bluuebunny/crossref_metadata_2025 huggingface dataset:
Campos Basin: An evaluation about 20 years of operations
Authors: Vargas R.J.B. , Coutinho C.M.
Published: October 2008

Campos Basin started his production in 13 august 1977 with 10 thousand barrels of oil per day from the well EN-01 which produced to a semi submersible platform. Nowadays Campos Basin operations comprises 28 production platforms, 1500 wells (30% in operation), 17 drilling rigs, and 3,950 kilometers of flowlines, pipelines, and umbilicals. Present daily production is 610 thousand barrels of oil and 11 million cubic meters of natural gas.

The evolution of the production in Campos Basin was supported by investments in exploration and production, in deep water technology developments, and continuous management improvement. This evolution is summarized in several management programs focusing production growth, cost reduction and general progress of other performance indexes.

The main management programs supporting an increasing productivity added to the current development projects portfolio in deep waters, anticipates a daily production of 1.3 million barrels of oil and 22 million cubic meters of natural gas in next five years, with significant improvement in all economics indexes.

Introduction

Campos Basin is located in the north coast of Rio de Janeiro State comprising an area of more than 100.000 km2. The producing oil fields are among 70 and 140 km far from the seashore, and are located in front of Campos, Macae and Cabo Frio cities (Figure 1). This is the main production area in Brazil. It contributes with almost 70% of the total oil production and about 60% of the total natural gas production. A11 the production in this basin is exclusively done by PETROBUS. Formerly by the Southeast Production District, which was succeeded by the Southeast Production Region, and latterly by the E&P-BC (Campos Basin Exploration and Production). E&P-BC is now the division of PETROBRAS that is in charge of developing and exploring this area. The headquarters of E&P-BC are located in Macae city, that is almost 200 km distant from Rio de Janeiro city. Both cities are connected by a highway known as BR- I0 I, that makes part of the extensive national highway complex. Besides it's headquarters, PETROBRAS, have in Macae an oil treatment station, stock tanks and pumping stations. The latter is responsible for the displacement of 45% of the total crude oilproduced in Campos Basin. This crude oil is displaced to the company refineries in Rio de Janeiro, Sào Paulo and Minas Gerais States, through a network of pipelines. In the same area is located a liquefied petroleum gas plant, which uses natural gas as primary input. It has also a gas compression station that recompresses all the gas received from the offshore platforms and displaces it through two gas pipelines to the same refineries.
The Eight Best H2S Removal Methods in Federal Waters, Offshore California
Authors: Konczvald A.
Published: October 2008

In Federal waters offshore California, there are currently many desulfurization techniques implemented on 23 platforms to address different H, S levels as a function of daily production rates. This paper describes the individual effectiveness by design criteria, repair history, and performance under overload. It is intended to help future platform operators in the selection of a gas sweetening technique based on raw gas volume and H, S contamination. It also describes two methods applicable in other offshore areas, but abandoned recently in the Pacific Federal waters due to strict air quality restrictions and costly emission source-offset requirements.

Introduction

This is the first attempt to evaluate the current H,S removal technologies in offshore California. (See table 1 on platform characteristics and the H,S contamination range of 3 ppm - 18,000 ppm). The criteria for evaluation are: removal efficiency, safety, and economics. The author noticed that low H,S levels can be treated efficiently with regenerable sluny methods, while high gas contamination may need robust, amine type processes. The paper also includes an example for total pre-flare sour gas sweetening. The summary contains a suggested selection processes for the right technology.

1. Platform Elly, Beta Field(Shell/CalResources, LLC After 6 years of water reinjection of up to 20,000 BPD, the underground chemical reaction yielded increasing H,S content in produced gas. In 1988, when hydrogen sulfide levels reached 14 ppm, Shell Western Exploration & Production, Inc. (SWEPI) initiated the Petrolite SX-600 injection for fuel gas sweetening. In 1990, H2S contamination in raw gas reached 19 ppm, while in 1992 routinely exceeded 28 ppm, causing the sweetened fuel gas readings to exceed the 3 ppm maximum admissible H2S level posted by the South Coast Air Quality Management District' in the Los Angeles air basin. Excursion data triggered by system dynamics show that during the sweetening process part of the mercaptans became trapped in the oil phase, causing instrumental readings of 1-7 ppm H2S in the sweet fuel gas for turbines and heater trehters:

H2S + SX-600 ?=? (mercaptans + gas + H2S)

At this point, SWEPI decided to implement the Sulfa Treat technology to comply with county, State, and Federal requirements for the Pacific Outer Continental Shelf (Pacific OCS).

