bluuebunny/crossref_metadata_2025 huggingface dataset:
Beyond the Watch Circle Wellhead System Global Weak Point Analysis
Authors: Grohmann Andrew J. , Kaculi Jim T.
Published: April 2015

Watch circles are established by operators to ensure a dynamically positioned vessel does not induce loads that exceed wellhead system equipment capacities. In the event the vessel moves off station, beyond the boundary of the watch circle, loads could be transmitted that may approach or exceed the equipment ratings and possibly cause failure. A whole system weak point analysis approach is required to determine and identify the likely failure modes and locations throughout the system.

This paper presents a system weak point analysis using a 3D finite element analysis (FEA) of an API Studded BOP Flange, Hydraulic Wellhead Connector, and Subsea Wellhead System. The FEA models include the first 200 ft below the mudline and are used to evaluate the capabilities of the entire system to failure. To ensure accurate load transfer between the components the actual field installation sequence was modeled, which included contact between components, all preloads, soil resistance, casing string weights, and cements. Subsequently, the global external loads from the rig were incrementally increased beyond the rated load capacities of the entire system to determine failure points. Loads, stresses, and strains in each component were determined as a function of the global external loads. Each component of the system was modeled using elastic-plastic material properties per ASME BPVC, Section VIII, Division 3, Paragraph KD-231.4.

Critical points throughout the wellhead system were monitored for failure which was defined as either through wall plastic strain or through wall stress above yield across the entire wall of a component. A sequential order of limiting locations, or weak points, was determined (first limiting location, second limiting location, etc.). The weak point analysis performed provided valuable information to assess and help mitigate risk. The analysis results also provided valuable insight and context to the equipment manufacturer to develop more robust and reliable system designs.

The insights gathered by doing a weak point analysis using large 3D FEA models of the entire system, inclusive of the wellhead system, wellhead connector, and flanged connection, are presented and provide a better understanding of the system behavior and failure mechanisms.
A diverless chain connector for the high integrity connection of mooring legs
Authors: Bedini Mauro , Bauduin Christian
Published: April 2015

This paper presents a new design of chain connector that allows disconnection of the mooring line, and inspection and possible replacement of the chain connector's articulation bushes, without the assistance of divers. This design brings dual benefits: Reduced risk of mooring line failure caused by unexpected wear or damage to chain connector articulations, which could not have been inspected with traditional chain connector designsIncreased safety by removing the need for diver intervention.

The paper presents the development of the chain connector, including the latching system that enables connection and disconnection without diver assistance. The development has been performed following a structured process with milestones. The main development steps have been the concept engineering phase, an extensive phase of sub-component testing, a phase of assembly prototype testing at a reduced scale, realization of detailed engineering phase of the component, and the development of full scale prototype test rig.

Chain connectors are a key component of any mooring system, transferring the load from the mooring leg to the FPU. The chain connector also forms an articulation between the mooring leg and structure, and its reliable behaviour is fundamental to avoiding Out-of-Plane Bending (OPB) fatigue failure of the chain links. The described development process and especially the system testing demonstrate the functionality of the diverless chain connector having as aim the high integrity of the mooring legs. Furthermore, it allows assessing the envelope of its connection and disconnection functionality, given different mooring line configurations. Testing provides complete and reliable results of connection and disconnection functionality for different values of in plane and out of plane angles, and pretension. In addition to that, the testing results allow sizing the installation winches adapted to different mooring line configurations.

The trend towards offshore developments in increasing harsh environments is leading to increased technical challenges in ensuring the integrity of Floating Production Units. In parallel, the design life of these systems is increasing above 20 years, and up to 50 years. The ability to monitor the condition of the chain connectors, and to safely maintain or replace any element in case of unpredicted aging effects is the benefit given by the component development described here.
Dynamic Risers for Floating Production Systems API Standard 2RD, Second Edition
Authors: Garrett David L. , Stanton Paul N. , Sharma Partha
Published: April 2015

Since the first edition of API RP 2RD, Recommended Practice for Design of Risers for Floating Production Systems (FPSs) and Tensioned-Leg Platforms (TLPs), was issued in June 1998, hydrocarbon exploration and production in deep water environments have increased significantly. As a consequence, the need was identified to update that code of practice to address the issues and lessons learned from that experience. The title of the document has been changed to eliminate reference to any one type of floating hull. A broad scope of marine dynamic risers is covered, including various steel catenary risers and top tensioned risers.

