bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Pneumatic Seismic Energy Source for Shallow-Water/Marsh Areas
Authors: Brede E.C. , Viger H.L. , Johnston R.C. , Sullivan L.B. 
Published: October 2008

ABSTRACT
Non dynamite seismic energy sources have shown only limited success in difficult shallow water or marsh prospect areas, and none have shown applicability to both environments. Recently, a method has been devised to adapt a marine pneumatic source for operation in abrasive surroundings. A system composed of, four of these modified sources together with associated emplacement and retrieval mechanisms has been developed and has proven to be a reliable and efficient Seismic energy source for both shallow-water and marsh applications.

INTRODUCTION
During the last few years, numerous energy sources have been developed to replace dynamite as the primary means of generating seismic energy in offshore exploration for petroleum. One of these non dynamite sources is popularly called the "air gun". It has received wide acceptance by the exploration industry for work in both offshore and shallow-water prospect areas. In the latter case, the air guns are normally de played from a self-propelled, shallow-draft barge and may operate in water depths from four to forty feet.
When an air gun is suspended in water at depths of less than four feet, its acoustic output is severely degraded because of the proximity of both the bottom and the water surface. Under these circumstances increased acoustic efficiency can be effected by firing the gun on or the bottom. This procedure prevents the expanding air released by the gun from erupting through the atmosphere-water interface and thus eliminates a major source of acoustic energy loss. However, the entry of mud and sand into the gun during firing in this manner so accelerates the wearing of the gun exposed parts that reliability suffers. The substantial maintenance required on a marine gun during extended operations of this type makes the technique economically unjustified.
These difficulties have been overcome by the successful completion of a program to modify the marine air gun so that it operates reliably in both the shallow-water sub-bottom and the marsh. This modified gun is the heart of a four-gun self-contained energy source system that has been developed for operation in marsh and shallow water. The four guns of the system may be inserted up to ten feet deep into marsh of any foreseeable consistency in two minutes by hydraulically-actuated rams and withdrawn in a similar period of time. Sufficient air capacity is available to fire the guns up to 15 times in one location, retrieve the guns, move up to the next shot point and insert the guns, all within a lapsed time of ten minutes.
Comparison records obtained in the same prospect area with the modified guns embedded to various depths in marsh and marine guns fired in very shallow water clearly show the superiority of the "marsh" gun. The effect of varying the gun chamber sizes in the four gun array is shown by a record shot in the marsh with two different arrays.
How this system was developed - from qualifying the gun to results obtained with production system - is the subject of this paper.
A Variable Area Recorder for Offshore Seismic Data
Authors: Badger A.S. 
Published: October 2008

Abstract
The variable area display o£ seismic data has achieved practically universal acceptance by geophysicists for easy interpretation. In the past, survey recorders aboard ship displayed seismic data in a variable density mode using depth sounder instruments. This report describes a recorder capable of plotting offshore seismic data with rapid access to the recorded data and the visual benefits of variable area recording displays.
The recorder uses a new technique to permit slave operation from the energy source to initiate the display sweep. This permits variable cycle timing of the energy input without concern for the recorder mechanism.
The plot is made by galvanometers on direct write type oscillograph paper for viewing the section as the survey progresses. From one to four galvanometers can be used to record the seismic data. Timing lines are added coincidentally by a xenon flash lamp with .1 second and emphasized 1 second intervals beginning at TØ A crystal oscillator provides the stable time base for the timing line generation and synchronous motor drive as well. A magazine is provided for receiving the exposed section and is always used when film sections are made.
The plot is made on 10 inch wide paper using 9 inches of the surface for the data. Typical plotting speed is 2 inches/second for 4.5 seconds of data. The paper advances automatically at the end of the sweep and the mechanism resets in less than 3 seconds to await another input.
Field results of offshore data are displayed to show typical output of the recorder.

