bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preventing Vibration Problems. Caused by Reciprocating Compressor Pressure Pulsation
Authors: Floyd James K. 
Published: October 2008

ABSTRACT
Pressure pulsation from reciprocating compressors can cause excessive piping and structure vibration on offshore platforms, which may result in shutdowns or piping fatigue failures. This paper describes how to avoid such problems through proper use of pulsation dampeners, analog computer analyses, piping layout and supports. Field test results on actual installations are used to illustrate the effectiveness of these measures.

INTRODUCTION
Reciprocating compressors are sources of pressure pulsation. This pulsation propagates through the compressor piping, frequently causing appreciable vibration of both the piping and its supporting structure. The vibration can be strong enough to result in piping fatigue cracks and unscheduled shutdowns.
Particular attention must be given to pulsation induced compressor piping vibration on offshore platforms because of the greater potential for exciting other systems coupled through the structure. The common compressor pulsation frequency range of 5 to 100 Hz. often coincides with the natural vibratory frequencies of both the piping and structural members supporting the piping. When excitation and natural vibration response frequencies coincide, high vibration amplitudes and cyclic stresses can develop.
This paper discusses prevention of pressure pulsation induced vibration problems through the proper selection and use of:Pulsation dampeners.Analog computer analysis.Piping layout and supports.

PRESSURE PULSATION CHARACTERISTICS
By its inherent design, a reciprocating compressor does not provide a smooth steady flow but, instead, produces a series of periodic displacements produced by the intake, compression, and 0ischarge cycle basic to this type of compressor. This periodic displacement action superimposes a pressure pulsation wave on the intake and discharge system mean pressures. In addition, higher harmonic pulsation components are usually present because of the abrupt opening of the compressor valves which excites the acoustic response properties of the gas columns within the compressor passages and piping.
The origin of a pressure pulsation wave can be illustrated by the single reciprocating compressor cylinder shown in Fig. 1. The gas is compressed until the cylinder pressure exceeds that of the discharge system sufficiently to open the discharge valves. The discharge piping and passages are acted upon by a pressure pulsation having a fundamental frequency coinciding with the compressor displacement frequency and higher harmonic components. Similar effects are seen in the suction passages and piping.
Pressure pulsation waves propagate at sonic velocity (approximately 1400 fps for natural gas) through gas contained in both the suction and discharge piping. The pulsation travels upstream and downstream through the gas media which is flowing at a slower velocity of approximately 3D to 60 ft/sec. This can be visualized as being similar to the ripple action produced from a rock thrown into a flowing stream.
Problems Encountered in Maintaining Deep Draft Channel at Mouth of Mississippi River During and After Flood of 1973
Authors: Curtis William W. , Schorr Henry R. 
Published: October 2008

THE MISSISSIPPI RIVER
The Mississippi River and its tributaries drain forty-one percent of the 48 contiguous states. The basin covers 1,245,000 square miles and includes all or parts of 31 states and parts of two provinces of Canada. The waters of the Mississippi River are distributed to the Gulf of Mexico through several outlets. The principal outlets at the mouth of the river are Pass A Loutre, South Pass and Southwest Pass. The intersection of these three outlets is known as the Head of Passes. Points located above or below this intersection are measured as miles Above Head of Passes (ARP) or miles Below Head of Passes (BHP). Figure 1. Another main outlet of the river is through Old River Control Structure, Mile 314 ARP, into the Atchafalaya River.
The Mississippi River and Tributaries is also the main artery of transportation for waterborne commerce for the Central United States. The river system interconnects the inland ports and also provides access to other United States ports and the ports of the world. The two major ports located in the lower reaches of the river are Baton Rouge, at Mile 229 AHP, and New Orleans, at Mile 95 ARP. The Port of New Orleans handled 130,000,000 tons of cargo and Baton Rouge handled 53,500,000 tons in 1973, being the second and seventh largest ports respectively in the Nation.
A channel 40 feet deep is maintained from Baton Rouge to the Gulf' through Southwest Pass. The width of the channel varies from 500 to 1,000 feet because of natural river characteristics or structures built to constrict the flow.

