bluuebunny/crossref_metadata_2025_split huggingface dataset:
Multicomponent Analysis of OBC Data
Authors: MacLeod M.K. , Hadley M.J. , Reynolds K.J. , Tura A. 
Published: October 2008

Abstract
In early 1998, Chevron acquired one of the world's first fullfieldfour-component ocean bottom cable surveys at the Alba field in the central UKNorth Sea. The primary objective of the survey was to use converted shear wavesto image the top of the reservoir and internal shales within the reservoirinterval. The secondary objective was to map water movement in the reservoirafter four years of production and water injection by comparing the P-wave OBCdata with the original 1989 streamer data. Our interpretation shows that bothobjectives were achieved with dramatic results - the converted shear wave dataprovide the clearest image of the Alba reservoir sands ever seen and productioneffects are obvious on the new P-wave OBC data.

Introduction
The Alba field is located in the central North Sea at an average subsea depthof 2000 meters. The reservoir is a poorly consolidated Eocene turbidite sandchannel that can be up to 100 meters thick1. The main channel isroughly 9 kilometers long and 1.5 kilometers wide. The channel containsintra-reservoir shales that can cause significant drilling and productionproblems. Oil production is from horizontal wells drilled from a platform atthe northern end of the field. Development drilling is ongoing and severallong-reach and re-drill wells are planned.
Since December 1993, the Alba field has produced 130 million barrels of oil. The field is currently producing 83,000 barrels per day of 19–20 degree API oilfrom 15 horizontal wells. Pressure is maintained by water injection from 5injector wells.
For efficient reservoir development, it is vital that the horizontal wells beplaced as close to the top of the reservoir as possible. Therefore we needaccurate maps of the top of the oil-filled sandstone and the location of theintra-reservoir shales. This mapping is extremely difficult on the existing1989 seismic data because there is a weak, inconsistent seismic event at thetop of the reservoir and the intra-reservoir shales are often seismicallyinvisible. This has led to some surprises in recently drilled wells -encountering shale bodies and the top reservoir off depth from theprognosis.
Furthermore, as we drill more wells close to producer and injector wells, anunderstanding of water movement becomes critical. For example, two recentlydrilled wells were found to have anomalous water saturation profiles. In onewell, waterwet sands were encountered above a sand with primary oil saturation. In the other well, partially oil-saturated sands were found below the originaloil-water-contact.
In this paper we first review the pre-survey technical evaluation used to helpjustify acquiring a 3D OBC survey at Alba. Then we describe 2D field trialresults that supported using the OBC method to achieve the objectives of thesurvey. Finally, we present some results from the new survey.

Methods
On conventional streamer seismic data at Alba field, we observe a weak, inconsistent seismic reflector at the top of the reservoir and intra-reservoirshales and a strong reflector at the oil-water contact.
Economic Benefits of FPSO Construction and Deployment in the Gulf of Mexico
Authors: Pike William J. 
Published: October 2008

Abstract
As oil and gas production in the Gulf of Mexico has moved to larger fields farther offshore, increased logistical and technical difficulties have mandated selection and utilization of increasingly complex floating production systems. Yet to be adopted, but viable candidates for developing fields in increasing water depths, are Floating Production, Storage and Offloading (FPSO) units whose practical application has been proven in most other offshore producing provinces worldwide. While questions have arisen about the timing of FPSO deployment in the Gulf of Mexico, it is likely that several units will be employed in the near to medium term as field conditions, project economics and logistical considerations warrant their selection.
Given current concerns about pollution risk, it is almost certain that FPSO's deployed in the Gulf of Mexico will, by regulatory mandate be double-hulled, double-bottomed, new-build units. It is also likely that a substantial number of these units will be of primarily U.S. construction due to pressure for local content; availability of construction finance underwriting from the U.S. government (loan guarantees approved under the federal ship financing program know as Title XI and administered by the Maritime Administration [MARAD]); availability of Gulf Coast building and outfitting yards; and local competence in Gulf of Mexico production parameters. Construction and outfitting of an FPSO and possible associated shuttle tankerage on the Gulf of Mexico will require expenditures of approximately U.S. $159 to U.S. $239 million. These funds will, in turn, generate economic benefits to the region of U.S. $463 to U.S. $720 million (with shuttle tanker construction) using an industry accepted economic multiplier of 2.0 to 2.5. These funds will be dispersed to the economy through direct and ancillary employment; local, regional and federal taxation; and increased demand for capital and consumer goods.