Introduction
One of the least documented subjects in the field of seismic exploration is that of data display. Volumes of material are written on the theory, the sources, processing techniques and results, but very little on the actual display of the information gathered. The man/machine interface is the ultimate result of all the effort and its importance should not be underestimated. The device to be described, is a variable area recorder for displaying offshore data in the form of a section plot that is accessable as the work actually progresses.
Rieber, in 1936, described a system for field recording using variable density photographic techniques adopted from sound-on-film work.1 This recording method did not receive wide spread adoption but was well known in the industry. A continuous profile of seismic data made from oscillograph film strips placed in sequence was described by Prescott in 1951.2. He remarks that a variable density or variable area oscillograph field record could be used but his displays were all of wiggle trace recordings. A step further in seismic section display was described by Palmer.3 This apparatus used variable density form of presentation from data recorded in the field on 70 mm film strips by variable density tracks. Time corrections were made to the data in plotting the variable density section and the results were of good quality. The use of film recording in the field was not widely adopted due to the emergence of magnetic tape recording techniques.
Salvage and Relocation of Offshore Platform with Minimum Equipment
Authors: McDonald William M. 
Published: October 2008

ABSTRACT
This paper describes the planning and operations involved in the intact salvage and relocation of a five-well drilling platform in the Gulf of Mexico. The operation employed unique procedures to plug, abandon, and remove existing dry hole wells; to free the below-mudline portions of the platform jacket; and to minimize the size and amount of lifting equipment required. These planning and methods innovations resulted in a significant reduction in heavy lift equipment requirements, with a corresponding reduction in cost of the project.

INTRODUCTION
Humble Oil &Refining Company's South Pass Block 36 "A" Platform was originally erected in September 1963. This structure was a four-pile, five-well, tender type platform in 165 feet of water. It utilized a special five-well drilling rig sub-structure and derrick which required no rig skidding. The platform foundation jacket weighed 576 tons, and three 250 ton derrick barges were required to originally set it in position (Figure 1). Pertinent features of the jacket (Figure 2) included (1) four 34 inch O.D. main legs, battered 1 in 5, (2) a center 34 inch O.D.; combination non-bearing leg and conductor guide, (3) four 36 inch O.D., skirt pile guides, and (4) a 50 feet × 50 feet square, solid plate "shear box" attached to the bottom of the jacket and extending 28 feet below the mudline.
Drilling operations resulted in three unsuccessful wells, and the drilling rig was removed in August 1964.
In mid-1966 it was proposed to salvage the foundation jacket for reuse to support a new 62 man self-contained living quarters building in West Delta Block 73, where the water depth was the same 165 feet.
The salvage and re-installation of this structure presented four major problem areas which correspond to the four operational phases of the project.Well Abandonment and RemovalThree unperforated wells were left standing. Two required abandonment in conformance with governmental regulations. The required cement plugs had been placed in the third well by the drilling rig. All three had to be cut off below mudline, and if possible, removed prior to moving the jacket.Foundation Jacket RemovalThe dead weight of the jacket plus the frictional resistance of the "shear box" indicated an upward lift in excess of 800 tons would be necessary to remove the structure.Transport of Jacket to New LocationThree methods of transporting the jacket approximately 30 miles in semi-open Gulf waters appeared to be possible.The jacket could be set on a barge, and the barge towed to the new location. This would require over 500 tons of lifting capacity to re-install.The jacket could be made buoyant and towed in a horizontal plane.The jacket could be lifted vertically with the derrick barge crane, held with the crane, and the derrick barge towed to the new location.Installation at New LocationThe "shear box" created a problem at the new location. Although needed at South Pass, it was not needed and assumed to be extremely difficult to install at West Delta.
Sloping Sea Floors
Authors: Stanton P.N. , Tidwell D.R. , Lloyd J.R. 
Published: October 2008

ABSTRACT
The effect of slope of the seafloor on the significant variables for multiline spread moorings with composite mooring lines containing both wire rope and chain has been investigated mathematically. A field test of the mooring calculations was conducted using an actual drilling vessel in the Santa Barbara Channel moored over a sloping ocean floor in water 1300 ft deep at the vessel and with anchors in depths of from 1056 to 1494 ft. The tests demonstrated the ability of the calculations to accurately describe the tensions in the tested lines.

INTRODUCTION
Floating drilling vessels use spread mooring systems to limit the horizontal offset from the wellhead that results from environmental forces acting on the vessel. In deep water, a spread mooring pattern may have anchors that are as far as two miles apart. In some areas, the ocean floor slopes sufficiently that the water depth can vary by several hundred feet from one side of a mooring pattern to the other. One such area is the Santa Barbara Channel, where the slope of the ocean floor sometimes exceeds 1200 ft/mile. Conventional mooring calculations for a flat bottom were considered inappropriate for these sloping bottom conditions. A numerical method accounting for a sloping bottom was developed and computer programmed. It accounts for all of the significant variables, such as mooring line tension, suspended line length, horizontal restoring force, and horizontal vessel offset; and it can handle composite mooring lines that contain wire rope and chain.
The equations used to relate the mooringline variables were derived from basic catenary equations. As the tension in a composite line consisting of both wire rope and chain increases, the equations describing the line change when the junction between the wire rope and chain is picked up from the sea floor or when the line becomes completely suspended. The equations were set up in a way that, with proper definition of variables, allows a single equation which is continuous and has continuous derivatives to apply for all ranges of tensions.