The concept consists of two beds operating in series, while one is approaching the allowable depletion level the other is replaced and kept in stand-by mode to correct excessive volume fluctuations during kicks in the wells. The catalyst is non-regenerable; it must be barged offshore. The end product is classified environmentally friendly by the EPA and by California Title 22 criteria, therefore, it can be disposed of in local landfills. The piping, skids, accessories, and the two catalytic beds weigh 90,000 lbs.
MMS 1200: Cooperation on a Subsea Multiphase Flow Meter Application
Authors: Caetano E.F. , Pinheiro J.A.S.F. , Moreira C.C. , Farestvedt L.
Published: October 2008

PETROBRAS (Brazil) and FLIJENTA (Norway and USA) are since beginning of 1996 working on this multiphase flow metering route development under a Technological Cooperation Agreement. This Cooperation involves flow meters that are making use of innovative arrangements and physical principles, and are being applied to oil-in-water monitoring, water-in-oil monitoring and multiphase (oil, water and gas) flow metering, which also includes a subsea version. All the meters are going to be prior tested at the PETROBRAS Test Site for Multiphase Equipment - a test site, built onshore (Atalia, city of Aracaju) that allows performing highly representative tests, when compared with-actual production installations - in the qualification process aiming at the usage at the PETROBRAS fields. The FLIJENTA conception for a subsea multiphase flow meter (SMFM 1000) will be combined with the PETROBRAS' experience associated to system architecture adequacy to the subsea deep waters deployment and then resulting on the MMS-1200 - a subsea retrievable multiphase meter module. Such module - a guidelineless conception - will be installed on a subsea production manifold (08 wells, 450 m. of water depth, WD, 5 km away from the host FPSO - floating production, storage and off-loading vessel) in the deep water Albacora field in the Campos Basin (April 1997). This paper presents the major characteristics and benefits of the multiphase metering technology and focus on the MMS-1200 description, its development phases, test planning, associated time tables and results obtained up to date.

Introduction

The main purpose of this multiphase flow metering technological route when applied to be untreated usually produced fluids (e.g., oil, gas, water and occurring solids), without the need to separate them first, is to determine the phases fractions and their associated flow rates. The route is based on multiphase flow meters, which are devices, usually non-intrusive to the flow, that by the combined usage of selected physical principles and flow signal interpretation - under the knowledge of the main physical principles governing multiphase flows - are able to determine the phases (e.g., oil, gas and water) fractions and their actual flow rates.

Currently, the trend in the industry is to increase the distance from wellhead to SPVs (stationary production unit). As this distance grows, the costs and problems of traditional systems grow; whereas for multiphase meters the cost is fixed and, in general, the performance improves as the distance grows (due to an increase in wellhead pressure). The shorter well test duration typical of a multiphase meter allows reservoir and operations engineers to have more current data for field management.

The oil and gas reserves in deep waters (400 to 1,000 m) and ultra-deep waters (1,000 to 2,000 m) off Brazil correspond to almost 64 % of the total Brazilian oil and natural gas liquid (NGL).
Captain Field Development Project Overview
Authors: Etebar S.
Published: October 2008

The Captain Field is approximately 90 miles north-east of Aberdeen, Scotland in the UK Continental Shelf Block 13122a (Fig. 1). The field was discovered in 1977 and it was clear then that economic extraction of the viscous, low GOR and low API crude from a shallow, unconsolidated sandstone reservoir at a depth of 3000 ft and with a large a real extent (7 mile by 3.3 mile) would not be easy.

The Captain Field overview presentation will focus on how the dedicated, multidiscipline team brought the asset to commercial reality as quickly as possible through a parallel appraisal and engineering programme. Also, the appraisal programme was tasked with proving the horizontal drilling, completion, artificial lift and reservoir performance technology through the use of extended well tests (EWT). Contractor qualification and concept selection began while appraisal drilling and testing were being carried out. Information gained from the appraisal programme was fed directly into the Front end Engineering Design (FEED) which was carried forward with three development concepts. Detailed bids from the three FEED contractors were used to select the optimum economic development concept and plan.

From inception, the team was empowered to drive the project forward and quickly developed a set of principles that has driven its success. These principles include a shared vision, innovation, dedication, open communication, quality, standardisation, teamwork and trust.

Introduction

The Captain Field was discovered in 1977 and it was clear then that economical extraction of the low mobility viscous, low GOR crude oil, from a shallow field (3000 feet) with a large a real extent and unconsolidated sand would not be easy (Fig. 2).

The discovery well (13122a-1) drilled in 1977, contained viscous oil with little gas and did not have sufficient reservoir pressure to allow production without artificial lift. The appraisal well 13122a-2 was drilled in 1989 and tested 740 BOPD with an electric submersible pump(ESP). In 1990, a well (13122a-8) was drilled with 1000 ft Presented. horizontal section and produced 6500 BOPD, again using an ESP. The gap between the 1977 discovery well and follow-up drilling was extensive because the technical challenges were immense.

Operating Under A Business Umbrella

To meet these challenges and to bring Captain to commercial reality, a multi-discipline team was formed in January 1992 (Fig 3) as part of Texaco's U.K. Upstream reorganisation which implemented sweeping changes in the way projects were to be developed. Multidiscipline and cross-functional teams were formed in a new "Asset Development" department to address problems, such as Captain. Their charter was to map issues accurately and to develop solutions that could be implemented in a variety of settings, and then advocate the adoption of these solutions as quickly as possible, with the goal to add significant value to the Company
Captain Field Reservoir Development Planning and Horizontal Well Performance
Authors: Lach J.R.
Published: October 2008

The Captain Field, in UK North Sea Block 13/22a, is an accumulation of viscous, high density oil which required a development plan utilizing only extended reach horizontal wells. Parallel field appraisal and facilities engineering required a close working team since during the period of 1992 to 1994 major changes occurred in the description of reservoir fluids. Oil viscosity decreased due to improvements in sampling methods which had significant impact on recommended design parameters. Other key data acquisition and field testing provided confidence in and a linking of relative permeability data and KvKh

Fluid movement in the interwell region is dominated by gravity forces where up dip injected water slumps to bottom and water coning is a dominant feature. Well spacing of around 700-800 feet are planned. Significant water will be produced, and the cost of water handling is a primary consideration when designing well liquid flow rate. In Captain Field, the optimum well off take rate is found to be between 15,000 to 20,000 bpd.