CONTROL STRUCTURES IN SOUTHWEST PASS
There are two rock and pile dike structures at the Head of Passes that maintain an optimum distribution of flows between the three principal outlets. One of the structures is located between Pass A Loutre and South Pass and the other between South Pass and Southwest Pass.
There are additional structures along the Southwest Pass channel and at the entrance to the Gulf to constrict the flow so that some natural assistance is achieved in maintaining the 40-foot deep channel. Permeable pile dikes perpendicular to the flow are located along the channel to contract the surface width of the flow to 1,420 feet. In this reach the navigable channel is 800 feet wide. There are controlled outlets through the banks on both sides of the pass that allow some loss of discharge; however, this is necessary because the material carried by the flow through these outlets strengthens the banks and nourishes the adjacent marches. There are jetties at the lower end of the 20.2-mile long Pass to guide the flow. The east jetty is 25,000 feet long and constructed of stone with a cover of heavy stone graded between 4 and 10 tons each.
The Reel Pipelay Ship - A New Concept
Authors: Goren Y. , Yenzer D.E. , Cushing C.R. , Friedland N. 
Published: October 2008

ABSTRACT
To insure economic success, technological development must blaze the trail of any undertaking in the field of offshore oil production. In order to meet the requirements and challenges of pipelaying in deep and rough waters, the team who designed, constructed, and is successfully operating the world's first and only column-stabilized lay barges, have concentrated a massive effort to design the Reel Ship - a new concept, which is presented in this paper.
Following a discussion of the application, advantages and special features of the ship the paper describes the details of the Reel Ship system pipe lay operation. Following that, the paper presents the design criteria and features of the vessel, and, finally, a description of the various components of the pipe-handling equipment and the design procedures which led to their selection. The Reel Ship described herein is an engineering breakthrough which, without a doubt, will have a significant impact on future offshore development and production operations.

INTRODUCTION

1. General
Analysis of the requirements of the Offshore Oil Industry revealed the following general trends:
(Available In Full Paper)
Operational and economic analyses of the above trends led Santa Fe Engineering and Construction Co. to the development of the Reel Pipe-lay Ship discussed in this presentation. The engineering effort for the design of the ship and its systems was undertaken by Santa Fe Engineering Services Co. in late 1973. Utilizing the experience and know how acquired by the Company in pipe laying in rough sea conditions as well as operating the world's only reel pipe-lay barges. Santa Fe Engineering Services Co. designed the ship and is currently negotiating a contract for its construction. The design and preparation of the pipe- handling system and the final bid package preparation was the result of a massive effort by Santa Fe engineers, aided by number of subcontractor engineering firms.

2. Advantages of the Reel Ship
The primary advantage of the Reel Ship is attributed to the speed with which the pipe can be discharged at sea. This is due to the patented technique of straightening the pipe during unspooling and discharging operations. Another unique advantage of the Reel Ship is the welding of the pipe into continuous strings onshore, the x-ray examination and the corrosion protective coating applied irrespective of sea conditions and space constraints experienced by conventional barges.
The Reel Ship also has an advantage in being able to discharge pipe in very deep waters where it is extremely difficult or impossible for conventional welding barges to operate. This advantage stems from the peculiar geometry of the ship which allows the pipe to enter the water at very steep angles (up to 50°)while conventional barges are limited to about a 15 entry angle. This also allows the Reel Ship to work without a stinger, which is required by conventional barges.
Underwater Mateable Electromechanical Connectors for Power and Signal Cables
Authors: Wilson Jeffrey V. 
Published: October 2008