DESCRIPTION OF MOORING PROGRAM
Given an initial configuration of the mooring system, the computer finds the restoring force in pounds that will be produced by a prescribed horizontal offset of the vessel. This restoring force is equal to and opposite in direction to the steady environmental force acting on the vessel. The number of mooring lines, the mooring pattern, the initial tensions in the lines, a description of each line, the slope of the ocean bottom or the water depth of each anchor, and the depth at the initial vessel position must be given as input to the program along with the magnitude and direction of specified vessel offsets. As output, the program gives (at each offset) the tension in the most heavily loaded line, the suspended length of that line, the maximum anchor load, and the total restoring force exerted by the mooring system in response to the offsetting environmental force.
Artificial Upwelling
Authors: Roels Oswald A. , Gerard Robert D. , Haines Kenneth C. , Centeno Pedro A. 
Published: October 2008

ABSTRACT
R.D. Gerard and J.L. Worzel of our laboratory have recently suggested pumping cold sea water from 1,000 meters depth through large diameter pipes into a condenser area located on shore to intercept the flow of moisture-saturated trade winds. This air, when cooled, condenses much of its moisture, which will be conducted to storage tanks for use as drinking water, avoiding brine pollution of the sea caused by conventional desalination systems. The deep cold water of the ocean is many times richer in inorganic nutrients necessary to initiate the photosynthetic process than the surface waters of the euphotic zone. The deep sea water, which has been utilized as a source of cold for moisture condensation, will flow into closed-off lagoons near shore, where it will act as a fertilizer to stimulate primary production. A pilot scheme is now under way on the north shore of St. Croix in the U.S. Virgin Islands, where deep water is less than one mile offshore and where we have conclusively established that the waters from the nutrient maximum (700 to 900 meters deep) will create a phytoplankton bloom. This, in turn, could sustain commercial yields of organisms such as shellfish, crustaceans, fish, etc. The cost of pumping could be offset by the production of energy by the Claude process and by other cooling applications, such as air-conditioning, ice-making, cooling of conventional desalination systems, nuclear reactors, etc.

Introduction
As population growth increases the pressure on our resources, we should more and more look towards the oceans for many of our needs and attempt to use their enormous potential in a rational way. A thorough understanding of the meteorological, oceanographic, geological and biological factors in the natural environment can help us in utilizing the sea to advantage rather than struggling to overcome the natural conditions and further pollute the oceans and adjacent shores.
Just as mankind in its history on land has gone through a hunting stage and has then slowly turned to agriculture for its food production by domestication of animals instead of hunting wild ones, and by cultivating crops rather than picking roots and berries growing wild in the forests, the day is here when we have started to plan marine harvests in a rational way.
The culture of mussels is now a large industry in Spain. Oyster culture has been introduced with varying degrees of success in different parts of the world. Shrimp farming is here, and fish are raised in many places now. The selection of breeding stock is a well-established science. However, to grow mussels, shrimp or fish, these animals must be provided with adequate food, usually algae. An early attempt to grow phytoplankton was made by the Pfizer Company in the New York area: Thacker and Babcock (1)* built a pilot plant for the mass culture of algae, which gave trouble-free operation over a period of almost a year (Fig. 1).
Gemini Subsea System Design
Authors: Beer Paul , Ribbeck Larry R. , Jefferies Andrew 
Published: October 2008

Abstract
Field development planning and execution is influenced by a number of different factors, but ultimately must be based on a project's ability to deliver the maximum economic benefit to the project partners while maintaining safety and environmental goals.
The Gemini development was executed as a fast track project with simultaneous appraisal and implementation tasks. This approach brings with it an inherent reduced scope definition which must be accommodated by the system design while still remaining focused on the project drivers.
The Gemini development reflects a sound project execution plan that accommodated significant unknowns while still delivering production ahead of schedule and improving on the capital cost expectations for the development.

