bluuebunny/crossref_metadata_2025_split huggingface dataset:
Innovative Method for Creating New Deepwater Tie-in Points on Existing Pipeline System, Using Proven Pipeline Repair Equipment
Authors: Keijser Edgar , Povloski Bo , Robles Marcio , Mota Helena 
Published: October 2011

1) ABSTRACT
Over the last decade, the oil and gas industry has continued expanding exploration and production activities into deep and ultra deep waters worldwide.
Production of these deepwater fields is greatly dependent on subsea pipelines and failure of a pipeline can lead to loss of production and, in the worst case, can cause pollution.
Diverless deepwater pipeline repair systems have been developed in order to be able to intervene rapidly and efficiently in case of severe pipeline damage. Some of this repair equipment has been deployed offshore following major pipeline failures.
The successful subsea repairs confirmed the suitability and reliability of the equipment and, moreover, ‘lessons learned’ allowed the development of more compact repair solutions.
Innovative engineering led to the utilization of diverless pipeline repair equipment for a construction purpose since there was no existing technology readily available. For this particular case, significant cost savings could be achieved when the export pipeline of a new deepwater field could be connected to an existing producing pipeline nearby instead of constructing a long pipeline to shore. A combination of proven diverless pipeline repair and standard subsea construction equipment is used to accomplish the goal.
This paper will describe the achievements that are made in deepwater diverless pipeline repair technology, will address specific repair cases, lessons learned and will develop the actual case where for the first time diverless pipeline repair equipment combined with standard subsea construction equipment was used for connecting, in a diverless manner, a new deepwater pipeline onto an existing producing pipeline.
Early Life Cycle Field Development Optimization of a Complex Deepwater Gulf of Mexico Field
Authors: Angert Patrick F. , Isebor Obiajulu J. , Litvak Michael Lev 
Published: October 2011

Abstract
Early life cycle field development planning in a complex Deepwater Gulf of Mexico (GOM) Field is considered. The field contains several stacked hydrocarbon bearing intervals charged with volatile oil or rich gas condensate.
Well locations, drilling schedule and reservoir units into which wells will be initially completed and then later recompleted, have been optimized, maximizing net present value while matching field development constraints. Potential well locations and recompletion locations in geologically justified areas have been evaluated. Drilling rig pace, order and associated project and drilling economic constraints have been considered.
BP's TDRM™ Option Evaluation (OE) technology has recently been extended to cover the simultaneous optimization of well completions and recompletions in reservoirs containing multiple stacked pay. This new capability has now been very successfully applied to assisted analysis of more than twenty thousand possible field development scenarios.
Several development plans have been identified which exhibit improved NPV, recovery, sweep efficiency, extension of oil production plateau and an expanded drilling holiday, in comparison with a manually designed development plan reference case. Balanced production from different reservoir zones has been achieved. Finally, TDRM™ OE results were demonstrated to be robust across multiple structural and faulting interpretations of the subsurface, generated by independently determined seismic interpretations of the subsurface strata.
Computations were predominately performed in a black oil simulator formulation, with high potential cases being repeated using a 16 component compositional formulation in order to more accurately represent the rich condensate zones. The Nexus® reservoir simulator, run under the control of TDRM™ OE was successfully used to carry out the actual computations.

Introduction
Assisted history matching technologies have been under development and deployment within BP for over a decade now (Williams et al., 2004). Utilization of these technologies has proven extremely useful in identifying multiple geologically plausible matches of historical production and surveillance data within existing fields. Assisted field development optimization, although slightly newer, is nevertheless proving extremely useful in the identification, categorization, understanding and ranking in economic and recovery terms of the multitude of possible development scenarios that could be implemented to produce oil, gas or condensate from a particular field (Litvak, et al., 2007).
These technologies couple with existing full physics reservoir simulators such as Nexus®, VIP® and ECLIPSE®. They rely upon search and optimization algorithms such as genetic algorithms, Monte-Carlo and / or other optimization / search routines. Within BP workflows using these technologies are becoming common place for establishing the development plan for an oil, gas or condensate field.
Importance of Topsides in Design and Selection of Deepwater Floating Platforms
Authors: D&apos;Souza Richard B. , Basu Shiladitya 
Published: October 2011

Abstract
The intent of this paper is to demonstrate the important role that the functionality and weight of a topsides has on the design and selection of a deepwater floating production platform. The discussion will focus on topsides of Tension Leg Platform, (TLP), Spar and Semisubmersible floating platforms in the deepwater Gulf of Mexico (GoM), but the principles apply to other deepwater regions as well. Early field development planning decisions that impact key topsides functions are addressed. These include whether or not to include a drilling or workover rig and choosing between developing the field with subsea (wet) or surface (dry) trees. Selecting a topsides installation method is a critical design consideration and must be firmed up early in the design cycle. Topsides installation options are presented as a function of topsides weight and platform type. The strong symbiosis between topsides weight and hull design is demonstrated. The need to prioritize topsides weight management is emphasized and some topsides weight reduction strategies are offered. Finally, topsides weight and water depth domains of applicability for various platform types are presented. These will allow development planning teams to rapidly converge on practical platform options during the screening process.

