bluuebunny/crossref_metadata_2025 huggingface dataset:
Fundamental Study of Underwater Welding
Authors: Brown Alan J. , Staub James A. , Masubuchi Koichi
Published: June 2014

This paper stresses the need for a reliable underwater "wet" welding process and points out the value of fundamental research in this area. Various heat transfer mechanisms are sited as being ultimately responsible for metallurgical structure and residual stress. A finite element heat transfer model including radiation, boiling and the arc bubble mechanism is described. Results are evaluated in relation to individual phenomena and areas for future research are defined.

Introduction

The need for a reliable underwater joining process is very real in today's offshore technology. Although underwater chamber welding "in the dry" has proven to be a partial solution to the problem, this process is limited to the welding of regular shapes, such as pipelines and is very expensive. For more general underwater repairs and fabrication chambers are impractical and welding "in the wet" is desirable. The only other alternatives for such work are prefabrication and dry-docking, but complete prefabrication is not always possible and dry-docking is costly. Unfortunately the "state-of-threat" in underwater wet welding has advanced very little since World War II and for this reason its use has been limited to temporary repair and salvage work. The standard U. S. Navy rule of thumb for wet underwater welds predicts 80% strength and 50% ductility when compared to similar surface welds. Before the use of underwater welding can be expanded to permanent repairs and structural fabrication present methods must be modified or radically changed. There are two basic approaches to select from when solving such a problem:Conduct an empirical study in which proposed processes might be tested, optimized, and evaluated. This first requires a proposed process to test.Conduct a fundamental study in which the various arc, heat, metallurgical and physical phenomena may be analyzed and modeled. An understanding of these phenomena could then be used in more rational selection and development of new processes. We have chosen to undertake the second of these approaches combined with an empirical study sufficient to substantiate our mathematical models.

Such work is particularly compatible to the university whereas development of hardware and technique might best be done in industry.
Cantinuous Vertical Profile Measurements of Physical Variables off the South Shore of Long Island Using a Variable Buoyancy Instrument Package
Authors: McIlroy William , McCoyd Gerard C. , Speidel M. Arthur
Published: June 2014

A brief description is given of a Grumman-designed oceanographic instrument that was used to obtain vertical profiles of temperature, salinity, and current speed and direction in a year-long oceanographic study of an area of the New York Bight. The variable buoyancy device that controls the instrumented package, the mooring system, and the computer programs that are used to reduce the data are discussed. Some typical data illustrate the Potential of the device.

Introduction

During the period October 1973 to November 1974 Grumman Ecosystems Corporation performed an oceanographic survey for the New York Atomic and Space Development Authority in an 800 square mile section off the south shore of Long Island, shown in Fig. 1. The data obtained, included vertical profiles of, current, temperature and salinity collected using Grumman profilers. These instruments were left unattended at moorings for periods ranging from one week to one month collecting data at one and five minute intervals respectively.

The profilers move up and down a taut mooring line controlled by a pneumatic variable buoyancy device (VBD). This device and a recording instrument package are enclosed in a streamlined hull. A description of the YED, the profiler and the recording package along with examples of data are presented in the following sections.

Variable Buoyancy Device

The VBD consists of an aluminum scuba tank, pressure regulator, differential pressure valve, a deep and a shallow valve and a bladder assembly. The tank containing helium is a standard aluminum scuba tank with a capacity of 12 liters and storage pressure of 174 kg/cm2. Not only is this tank lightweight and corrosion resistant but it is also non-magnetic and will not interfere with the compass readings. The regulator valve is a standard DACOR model 200 scuba valve of chrome plated brass which is antimagnetic and corrosion resistant. Since the design output pressure is higher than necessary to inflate the bladder the reference spring in this valve has been placed by a weaker spring. The valve bodies are manufactured from Lexan, a clear plastic, which is much more economical to use than stainless steel. It can be easily machined and is noncorrosive. The use of transparent valves is also convenient when troubleshooting during bench tests. These valves are adjusted by means of stainless steel pressure caps, with the number of turns marked on their sides. By means of a calibration curve selected shallow and deep water depths defining the extent of travel of the profiler can be set by the indicated number of turns. This system was originally designed for deep water operation but in this case was operated in relatively shallow water depths up to 30 meters. As a consequence very fine adjustment of the valves was necessary, as any error or malfunction of the valve could result in travel depth errors which are a considerable fraction of the actual depth.
Microsphere Based Drilling Fluid to Control Hole Enlargement during Drilling in Permafrost
Authors: Sengupta Soumyadipta
Published: June 2014

Hole enlargement is a serious problem while drilling in permafrostconditions. The hole enlargement problems leads to lost circulation. Irregularand unstable holes also affect the quality of cement jobs. The drilling fluidis generally at a higher temperature than the permafrost formation. This causesa heat transfer from the drilling fluid to the formation. The ice particlesbinding the sediments together start to melt. This loosens up thesediments and causes caving. This paper proposes to minimize this problem witha low thermal conductivity fluid.