Introduction
The Gemini prospect was discovered by Texaco with the drilling and testing of the Mississippi Canyon Block 292 Well No. 1 in the third quarter of 1995. Following the discovery, Texaco (60% GWI) and their partner Chevron (40% GWI) continued their appraisal process with two additional wells with sidetracks to investigate the original discovery and other deeper potential areas. Concurrent with the appraisal process, Texaco began preparations for a phased development of Gemini with an early gas development in the Allison reservoir.
In January 1998, both project partners received board approval to proceed with the early Allison gas development with a subsea tie back to a shallow water host facility. The facility selected based on location and expansion potential was VK-900 which is jointly owned by Texaco (25% GWI) and Chevron (GWI 75%, operator).
An integrated project team was formed to implement the project and a subsea equipment contracting strategy already established by Texaco was extended into the Gemini development. The subsea trees and control system under fabrication for Texaco's inventory program was adopted for Gemini to reduce the project cycle time with the goal of improving project NPV.

Project Drivers
The project team identified the following drivers for the development:The development wells could be clustered around the MC-292 Well No. 1 location to provide a single drilling center.Due to schedule requirements, the rig would be on location prior to the subsea equipment being ready for installation.A first production target date of July 1, 1999 was committed to by the project team.The system should consider the potential for future expansion in the area. This included sizing flowlines to meet the corridor development needs.The Ocean Star semi-submersible rig would be used due to long term contract commitments by Texaco. This would also be the primary installation vessel for the subsea equipment.System operability would be critical since an overall production uptime target of 90% was a development goal.

Field Layout
The subsurface team determined that the reservoir take points could all be accessed from the single drilling center at the MC-292 Well No. 1 location. Fig. 1 is an illustration of the local seafloor layout.
Fast-Track Development of Deepwater Kuito Field, Offshore Angola
Authors: Davison C. , Dyberg P. , Menier P. 
Published: October 2008

Abstract
This paper describes the development of CABGOC's Kuito field offshore Angola using an FPSO and subsea facilities. This field development marks the start of deepwater production off Angola, and is in addition particularly significant in view of the extremely short project duration from contract award to start of production. This was achieved while incorporating the highest international environmental standards, including the re-injection of produced gas.

Field Description and Development Plan
The Kuito field, which has an average water depth of 400 metres, lies in Block 14 offshore Cabinda. Block 14 covers some 1.5 million acres, with water depths ranging from 200 to 1,500 metres. CABGOC, as operator of Block 14, have also announced discovery of three other fields in the same block. Apart from CABGOC's 31% share as operator, Agip, Total and Sonangol have 20% shares each, and Petrogal has the remaining 9%.
The Kuito field was discovered in April 1997, and first oil was produced in December 1999.
The field development plan divides the development into two main Phases, 1 and 2, with Phase 1 itself being divided into Phases 1A, 1B and 1C.
Phase 1A is the first production phase of the field development, with surface production facilities consisting of a spread moored FPSO based on a converted VLCC tanker. The subsea facilities consist of 12 production wells produced via a subsea manifold, which is located at a distance of 1.9 statute miles from the FPSO. The manifold is tied back to the FPSO via two production lines, each with a diameter of 11", a test line with a diameter of 6", and associated gas lift and control umbilicals. Associated gas is used as fuel on the FPSO, and for gas lift of the production wells, with any unused amounts being re-injected, such that under normal operations there is no flaring.
Stabilised crude is pumped to export tankers via a CALM buoy offloading system. The CALM buoy is located 1.15 statute miles from the FPSO and connected to the FPSO via two flexible flowlines, which each have an internal diameter of 15". A schematic of the Phase 1A field layout is shown in Figure 1.
Phase 1B covers Water Injection facilities, with seawater treatment and pumps already provided on the FPSO, and a 10" flowline and control umbilical leading to an 8-slot manifold.
Phase 1C will consist of an additional subsea production centre, similar to the 1A arrangement.
Design life for the FPSO is 10 years, with all other field facilities and FPSO mooring system having a design life of 25 years.
As of January 2000, Phase 1A is producing through 7 wells, with the remaining trees in the course of being installed and hooked up. Phase 1B is in the course of development with the start of operations set for second quarter 2000, and Phase 1C is at the engineering and evaluation stage.
Consortium Arrangement