bluuebunny/crossref_metadata_2025 huggingface dataset:
Sociedad y economía durante el Bronce Final y la primera Edad del Hierro en el Noreste Peninsular: una aproximación a partir de las evidencias arqueológicas
Authors: López Cachero F. Javier
Published: October 2008

A finales de la Edad del Bronce comienzan a producirse importantes transformaciones en el seno de las comunidades del noreste peninsular que tendrán continuidad durante los siglos VII y VI ANE y que se caracterizarán por la paulatina formación de una clase aristocrática de carácter guerrero. Sin embargo, esta élite no se consolidará definitivamente en el poder hasta el ibérico antiguo, constituyéndose así la estructura social sobre la que se desarrollarán los estados arcaicos durante el ibérico pleno. No obstante, los procesos de gestación de las desigualdades sociales que se observan en el noreste peninsular son diferentes en función del territorio que analicemos, ya que mientras que en el caso de los territorios interiores (Segre- Cinca, Guadalope y Matarraña-Algás) la dinámica emprendida parece ser consecuencia del desarrollo interno de estas sociedades, en la costa el cambio se produce en paralelo a la presencia del comercio fenicio y, por lo tanto, con la integración del territorio dentro de un sistema mundial de ámbito mediterráneo. La respuesta indígena a este fenómeno tampoco se muestra homogénea, pues se perciben importantes diferencias en la cronología de los cambios y en la evolución de los mismos, así como en los modelos de poblamiento y en el reparto de la riqueza en las necrópolis de incineración. Se trata, pues, de un proceso sumamente complejo que conviene analizar detenidamente en cada uno de los territorios afectados. Con este trabajo pretendemos relanzar la discusión entorno al desarrollo social y económico de las sociedades del noreste peninsular. Para la elaboración de nuestro discurso realizaremos un breve estado de la cuestion de los períodos analizados donde nos replanteamos algunos de los argumentos tradicionalmente asumidos referentes a la cuestión de la denominada Cultura de los Campos de Urnas y valoraremos las últimas aportaciones realizadas a partir de determinados contextos arqueológicos que han comenzado a ver la luz durante la última década.
Hilos de continuidad y cambio. Tejiendo unidad en antropología
Authors: Brumfiel Elizabeth M.
Published: October 2008

En este artículo comparo el proceso de tejido en telares de cintura de tres contextos culturales: los Maya, los antiguos aztecas y la Mesoamérica del siglo XX. Aunque existen evidentes continuidades, también hay importantes diferencias en sus contextos históricos. En el Maya Clásico el tejido marcó la clase social, el género entre los Azteca de México y el origen étnico en la Mesoamérica del siglo XX. El análisis comparativo de estos casos históricos sugiere que la comparación es una herramienta útil tanto para arqueólogos como para los etnógrafos: promueve el reconocimiento de la diversidad de las prácticas y las creencias de las sociedades antiguas; contribuye a definir el alcance del estudio etnográfico contemporáneo; combate el esencialismo cultural y carga a nuestras narrativas de capacidad transformadora; nos permite reconocer el rico patrimonio de los pueblos indígenas y el hecho cultural del cambio. El análisis histórico comparativo proporciona un fundamento sólido para mantener la asociación de la arqueología y la antropología cultural como partes de un todo antropológico mayor.
Investigaciones etnoarqueológicas en Tierra del Fuego (1986-2006): reflexiones para la arqueología prehistórica europea
Authors: Vila Assumpció , Mameli Laura , Terradas Xavier , Estevez Jordi , Moreno Federica , Verdún Ester , Zurro Debora , Clemente Ignacio , Piqué Raquel , Briz Ivan , Barcelo Joan Antón
Published: October 2008

Durante 20 años se han llevado a cabo en Tierra del Fuego investigaciones dirigidas a contrastar etnográficamente el registro arqueológico de sociedades cazadoras recolectoras. Se trataba de elaborar una metodología específica de abordaje arqueológico para estas sociedades que pudiera aplicarse a otros contextos arqueológicos. Aquí se exponen los diferentes proyectos y sus conclusiones más importantes haciendo especial hincapié en dos aspectos fundamentales, por un lado el técnico-metodológico, de recuperación y tratamiento de la información; y por otro la reconstrucción de las relaciones sociales de producción y reproducción en grupos cazadores recolectores.
La evolución del paisaje en la transición al Holoceno Desarrollo de un modelo predictivo de vegetación en el Valle del Asón (Cantabria)
Authors: García Moreno Alejandro
Published: October 2008