The drilling fluid can be cooled at the surface after it comes out of theannulus and before it is circulated back into the drill string. Cooling reducesthe temperature gradient between the fluid and formation. But this cooling isnot enough since the permafrost is at subzero temperatures and cooling to suchlow temperatures is not economically and practically feasible. This is wherethe innovative drilling fluid comes in. The drilling fluid shall have hollowmicrospheres. These microspheres are easily available commercially undervarious trade names. These microspheres lower the heat transfer coefficient ofthe fluid. This means that a significantly small amount of heat will betransferred from the drilling fluid to the formation. Low temperaturegradient and low thermal conductivity will work in conjunction.

The drilling fluid shall have a low heat transfer coefficient of 2.9-3BTU/hr.ft2.°F. The composition of the fluid and the heattransfer coefficient measuring experimental setup shall be discussed in thepaper. The paper shall also discuss the effects of heat transfer coefficient, circulation rates etc. on the thawing of permafrost.

The technique in this paper could go a long way in mitigating drillingproblems in permafrost regions.

Introduction

Conventional oil and gas reserves are fast depleting and becoming scarce dayby day. Hence, there is a need to find oil and gas reserves in previouslyunexplored areas of the earth. Arctic regions present one such area with hugepotential of untapped oil and gas reserves. Producing oil and gas in such harshenvironments require special techniques designed for these conditions. Everyoperation in the arctic has its own set of challenges.
Arctic intervention vessels !! design considerations and verification studies
Authors: Berg T.E. , Berg B.O. , Borgen H.
Published: June 2014

The pristine Arctic region is vulnerable and the robustness of Arcticecosystems is not fully known. Bearing in mind serious accidents in oil and gasproduction in other parts of the world, it is important to develop methods, equipment, procedures and human competences that will make oil and gasexploration, production and export at least as safe as current activity in theNorth Sea. This paper discusses how to extend access to subsea productionequipment in regions with seasonial ice. Important factors such as longdistances to shore-based infrastructure, harsh environmental conditionsincluding ice, icing and polar lows, low quality of communication systemsservices and lack of workers with experience of working under Arctic conditionswill have to be investigated and analysed as inputs to the development of safeoperational procedures.
Ovality of High-Strength Linepipes Subject to Combined Loads
Authors: Fatemi A. , Kenny S.
Published: June 2014

A numerical modeling procedure was developed, using the finite-elementsimulator ABAQUS/Standard, to predict the local buckling and post-bucklingresponse of high strength pipelines subject to combined state of loading. Thenumerical procedures were validated using test data from large-scaleexperiments examining the pure bending and local buckling of high strengthlinepipe. The numerical simulations were consistent with the measuredexperimental response for predicting the peak moment, strain capacity, deformation mechanism and local buckling response well into the post-yieldrange.

A parametric study on the local buckling response of high strength plainpipelines was conducted. The influence of pipe diameter to wall thickness ratio(D/t of 40, 60 and 80), pipe segment length to diameter ratio (L/D of 3.5, 5, 7and 12), yield strength to tensile strength ratio (Y/T of 0.7, 0.8 and 0.9) andinitial geometric imperfections on the local buckling response was examined. The loading conditions included internal pressure and end rotation. Mechanicalresponse parameters examined included moment-curvature, ovalization, localstrain and modal response.
Iceberg Interaction Frequency Model for Subsea Structures
Authors: King Tony
Published: June 2014

Subsea structures on the seabed may be impacted by free-floating or scouringicebergs. A drift-based Monte Carlo iceberg contact model was developed as partof the SIRAM (Subsea Ice Risk Assessment and Mitigation) program forcalculating iceberg impact risk for subsea structures on the northeast GrandBanks offshore Newfoundland and the Makkovik Bank on the Labrador Shelf. Themotivation for developing this model was to characterize the influence ofbathymetry (i.e., seabed orientation, ridges and basins) on iceberg interactionrates with subsea structures. Results were incorporated into a GIS-basedapplication to allow iceberg contact rates to be calculated for structures witha range of plan dimensions and elevations at various locations.
PIRAM: Pipeline Response to Ice Gouging
Authors: Phillips Ryan , Barrett John
Published: June 2014

The Pipeline Ice Risk Assessment & Mitigation JIP (PIRAM) developed aset of engineering models and design procedures for implementation intoindustry best practices for risk mitigation and protection of pipelineinfrastructure from ice keel loading. The models established the pipelinemechanical behaviour in response to ice keel load events, and assessedengineering concepts for protection and risk mitigation strategies. Improvedmethodologies for contact frequency and ice keel loads determination formedpart of the integrated model.