FPSO Development Scenarios in the Gulf of Mexico
At present, there are approximately 40 discovered fields in the deepwater Gulf of Mexico that might be candidates for development by FPSO. In most cases, the fields are outside reasonable reach of an established pipeline infrastructure, making an FPSO's tanker offloading system an attractive alternative to deepwater pipeline installation.
Since recovery ratios, production rates, fluid and reservoir conditions, and logistical requirements vary from field to field, a generic FPSO development scenario was developed for this paper to illustrate an economic benefit analysis format rather than an economic benefit analysis for a specific Gulf of Mexico asset. With regard to a generic development analysis of a field within the limits of those noted above as possible candidates for FPSO development, the following development assumptions were made for the purpose of this paper.
The Siri Production Jack-up Platform
Authors: Bærheim Morten , Manschot Dirk , Olsen Torgeir , Eide Henning 
Published: October 2008

Abstract
The Siri field is located in 60 metres water depth in the Danish sector of the North Sea. It was developed by a purpose built three legged jack-up standing on the top of a steel storage tank. The tank was installed in May 1998 and the jack-up was installed six months later.
The reservoir development requires a maximum of 12 well slots, and these will be placed inside a wellhead tower connected to the side of the storage tank and hinged to the deck.
This paper will give a brief technical description of the field development and highlight the challenges in design and installation with an emphasis on the steel structures.

Introduction
The licence for exploration and production of the Siri Central / North structures was given medio May 1995 to the Statoil Group. The group consist of the following companies :Statoil E & P A/S (operator) 40.0 %Enterprise Oil Ltd. 20.0 %Dansk Olie og Gasproduktion A/S 20.0 %Phillips Petroleum Company 12.5 %Denerco K/S 7.5 %
The first exploration well in Siri Central was spudded at the end of November 1995, with a second appraisal well drilled in August 1996 on Siri Central. The two wells gave the basis for establishing the reserves for the field development studies. A third appraisal well was drilled on neighbouring Siri East proving non-commercial reserves in that area.
A "fast track" field development strategy was established in February 1996. Screening studies of alternatives were done, and the first feasibility study of what later became the selected field concept was initiated in July 1996. Conceptual studies linked with competitive bidding with three contractors for a full EPCI bid for the complete platform including an oil offloading system was concluded at the end of December 1996. After some further development work, the EPCI contract was signed with Kvaerner Oil and Gas (KOGAS) at the end of March 1997. The storage tank was installed medio May 1998, after which drilling started with the Noble George Sauvageau jack-up drilling rig operating in cantilever mode. The 8700 t jack-up production deck was installed medio November 1998 after 7 weeks waiting on weather. This gives a time span of 18 months from signature of EPCI contract to deck ready for towage, which is considered to be very quick for a project of this size.

The Siri field
The Siri field is located in block 5604/20 in the northwestern part of the Danish sector of the North Sea, some 220 km from the coast line. The field is marginal, and various development options were investigated in the middle of 1996 to find an economically attractive solution. These included:Jacket full process platform with storage tankerConcrete full process platform with storageCombinations of steel and concrete solutionsCombinations of wellhead and process platformsFPSO ship with sub sea wellheadsConverted jack-up platform with storage tankerNew built jack-ups with storage tanker
The Development of the First Expandable Sand Screen
Authors: Metcalfe Paul , Whitelaw Calum 
Published: October 2008

Abstract
Eliminating the annulus between sand screens and the wellbore allows the well to be slimmed down by one casing size. This can result in dramatic well cost savings.
Wells that require numerous casing strings to reach their objective, such as those in deep water environments, could benefit from such screens because they liberate an additional casing string for the same surface casing size.
Once installed against the wellbore, an expandable screens would allow enhanced reservoir management activities. Zone isolation or treatment would be possible because of the elimination of the annulus.
This paper describes the development of the first expandable sand screen from its concept to its successful application in producing wells. An expandable screen construction was developed using slotted tubes encased in filter strips. A filter media was chosen for the screen that offered the best balance between plugging resistance and sand retention efficiency.
New manufacturing techniques were developed to produce the screen in commercially viable quantities and with the required quality.
The screens were applied in both cased and openhole applications in offshore and land environments. The trials proved that the screens could be expanded to eliminate the annulus present in traditional sand control equipment applications. The system proved easy to install and reduces the likelihood of screen failure due to plugging and erosion.