Development plans include a large waterflood to maintain reservoir pressure at high off take rates. The waterflood will utilize only horizontal water injectors wit11 'tuned' completions. Also, careful consideration of injector placement has taken into account potential future use for polymer flooding.

Introduction

The Captain Field is approximately 90 miles north-east of Aberdeen, Scotland in the UK Continental Shelf Block 13122a in 350 feet of water. The field was discovered in 1977 and it was clear that, although large with nearly 1,500 mmbbl oil in-place, economical extraction of the high density (19° API), viscous (88 cP) and low gas-oil ratio crude (Table 1) would not be easy. Also, the two primary reservoirs, the Upper andLower Captain Sands, are permeable but unconsolidated and of greatly varying thickness (0 - 275 ft). To this end no fewer than 20 appraisal wells (Fig. 1) were required to determine reservoir extent. Also, an extensive aquifer is present and underlies approximately 65% of the hydrocarbons.

Not until performing a ten well appraisal program during 1993, which included a 90-day test of a field development prototype horizontal well, a vertical well water coning test, and further delineation drilling, was it clear that these technical challenges could be overcome. Conclusions from the 1993 appraisal program and subsequent reservoir simulation indicated that successful field development would require nearly 40 horizontal wells up to 6,000 ft long, artificial lift systems to deliver 15,000 bpd from each oil well producer, sand control completions, high temperature and high retention time fluid separation equipment to treat 60,000 bopd and 200,000 bwpd, and a single aquifer lift well to deliver 60,000 bwpd make up water for water flooding at full voidage replacement.
The Concept of Multitube Moment Factors in a Riser System and Its Applications
Authors: Li Yousun
Published: October 2008

In a concentric multitube riser system, individual tube motion response transfers through local contacts. The conventional riser composite model treats all the tubes as an equivalent tube and allocates the bending moments to tubes according to their stiffness ratios. Without consideration of contact mechanisms, this approach may induce large errors. Direct time domain simulation of a long duration of multitube response model including intermittent contacts may require excessive computational efforts. In the present study, the concept of Multitube Moment Factors is introduced, which accounts for the statistical correlations between the moment h mth e multitube model and those from the composite model. Multiplying by a multitube moment factor, the dynamic bending moment response from the composite model becomes equivalent to the tube moment based on the multitube model.

Introduction

A concentric multitube riser is a riser system consisting of a number of concentric tubes, such as casings and tubings. In the dynamic analyses of the riser response under stochastic wave and wind conditions, the riser system is normally modeled as an equivalent tube comprising all the individual tubes (riser composite model). The bending stiffness of the riser composite model is the summation of all the bending stiffness of individual tubes. The resulting bending moment from the composite model is allocated to the individual tubes according to their bending stiffness ratios. This approach implies that at any location along the riser all the tubes share the same bending curvature across their cross sections. In reality, all the tubes are intermittently contacting each other. The number of contacts is limited. Using the pair of an outer-casing and an inner-casing as an example, the inside diameter of the outer casing is normally uniform along its length, while the inner-casing has larger outside diameters at the connectors and centralizers than those along the tubular parts. The contacts tend to occur at the connectors and centralizers. The bending transfers from the outer casing to the inner-casing through these contacts. The bending moment is not distributed along the inner-casing smoothly. Since the contacts have clearances, the structural response of an individual tube is strongly nonlinear to the wave loads.

Direct time domain simulation of a riser model consisting individual tubes with intermittent contacts may produce more reliable results. The descriptions of the contact forces by Lagrangian Inequalities (Ref.2) can handle hundreds of intermittent contacts along the entire riser system. However, the time duration must be sufficiently long for statistics of the bending moment that may be deviated from Gaussianity. For example, the fatigue damage rate estimation by a rainflow-counting algorithm requires at least a three-hour duration of the response.
Hydrate Plug Dissociation Field Test
Authors: Hatton Gregory J. , Kruka Veet R. , Guinn James  A. , Greig Gary N.
Published: October 2008

Deep Star funded a unique hydrate plug dissociation field test in a 900-psi 4-inch flowline gathering system operated by Kerr-McGee Corporation/Devon Energy in the Powder River Basin in Wyoming. In addition to DeepStar, the field test was supported by seven DeepStar member f m s (Amoco, ARCO, BP, Chevron, Kerr-McGee, Shell, and Texaco) by loan of equipment and analytical and computer services. During the field test, the formation of naturally occurring hydrate plugs was allowed in an existing flowline by stopping methanol injection. After formation, plugs were remediated by a unique one-sided depressurization. This reduction of the pressure on one side of the plug to below the hydrate decomposition curve results in a substantial pressure drop across the plug, as well as partial dissociation of the low pressure end of the plug that is outside the hydrate region. Plug formation and remediation were monitored by five data stations along the line. The pressure drop across a plug was monitored as a function of time to determine plug permeability while the plug was stationary. The pressure drop across a plug and the plug length were used to determine plug yield strength at breakaway. A dual-station gamma-ray system was used to measure slug and plug lengths and velocities at one data station.