Pipeline protection against ice gouging is overviewed. A review of subgougeresponse and physical model tests provided a basis for refinement of threedimensional continuum finite element analyses of steady state gouging includingthe implementation of an effective stress based soil plasticity constitutiveroutine. A fully coupled ice, seabed and pipeline interaction model is used tocalibrate a simpler pipeline design approach for design purposes. Thestructural model, improved by considering 3D interaction effects, comparesstrains within the pipeline to those from continuum analyses and from physicalmodel tests. The PIRAM pipeline model provides the engine for the probabilisticassessment of pipeline cover depth using a GIS-based decision-support-systemfor route planning.
ColdShield Qualification: Waterproof Bonded Composite Reinforcements for FPSO HULL Repair - Seal Selection
Authors: Lamige Jean-Paul , Court Jean-Philippe , Grosjean Francois Luis , Geffroy Rene-Louis Luis , Lewandowski Alexandre , Heuillet Patrick
Published: June 2014

ColdShield is an innovative solution for making structural repairs and reinforcements in marine environments, specifically intended for the on-site maintenance of FPSO hulls. The purpose of this original process is to strengthen - in a safe and controlled manner - weakened offshore steel structures, without resorting to hot work such as welding or grinding, which involve naked flames. This paper presents the results of various laboratory tests, together with computer models for bringing this new technology up to qualification standard. The R&D campaign was conducted as a partnership between Total, the French Petroleum Institute (IFP - Energies Nouvelles) and COLD PAD, and involved four different private and public French laboratories.

ColdPad's original generic innovation has a potentially broad range of offshore applications such as bonded connections or structural repairs effected in situ. Its main advantage is that it allows safe repair with no down time. This permanent solution is designed to be installed under any environmental conditions, and even underwater. The prime specifically industrial application of ColdShield is in the maintenance and repair of FPSO hulls, mainly those damaged by severe corrosion. The renovation is intended to permanently restore the initial structural capacity and durably protect the damaged area against further corrosion.

This new technology is based on the proven techniques of bonded composite reinforcement already used in other industries such as aerospace, military and civil engineering. The current R&D program seeks to demonstrate through a qualification process that the ColdShield solution offers a reliable and lasting means of repairing FPSO hulls. This was achieved by demonstrating the full preservation of the bonded repair under severe offshore conditions.

Qualification of this bonded composite reinforcement involved many different steps. This paper focuses on one of them, showing how the material for the seal, the most critical component, was selected and tested through various research and development stages.

Although bonded composite reinforcements provide a real alternative to conventional " hot" structural repairs, they remain vulnerable to the humidity inherent to the offshore environment. ColdShield is designed to remain impervious to marine conditions, especially during the two critical phases of installation and servicing, suggesting high-potential future applications. In addition, the prequalified installation procedure has been turned into an industrial process intended to be faithfully reproduced on site for reliable, repeatable performances.
Ormen Lange Flow Assurance System (FAS) - Online Flow Assurance Monitoring and Advice
Authors: Lunde Glenn Gahr , Rudrum Graham , Angelo Pabs , Holmas Kristian , Setyadi Gandi Rahmawan
Published: June 2014

A Flow Assurance System (FAS) is installed on Ormen Lange in order to give information about the multiphase flow through the entire subsea production and pipeline system and onshore slug catchers to support the operation of the field. The FAS includes the following modules:Virtual Flow Metering System (VFMS):Model calculated values of flow rates as backup to physical multiphase meters.Pipeline Monitoring System (PMS):Model calculated values of pipeline flowing conditions and onshore receiving facilities.Leakage and Blockage Detection (LDS):Combining information from measurements and model calculated values of pressures and flow rates along with statistical process control methods.

In 2011 the FAS was upgraded with the transient multiphase flow simulator FlowManager™ Dynamic, replacing the previous simulator. In this paper, it is shown that the new simulator gives accurate model predictions, which is essential for all the modules in the FAS.

The flow assurance challenges of the Ormen Lange field are significant. Due to sub-zero temperatures at the sea bed, there is a risk of hydrate and ice formation. However, the FAS reduces the risk of hydrate and ice formation. The transient simulator calculates pressure, temperature, water content and MEG concentration through the entire subsea system, giving the margin to the hydrate formation curve for actual operation conditions.

Another flow assurance challenge is liquid surges. The long transport (120 km) of unprocessed fluids in a hilly seabed terrain induces liquid surges in the pipelines due to liquid accumulation at low rates. In this paper it is shown that the new transient simulator is able to accurately predict the liquid surges including arrival time and liquid level in the slug catchers. Thus, the operators and flow assurance engineers have a tool to optimize the ramp-up speed avoiding flooding of the slug catchers.