ABSTRACT
In support of a broad variety of submerged power and signal transmission applications, the Civil Engineering Laboratory is developing underwater mateable electromechanical connectors for the Naval Facilities Engineering Command and the Naval Sea Systems Command. These "wet" connectors are designed for the underwater interconnection of rigid structures (e.g., pressure housings), cable structures (e.g., instrumentation arrays) and for connection to submersible vehicle batteries. Power connector technology reported at the 1974 Offshore Technology Conference has been extended in several directions. The primary effort has been development of a coxial wet connector compatible with SD coaxial communication cable. This connector maintains an impedance match to within cable manufacturing tolerances (±O.7 percent), has a signal range from O. 1 to 1 mgH, has a corona noise extinction level of 6, OOO-v alternating current (rms), is designed for 20,OOO-ft immersion and carries the breaking strength of the cable (16,000 lb). These connectors maintain the true coaxial configuration of the cable and may be mated by submersible manipulators or by divers. Other CEL-developed connectors are described, including a 300-amp, 170-v-DC model used for connecting the battery charging umbilical cable of the Deep Submergence Rescue Vehicle and a 1,000 amp, 120-v-DC connector for the TRIESTE II battery harness. Work with the TRIESTE II connector has demonstrated that it is suitable for use in explosive environments because the sealed, oil-filled design effectively contains arcs drawn during unmating.
The availability of these wet-connector concepts offers new alternatives to a system designer. He can now plan undersea operations that are unencumbered by attached power and signal cables. With the availability of wet connectors, these cables can be connected after the equipment is properly located at its undersea site. In addition, by use of these wet connectors, reliable connections can be made now on the surface without protection from the environment. Typical offshore applications would include power distribution to seafloor production systems, power and signal umbilicals for running equipment, down-hole electrical connections, and emergency quick-release systems.

INTRODUCTION
The Navy program to develop wet (underwater-mateable) connectors was initially designed to fill two major gaps in able connector technology:power limitations (100 amp, 6OO-v maximum available) andwet mateability (existing commercial wet connectors could only carry low voltage and were not adapted to deep mating).
With the completion of the prototype development in 19731,2 CEL had established a successful concept that embodied new capabilities in both areas. The concept utilized an oil-filled female half that contained an 0-ring sealed piston. During mating the male pin and contact were wiped off by the O-ring as the piston was displaced any small leakage was dispersed through tile-liquid dielectric and was thus prevented from forming leakage paths.
Estimation of the Foundation Condition of a Fixed Platform by Measurement of Dynamic Response
Authors: Utt M.E. , Durning P.J. , Duthweiler F.C. , Engle D.D. 
Published: October 2008

ABSTRACT
We analyzed the recorded dynamic response of the Monopod platform, in Cook Inlet, and simulated the response with computer models in an attempt to discover the reason for observed changes in the fundamental frequency. Using a 3-dimensional linear dynamic structural analysis program we-modeled the recorded response to ice impacts and simulated model response to an assumed earthquake. We matched the results of the dynamic program with a non-linear finite-difference soil pile analysis program to model the soil structure interaction.
By varying model parameters we found that for the Monopod, dynamic response was insensitive to-changes in deck load mass or virtual water mass, but was strongly influenced by soil stiffness. Other investigators have found mass and hydrodynamic effects more important for other structures. By comparing numerical model output with recorded structural behavior, we were able to estimate the condition of the soil and the pile foundation. This analysis revealed that the change in the fundamental vibration period was related to changes in the soil around the piles near the mudline.
We conclude that, for small deflections, the upper 20 feet of the oil does not contribute to the dynamic response Of the Soil-structure system. For the larger motions, associated with an assumed earthquake, this zone would contribute to dynamic response.

Monopod Platform Has Acceleration and Strain Recording System
When the Monopod platform (FIGURES 1 and 2) was installed in 1966, a strain gage system was installed to indirectly measure ice forces (FIGURE 3). With this system, structural vibrations were also observed. An accelerometer system and recorder were installed in 1972. as described by Durning and Engle, 1976. The system consists of three triaxial accelerometers, two on the production deck and one at the mudline in an unused well conductor. The locations of the accelerometers are shown in FIGURE 4. Data from tile accelerometers and from the previously installed strain gages are recorded on cassette tape decks located in the production office on the platform. The recording system remains inactive until it is activated by a seismic starter located on the production deck. Acceleration and strain data are recorded automatically, and the system shuts off ten seconds after the vibrations cease. The analog tape records were later digitized, with an 0.02 second sampling interval, for computer analysis, such as calculation of spectra.