Reservoir Characteristics and Topsides Functions
When designing a floating platform topsides the first order of business is to establish its functional requirements (process, export, drilling, power, utilities, quarters etc.) and a design basis. These are primarily driven by the characteristics and fluid properties of the reservoir to be developed by the floating platform. Figure 1 is a schematic that shows how reservoir characteristics and its fluid properties influence decisions on topside functions.
The subsurface drilling and completions teams are responsible for specifying well count, top-hole locations, well production profiles, recovery mechanisms (natural drive, water injection, gas lift etc.) and fluid characteristics. These in turn determine the two most important topsides functional requirements: whether or not to have surface or subsea trees and whether to incorporate drilling or workover capability on the platform. These functional requirements fundamentally influence size and weight of topsides and platform selection.
HMPE Mooring Lines for Deepwater MODUs
Authors: Leite Sergio , Boesten Jorn 
Published: October 2011

Abstract
Polyester synthetic mooring lines are used widely in deepwater moorings for MODU (Mobile Offshore Drilling Units). However, practical and technical limitations in the deployment of polyester tethers beyond water depths of 2,000m for short-term MODU moorings has prompted the development of alternative synthetic mooring materials. This paper describes the application of Low Creep, High Modulus Polyethylene (HMPE) mooring systems for deepwater MODUs.
HMPE has many practical offshore handling benefits compared with polyester. The ropes are lighter, easier to handle and have a smaller diameter than comparable polyester ropes for the same minimum breaking load (MBL). From a technical perspective, the neutral buoyancy of HMPE, low creep rate and stiffer rope properties are ideal for ultra deepwater mooring systems. In addition, HMPE ropes are easier and quicker to deploy than polyester, leading to operational cost savings when moving MODU rigs between locations for drilling and work over.
Mooring system storm survivability is of increasing concern to operators. Hybrid mooring lines containing individual sections of rope made with HMPE and polyester yarns have been developed and shown to comply with the latest American Petroleum Institute (API) requirements. These hybrid lines combine the attributes of polyester and HMPE enabling naval architects to more accurately engineer the mooring systems to better suit prevailing offshore and storm conditions.
Development of API X70-X80 Grades Heavy-Wall Seamless Pipes With Low Temperature Toughness
Authors: Toma Diana , Rohden Volker , Kubla Guido 
Published: October 2011

Abstract
Based on the market demands regarding exploration in deep water fields, e.g. high pressures, low temperature and sour reservoirs, Vallourec & Mannesmann Tubes have developed new high strength steels up to grade X100 with low temperature toughness, sour service resistance and good weldability.
This work is part of a development program for high performance heavy wall seamless pipes for special applications such as J-lay collars, buckle arrestors and risers. The paper presents the latest results on industrial studies on high strength heavy-wall pipes in grades X70 and X80 with wall thickness up to 80mm, which are manufactured by seamless hot-rolling and subsequent quench and temper treated. Vallourec & Mannesmann Tubes's alloying concept based on carbon content below 0.10% and micro-alloying of vanadium and niobium used for grades X60/X65/X70 was extended to heavy wall seamless pipes in grades X70/X80. Mechanical properties, advanced metallographic examinations and results of sour service resistance are reported. To demonstrate weldability, test welds were performed and examined.

Introduction
The market demands regarding exploration in deep water for oil and gas reservoirs lead to technological trends in using high strength steels (grade X65 to X80 and higher) with special requirements regarding e.g. corrosion, toughness.
Increased yield strength and therefore thinner wall thickness enables the industry to reduce the costs of all components through the limitation of the string weight. On the same time the pipeline design includes special parts like J-lay collars for the pipe laying operation and buckle arrestors at regular intervals along the line for protection against an initiation and propagation of collapse and buckling [1]. All parts have to follow the demands for strength, ductility, toughness and sour service resistance combined with adequate welding performance [2, 3, 4, 5].
Over the last years Vallourec & Mannesmann Tubes have developed new high strength steels up to grade X100 [6]. Not only material development but also new technologies in the field of heat treatment capabilities allow the manufacturing of heavy wall seamless pipes with high strength and excellent corrosion properties. In this paper results of studies on X70 and X80 pipes with heavy wall (wall thickness between 40mm and 80mm) produced by the pilger mill are discussed. The pipes are quenched and tempered to create the suitable microstructure which provides good toughness and sour service properties. This work is a part of R&D program for high performance Q&T seamless pipes for deep water applications.
Simulation of SCR Behaviour at Touchdown Zone- Part I: Numerical Analysis of Global SCR Model Versus Sectional SCR Model
Authors: Bhattacharyya Anirban , Tognarelli Michael , Li George , Ghosh Rupak , Clukey Edward Charles , Sun Qunli 
Published: October 2011