The FAS gives full overview of current operation conditions and predicted changes in the subsea system and slug catchers the next hours. All operations (e.g. shut-in, restart or ramp-up) can be simulated in advance. This ensures safe and optimized operation of the complex Ormen Lange production systems.
Soft Rope Traction Winch (SRTW)
Authors: Schols Martijn , Carey Dean , De Jager Martijn , Mahar John
Published: June 2014

This paper presents an overview of the benefits of the use of synthetic rope winches as a direct replacement to wire-rope winches in ultra-deepwater applications. The Perdido was the first SPAR to use Direct Vertical Access (DVA) to access 22 planned well slots. The planning process invoked many new ideas on technologies required to operate in this ultra-deepwater environment. One of the many innovations that came out of this development was the need to develop a winch that could set Tubing Hangers and X-trees from the actual structure. Prior to the development of the Soft Rope Traction Winch, a wire rope winch was used to perform these tasks. Because of the weight of the wire rope in deeper applications, the actual winch pulling capacity was significantly reduced. The only other method available required utilizing a Multi-Service Vessel (MSV) that could accommodate the size of the winch to perform this two-step process. This approach was expensive and relied on Mother Nature's cooperation which was unpredictable at best. The development of the SRTW provided a viable option to using a MSV. By replacing wire-rope with synthetic rope the winch weight and size would be significantly reduced. The SRTW's small footprint and weight allowed it to be positioned on a cantilevered platform that did not use any of the deck space which is typically at a premium on these structures. The challenge was how to spool soft rope at these depths and not have the weight of the payload work its way between the spooled layers of rope when in tension. Additionally, the characteristic of synthetic rope when placed in various tensions causes deformation and stretching resulting in slippage of the rope during spooling operations. This slippage results in heat being generated due to friction which will ultimately damage the rope. All these challenges were over-come and the winch has proven to be a safe, reliable and economic substitute for wire-rope winches.

Introduction

This paper presents an overview of the benefits that can be achieved by replacing wire-rope winches for synthetic rope winches in deep and ultra-deepwater applications.

As demand for energy continues to increase, the search for vital energy resources is expanding further offshore into harsher and deeper waters. Globally, there are more than 150 major deep and ultra-deep water developments that have the potential to come on-stream over the next 5 to 10 years (figure 1). This growth is centering upon the ‘Deepwater Triangle’ of Brazil, West Africa and the North American Gulf of Mexico.
Dry Tree Solutions for Ultra-Deepwater in Offshore Brazil
Authors: Yan Lu Jenny , Davis Heather , Raposo Celso , Hansen Vigleik L
Published: June 2014

With Pre-salt area being a massive new offshore oil frontier, there is a high demand for deepwater floaters for both drilling and production. There are some unique challenges related to the ultra-deepwater (water depth beyond 1500m) and the Brazilian environment for the pre-salt area. Various floater concepts have been evaluated with specific focus for Offshore Brazil applications.

This paper provides an overview of the current technology related to dry tree solutions as well as discussion of the pros and cons of various concepts. The paper also discusses some new concepts emerging in the industry attractive for Offshore Brazil.

A dry tree solution has the advantage of direct access into reservoirs from the floaters. This allows the operators to drill, complete and workover the well directly from the same hosting unit. The result could be increased reserves and productions in Offshore Brazil as well as significant cost reduction. Proper validation of the concepts and technology qualification of all the systems/components associated with novel technology, establish the basis for a safe and successful project implementation while reducing potential risk to personnel, environment and property.

DNV has established processes to systematically evaluate new concepts and new technologies, e.g. Approval in Principle (AiP) and Technology Qualification (TQ). A brief introduction to these processes is included in the paper and how they support the development of these new concepts.
Regulatory Challenges of Local Content Rules in Brazil
Authors: Mirilli Miguel Oliveira
Published: June 2014

This paper addresses some issues that E&P companies in Brazil have been struggling in relation to Local Content Rules, whether to understand the regulation enforced by clause twenty of the concession agreement and regulatory provisions or to meet the targets set in the tenders' bids. Several public data was gathered to support a better analysis of some regulatory challenges of Local Content Rules.

Introduction to Local Content in Brazil

The oil companies interested in E&P activities in Brazil must previously win a bidding round for the chosen block, which activities will be regulated by a concession agreement and several regulatory provisions issued by the federal agency responsible to the industry, ANP, which name stands for Agency of National Petroleum, Natural Gas and Biofuels. Another possibility is entering into a farm-in agreement with an oil company that already has a concession agreement.

In this context, Local Content presents a twofold nature:Local Content target weighting 20% in the tender bids;a contractual obligation based on the tender bids, once the oil company wins the block bidding.

Nowadays, the legal provision of Local Content is Law #9478/97 article 2, item X, included by Law#12351 issued on 2010. The sole logical deduction arising from the aforementioned rule is that Local Content can be used as a national policy instrument, although there is no definition of how it should be calculated and what it is the exactly definition thereof.

Even prior to 2010, Local Content was enforced by regulatory provisions issued by ANP and the clause twenty of the concession agreement.

Several authors from many countries defines Local Content as a political orientation designed to improve the participation of local/domestic companies in providing services and goods for a specific economic sector, generating revenue, jobs and technological development. A secondary goal of Local/Domestic Content policies is to increase the likelihood of local companies to export to other countries, as it will be increased in scale production and technological competitiveness along the years of this policy protection.