Change in Vibration Period
The platform's fundamental period was determined to be 1.1 seconds from the strain gage measurements of 1967. After the accelerometer system was installed in 1972, the fundamental period was 1.3 seconds. This 18% increase in the fundamental period caused concern.
In 1974, we undertook research to investigate and verify the available dynamic and nonlinear analysis methods, and to determine the cause of the observed change in the Monopod's fundamental vibration period.
Cotton- The Natural Sorbent for Combating Oil Pollution
Authors: Meenaghan G.F. , Halligan J.E. , Ball A.A. , Leary John F. 
Published: October 2008

ABSTRACT
On June 1, 1974, a nineteen month study was initiated between the United States Coast Guard and Texas Tech University. The overall purpose of this contract was to develop a sorbent dispersal, retrieval, and disposal system using cotton wasties to combat oil spill pollution.
A test program was conducted to develop the design data base required to evaluate the concept as well as the system components. Major variables studied included crude oil type, sorbent to oil weight ratios, sorbent contact time, removal efficiencies, squeezing techniques, disposal via incineration, and air pollution parameters.
The results of this effort has shown that the concept of using cotton as an oil spill cleanup agent is viable and that the system as operated was capable of retrieving approximately 95 percent of the oil confronted for water velocities of 2 feet per second or less and dispersion ratios of 0.05 pounds, or greater, of cotton per pound of oil.

INTRODUCTION
The first question which must be addressed when considering sorbent systems concerns the advisability of adding an additional component to an oil spill. At first, this may seem to complicate the cleanup process. However, practical experience in analogous situations has shown that such an addition is desirable. Examples include putting oiled sawdust down to clean up a floor, and the use of a mop to pick up spilled water. Therefore, the use of a sorbent to clean up oil spills may have practical advantages.
The purpose of the sorbent is to facilitate a change of phase. The desired effect is similar to that observed with the addition of a small amount of solid gelatin to water which forms a semisolid. Similarly, a properly dispersed sorbent can markedly change the properties of fifty to one-hundred times its weight of oil. Just as it is no particular task to pick up a gelled material with a fork, The opinions or assertions contained herein are the private ones of the writer(s) and are not to be construed as official or reflecting the views of the Commandant or the Coast Guard at large.
It is not difficult to pick up oil once it is within a sorbent structure. Since the sorbent oil, mixture has decidedly different physical properties than those of a fluid, this will aid in retrieval operations. This is particularly true when using vacuum hoses where a sorbent and a simple rake can markedly increase the efficiency with which small pockets of oil can be retrieved.
Another benefit of using a sorbent is its ability to capture and retain oil for retrieval at a later time. This may be a major advantage due to the rapid initial rate of spreading of oil slicks on water. In many cases, the oil sorbent mass is highly oleophillic and hydrophobic which leads to coalescence into clumps facilitating later retrieval.
Additional advantages of a properly chosen sorbent are selectivity, effectiveness, and general applicability.
Nile Submarine Fan: Sedimentation, Deformation And Oil Potential
Authors: Summerhayes Colin P. , Ross David A. , Stoffers Peter P. 
Published: October 2008

ABSTRACT
The Nile Submarine Fan is one of the largest in the world. Fan sedimentation probably began in the late Pliocene, burying Miocene carbonates and evaporites (Messinian). Salt flow due to sediment loading caused uplift of the fan's eaStern flank to form the salt dome-studded Levant platform. The fan's western flank - the Nile Cone - is deformed by minor folding, faulting, and slumping. The modern fan ends at the Mediterranean Ridge, but formerly extended further, as Nile-derived turbidites are found beneath the ridge. Tectonic and salt-flow deformation of the ridge occurs as a response to subduction of the African plate beneath the European plate.
Piston cores about 10 m long show that carbonate sediment occurs west of the fan and on the Mediterranean Ridge. Channels on the Nile Cone contain thick, clean, well-sorted, coarse-medium sands. Thick sequences of thinly-bedded muddy turbidites occur between channels. On the Levant Platform are complex mixtures of thin turbidite sequences and carbonate muds, while young channel deposits are lacking. East of the platform in the Cyprus Basin are mainly grey hemipelagic muds. Thin sapropels (with up to 25% organic matter) are common in cores' from allover the area. The turbidites also contain substantial organic matter (up to 2%) mostly as plant fragments.
Sapropels and turbidites form potential petroleum source beds over the entire fan; channel sands form potential petroleum reservoirs that may be most common on the Nile Cone. Up-dip migration of oil to stratigraphic traps in abandoned channels makes the middle and upper parts (apex) of the Nile Cone of interest as a potential petroleum reserve. Similar traps, as well a8 structural traps, may occur beneath the Levant Platform.

