bluuebunny/crossref_metadata_2025_split huggingface dataset:
Joint Inversion Of Resistivity Logs: Limits And Possibilities
Authors: Strack K.M. , Mezzatesta A.G. , Frenkel M.A. 
Published: October 2008

Abstract
In the search of hydrocarbon bearing formations, borehole electrical logging techniques play a key role in distinguishing between oil and water saturated rocks. Among the electrical techniques, both induction and current injection (galvanic) tools, are of significant importance in determining movable and residual hydrocarbons. In the past, the borehole electrical logs have been mostly interpreted using curve matching or approximate modeling techniques. This often resulted in underestimating the hydrocarbons in the subsurface and/or misled distinction between the water and oil bearing zones. Here, we present an automated interpretation technique which has become feasible to the oil industry with the advancement in geophysical inversion and modeling and the event of smaller parallel computers. In addition to being able to provide an automated and more reliable interpretation, one can also combine numerous different electrical measurements to avoid the inherent bias of the individual logging tools. Further, a thorough analysis of the interpretation methodologies used (namely inversion) allows us to provide uncertainty estimates for the interpretation results which can be translated directly into confidence intervals with minimum and maximum pay values. The benefits of this technology can be best presented using case histories from different environments.

Introduction
In estimating the amount of hydrocarbons in the ground, one interprets the characteristics of the earth's formation by using borehole logs. Figure 1 shows a typical sketch of formation intervals where electrical logs are being used to determine the existence of oil in the formation. In the left part of the figure, the formation is usually a thin zone where the pore fluid is replaced by the borehole mud. This zone is called the invaded zone. The character of this invaded m e can change from being exclusively by the borehole mud or mixed invasion of borehole fluid, formation water and formation hydrocarbons (Fig. 1). The distinction between these zones are mostly done through induction or current injection (galvanic) logs. This is because the oil is resistive while the formation water in general, is very conductive. During the tuna when the industry was predominately producing large pay zones, curve and approximate numerical techniques were quite sufficient to distinguish between the oil and the water. As the targets move to thinner and thinner reservoirs and more complicated environments, the systematic underestimation of reservoir reserves and a decreasing hit to miss ratio of oil bearing zones become apparent.@Although solutions have been suggested many years ago1,2 the techniques have only been used on a research level because commercial applications to real log data was not feasible because of the large amount of data being obtained during a logging run and also the complexity of the numerical problems on hand.
Efficient F-K Domain Wavefield Interpolation
Authors: Gulunay Necati , Chambers Ronald E. 
Published: October 2008

Abstract
Often, economic reasons dictate that seismic data be recorded with much larger spatial sampling intervals than basic sampling interval. This can cause harmful aliasing effects in prestack and post stack multi channel processing algorithms such as f-k filtering, Radon transform filtering, DMO, and migration. A common solution to sampling deficiencies is to use trace interpolation during processing. Among methods used in trace interpolation are sinc interpolation, dip search and slant stack, f-k domain deterministic dealiasing and the popular prediction filter based algorithms. Only the last class of algorithms can interpolate aliased temporal frequencies for steeply dipping events, but are expensive. Because of wrapping of aliased data inherent in the f-k domain, this domain was previously thought unsuitable for trace interpolation in the presense of steep dips. But, because of its efficiency, the f-k domain is an attractive domain to work with. This paper will present an efficient f-k domain data adaptive interpolation method that overcomes the problems in aliased data. The capabilities to interpolate steeply dipping events, to handle curvature by spatial windowing and to help in the removal of multiple interference will be illustrated. This new f-k wavefield interpolation is now used in production to minimize the aliasing effects in 3-D prestack multichannel processing.