Accordingly, Local Content can be defined in its political aspect as a policy to enhance local goods and services industry capacities, helping forward the country's development and increasing employment offers.

In light of this, Local Content aims to increase the participation of local inputs in the product's added value either by employing goods manufactured locally or services provided by local workforce.
Movable Chain Jacks and Winches, Case Study of Petrobras' P58/P62 and Eni's Goliat FPSOs
Authors: Grindheim Reidar
Published: June 2014

Recently, Aker Solutions delivered a movable chain jack system to Petrobras's P58/P62 FPSOs and a movable windlass system to ENI's Goliat FPSO. This paper highlights the main differences between the two systems and when it is beneficial to employ movable systems. There are many parameters to consider in determining which system to use - also a traditional system involving a single winch or chain jack per mooring line may in many cases be preferred. The movable chain jack concept is designed to operate multiple mooring lines within the same cluster. A single chain jack is lifted by a skidding gantry and moved to the next mooring line and so forth. Installation and messenger chains are moved using a large sliding chain locker allowing for later offloading of the surplus chain. The movable windlass system is also designed to operate multiple mooring lines within the same cluster. However, in this case the winch is rotary and can operate via electric or hydraulic power. One of the main considerations is to move the windlass and keep the mooring lines intact without cutting them.

Introduction

The primary purpose of an offshore mooring system is to maintain a floating unit on station within specified tolerances. These tolerances are often based on offset limits determined from the configuration of the riser system. The mooring system provides restoring forces that act against environmental forces (wind, waves and currents) that are trying to move the unit off station. Most mooring systems for offshore application are spread moored or single point moored (including turret systems). Spread mooring is the conventional mooring approach and is widely used for both drilling and production units. Spread mooring keeps the unit in position at an optimal heading but does not allow weathervaning. Single point mooring (internal/external turrets) is used primarily for ship-shaped vessels allowing the vessel to weathervane. However, a spread moored system can also be applied to ship-shaped vessels and we see many of this type off the coast of West Africa and Brazil.

Traditionally, on-vessel mooring equipment has consisted of individual winches, fairleads and chain stoppers located at each mooring line. The mooring lines can be chain, wire rope, fiber rope or a combination. This paper discusses movable chain jacks and winches recently supplied for spread mooring systems on both ship-shaped and cylindrical- shaped FPSOs.

1. Traditional Spread-Moored Platform Designs

Position moored production and drilling units come in various shapes and sizes. Traditionally, we have seen semisubmersible, spar and ship-shaped units. All these units have applied winch or chain jack systems. Figure 1 shows typical designs that have been in use for several decades.
Analysis of Jump-out of Casing Connectors
Authors: Placido Joao Carlos Ribeiro , Fonseca Carlos Eduardo , Anjos Jorel Lopes Rodrigues dos , Roveri Francisco Edward
Published: June 2014

Failures related to casing connectors jump-out have occurred, causing flat time of deep water drilling rigs, which generates great losses due to very high daily rate of these rigs. The objective of this paper is to show a methodology for performing post analysis of this type of failure. In order to do the analysis, it is mandatory to obtain the mechanical properties and dimensions of the casing connector. It is important to raise the stress-strain curve of samples extracted from the connector. In case of proprietary connectors, the dimensions should be obtained with the manufacturer, once it is necessary detailed dimensions.

Aiming to verify the structural integrity of the casing connector, a proper definition of the load scenario prior to failure must be done. Provided the meteocean condition during the analyzed operation, a dynamic finite element analysis of the whole casing string is performed. The string is treated as beam elements and bending moments and axial stresses are tracked. Varying wave parameters it is possible to define a load envelope. Due to the geometric and material complexity of casing connectors, axisymmetric and 3D finite element models were developed to reproduce the problem domain and load scenarios. Based on an excessive displacement and plasticity criteria, a strength envelope was evaluated. Combining load and strength conditions, it was possible to access some issues that may have caused the connector failure.

Introduction

In deep water drilling operation with floating rigs, while running in offshore surface casing, sometimes jump-out of connectors has been observed. This problem usually causes big losses and, therefore, it is very important to find out the reasons in order to avoid them.

Objective

The main objective of this study is to determine the possible causes of jump-out of casing connectors while running these pipes into a well in offshore floating rigs.

History

Since 2002 Petrobras has been using connectors welded to the surface casing X-56, 20?? × 5/8??, 131.5 ppf. This connector has tension strength approximately 40% lower than the pipe body. The length of the joint is 12m (40ft). The connection makeup is done with ¾ of turn and a key seat must be used to guarantee the connection will be safe.

