detailed delineation of reservoir structures. The results also lie a good foundation for lithological prediction. In this paper, a wavelet package constructed with a scaling function differing from the literatures is used to detect it. The synthetic example shows the procedure of singularity analysis, and the practical example shows the validity and reliability of the algorithm.

Introduction
Today whether the exploration or the reservoir description and manage, it starves for high resolution of seismic data, but can't now. There are problems in two aspects.
The first, because seismic wavelet isn't well and truly pick up and there is some change of the wavelet with the space and time both, after the deconvolution, that now is good for improving resolution of seismic data, always a residual wavelet is leave behind. The band-limited residual wavelet badly restricts the resolution of seismic data.
The second, on one hand maybe people is restricted by the viewpoint of band-limited seismic data, which insists on that the bandwidth of seismic data is a deadline of the resolution, so processing must be all-pass in frequency domain (Li, Q., 1993). On the other hand because low resolution is so easy to process and interpret, and higher resolution is more difficult, maybe people prefer easy to difficult (Kerekes, A. K., 1998).
It is believed by a lot of successful experiment of the coherency slices, that there is plenty geologic information in the singularity feature of the seismic data. The coherency slices character the singularity of seismic data in spatial domain (Marfurt, M. J., et al 1999), whereas in temporal domain it is not yet sufficiently understood and used so far. My work (Cao, Y., 1996) exposed the fact that seismic data in temporal domain have abundant singularity too. And thed-spline function was used to construct a wavelet package for singularity analysis of seismic traces. Then the singularity analysis alternates with deconvolution, the residual wavelet was compressed availably and the resolution of seismic section could be improved visibly. In this paper, a formula of detecting singularity is used as scaling function to construct a wavelet package to get over the problem of residual wavelet. It is equivalent to the revised d-spline fitting of the regular component of a seismic trace in substance.

The singularity of a seismic trace
There are many interfaces of layers, faults, change of epositional facies and so on inside the earth.
Case History: First Coiled-Tubing-Conveyed Live-Well Intervention Run From a Semisubmersible Platform in Brazil to Increase Perforation Length in a Deepwater Horizontal Wellbore
Authors: Rosetto Ilton , Scott Martin Schoener , Etcheverry Carlos Fulvio , Almeida Jose 
Published: October 2008

Abstract
Coiled tubing has been used to deploy perforating guns for several years, and use of this technology has enabled many operators to complete high-angle wells with optimum completion designs. Until recently, however, this perforating method was not used in Brazil because of the complexity and risks involved, particularly on offshore platforms (semisubmersible rigs and/or drill ships) where daily costs are extremely high.
This paper will describe the first experience of coiledtubing-conveyed perforating (CTCP) performed offshore in a horizontal well in this South American country.
The first CTCP job was to be performed not only to obtain the well objectives needed for the well but also to be used as a "learning curve" for a major job that was to be run subsequent to this job using the same method. The second job was to be in a water depth of 968 ft. and more than 1,000 ft. of guns would be run. Both jobs will be discussed, along with the advantages gained on the second job from the first experience.
The first procedure required perforating of a 262-ft. interval in a 92-degree horizontal well using 2 in., 6 SPF super deep penetration scalloped guns that would be coiled-tubing deployed through 3−½ in. production tubing. The operation was to be performed from a semi-submersible platform, and the running and retrieving of the perforating guns would have to be accomplished without killing the well so that damagingcompletion fluids would not come into contact with the reservoir. Requirements for the job were that a safe method be used and that equipment and operational costs be kept at minimum so that a greater return on investment could be realized.
Operational conditions included the following:Perforation was to be conducted with the well in an underbalanced condition so that no formation damage would be sustained.The operation had to be run from a semi-submersible platform that was set in a water depth of 430 ft. (2nd d job performed in a water depth of 968 ft.)The gun assembly would have to pass through a 2.81-in. minimum ID.

Introduction
For twenty years, Petrobras has been developing state-of-theart technology for deepwater environments in order to determine best practices to realize the most efficient production. From the time of its first oil production in 1977, the Campos Basin, located off the northern part of the state of Rio de Janeiro has been proving its potential as a major oilproducing province. Already responsible for three-quarters of the country's production, Campos is by far the main production area in Brazil. During those twenty years, 66 fields have been discovered, and exploration and drilling operations have been ongoing. (See Fig. 1)
This paper will cover the two CTCP jobs that were performed in the Moreia and Albacora Fields.
Acoustic Re-Entry And The Deep Sea Drilling Program
Authors: Sims Darrell L. 
Published: October 2008

Abstract
High resolution scanning sonar can be used in water depths up to 15, ODD to locate a target and guide a drill string to that target.
The bit (or tool) end of the drill string can be placed over the 16 foot diameter cone target by moving the drill ship so that the bit can be lowered into the cone.
The latest sea trials indicate interrupted operations can be scheduled for bore holes in deep water without having a mechanical connection from the drill ship to the riser.
Valuable core samples for the scientific party were recovered that could not have been reached with only one bit.

Introduction
The coring equipment that went to sea on the Glomar Challenger was designed to drill and core soft sediments with minimum recovery in the basement.
It soon became apparent increased coring capabilities would be required to penetrate the unexpected hard formations that were encountered at most of the sites. In addition, the scientific community was expressing interest in deeper penetration into the basement.