Introduction
The decision to install sand control means in petroleum wells must take into account many varied factors; It is often difficult to predict from core analysis and production testing whether a particular field development will require sand control or sand management during its producing life. If the decision to install sand control equipment is taken, it can have a large impact on the design and operation of the well. There are numerous techniques for controlling sand production, but by far the most common techniques involve the installation of screens of varying design.
Some disadvantages associated with the installation of sand control equipment in a well are:-–Higher equipment capital costs–Increased well installation time.–Reduced ability to modify or treat the reservoir inflow Profile.–Modification of the casing scheme to achieve the optimum screen internal flowing diameter.
The authors believe that the major disadvantages of current screen related techniques are those associated with the presence of the annulus between the screen and the wellbore. The existence of the annulus results in a larger casing scheme design than ideally required and severely limits the ability to control the reservoir inflow profile. In some instances the screens are surrounded by a highly permeable gravel (gravel packs). Even with this technique, the permeability contrast between the gravel and the surrounding formation means that the gravel still acts as an empty annulus in terms of the ability to control the reservoir flow from within the screen.
The International Legal Environment for Ocean Exploitation
Authors: Browning David S. 
Published: October 2008

There are numerous unresolved international legal problems which may affect the exploitation and investigation of the ocean. Most of the uncertainties probably will not be resolved for several years. There will be increasing international discussion and negotiation regarding the law of the sea in the future. United States industry and government should continue to analyze the issues involved and begin to formulate positions on some of the key issues. The recent report of the Commission on Marine Science, Engineering and Resources is a significant part of this process.
A number of different legal frameworks govern the use of different areas of the world's oceans. For the purposes of this discussion, the following frameworks will be distinguished:internal and territorial waters,continental shelf,contiguous zone, andhigh seas, including the bed and subsoil.
These distinctions are significant for the exploitation of mineral and living resources of the sea, as well as for the conduct of scientific investigations at sea. [1]

Internal Waters and Territorial Sea
The coastal nation generally has full control over the exploitation of mineral and living resources, and the conduct of scientific investigation, within its internal waters and territorial sea, including the resources of the seabed and subsoil of these areas. Except as may be limited by treaty, under international law each coastal nation may establish or enforce its rules of law in its internal waters and territorial sea. The coastal nation may exclude anyone from exploring or exploiting any resources in these waters. These claims of the coastal nation are recognized even with regard to living resources which usually live in the high seas, so long as such resources are found in the territorial waters.
The International Convention on the Territorial Sea and the Contiguous Zone provides that the sovereignty of the coastal nation extends beyond its land territory and its internal waters "to a belt of sea adjacent to its coast, described as its territorial sea" and "to the air space over the territorial sea as well as to its bed and subsoil." [2] The Convention does not specify the breadth of the territorial sea, and national claims vary from three nautical miles to 200 miles or more. The position of the United States has been that no claim to a width greater than three miles has received sufficient acceptance to be a rule of international law. However, there are some indications that the United States may be moving toward a 12-mile limitation for purposes of the territorial sea. This would generally be in accord with the majority of nations which agrees that the width of the territorial sea is no greater than 12 miles. [3]
The coastal nation's "internal waters" consist of the waters "on the landward side of the baseline of the territorial sea," as well as the rivers, lakes, and canals within its land area. [4]
The "normal baseline for measuring the breadth of the territorial sea is the low water line along the coast."
World's First TLP to Achieve Classification
Authors: Major R.A. , Frazer G.R. , Taylor J.E. , Mercier J.A. 
Published: October 2008

Figure 1 Sir Douglas Morpeth TLP, installed at Ewing Bank Block 921 (Available in full paper)

Abstract
The Sir Douglas Morpeth Tension Leg Platform (TLP) became the first TLP in the world to achieve classification in September 1998. British-Borneo Exploration, Inc. (British-Borneo) contracted with the American Bureau of Shipping (ABS) for this function. This step is a major part of British-Borneo's overall quality management program for both the project and the continuing operation of this TLP. While all of the TLPs presently operating in the Gulf of Mexico have had their structural adequacy verified by ABS acting as CVA, British-Borneo added reviews of all marine systems, enabling the vessel to be classed. Reviews of the Atlanta Offshore Limited design covered the complete hull structure, the truss-type deck structure, the tendon mooring system, the quarters, the electrical power supply, the marine piping systems and all other aspects needed for safe operations except the process plant itself. Regulatory requirements were considered simultaneously with those of class to speed the review process. Besides classification and verification the project used selected special studies to check critical elements of designs and analyses. The marine activities on the project were scrutinized by Global Maritime, acting as marine advisors and warranty surveyors. The approach described in the paper enabled a small oil company to effectively manage the quality requirements of an advanced deep-water development by bringing highly qualified outside resources to bear within the stringent time scale of the project.

Introduction
This paper seeks to answer:What is classification?What is the process by which it is achieved?What is different with classification from previously un-classed developments?What was done during the Morpeth Project to manage the process?What other quality assurance techniques were employed in this project?
Last year, a paper was presented to OTC which proposed a number of advantages to the classification of floating production systems for the Gulf of Mexico1. This year, we are pleased to describe the first application of that process to a TLP.