El conocimiento de la distribución espacial de la vegetación prehistórica, y su evolución a lo largo de la transición al Holoceno, es fundamental para entender los cambios en los patrones de explotación del territorio y de asentamiento que se producen en los grupos de cazadores-recolectores del final del Paleolítico Superior. Para calcular dicha distribución, se emplea un modelo predictivo basado en el método de weighted values (valores ponderados), a partir de los requerimientos ecológicos de la vegetación arbórea, analizando su evolución en el Valle del Asón (Cantabria) y su relación con los yacimientos paleolíticos que allí existen.
Identificaciones del Gravetiense en las estribaciones occidentales del Pirineo: modelos de ocupación y uso
Authors: Barandiarán Ignacio , Cava Ana
Published: October 2008

Es hoy progresiva la identificación de ocupaciones de interior en el Paleolítico superior peninsular. Se presentan las cuatro primeras identificaciones del Gravetiense en el extremo occidental del Pirineo: estratigrafías, industrias y dataciones. Se interpretan los distintos modelos de ocupación y uso que representan: un sitio integrado en la ecumene habitual franco-cantábrica (Alkerdi), dos lugares inmediatamente dependientes de la explotación de filones de sílex (el taller de Mugarduia y el centro de distribución de Coscobilo) y un alto de caza estacional en medio pirenaico (Zatoya).
Patrones de movilidad y control del territorio en el Cantábrico Oriental durante el Tardiglaciar
Authors: Marín Arroyo Ana Belén
Published: October 2008

El tipo de ocupación y uso del territorio constituyó una de las herramientas adaptativas a disposición de los grupos cazadores-recolectores del final del Pleistoceno para optimizar el acceso a los recursos y permitir una explotación eficiente del medio en el que habitaron. La Cornisa Cantábrica, por sus especiales cualidades topográficas y ambientales resulta idónea para la investigación de este tipo de mecanismos, habiéndose identificado una tendencia hacia el aprovechamiento del entorno más inmediato de los asentamientos, que es necesario constatar con rigor, como paso previo a la obtención de conclusiones económicas generales. En el trabajo que aquí se presenta, se contrasta positivamente el papel de la orografía en las decisiones cinegéticas humanas, a través del cálculo de las áreas de captación de 19 yacimientos magdalenienses. Además, se propone un nuevo modelo de poblamiento a partir de recientes datos de estacionalidad y funcionalidad de yacimientos del Valle del Asón.
El uso de las evidencias materiales en la investigación de la Cultura Celtibérica: la zona arqueológica de El Ceremeño (Guadalajara, España)
Authors: Cerdeño Mª Luisa
Published: October 2008

Los estudios sobre la cultura celtibérica han avanzado notablemente en los últimos años debido tanto a nuevos planteamientos, como al hallazgo de nuevos enclaves que están proporcionando importante información arqueológica, hasta hace poco tiempo deficitaria. Entre ellos, el castro de El Ceremeño y su necrópolis asociada se han convertido en una de las referencias más significativas de esta cultura. En el presente trabajo se subraya la necesidad de analizar en profundidad, dentro del marco más general de la cultura celtibérica meseteña, los datos y fechas radiocarbónicas allí obtenidas para evitar desenfoques y sesgos en su interpretación.
Some Results of Deep Ocean Drilling
Authors: Ewing Maurice
Published: October 2008

The initial campaign for drilling and coring deep-sea sediments by use of the ship Glomar Challenger has reached its half-way point and has been a brilliant success. The scientific planning of the project was the work of a consortium of oceanographic institutions known as JOIDES. Through a system of committees and panels, JOIDES solicited input and participation from representatives of all segments of the community of earth scientists. The project was made part of the national program for sampling deep-sea sediments by the National Science Foundation, and was implemented by a contract between that agency and the University of California.

Through a subcontract, Global Marine Inc. has constructed the drilling vessel and is operating her for an initial campaign of eighteen months -- half in the Atlantic and half in the Pacific according to the program established by JOIDES.

The shipboard work has been organized in eight "legs" of two months each. The scientific part of the work on each leg and the preliminary report on the samples obtained is the responsibility of a scientific staff chosen for that leg on the basis of special qualifications and of particular interest in the area to be visited. I shall attempt to review the background, objectives, and accomplishments of this activity, on the basis of a long association with it.

As Distinguished Lecturer for AAPG and SEG in 1947 and 1953, I had addressed the local chapters in many parts of the country, about the sediment cover of the deep-sea floor. I stated that geophysical measurements showed that the total sediment accumulation was thin, and urged the importance of sampling it by drilling. The only tangible response to this was an article by Earl Ubell in the New York Herald Tribune. I estimated that the work could be done from our small research vessel Vema, held in position by her normal propulsion and steering machinery, manually controlled by use of information from an acoustic link to a transducer on bottom. By considering a much slimmer hole than those now being drilled, we thought the operation could be undertaken on a vessel of about 1000 tons, and estimated a cost of about $1 million for the first hole, and about $200,000 each for subsequent ones.