In August 4th, 2011, it was initiated the operation of running a 20?? surface casing into the well. After 7 (seven) joints have been assembled using an auxiliary table, the casing string was moved to the main table with a trolley (Figure 1). The casing was lifted up to the main table and the trolley stayed below the rotary table functioning as a guide.
A Diagnostic and Prognostic Framework for Integrated Reservoir-Completion Management Using Intelligent Well Data
Authors: da Silva Jr Manoel Feliciano , Radespiel Eduardo dos Santos , Jacinto Carlos Magno Couto
Published: June 2014

Well construction and maintenance represent most of the costs of a deepwater offshore field exploitation. Planning and execution times in this scenario are normally impacted by geological and operational uncertainties leading to deviation on the actual times and consequently costs. Intelligent wells have been used to face the geological uncertainties for heterogeneous reservoirs with multiple pay zones in Brazil's Pre-Salt reservoirs. Robust diagnostic and prognostic of abnormal operational situations have not been addressed completely up to now even with real-time data available from the Intelligent Wells.

The completion design, cost and reliability are the basis for the identification of all sensors needed to provide a rich data set for a fit for purpose application using a system view. Even though these are permanent sensors, the idea is suitable for coiled tubing and e-line operations where additional sensing options are available, but without the capability to capture the dynamic behavior.

Data quality methods as well as integrated modeling simulation are all at a very early stage. This challenge is aggravated by the huge amounts of data coming from an Intelligent Well which is far greater than the data flow that the petroleum industry normally has to deal with. Additionally, the increased complexity of the completion affects the coupled well-reservoir modeling used in today's analysis.

The evaluation of the well equipment degradation is also vital to prevent future complications that will lead to unexpected well shut-ins. Flow control, well integrity, artificial lift, and their related equipment are all targets for tuning the maintenance practices.

In this paper, we propose a framework which includes:real-time data quality control;non-isothermal coupled well-reservoir modeling taking into account completion equipment;appropriate analysis tools.

The aim is to simultaneously optimize well completion operations and maintenance practices. We focus our strategy on: initial well completion design; formation evaluation; stimulation, and equipment reliability, discussing applications that support our proposition.

Introduction

One of the most representative recent oil discoveries worldwide is the Santos Basin Pre-Salt Cluster (Moczydlower et al, 2012), offshore Brazil. Considering the importance of the reserves and intending to accelerate cash flow, Petrobras and its associates decided to fast track its development. Several subsurface uncertainties resulted from this choice which leaded to a mix of classical strategies (information, flexibility and robustness) for the development plan. IW (Intelligent Well), in this context, was identified as an extra flexibility that was worth investing in. Fast response to unexpected events and better production system behavior prediction were the main issues to address.
Regaining Wellbore Access and Enhancing Safety Devices Operation by Removing Obstructions Using E-line Conveyed Technology
Authors: Torres Rafael , Carrillo J.G. Rego , Higa Rogelio M , Martinez Arturo , Huerta Juan Martin , Soto Alan , Ramos Jaime A
Published: June 2014

The Marine regions represent a significant portion of the total oil production in México. Sustaining oil production at current levels is a constant challenge; thus a large local operator is exploring unconventional methods in their quest to optimize rig utilization by implementing novel rigless work-over interventions.

One of the Marine Region most common interventions is production tubing clean-out. The objective of these interventions is the removal of deposits layers, asphaltenes and scale bridges in order to regain access to the producing intervals, and in some cases to eliminate the detrimental effect in production caused by reduced flow in scaled areas. Traditional clean-out methodology includes tubing conveyance, pumping of cleaning fluids and the operation of hydraulic or mechanical downhole tools.

E-line conveyed technology enables rigless clean-outs by mechanical removal of debris from production tubing, safety devices like SSSV and plug seats, saving deferred production and allowing the operator to optimize rig utilization. The cleaning tool run on a well tractor and e-line has proved to be a reliable and effective solution for clean-out applications.

E-line tractor assisted clean-out technology induces zero damage to the produced zone. The ability of removing debris from the wellbore without pumping a single drop of fluid into the well represents a major turnover into traditional workover approach. E-line conveyed clean-out enables operators to perform environmental friendly interventions, with reduced personnel and carbon footprint, enabling logistics optimization.

This paper examines these recent applications of through-tubing e-line conveyed well intervention solutions in Mexico's marine regions and presents the relevant well conditions and criteria used for selection. It provides case histories with operational challenges as well as the results of several successful, rig-less cleaning operations on an important producing wells.

Introduction

A large operator located in the Mexican marine region (Fig. 1), which is located in the the Gulf of Mexico, is responsible for maintaining nearly 75% of the overall oil production of Mexico

One of the major challenges that the marine regions face's is to minimize deferred production, therefore, they are continuously looking for workover alternatives that allows them to keep production at maximum levels.