Introduction

Hydrates are ice-like solids that form in hydrocarbon flowlines. Hydrates can deposit on the flowline inner wall and agglomerate in the flow stream, and with time, hydrates can block the flowline. Hydrate operational problems are most severe in high pressure flowlines in cold environments, such as in deep waters around the world where the seawater tem- perature is typically between 34° and 40°F.

Hydrates are members of a chemical class of compounds Hydrocarbon water systems. Hydrates are solids composed of water and a gas (methane, CO,, etc.). The water forms a crystal lattice of cavities with pentagonal and hexagonal surfaces. Each cavity, or cage, may enclose a single mkthane (or other foreign) molecule.

In some ways. hydrates are similar to ice. Hydrates have a density close to that of ice, and have an appearance like frost or ice. However, in contrast to ice, the decomposition temperature of hydrates increases with increasing pressure at pressures below 15,000 psi. A hydrate thermodynamic equilibriumcurve, or decomposition curve, (bold line) for a hypothetical oil/water/gas production system is shown in Fig. 1. The decomposition curve starts at around 100 psi and 34°F and rises to 3,000 psi at around 70°F. Hydrates may form at temperatures below and pressures above the hydrate decomposition curve. Also shown in Fig. 1 is a pressure-temperature profile curve (thin line with arrows) of produced fluids in a flowline from deepwater wells to a shallow water platform 40 to 60 miles away.
DeepStar's Evaluation Of Shallow Water Flow Problems In The Gulf Of Mexico
Authors: Nations Joe F. , Medley George H.
Published: October 2008

The DeepStar Consortium of 18 energy companies is leading the development of new technologies to allow the economic exploitation of deep-water Gulf of Mexico reservoirs. During the past several years, DeepStar's Drilling and Completions Committee has focused on solving shallow water flow (SWF) problems encountered while drilling in deep water. Because the fracture gradient is low at this depth, it is difficult, if not impossible, to drill with enough mud weight to keep the well from flowing, which results in several related problems.

DeepStar has conducted several studies to address this issue. These studies include the development of a SWF database, the investigation and development of polymeric mud systems that can shut off shallow water sands and impair permeability of shallow water zones, research and development of cement slurry designs that are effective in shutting off the annulus to a shallow water flow, unique methods of placing casing seats below water sands, and other studies. These studies have been instrumental in advancing the development of deep-water reservoirs. This paper reviews the results of these studies.

Introduction

The DeepStar Consortium Drilling and Completions committee identified SWF as one of the most imposing problems encountered in deep-water drilling. Shallow water flows, occurring when shallow, over-pressured sands are penetrated, are encountered all across deep-water sections of the Gulf of Mexico. They are most common in water depths exceeding 2,000 feet, and may be found as single or multiple lenses. The sands typically occur at depths below the mud line (BML) of 300 to 2,000 feet, but may occur as deep as 7,000 feet or more BML.

Handling the actual water flow is only one problem as- sociated with these zones. Pore pressure -in these shallow sands is normally very close to fracture pressure. This makes well control very difficult. As the water depth increases, the difference between fracture and pore pressure decreases. The pore pressure gradient remains relatively constant, but the fracture gradient decreases. This has long been recognized, and is well documented Figure 1 illustrates this importantconcept.

Losing circulation makes continued drilling difficult and increases the likelihood of poor cement jobs. In the worst case, if the well is shut in without having sufficient casing set, the resulting formation fracture could broach to the surface3

These over-pressured sands are normally unconsolidated, which exacerbates the problems associated with drilling into a SWF zone. Sand will be produced along with the water. This can result in the accumulation of sand mounds on and around well heads. When the flow cannot be controlled, hole enlargement results. Continued hole erosion may result in subsidence and buckling of one or more casing strings, and the possible loss of the well. The flows have the potential of eroding the soil around the sea floor templates of tension leg platforms with a resultant multi-million dollar loss.
Design, Planning, Implementation & Management of a Multi-Lateral Well on the Forties Field: A North Sea Case History
Authors: Jones R.D. , Lurie P. , Hibbert E.B. , Butler P. , Freeman A.
Published: October 2008

This paper describes the experience and learning gained whilst, designing, planning and installing a Multi-Lateral Well on the Forties field operated by BP Exploration in the UKCS. This project was initiated by the Research and Development groups of BP Exploration and Halliburton Energy Services, and sponsored by the European Union's Joule-THERMIE Program which supports the implementation of technology in Europe. The objectives of the project were to drill and complete a dual lateral well with commingled production, at minimum risk and cost, and to monitor and report the production performance. The difference between this project and the majority of multi-lateral wells drilled to date will be the installation of a cemented junction with connectivity, isolation and re-entry capability. The successful execution of this project will provide the industry with data on the long term performance of a cased hole, cemented, junction design. It will also provide production performance from a dual lateral well and give details of the challenges facing the management of such a well in a mature field environment. It is anticipated that this will lead to increases in the application of this technology, improve the economical recoverable reserves from mature fields and reduce the cost of new fields.