Our proposal was based on newly obtained evidence that a moderate penetration would reach the oldest sediments present on the deepsea floor, and on experience in ship-handling which indicated that the proposed drilling was feasible.

The amount of geophysical information about sediment thickness was at that time rather scant. It consisted of about twenty seismic refraction profiles and a few seismic reflection traverses along which measurements that were spaced ten to thirty or forty miles apart indicated depths to reflecting horizons, the deepest of which was judged to be basement from the refraction results.

In addition, there were a few grand averages for sediment thickness over oceanic routes hundreds to thousands of miles long that had been obtained from study of the dispersion of earthquake surface waves.
Research in Tubular Joints: Static and Fatigue Loans
Authors: Toprac A.A. , Natarajan M.A. , Erzurumlu H.A. , Kanoo A.L.J.
Published: October 2008

This paper reports the results of research in welded connections between steel tubes. Static and fatigue behavior of such tubular joints are described.

Static tests include eleven T-joints, three Y-joints and three K-joints. The reserve strengths, the modes of failure and the influence of geometrical parameters on the distribution of elastic stresses are discussed for the specimens tested. Typical contours of isostatics and isobars are given. Nomographs are presented for T-joints. A brief description of the theoretical analyses of tubular joints is incorporated.

Fatigue tests of one hundred smallsize T-joints under different cyclic loadings are also described. The influence of important geometrical parameters on the response of small-size T-joints is discussed.

1. INTRODUCTION

The recurring problem of joint failures in offshore structures with tubular joints has made it imperative for interested bodies, such as oil companies, universities, and research firms, to embark on experimental and analytical research programs. The factors which influence the behavior of tubular joints are too many and some of these factors are not yet clearly understood. The variety of joints and the different methods of stiffening used in offshore structures suggested that studies were necessary to provide improved design methods that result in economical connections.

In an attempt to furnish the needed research data, a four phase program was planned at the Structures Fatigue Research Laboratory of The University of Texas at Austin, and incorporated the following major objectives:To study the effect of static loads on various types of connections that include T, Y and K - joints.To study the effect of fatigue loading on various joints, starting with T joints.To verify the effect of certain parameters on the stresses and their distribution.To observe modes of failures of the various joint types.To correlate, if possible, theoretical analyses with experimental data.

The four phase program that has been considered to incorporate the main objectives includes:Static tests on T, Y and K-joints. (Phase I and II).Fatigue tests on T-joints. (Phase III).Fatigue tests of more complicated joints. (Phase IV).

Phase I, II and part of III have been completed and this report presents a concise summary of the various aspects of these studies, and includes data on T, Y and K joints and the results of fatigue tests performed on a large number of small-size T joint specimens.

The specimens tested under static loads were designed in such a way as to cover a broad and practical range of parameters. The geometrical parameters (see Table I) selected for this research were as follows:The ratio of chord length to mean chord radius,?.The ratio of mean radii of brace and chord,?.The ratio of mean chord radius to chord thickness,?.The ratio of the brace thickness to the chord thickness, ?.

2. STATIC TESTS

2. 1 General

The initial portion of the research program dealt with the investigation of the static behavior of T, Y and K-joints.
Reservoir Technology Resources in the Next Millennium
Authors: Hopkins John R.
Published: October 2008

As the world enters the new millennium, many questions are being raised about energy supply and demand. Although various new sources of energy are being introduced to satisfy future global needs, it is expected that at least for the next twenty years petroleum will still be the dominant fuel. The question then becomes "What human and technical resources will be required to meet the world's oil and gas needs over the next couple of decades" The manpower pipeline upon which the industry has relied over the last 100 years to supply new technologists is no longer capable of delivering the geoscientists and engineers that the oil business has required in the past. Other opportunities, particularly in the environmental arena, have aggravated the situation for petroleum by enticing future reservoir engineers, geologists, etc. to pursue non-petroleum careers. An offset to this future manpower struggle is the industry's ability to develop technologies which hopefully will make technologists more productive and effective. Some of these new and emerging technologies will be discussed as well as the human characteristics and skill sets which will be critical in reservoir technologists of the future.

Introduction

According to an American Geological Institute estimate,1 of the seven trillion barrels of potential global resources, only twenty-five percent has been produced or booked as proven. This means that approximately three-quarters of the world's potential resources are either yet to be discovered or are currently considered non-producible. With demand for petroleum expected to increase to over 100 MMBOEPD by the year 2020,2 the petroleum industry will continue to be called upon to provide the human and technical resources to ensure there are no interruptions in supply.

In the past the industry has risen to similar challenges through technical innovation and aggressive recruiting. However, over the past twenty years, there has been so much turmoil in the industry due to wild oil price fluctuations and the resulting restructuring of most petroleum employers that many of the traditional sources of reservoir engineers and geoscientists have radically been reduced or eliminated altogether.