Abstract
SCRs have been widely used in new field developments and tiebacks in deep water and ultra-deep water. However, riser fatigue at touchdown and SCR pipe - soil interaction is not fully understood. A number of experimental programs such as the STRIDE and CARISIMA JIPs have been carried out in recent years to get a better understanding of SCR touchdown behaviour in the context of riser fatigue at the touchdown and SCR pipe - soil interaction. Experimental studies were conducted using SCR sectional models of the touchdown region and by applying uni-directional displacements at the cut-off point to simulate SCR movement at the touchdown. However, application of uni-directional motions introduces significant errors compared to the true touchdown behaviour of a global SCR for a given sea state. This paper addresses how, by simultaneously applying surge and heave motions at the cut off point while removing the rotational constraint, a sectional SCR model can satisfactorily replicate the touchdown behaviour of a global SCR for any sea state in terms of riser displacements at the touchdown area, sag bend strain and SCR touchdown fatigue due to SCR pipe - soil interaction. As a result, more realistic SCR touchdown behaviours can be simulated in centrifuge model tests performed using sectional SCR models to investigate pipe - soil interaction at riser touchdown.

Introduction
To better understand the influence on the response of steel catenary risers (SCRs) on soil-structure interaction at the touchdown zone, a centrifuge testing program was initiated. The physical SCR model utilized in the centrifuge tests was truncated at a point equivalent in full scale to about 5m (16 ft.) above the sea floor. The results from this test program are discussed in a companion paper (Clukey et. al., 2011). The purpose of the centrifuge program was to examine the fatigue response for a model which realistically simulates the conditions throughout the touchdown region. However, before the centrifuge program could be initiated, extensive finite-element numerical studies were performed to determine:the validity of a simplified local " sectional?? riser model to represent the complete global model;the types of motions required at a mean position about 5m (16 ft) above the seafloor as simulated by the centrifuge tests; and,the applied motions in the centrifuge to capture the random motions encountered in the field.
Figure 1 presents a schematic of the global and local sectional SCR models respectively. The cut-off location is 5m (16 ft) above the seabed as represented in the figure; and forms the " free end?? of the local sectional model.
A General Analytical Solution for the Multidimensional Transient Linear Hydraulic Diffusivity Equation in Heterogeneous and Anisotropic Porous Media
Authors: Couto Paulo , Moreira Richard , Marsili Marcelo Danemberg 
Published: October 2011

Abstract
A general analytical solution for the multidimensional transient linear hydraulic diffusivity equation is presented and its application is discussed in this work. The analytical solution is valid for heterogeneous and anisotropic porous media in any orthogonal coordinate system within a regular boundary domain. A source term, dependent on position and time, was included in the partial differential equation to represent production and/or injection wells. A general boundary condition is considered to account for a constant pressure boundary, a no-flow boundary (symmetry or impermeable boundary) or any prescribed flow boundary. The Generalized Integral Transform Technique (GITT) was used to obtain the analytical solution of the proposed problem. This technique transforms a complex partial differential equation into a system of simpler ordinary differential equations that can be solved by analytical, numerical or hybrid methods. Here, we consider a fully analytical solution to the problem. The general solution is then applied to a one-phase tank model in a homogeneous and isotropic porous medium for validation and analysis. A wide variety of applications can be envisioned and discussed for the proposed general solution: well testing in regular and irregular domains, analysis of local reservoir heterogeneities, analysis of reservoir anisotropy degree, analysis of stream lines in naturally fractured and hydraulic fractured reservoirs, formation damage quantification, reservoir shape factor calculations, oil recovery in different waterflood patterns, amongst many others. These applications are discussed and analyzed in the light of the presented general analytical solution.

Introduction
Pressure and flow rate are two important quantities to be determined in reservoir engineering problems. While the pressure at any point in the reservoir is completely defined by its numerical value (it is a scalar quantity), the flow rate is defined by its value and direction. Experience has shown1 that there is flow rate when the pressure distribution in not uniform within the reservoir. The magnitude and direction of the flow rate depend on the pressure distribution and the flow is always in the direction of decreasing pressure.
The Aging of Offshore Polyamides under Services Conditions in Subsea Applications
Authors: Berger Jan , Franosch Juergen , Schuett Carsten , Dowe Andreas 
Published: October 2011