Introduction

Application of multi-lateral wells was limited to wells that did not require through tubing reservoir access for stimulation or water, scale and sand management.

Junction construction advances through system development and testing by Longbottom 1 demonstrated the possibility existed of cost effectively constructing and installing a design which provided isolation, access and connectivity. The experience and learning gained by the implementation of this project, enhances the ability to construct a cased and cemented dual lateral, operate each lateral as a separate well and perform those remedial operations presently available to the industry.

The risk and uncertainty surrounding a project of this nature means that without the support of programmes like THERMIE, initial economics are sensitive when it comes to applying new technology in a mature field environment such as Forties. Remaining well targets are relatively small and production is complicated by demands for sand, scale and water management. In-fill and sidetrack drilling is expected to continue at least until 1999. If the recent success of the in-fill program continues, some platforms will become slot constrained. The application of new technologies, like multilateral wells, are expected to enable more targets to be reached from fewer surface locations. This well is the first step in this new direction.
Design and Analysis of High Temperature, Thermally Insulated, Pipe-in-Pipe Risers
Authors: Delafkaran M. , Demetriou D.H.
Published: October 2008

Bottom tow pipeline bundle installations are gaining acceptance in deepwater developments. This is particularly the case where paraffins and hydrates pose a problem, since insulation and heating lines may easily be added inside the buoyancy casing, with less cost impact than in vessel based methods.

However, barriers to more extensive use of the bottom towed bundle technique are perceived problems of potential leakage into the outer casing and perceived problems related to the pressurization of the casing.

Approaches to mitigation of such problems, such as Bulk heading and foam filling are proposed and evaluated herein.

Introduction

Deepwater developments currently underway are increasingly requiring either insulation or heating to prevent hydrate formation or waxing in flowlines traversing cold ambient waters. Flowlines may be insulated either with directly applied insulation, pipe-in-pipe insulation, or insulation wraps within cased bundles. Heating may be achieved utilizing heating water in separate lines or annular jackets, or electrically, utilizing skin effect current transfer or other means.

Possible installation methods, already in use or imminent, include reeling, J-lay, S-lay or towing of bundled pipelines. In a towed installation, the pipelines and casing are welded into strings on a beach. To date, all Gulf of Mexico bottom towed bundles have been fabricated at Matagorda Peninsula, just down the coast from the mouth of the Colorado River. Thus site accommodates bundles up to 10 miles long. The bundle is then deflected laterally off of the beach and towed to the site. Pipelines may be towed on the sea dace, at mid- depth, or on bottom. All the Gulf of Mexico bundled installations have been by bottom tow.@ The bundled approach to installation of multiple pipelines, is to gather the several pipelines into a single package, and to provide a casing around the entire package which brings the total bundle submerged weight into a desired range. For a bottom towed bundle this submerged weight must be great enough to provide stability during the launch and tow process but low enough to permit towing by available vessels. The casing diameter required for correct submerged weight is normally sufficiently large such that an insulating wrap layer may be added to the flowlines without change in the design of the bundle, and the low density of insulating materials makes only a modest change in the submerged weight.

In shallow water depths the casing may resist hydrostatic collapse through its inherent stiffness, however, as water depths increase the increase in wall thickness required to prevent buckling makes it impossible to achieve a desired submerged weight.
Large Scale Model Testing Of Deep Sea Risers
Authors: Huse E. , Kleiven G. , Nielsen F.G.
Published: October 2008

The paper describes a series of tests with 90 m long models of deep sea risers, performed at an open air test site in a Norwegian fjord. The main purpose of the tests was to provide experimental data for the vortex induced vibrations (VIV) of such risers in a shear current. The test results can also be used to study collision criteria, drag coefficients, etc. The paper concentrates on a discussion of one of the phenomena observed in the tests, the axial vibrations of the risers. A theory for estimating the fatigue stresses due to such axial vibrations, induced by the VIV, is developed and presented in the paper. If the VIV frequency coincides with half the frequency of the first axial vibratory mode of the riser, the theory predicts extreme stresses to occur. The phenomenon of axial vibrations may become an important aspect of future deep sea riser designs.