This paper addresses one question. Will the industry experience a shortfall in reservoir engineers and geoscientists over the next few years? If so, what technologies and processes are being pursued and/or implemented to offset the shortage of the personnel who are responsible for the characterization of existing, newly discovered, or to be discovered reservoirs?

Manpower Trends

Figure 1 graphically illustrates the impact of crude oil prices on manpower level in the petroleum business over the past sixty years.3 The correlation is very good overall with a slight lag in the manpower curve occurring after the 1981 price aberration.
Genesis Project: Development Well Planning
Authors: Barton D.R. , Clark W.Y. , Howard W.J. , Hudson T.A. , Newhouse C.C. , Martin B.H. , Naquin C.J. , Waltman R.B.
Published: October 2008

This paper discusses the development well planning for the Genesis Project which is a deepwater development project using a floating spar for simultaneous drilling and production operations. Included are geological and reservoir overviews, major equipment systems overviews, and well planning considerations for drilling and completion operations.

Others involved in development well planning for deepwater developments can use the results of this work, and in particular, those developments considering utilization of a floating spar.

Introduction

The Genesis Project is the first deepwater development project in the world to use a floating spar with simultaneous drilling and production capabilities. The field is located in Green Canyon Blocks 160, 161, and 205 in the Gulf of Mexico. The development wells will be drilled and completed from the spar located in Green Canyon Block 205 in 2590 feet of water.

The discovery well was drilled in 1988 and several delineation wells followed in the early 1990's. Development funding was approved in early 1996.

A semi-submersible rig was used to batch set 36, 26, and 20 inch casing strings on 19 wells. The seafloor well pattern included locations for 20 wells and two export riser bases. One of the well locations in the pattern is actually one of the early delineation wells and was not included in the batch set program. Spacing between locations is 20 feet in a 140-foot diameter circle.

A shallow water flow zone was successfully isolated on all batch set wells. The 26-inch casing was set just above the shallow water flow zone. Deepwater foam cementing was used to cement the 20-inch casing, set below the shallow water flow zone. A wellhead isolation system was also used to shut off the shallow water flow zone.

In addition to the batch setting operations, the semisubmersible rig was used to drill the first two development wells with 9-5/8 inch production casing set at total depth. The batch setting and drilling of these first two wells was completed in the summer of 1997.

The spar was installed in early summer of 1998 followed by topsides and rig installation. Hook up work commenced and the first rig operations, running the export risers, began in November, 1998.

Geological Overview

The Genesis Field is a major Plio-Pleistocene oil accumulation with five major sands (N1, N2, N3, 14,200', and 14,800') targeted for primary development. These sands were deposited as turbidites in bathyal water depths on the middle to lower continental slope. An eastward dipping series of combined structural and stratigraphic traps hold oil in columns up to 1400 feet in height. Small faults and stratigraphic barriers near or below the limit of seismic resolution may be an indication of significant reservoir compartmentalization.
Information Management for the Genesis Development Project
Authors: Saines J.M. , Goulding A.
Published: October 2008

This paper describes the fundamental strategies, technologies and processes used to address the Information Management needs of Chevron's first deepwater spar facility, the Genesis Development Project. It includes enabling and supporting the Project's information sharing needs during project execution, and its capture for handover and use by the post-project phase customer: the Asset Management Team. The following four areas will be covered:Infrastructure,Communications,Data Management, andDocument Management This paper will also describe the specific solutions employed, problems encountered and lessons learned.

Utilization of current technology to provide electronic access to key project information is now considered essential and provides opportunities for cost savings. Overviews of the key strategic goals in each of the four areas will be highlighted, as will examples of the technology solutions employed in support of those strategies. High level overviews of the specific Data and Document Management System solutions and their functionality will be included. The solutions employed for Genesis have evolved from and leveraged off previous solutions utilized on other major Chevron projects in the North Sea and Canada.

As offshore projects become more complex the ability to apply technology solutions to the mountain of information generated becomes critical to enable more accurate and timely decisions. In addition to supporting decision making, technology can also support the management of change process by ensuring access to and control of the latest key project information.

Purpose and Introduction

Effectively managing a project's critical information is a challenge. This challenge only increases with the scope of the project. The Genesis Project is Chevron's first deepwater Gulf of Mexico spar facility. Key project information was supplied from numerous Project Team and contractor locations around the world (New Orleans, LA., Houston, TX., Pori, Finland, Morgan City, LA. and Corpus Christi, TX.). In addition to these locations, the Project had over 150 major equipment vendors and suppliers located throughout the world.