Abstract
Recent offshore deepwater and ultra deepwater projects have to meet new technically challenging demands of ever increasing drilling depths. Up to 2000 m water and some additional 5000 m solid is the aim. Harsher and chemically more aggressive environments are encountered. That means high pressure and heat and for example CO2 in supercritical state. These conditions have an increased impact upon the aging of the materials incorporated. Also contact with various production fluids used during oilfield recovery have to be considered. To investigate how Polyamides in use with flexible pipes perform under these conditions a comprehensive screening test program was started. With respect to conditions and fluids in contact with the material in service state, existing accelerated aging and testing standards appear to be in need of an extension covering the aging of Polyamides under these conditions. Therefore the need arises to design aging methods according to these new demands. This paper deals with new accelerated aging methods for Polyamides with focus on hydrolytic degradation under service conditions. Included is:–aging under high pressure (up to 500 bar) in deionized water-supercritical CO2 phase equilibrium–aging in substitute ocean water (ASTM D1141-98) under sour and neutral conditions–aging of polyamides previously saturated with crude oil hydrocarbons under sour and neutral conditions in deionized water
Also aging due to Methanolysis and Ethanolysis is further analyzed. All samples are tested in various states of aging for elongation at break derived from tensile tests and corrected inherent viscosity (CIV).

Observations:
All data is achieved in laboratory work and analyzed with respect to the aging conditions. Significant differences compared to standardized Polyamide aging methods are observed. The assumptions concerning hydrolytic degradation are confirmed. Dependencies of elongation at break and CIV on degradation are evaluated.

Significance of subject matter:
The results indicate that supercritical CO2 and ocean water do influence the predicted lifetime of Polyamide components In order to minimize costs caused by untimely pipe exchanges and to maintain safety, these results should be taken into account
for pipe design.

Applications:
Flowlines, Risers, Umbilicals

Introduction
In deep sea application, unbonded flexible pipelines offer safe, reliable and efficient production. Up to a temperature of about 90°C, Polyamides are the choice for the barrier layer. The manufacturing of those layers with Polyamides is reliable and reproducable.
The most limiting factor for Polyamides is the aging due to hydrolysis, an effect of water at raised temperatures. API17TR2 describes the testing procedure to determine possible operating temperatures. The results of API 17TR2 tests can be transferred in Arrhenius lifetime curves from which the temperature dependent lifetime of the tested PA12 can be derived.
Successful Hole Enlargement While Drilling in Deepwater Offshore Brazil
Authors: Vila Priscila , Dhaher Karam Sulaiman , Miller Gregory Charles , Machado Marcia , Strachan Phil , Nelson Gail , Compton Molly , Davis Patrick , Wu Xianping 
Published: October 2011

Abstract
Deepwater drilling often requires simultaneous hole-enlargement-while-drilling (HEWD) to improve project economics and deliver the required wellbore geometry. World-wide applications have shown that certain formations have caused damage to under-reamer cutting structures through premature cutter wear, particularly in abrasive sections with high formation strength. To mitigate cutting structure damage the operator and service provider need to collaborate to ensure the under-reamer cutting structure is designed for superior stability, PDC cutters are engineered for thermal stability and abrasion resistance, BHA configuration is optimized and drilling parameters are carefully selected and managed. Advanced BHA modeling and real-time vibration measurement are the enabling technologies for breakthrough HEWD performance.
Working off the coast of Brazil, an operator was preparing to HEWD two hole sections (17½??×20?? and 14¾??×16½??) through hard and abrasive formation, which would be encountered at shallower depths than usually expected. An offset well had significant difficulty attempting to HEWD a 17½??×20?? section, wearing out two reamer cutting structures. HEWD was not attempted on the offset's 14¾?? section because of the difficulty with HEWD on the 17½??×20?? section. Offset lithology data suggested the formations were composed of soft shale and hard sand formations, with a few limestone stringers.
To solve the challenges on the new well, the operator and service provider implemented a comprehensive process to identify hazards and evaluate the solutions, which included a unique approach to BHA design and strict parameter management through the problem formations. This paper will discuss the following contributing factors to the successful HEWD operation:Extensive pre-well planning and communicationAdvanced under-reamer cutting structure design and cutter technologyDynamic BHA modeling and optimization of unique BHA designDrilling parameter testing and selectionUtilization of an operational road map to aid well-site personnel in properly managing drilling parameters
The holistic optimization process, along with the operator's best practice, resulted in successful HEWD operations for both hole sections drilling to the targeted depth without premature failures. The cutters on the under-reamers were only mildly worn and the measured stick-slip and vibrations were significantly lower than on offset wells.

Introduction
In January 2009, the operator began an extensive offshore exploration program in Brazil as operator of the Transocean Deepwater Discovery. The dynamically positioned ship is capable of drilling in water depths of up to 10,000 feet. BP holds interests in 10 blocks offshore Brazil including seven as operator. The company has joined Petrobras on six of these blocks to explore the country's promising offshore areas.