Introduction

The riser system represents one of the main challenges in the design of safe and cost-effective concepts for production of oil and gas at sites with ocean depth of one to two thousand meters or more. The loads and responses of deep sea risers due to current can to a certain extent be predicted by numerical methods. However, for verification of the theory, and for detecting possible unexpected phenomena or problems encountered when designing for conditions beyond previous experience, model testing is the best, if not the only possible tool. One of the problems in the design of such systems is that there is no model tank: in the world today deep enough to model the complete riser and mooring systems at a scale which has traditionally been considered necessary to achieve reliable predictions. One possibility is to do model tests in fjords or the open sea. In Norway an extensive test program was done in August 1997 at an open air site with 90 m long models of steel risers, at a geometric model scale of about 1:15. The present paper describes the tests and shows examples of results. An interesting aspect of the results was the considerable axial tension fluctuations induced by the vortex induced transverse vibrations (VIV). This triggered the authors to study VIV-induced axial vibrations in deep sea risers in more detail. The results indicate that for steel production risers of the order of 1500 m length the VIV may induce resonant axial vibrations causing such dramatic stresses that it becomes an important aspect of future deep sea riser designs.

Objective

The objective of this paper is to present a recently conducted research project, including a series of model test on deep sea risers, and to show some examples of the results. A main part of the objective is to present the development of a theory for VIV-induced axial tension fluctuations.

Large scale tests

Test philosophy, test site.

Since there are no model tanks deep enough for complete modeling of deep sea systems at what has traditionally been considered a suitable model scale, one has to look for other possibilities.
Albacora Manifold Hydrate Plug Formation:Cause And Solution
Authors: Teixeira Guilherme , Terry Artur Pader , Vieira Leonardo , Spinelli Geraldo
Published: October 2008

The platform PETROBRAS 25 (P-25) is operating at Albacora field, located at the northeast portion of Campos Basin, offshore Brazil, about I 10 Km from the coast, in a water depth that varies from 230 to 1600 m. This unit, originally a drilling platform, was converted into a production floating system with process capacity of 100,000 bpd of oil and 3,000,000 m3/d of gas, P-25 is moored in a water depth of 520 m, receiving the production from 13 satellite wells and 2 diverless subsea production manifolds (MSPDL-I e MSPDL-2), with 8 wells each. These 2 manifolds were considered the deepest in the world at that time, installed in 500 and 620 m, and are improved with features like multiplex control pod and vertical connection. To reach this important mark, a lot of things have been done, including operational procedures to prevent hydrate formation. Nevertheless, seven months after the unit started producing, a total blockage in two wells in each manifold caused by hydrates occurred. The purpose of this paper is to describe how hydrate formation took place and the actions taken to unblock the manifold and restore the production.

Introduction

Historically, the hydrate formation in petroleum multiphase flow lines occurs after a shutdown or when the well went on stream. One classic example is, after an emergency shutdown in the unit, the down-hole safety valve (DHSV) of the well closes. Then could occur some gas segregation right down the DHSV and some free water right over it. When the well is open, the contact gas-water on a high pressure and low temperature ambient occurs around the DHSV, creating conditions to hydrate formation and, as a consequence, the production line is plugged. To avoid hydrate formation in P-25, the following procedure was adopted: Before open any well, we circulated diesel on the wellhead, flowing by the gas-lift line and keeping WI, W2 and XOV valves open. We calculated the gas-lift and production lines volume and filled them with diesel. Whenever it was possible, we launched a low-density foam pig, lead by the diesel flow, cleaning completely the lines. Then, we equalized the pressure over the DHSV valve, pumping diesel and keeping the MI valve open and WI valve closed, When, there was a diesel injection right through the DHSV, we pressurize the hydraulic line to open this valve. After the confirmation of the DHSV opening, we put the well on stream.

Problem Detection

The start-up of the wells AB-43 (MSPDL I) and AB-38 (MSPDL2) follows the procedure that was described before, with some changes, because these wells are connected to the subsea production manifolds. As we can see in the P-25 submarine system diagram (figure I), connecting each manifold to the platform, there are a main production line (10 in at MSPDL-I and 8 in at MSPDL-2), a main gas-lift injection line (4 in for both manifolds), a test production line (4 in for both manifolds) and a service line (8 in for both manifolds) used to individual measurement of the gas-lift injection.
Using Cell‐ID 1.4 with R for Microscope‐Based Cytometry
Authors: Chernomoretz Ariel , Bush Alan , Yu Richard , Gordon Andrew , Colman‐Lerner Alejandro
Published: October 2008

This unit describes a method for quantifying various cellular parameters (e.g., volume, total and subcellular fluorescence localization) from sets of microscope images of individual cells. It includes procedures for tracking cells over time. One purposefully defocused transmission image (sometimes referred to as bright‐field or BF) is acquired to locate each cell. Fluorescent images (one for each of the color channels to be analyzed) are then acquired by conventional wide‐field epifluorescence or confocal microscopy. This method uses the image processing capabilities of Cell‐ID (Gordon et al., 2007) and data analysis by the statistical programming framework R (R‐Development‐Team, 2008), which we have supplemented with a package tailored to analyze Cell‐ID output. Both programs are open‐source software packages. Curr. Protoc. Mol. Biol. 84:14.18.1‐14.18.27. © 2008 by John Wiley & Sons, Inc.
Visualization of Microscopy‐Based Spectral Imaging Data from Multi‐Label Tissue Sections
Authors: Mansfield James R. , Hoyt Clifford , Levenson Richard M.
Published: October 2008