This paper will highlight the strategies used to implement Information Management for the Genesis Development Project.
A Winning Approach for Technology Transfer
Authors: Pugh David
Published: October 2008

Technology-no matter how advanced or "cutting edge"- doesn't communicate itself and, if poorly communicated, may be partly or totally rejected. In fact, well-communicated good technology will usually be better accepted than poorly communicated great technology. The reason is twofold:The message simply got through more effectively, giving the customer understandable and substantive reasons to want that technology, andAll the customer truly understands about the so-called superior technology is that it's profoundly more expensive.

Most technology professionals would rank sales communication, especially writing, as one of the least savory parts of their work. But the painful truth is that written documents, more than any other form of communication, stimulate and sustain interest throughout the sales cycle. Oral and visual communication certainly have their place in the process, but it makes both legal and common sense to understand that messages don't truly exist until they're recorded, set down in a common language for all parties to examine and consider. This means that technology-based solutions get funded, built, or otherwise adopted only when decision-makers have clear and compelling reasons to endorse your written messages (as opposed to your competitors') about those solutions.

Thus designing and writing the most persuasive proposal becomes a critical step in moving technology to the marketplace. Yet technical people who contribute to proposals typically want to sell their technology by attempting to establish technical superiority in technical terms. Problem? Relatively few people in the customer's buying chain care about technical superiority and even fewer understand the technical nuances that establish superiority. What they do care about is getting the job done the right way with the right technology for the right price to achieve the right business goals as the right return on their investment. Right?

In today's fiercely competitive marketplace, then, one of the key success factors in selling technology is not just having a great message, which all the technology leaders do, but getting that message through better than anyone else. In other words, winning business today means competing with communication. For today's bottom-line customers, it's not enough to know in some technically elegant sense what the solution is; they need to know why they should buy it, and that crucial message may be anything but technical.

Fortunately, learning to compete with communication rather than the never-ending technology shootout on State-of-the-Art Avenue gets very simple very fast. It also gets results. Therefore, those who develop, sell, and/or deliver technology can build their business by addressing three basic questions:What is our technology and/or technical approach for this customer?Where does the customer perceive, or need to perceive, that we are differentiated from our competitors?
Morpeth SeaStar Mini-TLP
Authors: Kibbee Stephen E. , Leverette Steven J. , Davies Kent B. , Matten Richard B.
Published: October 2008

The Morpeth project is the world's first application of a SeaStar®1 Mini-TLP and establishes that mono-column TLP's can be used to economically develop deepwater fields. This paper discusses the evolution and development of SeaStar technology and its niche in the deepwater platform market. Specifics of the Morpeth SeaStar platform are presented along with a discussion of some execution challenges that arose during the execution of this prototype project.

Introduction

The inventory of undeveloped deepwater discoveries is evidence that the offshore industry's ability to discover deepwater hydrocarbons exceeds its ability to economically exploit them. This inventory, which grew as deepwater wells were drilled, pointed out the need to develop more economic field development solutions for large and small deepwater fields.

The Morpeth Field provides a specific example of discovery, deferral, and development of a deepwater discovery. Although discovered reserves were potentially substantial, proven reserves were not sufficient, or near enough to existing platform and pipeline infrastructure, to become a development priority in comparison to other opportunities in the operator's portfolio. Consequently, after the discovery was made, development was deferred.

After a long offset subsea tie-back solution was deemed sub-optimal for this field, British-Borneo proposed a standalone SeaStar oil and gas production facility in the Morpeth Field to process oil and gas to pipeline specifications. This strategically located platform simplified the subsea system, improved flow assurance, increased recovery, and improved the economic attractiveness of future subsea developments in the area.

The Morpeth Field development project was sanctioned in February 1997 and the SeaStar platform was fully installed by August 10, 1998. First production was achieved on October 11, 1998 despite interruptions in offshore hook-up operations by three named tropical storms, including a direct hit by Hurricane Earl in September 1998. Successful production operations at Morpeth prove that mono-column TLP's can be used to successfully develop fields in deepwater areas.

Until Morpeth cost and schedule performance demonstrated otherwise, tension-leg mooring technology was widely believed to only be applicable to platforms that supported large numbers of dry trees. The Morpeth project demonstrates that tension-leg moorings provide reliable, cost-effective, stable, and expeditious means for mooring small deepwater platforms.