Introduction
The recorded wavefield is a sampled version of the continuous wavefield and field geometry serves as a digital sampling process. Coarse digital sampling is known to cause aliasing. Ideally, shot, receiver, and temporal sampling intervals should be selected so that it is possible to construct a continuous wavefield from the recorded samples. The data are then said to be "properly sampled." The resulting sampling intervals are called "basic sampling intervals'." Experience has shown that harmful aliasing effects in prestack and poststack multichannel processing result from data recorded with a much larger spatial sampling interval than the basic sampling interval. Even when the signal (primaries) is properly sampled, it is quite likely that organized noise such as ground roll, mud roll, and multiples is under sampled, especially in areas where the noise or multiple energy has a much lower move out velocity compared to the signal. With the improved dynamic range of current field equipment, it is common practice to use smaller arrays in the field and deal with the noise during processing. Although NMO correction is sometimes used to reduce the aliasing problem, for some recording geometries such as offend marine shooting, an inherent aliasing problem remains in the common offset and common midpoint domains, even when shot and receiver domains are properly sampled.
Mensa Project: Rig Operations
Authors: Saucier B.J. , Southworth M.E. , Browning S.W. , Wainwright W.M. , Piley D.A. 
Published: October 2008

Abstract
Mensa's subsea completion operations were conducted from a moored semi-submersible in 5300 ft. water. The rig based completion operations represent a milestone in deepwater subsea completion operations technology. The paper will focus on unique subsea completion operations employed from the rig, completion mooring operations, and the completion interface issues encountered during the installation of the subsea system.

Introduction
The Transocean George Richardson drilling rig was selected for executing the completion operations at Mensa. This selection was based on pre-existing work which had been performed jointly with Shell Offshore Inc. (SOl) on other projects, rig capacities, and schedule availability. The rig is a DNV classed, GVA 4500 semisubmersible. The deepwater operating environment at Mensa presented challenges in executing the offshore operations. Early rig selection and identification of key rig limitations contributed to the offshore operational success. Installation operations were governed by project economics, which drove the installation approach and sequence of operations. Subsea completion equipment interfaces with the rig were planned and identified early in the project engineering phase. To achieve the project goals, operations engineering and planning focused in the following areas:mooringlstationkeepingsubsea hardware interfaces with rig infrastructureBOP interfacesvariable deck load and lift capacitiesriser tensioningunloading operationsnovel installation techniques

Rig Operations
Early rig selection and identification of rig interfaces specific to the Mensa subsea completion allowed a unitized hardware and operational plan to be developed. Development of a "rigbased" sequence of operations and installation plan provided a basis from which the planning and engineering activities were structured. This enabled identification of areas that would impact the rig-based installation operations. Preliminary installation procedures were then developed early in the project development cycle. The following discussion highlights the rig interface challenges which were identified and resolved during the subsea installation completion cycle.

Completion Mooring Operations
SOl recognized that available anchor handling support vessels in the Gulf of Mexico were not capable of running and recovering anchors at Mensa. In January, 1995, SOI contracted to construct a purpose built anchor handling vessel for mooring the Richardson at Mensa to support initial development drilling operations. The vessel, Ross Chouest, was delivered in July of 1996 with 13,500 total BHP and 187 tons of bollard pull. Dual 500 mt winches capable of holding 6,500 ft. of 3¾' workwire were installed on the vessel to handle all eight 18mt anchors with chain and wire. The dedicated anchor handling vessel further supported the completion operations in the following areas:flowline/umbilical jumper installationtree mobilization/offloading (Fig. 1)fluid displacement operations
The Incredible Story of the Worlds Oceans: Will Global Warming Have an Impact?
Authors: Westbrook Gerald T. 
Published: October 2008