Combining images taken with light of specific wavelengths can dramatically enhance light‐microscopic images. This technology is enabled by the availability of programmable filters that can be set to transmit light only of particular wavelengths. Spectral imaging technologies have become an important part of microscopy, and are particularly useful for analyzing samples that have been labeled with multiple (two or more) molecular markers. The most commonly used methodology for separating the markers from each other is linear unmixing, which results in a quantitative image of the location and amount of each marker present in the sample. The very complexity of these multilabel samples requires a high degree of sophistication in methods to visualize the results of unmixing. This article describes a wide range of useful visualization tools designed to better enable discrimination of different features in multilabeled tissue or cell samples. These commercially available tools can be attached to the standard laboratory light microscope to significantly enhance the power of light microscopy. Curr. Protoc. Mol. Biol. 84:14.19.1‐14.19.15. © 2008 by John Wiley & Sons, Inc.
Immunophenotyping and DNA Content Analysis of Acetone‐Fixed Cells
Authors: Mancaniello Debora , Carbonari Maurizio
Published: October 2008

The flow acetone staining technique (FAST) allows one to concurrently study physical cell features revealed by light‐scatter analysis, surface/nuclear phenotypes, and cellular DNA content. Thus, diverse subpopulations of proliferating cells can be identified in heterogeneous populations by their immunophenotype and their cell cycle status, and DNA ploidy can be assessed. Acetone, a coagulant (precipitating) fixative that also has the ability to permeabilize cell membranes, is widely used in static cytometry, but rarely in flow cytometry because of its undesirable effects, namely causing cell shrinkage. Nevertheless, when employed under proper temperature conditions (∼8°C), it preserves cellular physical features and immunophenotype well, and is compatible with stoichiometric DNA staining and accurate measurement of DNA content. Due to these virtues of FAST, the method provides useful approaches for cell biology and hematology/oncology studies. Curr. Protocol. Cytom. 46:9.26.1‐9.26.11. © 2008 by John Wiley & Sons, Inc.
From material to tissue: Biomaterial development, scaffold fabrication, and tissue engineering
Authors: Kretlow James D. , Mikos Antonios G.
Published: October 2008

The need for techniques to facilitate the regeneration of failing or destroyed tissues remains great with the aging of the worldwide population and the continued incidence of trauma and diseases such as cancer. A 16‐year history in biomaterial scaffold development and tissue engineering is examined, beginning with the synthesis of novel materials and fabrication of 3D porous scaffolds. Exploring cell‐scaffold interactions and subsequently cellular delivery using biomaterial carriers, we have developed a variety of techniques for bone and cartilage engineering. In addition to delivering cells, we have utilized growth factors, DNA, and peptides to improve the in vitro and in vivo regeneration of tissues. This review covers important developments and discoveries within our laboratory, and the increasing breadth in the scope of our work within the expanding field of tissue engineering is presented. © 2008 American Institute of Chemical Engineers AIChE J, 2008
Electrodialysis‐based separation technologies: A critical review
Authors: Xu Tongwen , Huang Chuanhui
Published: October 2008

To support a sustainable industrial growth, chemical engineering today faces a crucial challenge of meeting the increasing demand for materials and energy. One possible solution is to decrease the equipment size/productivity ratio, energy consumption, and waste generation via process integration and optimization. This review focuses on the integration of electrodialysis with traditional unit operations and other membrane separations. Such integrations, due to their diversity and practicability, can be versatile tools to meet specific needs from chemical, biochemical, food, and pharmaceutical industries. © 2008 American Institute of Chemical Engineers AIChE J, 2009
DNA Binding, Photocleavage, and Topoisomerase Inhibition of Functionalized Ruthenium(II)‐Polypyridine Complexes
Authors: Gao Feng , Chao Hui , Ji Liang‐Nian
Published: October 2008

The interaction of ruthenium(II)‐polypyridyl complexes with DNA has attracted considerable interests during the past two decades. This paper presents some recent progresses in our laboratory on the interaction of RuII‐polypyridyl complexes with DNA. The first part describes the effect of modulating the intercalative ligand on the DNA‐binding behaviors of the complexes, such as DNA‐binding affinity, DNA‐binding enantioselectivity, DNA molecular ‘light switch’ effect, and DNA sequence selectivity. The second part focuses on the DNA photocleavage by the complexes and its mechanism. In the final part, we discuss the topoisomerase inhibition and its mechanism, as well as the antitumor activity of the RuII‐polypyridyl complexes.
Cyclic Peptides from Oldenlandia affinis DC. Molecular and Biological Properties
Authors: Gran Lorents , Sletten Knut , Skjeldal Lars
Published: October 2008

A new isolation procedure for Kalata polypeptides from the tropical plant Oldenlandia affinis DC is described. Fractions were screened by thin‐layer chromatography, and Van Urk positive fractions were tested for oxytocic activity in estrogenized rat uteri. By using this procedure, we were able to isolate and characterize three macrocyclic polypeptides with uterine activity. Their amino acid sequence and biological effects have been analyzed, and their NMR spectra were compared with those of the earlier ones. All three peptides showed hemolytic activity on human blood, and were tested for antibiotic effect against E. coli, Staphylococccus aureus, and Hemophilus influenzae.
X‐Ray Absorption Spectroscopy of Cuprous‐Thiolate Clusters in Saccharomyces cerevisiae Metallothionein
Authors: Zhang Limei , Pickering Ingrid J. , Winge Dennis R. , George Graham N.
Published: October 2008