The Morpeth project also achieved several other industry firsts including the first TLP hull fabricated in the USA, and the first TLP classed by a Classification Society.
Cantarell Oilfield Automation
Authors: Villegas Ricardo , Montes Francisco , Ruiz Jaime
Published: October 2008

The current demand of the International Consumption Markets has created the need for a Productive Plant that responds to the increasing demand for quality products. It also has obliged that these industrial processes be endowed with state of the art technology, in its different fields of application, in order to respond to these requirements and be competitive on a world level. Related to the Oil Industry, concretely in the crude and gas extraction and production, the enterprise Petroleos Mexicanos, in its offshore installations located in the Gulf of Mexico, is currently developing the modernization and optimization of the Campo Cantarell infrastucture. It is applying the most avant-garde technologic developments and control criteria, through the arrangement of the mutual interrelation of mechanisms which conform specific patterns of behavior, allowing for an automatic operation of its different processes within a safety framework for operative personnel, the installations and the environment. Maintaining at all times the productive indexes demanded by domestic consumption and the export commitments established by the Mexican Government.

Introduction

The installations of the Cantarell Oil Field, comprehended by the AKAL-J, AKAL-C, NOHOCH-A, AKAL-N COMPLEXES AND THEIR SATELLITE PLATFORMS, is located 90 km NE offshore Ciudad del Carmen, in the Gulf of Mexico. The current operation of extraction and production processes is based on a platform control with pneumatic technology, relays and discrete electronics, which impedes handling the processes and necessary information volumes automatically, in order to take the decisions which may allow its optimization. The facilities also have a SCADA system, which is operatively limited to monitoring the operational conditions of the extraction and production processes, without exercising any digital control or continuous analogue phases.

For all of the above and due to the creation of new oil installations, comprehended within the AKAL-L, AKAL-B, AKAL-G, AKAL-P COMPLEXES AND THEIR ASSOCIATED SATELLITE PLATFORMS, which shall be integrated in the quoted field, the need to modernize its control processes was established. This would be achieved by equipping it with a state of the art digital system, operating under the concept of an "Open System", through which the control systems of each and every one of the installations are integrated by implementing intelligent instruments, directed by appliiince software. These are: gas lift optimization, monitoring the operating conditions of all the systems in order to maintain an updating, in real time, of the maintenance programs, the appliance of security systems with technologies which guarantee the integrity levels required by risk analysis. This includes the control of nitrogen gas injection to the said field, in order to maintain the adequate pressure conditions, allowing for the extraction of gas and crude.
Deep Water Development Drilling from a Spar
Authors: Leach C.P. , Stanton P.N.
Published: October 2008

This paper describes the design of a well system for development drilling from a Spar(1). In particular, the paper gives results of realistic well control modeling which has been used to confirm the design specifications for a system consisting of a surface BOP, pressured riser and partial seabed BOP (split BOP). Details of the pressures that would be expected from typical Gulf of Mexico (GOM) deep water well kicks will be given. The results of the work show:Most kicks that will be encountered can be dealt with using a pressured riser and a surface BOP if this riser is rated to 3000 psi for surface holes and 6500 psi for deeper hole sectionsA seabed choke and seabed BOP may be used under certain circumstances to limit riser pressures

The well control system as conceived also allows for:More effective deep water drilling when compared to a "conventional" subsea drilling system - casing strings can be pushed furtherA dual barrier such that failure of the riser during drilling does not result in a blow-outMany areas for potential cost savings when compared with a "conventional" subsea drilling system

The system is designed to fit the capabilities of a Spar. The paper also shows how the design of the well system leads to some cost savings for the Spar system as a whole.

Introduction

Up until now, drilling operations in the ultra deep waters of the Gulf of Mexico have generally been carried out using a "conventional" drilling system consisting of a seabed (subsea) BOP and a non-pressured marine drilling riser. If a kick occurs, the seabed BOP is closed. The kill circulation path is through the drillstring to the bit, up the well annulus to the seabed and then through the choke or kill line (or both) to the choke manifold located on or close to the drilling rotary table.

This type of system has its merits but also its drawbacks which include:Significant friction pressures which are transmitted back through the well when circulating through the long choke and kill linesComplex seabed equipmentPotential high gas rates at the surface resultant from small undetected swabbed kicks (subsequently circulated through the riser) when synthetic oil base mud (SOBM) is in use(2)

The work described in this paper used a realistic well control simulator (RF Kick)(3) and an underbalanced drilling simulator (RF Dynaflodril)(4) to examine an alternative well system that could be used from a Spar and that would:eliminate (for the most part) the drawbacks of the "conventional" systemprovide all required well control capabilitiesallow for cost effective drilling.