Description of the TLP Sir Douglas Morpeth
The Sir Douglas Morpeth is a single-column TLP that British-Borneo used to develop its Morpeth field in Ewing Bank Blocks 921, 964 & 965 in the Gulf of Mexico. Figure 1 shows the TLP installed on location. The designer, Atlantia Corporation (now Atlantia Offshore Limited) has designated this design "SeaStar®".
Analytical and Experimental Study of the Dynamic Response of Cable Systems
Authors: Goeller Jack E. , Laura Patricio A. 
Published: October 2008

ABSTRACT
Segmented cables of steel and nylon are frequently used in oceanographic applications to support a suspended payload. This report contains an experimental and analytical study of the dynamic response of nylon rope and stranded steel cables with a suspended payload under simulated conditions of ocean wave motion. A generalized distributed mass model was developed for a segmented cable made up of two viscoelastic materials including internal damping and linear external damping of the payload and cable. Viscoelastic behavior was simulated by a two-parameter Voigt model. Linear viscous damping was used for the payload and the cable, but an approximate method was developed for taking into account nonlinear damping effects. The phenomenon of impact loading due to initiation of slack in the cable was modeled on the analog computer for elastic cables, and by a digital computer for segmented cables of two viscoelastic materials. Nonlinear water damping was included in these models.
Theoretical calculations of force in the 1/4-in. nylon rope during simulated ocean wave motion agreed reasonably well with experimental results for both air and water tests. Internal damping of the nylon rope was determined experimentally from free oscillation tests. Tests on stranded steel cables indicated snap loads due to cable slack are extremely important. Snap forces as high as nine times the static payload force were encountered. It was shown that these forces can be significantly mitigated by the addition of a short length of nylon rope added to the bottom of the cable. The predicted force response agreed very well with the experimental value.

INTRODUCTION
Nylon rope and stranded steel cable are frequently used in oceanographic cable systems. Nylon is highly desirable for buoy systems, mooring systems and other oceanographic applications because of its light weight, relatively good strength and ease of handling. However, in cases where fishbite is a problem1, steel stranded cable is used in the upper portion of the cable while nylon is used in the lower portion. Many applications involve the suspension of a payload by a segmented cable of steel and nylon where the upper end is excited by longitudinal oscillation due to ocean wave motion. This problem was studied analytically2 by approximating the wave motion as a sinusoidal displacement function. The cable segments were considered as distributed masses with viscoelastic behavior including internal damping and also external damping due to fluid viscosity. The purpose of this paper is to compare experimental data with theoretical prediction using this model and a second analytical model which approximates viscoelastic behavior of nylon rope by a three-parameter model frequently referred to as a stranded linear solid. Lumped parameter models were also developed to predict the cable force during a snap condition caused by slack in the cable.
Some Notes on Static Anchor Chain Curve
Authors: Korkut M. Deha , Hebert E.J. 
Published: October 2008

ABSTRACT
This paper offers fundamentals necessary to solve many of the problems posed in the design and evaluation of mooring systems for offshore operations. In addition to considering the mooring system requirements in place, the actual operational requirements of "running" anchors, dropping, etc., are also considered. Other aspects of mooring systems such as pile anchors and catenary "sinkers" are also covered. Special attention was given to anchor line stretch.

INTRODUCTION
To those involved in the offshore operations of mobile drilling units, derrick barges and pipe laying barges, the evaluation and design of mooring systems is an ever-present problem. The questions to be answered about any offshore mooring situation are many. Guidance in finding these answers is presented in this paper.
Included are fundamentals necessary or selection of proper number of anchor lines, proper fluke area, anchor type and anchor location. In addition, problems related to setting out anchors are considered dropping distance of anchors, type of dropping, required workboat pull requirements. The subject matter of this paper is relatively new and, of course, subject to discussion at the conference.

EQUATIONS OF CATENARY
Differential Equation and Solution the catenary is the curve in which a flexible chain or chord of uniform weight will hang when supported by its ends [Fig. 1].
Differential equation of the catenary can be obtained as follows: let an element of catenary ds, have Forces T and T t o acting at ends, as shown in Fig. 2.
Because any element with a force w.ds acting downward is in equilibrium, we can construct the force diagram, as shown in Fig. 3.[Ho is constant at any point on the curve.] From Fig. 3, it is easily seen that d tan ? is equal to [w.dS]/Ho or d[dy/dx], since:(Available in full paper)

Determination of The Tension in Field
Often it is required to know the tension in an anchor chain or cable of mooring systems or offshore drilling barges when it is impossible to measure the length of the chain. From experience, it has been found that existing tension measuring devices cannot provide accurate readings because of the friction developed in the hawse pipes. Eq. 14 gives an accurate value for tension when the water depth and the angle at the top of the chain are known.