Most of the wells in the fields of the marine region have carbonate scale building issues due to water production. Scale bridges across the production tubing restrict the access to the producing zones, creates downhole chokes with detrimental effects to production and may obstruct or even prevent correct functioning of subsurfarce safety valves.
Technological Innovations on FPSO P-63 for Operation at Papa Terra Field - Offshore Brazil
Authors: Rocha Anderson Cicero , Araujo Paulo Fonseca , Nicodemos J. Fernando
Published: June 2014

The Papa Terra oil field is operated by Petrobras in partnership with Chevron, located 110 kilometers from the coast in deep water at Campos Basin, offshore Brazil, has an extra heavy oil formation with several challenges for its production development. The purpose of this paper is to present the innovative strategy to exploit the field, as well as the technological innovations on the FPSO (Floating Production Storage and Offloading) P-63, designed and built to process, store and export the extra heavy oil of Papa Terra field. During the lifetime of the field, each new technology applied to the project will be closely monitored by the company in order to provide useful information to be considered when designing the next offshore production units.

The strategy of developing the heavy oil field production in deep waters, using three floating units, such as the TLWP (Tension Leg Wellhead Platform) P-61, in combination with a TAD (Tender Assisted Drilling), along with the innovative technologies onboard the FPSO P-63, can be considered an innovative and very attractive concept in Brazilian oil industry.

INTRODUCTION

The Papa Terra oilfield is located in the South portion of the Campos Basin, 111 Km off Cabo Frio city, in the state of Rio de Janeiro (figure 1). The field was discovered in June 2003 and extends over an area of 183 square kilometers, in water depths varying from 400 to 1,400 meters and is estimated to contain 700 million to a billion barrels of oil equivalent. The total volume of recoverable oil is approximately 400 million barrels.

The presence of extra heavy oil with high viscosity, low gas-oil ratio (GOR) and a large amount of produced water brings extra challenges, demanding a differentiated strategy for the field development.
Examining Progressive Collapse of Framed Structures in Response to Fire and Explosion Consequence Events
Authors: Reed Morgan , Peterson Eric
Published: June 2014

Inherent safety is well accepted in the oil and gas industry, with codes and standards' providing guidance and requirements to ensure its successful adoption. In the last decade, the offshore industry has made major shifts in ensuring the safety of personnel and asset preservation (e.g., platforms). Advances in computational power permit specialized software to evaluate safety concerns. Major safety concerns associated with offshore installations can be examined with particular attention paid to structural integrity, deformation and any impact on personnel safety (evacuation routes, temporary refuge, etc.).

Specialized software tools, Fire and Heat Transfer Simulator (FAHTS) and Ultimate Strength of Framed Offshore Structures (USFOS), enhance the capabilities to evaluate the survivability of offshore drilling structures from fire and explosion loading. When structures are subject to extreme loads due to fire and/or explosion, progressive collapse analyses are frequently used to predict both the resistance of structures subject to accidental loads and the residual strength of damaged structures after such loads. Coupling 3D Computerized Fluid Dynamics (CFD) software packages with those containing Finite Element Analysis (FEA) permits the progressive collapse of offshore platforms to be assessed.

Results presented evaluate structural member deformation and any subsequent collapse in and around Safety Critical Elements (SCEs) such as: escape routes, temporary refuge, and fire water pumps. When evaluating SCEs, particular attention is paid to which structural members collapse and if their failure is acceptable for the overall integrity of the structure to remain intact and specifically any effect upon the SCEs. Structural members supporting critical substructures, vessels, equipment which can lead to escalation need to be protected. Optimization of passive fire protection will be discussed for areas showing gross deformation or failure.

This paper focus is on simulated heat loads from fires and blast loads from explosions. The attendant structural responses are due to thermal radiation fluxes, blast overpressures and the associated applied mechanical loads. Early identification and appropriate mitigation responses to potential fire and blast scenarios that may threaten personnel or the survivability of an offshore installation can lead to additional safety and cost benefits for operators and engineering, procurement and construction companies.
Improvement of Viscosity and Stability of Polyacrylamide Aqueous Solution Using Carbon Black as a Nano-Additive
Authors: Silva Glaura Goulart , Oliveira A.L. De , Caliman Vinicius , Viana Marcelo Machado , Soares Meiriane Cristina Faria
Published: June 2014

Carbon black was oxidized (OCB) and added in the concentrations from 0.05 to 0.50 wt% to various aqueous solutions containing Poly(acrylamide-co-acrylic acid 1 wt%) in concentration of 3.0 g L−1. The nanofluids' viscosity were measured during 150 days and showed that small amount of the OCB nanoparticles improved the viscosity and the stability of aqueous and saline solutions. Therefore, the use of OCB onto polyacrylamide dispersions shows potential application in oil recovery.

Introduction

Polyacrylamide (PAM) is a water-soluble polymer that shows high viscosity, low toxicity and low cost [1]. This polymer has been used as a mobility control agent as well as an agent for permeability profile correction in improved oil recovery [2]. Partially hydrolyzed polyacrylamide (HPAM) (Figure 01) has also been used in oil recovery since its negative carboxyl groups in aqueous solution causes extension of its chain leading to viscosity increase of the solution [3]. However, its use is limited due to the low stability under several harsh conditions, e.g. temperature, shear stress and salinity [4].