The Magnitude of Nature's Forces
The more one understands the working of our planet in general and it's climate in particular, the more one becomes overcome with awe at the magnitude, complexity and grandeur of the natural scheme of things. Indeed, one can easily adopt a strong religious outlook to this work. So it is appropriate to open this paper with an example that has a strong religious couple. The emergence of the Earth from the Last Ice Age saw repeated warmings and coolings from about 20,000 years ago (20 KYs) to about 8 KYs before present (8 KYBP), when the Earth, approached its's present temperature. Over the past 20 KYs the oceans underwent about a 120 meter rise (a 400 foot rise) from their lowest levels seen in the Last Ice Age. Over the interval from 17 to 7.5 KYBP, as the ice sheets melted, and the oceans rose, the level of the Mediterranean gradually increased from 110 meters below present (mbp) to 15 mbp. At the end of this period an incredible event1 occurred in and around the Black Sea, coupled to this sea level rise. The Black Sea started as a lake. And its level oscillated over this 9.5 KY period, from 140 mbp to 15 to 127 to 156 mbp (Figure I). There was thus a head of 141 meters between the Mediterranean Sea and the Black Lake and sea water started to come through around the year 5500 Be. This occurred, first as a trickle, but soon as a torrent, with 1000 times the flow of Niagara Falls. This sea water intrusion would soon turn into an absolute disaster. It is estimated that the sea level rose 15 – 30 cms per day. The inhabitants would have had to retreat as much as one kilometer per day2 over a period of 100 – 200 days. Shelters would have disappeared rapidly as would most possessions and food, which would soon become the most pressing problem. Indeed this was an incredible event. Could this have been Noah's flood? We may never know. However legends of a great flood abound in many cultures around the world. If it was not Noah's flood it surely was one of Biblical proportions and helps depict the titanic magnitude of natural events around or connected to the behavior of our oceans.

Background
Global warming, as an environmental issue and as a priority of the Clinton/Gore Administration, has been much in the news with all of the publicity and hype around the Kyoto Treaty. The global warming issue is based on a gradually increasing level of greenhouse gases (GHGs) in our atmosphere, primarily CO2, that will increase the energy retained within the Earth's greenhouse system. There is no argument that such a system exists. And GHGs are real as is the global warming phenomenon. (Indeed, without the natural GHGs the Earth's average temperature would drop as much as 33° C. It should be noted in passing that the dominant GHG in this natural global warming is H2O, not CO2, not CH4, not chloro-flourocarbons, but H2O).
Optimizing 3D Seismic Surveys: Off-the-Shelf? or Out-of-the-Box?
Authors: Thomsen Leon 
Published: October 2008

Abstract
In seeking to optimize 3D seismic surveys, it is natural to define this as a minimization of the cost/benefit ratio resulting from such a survey. One way to do this is to minimize the costs of the survey (without major damage to the benefits), This frequently entailsuse of off-the-shelf components at every stage, thus avoiding the costs of customized equipment and procedures. A second way to minimize the same ratio is to maximize the benefits (without letting the costs get out of hand). Of course, a marginal increase in benefits may result from modifications of conventional design parameters or processing steps. However, the greatest increase in benefits is likely to occur if a radically different concept is employed. Such a new style of survey ("out-of-the-box") may have a lower cost/benefit ratio, even if the associated costs are higher! As an example, consider a 3D multicomponent survey. The costs of such a survey are certainly greater, but the increased benefits can often be worth the extra costs. These can include better P-wave imaging, better C-wave imaging, better subsurface formation characterization, and better timelapse repeatability.

What is it we optimize?
In this era of sharpened pencils, it is too common to assume that what we want to optimize is the costs of the survey. This is, of course, a laudable goal, and one easy to quantify. By contrast, the benefits of the survey may be less easy to quantify in precise economic terms. Nonetheless, I take it a self-evident that the parameter which we really want to optimize is the cost/benefit ratio, rather than the cost itself. The calculating of benefits is a complex task, beyond the scope of this work, and necessarily specific to each particular project. Nonetheless, it is appropriate to give the subject its proper emphasis by phrasing the optimization problem in this explicit way. If our goal is to minimize the cost/benefit ratio, this can obviously be done either by minimizing costs, by maximizing benefits, or some optimal combination of both strategies. A lot of attention has been paid, in the exploration community, to the strategy of minimizing costs, through clever design of the acquisition, and efficient pre-planned processing, and integrated interpretation, thus decreasing cycle time and saving costs in ways which are now obvious. It would be redundant to repeat or even to review those advances here. Instead, we concentrate the emphasis here on the other end of the continuum: to increase the value of the survey. Even if thecosts rise as a result of such a strategy, if the benefits rise even more, it is economically advantageous to do it. After all, this is the fundamental strategy of 3D itself: 3D is doubtless more costly than 2D, and in fact this dissuaded many companies from pursuing it in the eighties. But, after it was clearly demonstrated. by the early nineties, that 3D surveys yield benefits which more than compensate for the added cost, the utilization of such surveys skyrocketed, so that now, only 5 years later, it is routine.
Gravity Studies Across the Sula Arc
Authors: Rabinowitz Philip D. , Syed Fakhar H. , McCabeKexas Robert 
Published: October 2008