Copper (Cu) metallothioneins are cuprous‐thiolate proteins that contain multimetallic clusters, and are thought to have dual functions of Cu storage and Cu detoxification. We have used a combination of X‐ray absorption spectroscopy (XAS) and density‐functional theory (DFT) to investigate the nature of Cu binding to Saccharomyces cerevisiae metallothionein. We found that the XAS of metallothionein prepared, containing a full complement of Cu, was quantitatively consistent with the crystal structure, and that reconstitution of the apo‐metallothionein with stoichiometric Cu results in the formation of a tetracopper cluster, indicating cooperative binding of the Cu ions by the metallothionein.
Gaussian basis functions for chemometrics
Authors: Kärnä Tuomas , Corona Francesco , Lendasse Amaury
Published: October 2008

High‐dimensional data are becoming more and more common, especially in the field of chemometrics. Nevertheless, it is generally known that most of the commonly used prediction models suffer from curse of dimensionality that is the prediction performance degrades as data dimension grows. Therefore it is important to develop methodology for reliable dimensionality reduction. In this paper, we propose a method that is based on functional approximation using Gaussian basis functions. The basis functions are optimised to accurately fit the spectral data using nonlinear Gauss—Newton algorithm. The fitting weights are then used as training data to build a least‐squares support vector machine (LS‐SVM) model. To utilise the reduced data dimension, relevant variables are further selected using forward‐‐backward (FB) selection. The methodology is experimented with three datasets originating from the food industry. The results show that the proposed method can be used for dimensionality reduction without loss of precision. Copyright © 2008 John Wiley & Sons, Ltd.
Electronic and Vibronic Contributions to Two‐Photon Absorption in Donor–Acceptor–Donor Squaraine Chromophores
Authors: Ohira Shino , Rudra Indranil , Schmidt Karin , Barlow Stephen , Chung Sung‐Jae , Zhang Qing , Matichak Jon , Marder Seth R. , Brédas Jean‐Luc
Published: October 2008

Many squaraines have been observed to exhibit two‐photon absorption at transition energies close to those of the lowest energy one‐photon electronic transitions. Here, the electronic and vibronic contributions to these low‐energy two‐photon absorptions are elucidated by performing correlated quantum‐chemical calculations on model chromophores that differ in their terminal donor groups (diarylaminothienyl, indolenylidenemethyl, dimethylaminopolyenyl, or 4‐(dimethylamino)phenylpolyenyl). For squaraines with diarylaminothienyl and dimethylaminopolyenyl donors and for the longer examples of 4‐(dimethylamino)phenylpolyenyl donors, the calculated energies of the lowest two‐photon active states approach those of the lowest energy one‐photon active (1Bu) states. This is consistent with the existence of purely electronic channels for low‐energy two‐photon absorption (TPA) in these types of chromophores. On the other hand, for all squaraines containing indolinylidenemethyl donors, the calculations indicate that there are no low‐lying electronic states of appropriate symmetry for TPA. Actually, we find that the lowest energy TPA transitions can be explained through coupling of the one‐photon absorption (OPA) active 1Bu state with bu vibrational modes. Through implementation of Herzberg–Teller theory, we are able to identify the vibrational modes responsible for the low‐energy TPA peak and to reproduce, at least qualitatively, the experimental TPA spectra of several squaraines of this type.
Sichtstrukturen des Chemieunterrichts von Förderschullehrkräften einer Sprachheilschule – Auswertung einer Videostudie
Authors: Yahya Liane , Bader Hans Joachim
Published: October 2008

Im vorliegenden Beitrag wird über Ergebnisse des Forschungsfeldes „Chemieunterricht in der Förderschule”︁ berichtet. In einem ersten Aufsatz stellten wir auf der Basis einer umfassenden Erhebung die äußerst problematische Situation des naturwissenschaftlichen Unterrichts an hessischen Förderschulen dar [1]. Bereits dort wurden Maßnahmen diskutiert, um die vorgefundenen Probleme wie Unterrichtsausfall und fachfremd erteilten Unterricht zu reduzieren. Auch wurden in diesem ersten Aufsatz die unterschiedlichen Förderschwerpunkte hessischer Förderschulen dargelegt und deren differenzierte Lehrplanvorgaben erläutert. Im Zeitraum von 2004 – 2006 wurden von uns in erheblichem Umfang Lehrerfortbildungen für fachfremd unterrichtende Förderschullehrerinnen und ‐lehrer entwickelt und erprobt; der Schwerpunkt lag dabei auf den Schulformen Sprachheilschule und Schule für Lernhilfe [2, 3]. Um Kenntnisse über die Auswirkungen der Fortbildungsmaßnahmen zu erlangen, wurde eine Analyse von Unterrichtseinheiten der von uns fortgebildeten Lehrkräfte in Form einer Videostudie durchgeführt deren Schwerpunkt die Erfassung der Gestaltungsmerkmale des jeweiligen Unterrichts war. Die Ergebnisse werden hier vorgestellt.