Several key requirements had to be met. These were:Ability to deal with the pressures and other conditions that are likely to occurAbility to be able to deal with a catastrophic event (for example, evacuation of the wellbore following a well flow that has gotten out of control)Provision of a back up such that a single point failure does not cause the loss of the well
Large Bore 'HPHT' WeWieads and Christmas Trees
Authors: Chiasson Glenn , Smith Craig , Stewart Dave
Published: October 2008

As "Large Bore" and "HPHT" (High Pressure/High Tempemture) type completions are becoming a more common occurrence around the world, operators such as Shell are going a step further and are requiring a combination of both technologies thus creating new challenges for the industry. The use of 'Large Bore' and "HPHT" type completion equipment can reduce the number of wells drilled, depending on field architecture, which has significant cost savings for the operator considering the cost of "HPHT" well construction. One project which is using Large Bore "HPHT'"equipment is Shearwater, which is located in the Central Graben Area of the North Sea and operated by Shell UK Exploration and Production. The wells for this project are being completed with 6.3/8" bore 15,000 psi 350°F Christmas Trees with full metal to metal sealing wellheads. This paper will review the challenges that were experienced during the design phase which included, but not limited to, operational issues, such as manual versus remote valve actuation, tree configuration, qualification testing requirements, API scaling rules, thermal analysis and material selection of qualification test equipment. This paper will also review the use of this technology for subsea applications, which is another milestone for both "HPHT" and subsea wells.

Introduction

In late 1996 Cameron began working with Shell on the Shearwater Development Project. Shearwater is iocated in Ccntrat Graben Area of the North Sea east of Aberdeen (Fig. 1). This project required the development of a large bore high pressure/high temperature christmas tree and wellhead/tubing hanger system to integrate with the 7" × 5.1/2" completion philosophy. The use of field proven technology was of the utmost importance to reduce the risk to both parties, taking into consideration the project was underway and only a limited amount of time was available for development work and qualification testing.

The use of large bore completions can reduce the total number of wells required to complete a field. For example, on Shearwater the use of 7" completions eliminated three wells. Considering one "HPHT" well may take several months to drill and complete, there are significant cost savings, especially taking the current rig rates into consideration.

The majority of the development effort was centered around the christmas tree and the tubing hanger system. The wellhead required only minor design modifications as 13.5/8" 15,000 psi metal sealing wellheads have been in use for several years. The wellhend selected was a field proven two stack 21.1/4" 5000 psi × 13.5/8" 15,000 psi full metal to metal sealing, split compact type used in conjunction with a mudline casing support and adjustable surface hanger system. The tubing hanger for this wellhead, however was only designed for 4.1/2" completions, therefore required further development for a large bore completion. The casing program for these wells is 30" × 20" × 14" × 10.3/4" × 7" tubing.
DEEPSTAR: Harsh Environment Flow Assurance Test Facility
Authors: Milliken Mark , Schulte Ralph , Chitwood James
Published: October 2008

In 1998, Deep Star and the Rocky Mountain Oilfield Testing Center (RMOTC) began planning a field-scale, multi-phase flow loop at Teapot Dome Field, Wyoming. In August 1998, the Department of Energy and Texaco, Inc. jointly approved $3.2 million in funding for the project. The field's low ambient temperatures, terrain character, and existing oil field infrastructure attracted Deep Star and their technical advisor, Southwest Research Institute. RMOTC can simulate the harsh conditions typical of deep-water environments, where flow line hydrates pose risks to productivity and pipeline integrity.

Flow assurance R&D opportunities on land-based test facilities have typically been limited by pipeline length, terrain, and ambient temperature constraints. The RMOTC Deep Star facility includes a five mile long, 3600, 6" diameter test loop with additional pre-test cooling and post-test heating jacketed loops, multi-stage separation, natural gas and NGL supplies, and a large liquid storage capacity. Being located at a producing oil field, RMOTC presents minimal environmental risks during testing. The facility allows high pressure, high rate, multi-phase flow testing at low temperatures. State-of-the-art data collection and processing are critical to the facility's highly automated and round-the-clock operational capability.

DeepStar is planning for two to three years of paraffin and hydrate deposition testing. Several companies have expressed interest in testing chemicals and subsea hardware during the DeepStar testing period. Interested testing partners need not be DeepStar consortium members. After DeepStar's commitment, the RMOTC hydrate flow loop will continue to fulfill the research needs of DeepStar members, industry at large, and academia. All types and scales of flow assurance research will be encouraged to take advantage of this facility.

Introduction

Deepstar is an industry cooperative effort organized and managed by Texaco, Inc. on behalf of 21 offshore operators (participants) and some 35 contributing engineering, manufacturers, and service companies (contributors) supporting deep water producing activities. Deep Star's work was started in 1992 and is currently in the Phase IV development phase.

RMOTC is an oil field testing center based at Teapot Dome field near Casper, Wyoming (Figure 1).