Abstract
The basins of the Sulu and Celebes Seas are located within a complex geodynamic zone between Pacific, Indian-Australian, Eurasian and Philippine Sea Plates. Three models have been proposed for the tectonic origin of these basins; trapped fragments from a larger oceanic plate, back-arc spreading, and rifting from the Southeast Asia margin. The basins areseparated by the shallow partly emerged Sulu volcanic Ridge extending from Western Mindano to Northeast Borneo. The Sulu Volcanic Ridge is bounded on the northwest by the Sulu Trench with evidence for subduction of the Sulu Sea beneath the Sulu Ridge. The nature of the southeast margin of the Sulu Ridge is difficult to assess because of a thick sedimentary cover and the lack of reflection or refraction seismic data. Hamilton (1979) and Rangin (1989) proposed flipping of subduction along the Sulu Arc from its southeast margin (subduction of the Celebes Sea under the Sulu Arc) to its northwest margin (subduction of the Sulu Sea under the Sulu Arc). Gravity observations are modeled across the Sulu Arc and adjacent basinal structures using existing seismic data. The gravity modeling is consistent with the concept that subduction zones exist along both flanks of the Sulu Arc and also that extinct spreading centers exist in both the Sulu and Celebes Seas.

Introduction
The Southeastern Asian region where four prominent plate boundeies converge is an area of unique complexity marked by active arc-arc or arc-continent collision zones, and subduction zones. The Sulu and Celebes Seas are located within this region between the Pacific, Indian Australian, Eurasian, and Philippine Sea Plates (Fig. 1).
The Sulu Basin is a small marginal basin, elongated northeast southwest, bounded by Palawan, Negros, Negros Trench, Zamboanga, Sulu Ridge, and Borneo (Fig. 1). The Sulu Sea is about 400 km wide and is divided by a bathymetric high, the Cagayan Ridge. The Cagayan Ridge is an elongated submarine volcanic ridge parallel to the Palawan Trench which divides the Sulu Sea into two sub-basins, the Northwest Sulu Basin and the Southeast Sulu Basin. The Cagayan Ridge has been interpreted as an island arc associated with the Palawan Trench (Holloway, 1982) and also a remnant volcanic arc for the Sulu Arc. Palawan Island, located on theNorthwest Sulu Basin margin is a part of an older Eocene subduction complex associated with the extinct subduction atthe Palawan Trench (Fig. 1) (Holloway, 1982). The Northwest Sulu Basin is filled by relatively undeformed sediment disconformably overlying the deformed strata. The Southeast Sulu Basin is filled by 1–2 km thick sediments overlaying the acoustic basement ranging 4500 to SWOrn in depth (Rangin and Silver, 1990).
The Celebes Sea is underlain by oceanic crust and is bordered by the Cotabato Trench in the northeast and North Sulawesi Trench in the south. The sedimentary thickness in most of the Celebes Basin is about 1 km and increase to 2 km along its Southern margin (Hamilton, 1979).
Low Cost 10 MMCFID Gas to Syncrude Plant for Associated Gas
Authors: Antia David D.J. , Seddon Duncan 
Published: October 2008

Abstract
A low cost 10 MMCFID gas to sycrude plant design is described. The plant is suitable for retrofitting on to platforms, drilling rigs and ships/barges. Three different plant designs are described costing between US $10 and 20 MM with a product yield of &gt;800 Bbls/d. Operating costs are estimated at $1.8 MM/a. The plant weighs c.3300 tonnes and occupies &lt;800 sqm. The syncrude product is blended with the field's crude oil.