INTRODUCTION
In the opinion of many marine geologists today (cf. Emery, 1973) the continental rise, a thick wedge largely of terrigenous sediment at the foot of the continental slope, may contain vast new petroleum reserves. Much of the rise is built by overlapping submarine fans that grow at the ends of submarine canyons at the foot of the slope, by deposition, from turbidity currents, of sand in channels and mud on levees and between channels (Whitaker 1976). Fan growth, both lateral &vertical, is a key factor in shaping the continental rise in almost every ocean basin. Because their muds contain substantial organic matter (so are potential source beds), and their channel sands are potential reservoirs, fans deserve careful examination in the search for new hydrocarbon deposits beneath the sea (Wilde & others, 1977).
In this paper we examine the geological development of one of the worlds largest deep-sea fans, the 70,000 km2 Nile Submarine Fan, that covers much of the floor of the eastern Mediterranean, off the coast of Egypt (fig. 1), and attempt to assess its potential as a locus for oil &gas deposits.
Comparison With Observation At Sea Of Period Or Height Dependent Sea State Parameters From A Theoretical Model
Authors: Ezraty Robert , Laurent Maryse , Arhan Michel 
Published: October 2008

ABSTRACT
A theoretical joint probability density for individual wave heights and wave periods, originally developed to describe storm conditions, is here compared with some 2,000 routine wave recordings in the Bay of Biscay.
From the joint probability density, all other mean sea-state parameters (HT1/3, TH1/3, T1/3,) can be computed using H1/3, T and (Symbol available in full paper), the spectrum width parameter. The systematic discrepancy existing between theory and observation can, if necessary, be corrected empirically.

INTRODUCTION
The paper published by Cartwright and Longuet Higgins is widely used to predict the height of sea waves and to compute the significant wave height, h1/3, or similar variables h1/N, as well as the expectancy of the maximum, E(hmax), of a given number of waves, starting from mo respectively, the total energy and the width parameter of the spectrum.
To describe a sea state, it is necessary to have at least a characteristic period as well as a characteristic height. In the "zero-up-crossing" wave analysis, the following periods usually appear. T1/ 3 = mean of the highest third of the zero-upcrossing periods; TH1/3 = mean of the periods connected to the waves used to compute H1/ 3; T = mean of the zero-up-crossing periods.
In the same way, T1/N and TH1/N can be defined. Empirical relationships between these characteristic periods, based on observation at sea can be found in the literature.8
The theoretical model developed at C.N.E.X.O. is based on the theory of Gaussian noise as established by Rice7 and leads to an explicit formula for the joint probability density of wave heights and periods; this density is fixed, given three parameters a characteristic height, a characteristic period. Then, it is possible, by appropriate integrations, to relate the different average heights to the associated average periods that describe a given sea state. Although the narrow band spectrum hypothesis is not always satisfied in reality, computed values of mean quantities from observations at sea remain quite close to their theoretical equivalents; the discrepancy, being systematic, can be corrected, if necessary, for the theoretical model.

THE THEORETICAL MODEL
The model is developed, using as a starting point the joint probability density for a Gaussian noise signal to have a value?1, at a maximum and a second derivative, with respect to time ?3, in the notation of Cartwright and Longuet-Higgins.(Mathematical equation available in full paper)
To each positive maximum we have assigned a sinusoidal wave having for amplitude ?1 and period T given by(Mathematical equation available in full paper)