Figure 1. Location map of NPR-3 (RMOTC). (Available in full paper)

The field, owned by the U. S. Government and operated by the U. S. Department of Energy, has been in production since the 1920s, and is now approaching the end of its economic life.
Safe Sub-Sea Operations
Authors: Grenfell E.W.
Published: October 2008

For over 69 years since the advent of the USS HOLLAND on April the 11th, 1900, our American submarines have believed in the philosophy of safety, best portrayed by a short verse which I heard many years ago: I quote:Now I tell you, mate, we all temptFateWhen we dive beneath the seaFor a man is a fool to break theruleThat nature meant to be - - -Gardner Young

As a young man of 25, I joined our Submarine Force and quickly learned that to buck the laws of Mother Nature you had to maintain a constant "alert" when you operated in a medium you weren't designed to live in. You had to be "on watch" 24 hours a day if you wanted to operate safely under the sea. And so today as the growing number of new vehicles and their crews begin to challenge the deep sea more and more, the safety requirements and constant respect for Deep Sea operations must be adhered to at all times.

This became very apparent to me when as a consultant to General Motors Defense Research Laboratory in Santa Barbara, I noted that the early planning for the building of the Deep Ocean Work Boat (DOWB) included "safety" as a primary requirement - safety in the electrical design - safety in the life support system - safety in the ballasting system, etc. In other words safety seemed to be a prime factor. In this instance the normal attention to safety was probably enhanced due to the fact that the design characteristics were the responsibility of a former Naval Constructor who had the job of initial design planning for the USS DOLPHIN, the Navy's first Deep Submergence Submarine built and now operating out of Portsmouth, New Hampshire. That gentleman is Dr. Scott Daubin, now employed by Woods Hole Institute. Of equal influence in the operational planning was the current DOWB Project Manager, Captain Swede Momsen, USN (retired) whose responsibility covered all of the initial testing and operating schedule. Captain Momsen, son of a very prominent Submarine Admiral, and an active Submariner himself is a strong advocate of Safe Submarine Operations.

Last, but not least, the whole DOWB safety program was strongly supported by management who set up a "Safety Committee" to make certain that all in the program would be properly imbued with the "safetybrush."

Thus we see that with all this proper preliminary planning that the check-off lists for DOWE dives contain some 227 items from Pre-Dive status through to Post-Dive phase; of these 227 check-off items, about 20% are "safety" items.

To keep track of the DOWB on its dives, the Director of Operations, with a recorder at his elbow at all times, conducts and controls operations from the DSV tender and from a small boat which follows the movement of the DOWB acoustically. The Director talks, over the UQC, to the DOWB every 15 feet in depth for a communication check, every other one-half hour for an environmental check, and on every hour for a power parameter check.
Analysis of Peak Mooring Force Caused by Slow Vessel Drift Oscillation in Random Seas
Authors: Hsu F.H. , Blenkarn K.A.
Published: October 2008

INTRODUCTION

Traditional naval architecture technology has not devoted extensive efforts to understanding of the requirements for mooring a vessel in the open ocean under storm conditions. Perhaps it can be said that conventional maritime practice would consider mooring under such circumstances an act of foolishness and therefore not deserving of serious technological effort. The demand on the offshore petroleum industry for mooring under trying conditions has, however, created the need for a clearer understanding of the physical phenomena involved. The offshore industry has experienced major difficulties in mooring under storm conditions and has suffered extensive financial loss. Over the years, attempts have been made to solve offshore mooring problems, utilizing a variety of vessels and mooring techniques. Results of experience and practice offer conflicting indications of the relative merits of various mooring systems. Various engineering and scientific studies have contributed toward an understanding of many factors influencing forces; however, it appears that previous studies have, for the most part, ignored a governing phenomenon. Specifically, there has been little attention devoted to the effects of slow vessel drift oscillation in random or irregular seas. It is this phenomenon which is the prime subject of the present paper.

Fig. 1 illustrates results obtained from model tests of a moored vessel in irregular waves. Shown in the figure, as a function of time, a-re the variations of wave height and period, the surge or drift position of the vessel and the tension in the primary mooring line. It will be noted that the surge motion of the vessel involves both a direct wave induced surge and a gradual slow drift taking place over a period of 1 minute or more in prototype time. The drift behavior shown in Fig. 1 is the phenomenon of critical importance. This type of drift motion is found in the motion records of moored ships in an actual ocean storm environment. Moreover, the basic behavior of slow oscillations is not unique to moored vessels. For instance, such behavior has been observed in tests involving vessels towed through irregular waves with a constant towing force. In such case, it has been observed that the vessel velocity exhibits slow oscillations with periods in the range of 1 to 2 minutes.

When an ocean wave is propagated toward a moored vessel, part of the wave is reflected, the remainder being transmitted on beyond the vessel. The conservation of wave momentum results in a net force applied to the vessel for each wave. For regular waves the consequence is a steady drift force resulting in a static shift of the position of the moored vessel. For irregular waves, on the other hand, a varying sequence of drift forces arises in correspondence to changes in wave height and period. Investigations leading to this paper show that the ensuing long period drift of the vessel can for many cases be the completely dominating influence in determining maximum mooring line tension.