Introduction
The gas to syncrude technology was first commercialized in the 1930's. Since the 1930's, commercial plants have been built in the USA, South Africa, Japan, Germany, China and Malaysia. Currently, commercial plants are in operation in Malaysia and South Africa. Large onshore plants are currently planned for Russia, Bangladesh, and Qatar. These plants, if built, will produce a total of&gt;1 MM Bbls of syncrude a day from natural gas.
The feasibility of placing small-scale gas to syncrude plants offshore, either on a standalone basis, or to process associated gas has been examined elsewhere 1- 9 The conversion process consists of three key stages: -Production of a synthesis gas (a mixture of carbon monoxide and hydrogen) from natural gas by either partial oxidation or steam reformingConversion of the synthesis gas to hydrocarbons using Fischer-Tropsch technologySeparation of liquid hydrocarbons (syncrude) from the product gas and water.
The key problems in introducing this technology in the offshore environment are:-Cost (the cost of a traditional plant is high by comparison with typical offshore process equipment)The requirement to use an oxygen source for the manufacture of the synthesis gas. Some oil companies are not prepared to consider the use of an oxygen plant offshore (VSA or cryogenic), while a steam reformer is too large for most offshore locations.Plant size. A conventional plant cannot be retrofitted onto an existing production platform and requires a comparatively large plant area (3600 sq m with an operating weight of c.19 K tonnes, for a 100 MMCFIDplant)2
The challenge faced by a supplier of gas to syncrude plants is to create a plant, which has the following characteristics: -A low capital cost relative to the volume of gas processed. This capital cost should ideally be less than $1.5 MMIMMCFID of gas processed.Is able to process gas volumes in the range 5 to 12 MMCFID. This will allow the plant to remove a flaring or reinjection requirement for most offshore fields. Plant operation should be unaffected by motion.Significantly reduces the field's emissions of greenhouse gasesProvides additional energy for the field, which can be used to provide motive power, etc.Uses commercially proven generic catalysts and technology. It should not need a steam reformer, auto thermal reformer or an oxygen plant.Is designed to contain low technology equipment, which will allow fabrication in third world countries.
The Importance of Titrating Antibodies for Immunocytochemical Methods
Authors: Hoffman Gloria E. , Le Wei Wei , Sita Luciane V. 
Published: October 2008

AbstractWhen using immunocytochemistry, investigators may not know how to optimize staining or how to troubleshoot the method when staining fails. Lacking are guides for comparing techniques and applying information derived from one staining method to another. Newer methods amplify signal detection, but will not necessarily work at the same primary antibody concentrations used for less sensitive reactions. Recommendations of optimal titers are often not accurate and are not usually accompanied by information on the method used to test those antibodies or the specifics of the assay. When the staining does not work, the investigators do not know how to determine if the antiserum is bad, the tissue is bad, or the method is inappropriate for their staining. This unit describes detailed procedures for determining optimal staining and applying that information to three common immunofluorescence methods. Lastly, a formula is provided for converting among the different methods. Curr. Protoc. Neurosci. 45:2.12.1‐2.12.26. © 2008 by John Wiley & Sons, Inc.
DNA‐Dependent DNA Polymerases
Authors: Kucera Rebecca B. , Nichols Nicole M. 
Published: October 2008

AbstractThis unit presents characteristics and reaction conditions of the DNA‐dependent DNA polymerases, including E. coli DNA polymerase I and its Klenow fragment, T4 DNA polymerase, native and modified T7 DNA polymerase, phi29 DNA polymerase, Bst DNA polymerase, and Taq DNA polymerase. The unit also provides overviews of other classes of thermophilic DNA polymerases used in PCR applications (described fully in UNIT 15.1), and the rapidly expanding class of lesion‐bypass DNA polymerases that play a role in DNA damage repair. Curr. Protoc. Mol. Biol. 84:3.5.1‐3.5.19. © 2008 by John Wiley & Sons, Inc.