Previously work using polyacrylamide nanofluid prepared with carbon nanotubes as a nanofillers showed significant improvement in maintaining viscosity [5]. The carbon black (CB) is also a versatile carbonaceous nanomaterial which has highly developed porous structure and low cost [6]. The CB has been widely used as an adsorbent, catalyst and catalyst support. Surface modification of CB allows the direct modulation of its physicochemical properties to improve its suitability in various applications. Oxygen-containing functional groups can provide active sites and can change the hydrophobicity of the carbon surface. These functionalizations increase the dispersion of the carbon nanomaterials in water [7]. To improve the stability with time and saline solution of PAM solutions we have used oxidized carbon black (OCB) as a nano-additive.
Advances in Autonomous Deepwater Inspection
Authors: Mcleod D. , Jacobson J.
Published: June 2014

Advances in autonomous inspection of deepwater subsea facilities are examined to illustrate the favorable enhancement of safety, reliability, reduction in risks, economic benefits and superior data products compared to conventional means. These benefits provide operators with significant improvements over general visual inspection by the addition of sensors that produce 3D models of the structure being inspected. Examples are provided illustrating test data from operations conducted from 2011–2013.

Additional benefits include rapid response when a loss of well containment requires large standoff distances between the host vessel and the sensing platform. Three dimensional georegistered models of the entire scene can be rapidly collected within hours of the incident providing responders with a clear vision of the underwater scene along with in-situ status of critical components.

Introduction of new sensors support even more advanced capabilities leading to autonomous metrology, hydrocarbon detection tracking and fingerprinting, non-contact corrosion potential measurement, thermal measurements and three dimensional underwater scanning lasers.

Application to deepwater life of field inspection will be presented with evidence gained from offshore trials in 2011 and 2012. This emergent technology supports Subsea Facility Inspection Repair and Maintenance, Integrity Management Inspections of Marine Risers, Moorings and anchors, Subsea Pipelines, Flowlines, Umbilicals, and supporting subsea infrastructure.

Introduction

Frequent risk based assessment of the condition and integrity of subsea equipment is vital to predicting the life of the equipment and prevention of uncontrolled release of hydrocarbons into the environment. Oil and Gas operators must know the state of the equipment that is often thousands of meters below the ocean surface shrouded in the veil of darkness. " Protection of health, safety, and the environment is a critical component of the processes and procedures used to monitor the conditions of offshore surface and subsea facilities and structures" (1). Traditional means of inspecting this equipment employs visual sensors such as video or still cameras mounted on Remotely Operated Vehicles (ROVs) that are hardwired to the operators controlling the vehicle from a ship above the inspection site. Such General Visual Inspection (GVI) requires significant topside support equipment and numerous skilled operators on site to control observe and maintain the ROV and interpret the images along with a large vessel support crew (MTS Journal Article). While the quality of images has improved with the advent of digital High-Definition or HD sensors the images are often degraded by movement of the cameras and the turbidity of the water, reducing the effectiveness of the inspection. In addition, the data provided to clients is often hours upon hours of recorded video that must be archived and revisited by humans for detailed examination.
Wettability Alteration in Carbonates By Surfactants: The Effects of Interfacial Tension on this Process and Reflex in Porous Media Behavior
Authors: Pinto Michel Ferreira
Published: June 2014

Most rocks of carbonate reservoirs is preferably lipophilic, this feature of rock-fluid interaction, also known as wettability and is closely linked at low oil recovery rates. The application of surface modifying agents is a way to changing the wettability of carbonates, making them preferentially hydrophilic and thereby favoring the reduction of residual oil saturation (Ros).

Actually reservoirs with heterogeneous permeability, which have regions of low permeability and presence of fractures and high permeability channels, there is a tendency that the injection water to flow preferentially through these channels with high permeability. This type of reservoir, the oil recovery process is improved by capillary forces, spontaneous process known as imbibition, where water tends to soak the smaller pores, expelling the oil to the larger pores. This phenomenon retard " breakthrough" and reducing the residual oil saturation (Ros). However, spontaneous imbibition only occurs appreciably in water wet reservoir. In the oil wet formations, the water has less affinity for the wall of the pores and the capillary forces are small and in many cases could be negative.

The paper presents results of Enhanced Oil Recovery (EOR) Group from Cenpes/ Petrobras, evaluating two anionics and one cationic surfactants, with different interfacial tension (IFT) and their ability to increase hydrophilicity of carbonates. The results showed that the anionic surfactant with higher IFT values was responsible for increased to make the carbonate preferably hydrophilic, keeping in high values the capillary pressure.

The results were demonstrated by the core flow tests, which showed higher oil relative permeability and Ros reduction; spontaneous imbibition test, presents higher oil recovery and contact angle evaluated, which showed lower adhesion of the oil phase on the surface of carbonate.

The agent wettability modifying can be applied as a chemical method of EOR, as well as around the producing well. In this last one, could be created convergence zones for oil and be increased the effective oil permeability near the oil production well.