A fairly high level review of clarifications is presented followed by a brief overview of the content of the standard.
Conceptual Design for Offshore Pipeline Replacement in Mature Field, Using Reinforced Thermoplastic Pipe for CAPEX optimization in F-Field Pipeline Repair and Replacement Program
Authors: Yananto Hanto , Girindra Yuyung , Kennedy Steven
Published: April 2015

A study was initiated to evaluate the benefit of low capital cost and low maintenance cost technologies to rehabilitate pipelines in marginal fields and apply artificial lift solutions to marginal wells to keep them running profitably and with an attractive return on investment (and with no sacrifice to safety and environmental risks).

The challenge is to have a new technology with lower "Total" cost from design, procurement, installation, operation and maintenance during its life time. In addition, the technology must meet the required planned production flow, which, in some cases, can be higher than current flow.

RTP per API15S was shown as the most cost effective solution in rehabilitation of pipelines in marginal fields.
An Assessment of the Dynamic Moduli of Atmospherically Generated Foam Cements
Authors: Spaulding R. , Haljasmaa I. , Fazio J. , Gieger C. , Kutchko B. , Gardiner J. , Shine J.M. , Benge G. , DeBruijn G. , Harbert W.
Published: April 2015

The objective of this paper is to evaluate the dynamic moduli of atmospheric generated foamed cements at varying foam qualities routinely used for zonal isolation during well construction. Mechanical properties of the hardened foamed cement samples, such as Young's modulus (YM) and Poisson's ratio (PR) will be discussed, as well as permeability. All of these properties were obtained as a function of cyclic confining pressure ranging from 12 - 52 MPa (1,740 – 7,540-psi). The dynamic parameters were derived from ultrasonic velocity measurements, while permeability was measured using the transient method. Stepwise loading and unloading schedules were conducted to test the permeability and mechanical properties of the foamed cement at simulated wellbore conditions. Applied pressures varied between 6.5 MPa (943 psi) to 46.5 Ma (6,744 psi) in 4 MPa (580 psi) increments in two full up/down cycles. At every increment during these cycles, ultrasonic compressional (P), fast shear (S1), and slow shear (S2) wave velocities were measured, as well as the samples’ response to the upstream sine pressure wave of approximately 0.5 MPa amplitude. From the sonic velocity data the dynamic moduli including YM and PR were calculated, while the sample's response to the pressure wave was used for permeability calculations. Observations of both neat and foamed samples reveal variations in YM as well as changes in the other properties and characteristics. Differences were observed between the foam qualities, depending on the parameter being assessed. This information should enable design contingencies and allow for more resilient designs of foamed cements when used during well construction. In addition, industry can use these results as a baseline for comparison with previous, current, or future work including recently acquired field-generated foamed cement samples (Kutchko et al., 2014).
Safaniya Electrification Using High Power Field Power Supply Challenges: Design, Procurement and Shallow Water Installations
Authors: Al-Rashed Riyadh
Published: April 2015

The purpose of this paper is to share the knowledge and experience that Saudi Aramco went through during the execution of the "Upgrade Crude Gathering and Power Supply Facilities, Phase I - Safaniya Field" project. The paper focuses on the challenges associated with providing reliable power supply to the Safaniya field via a high voltage power system that includes high voltage submarine cables and the required topside substations and structural facilities.

The project will interface with SEC's 380 kV gas insulated switchgears (GIS) at Ma'aden and Manifa BSP substations. This project will expand Manifa 380 kV GIS to allow for the tie-in of the 380 kV transmission lines to be installed at Safaniya under this project . Additionally, the project will connect to Ma'aden 380 kV GIS. Additionally, the project will interface with existing 69 kV GIS switchgear at TP-17 and TP-19. The project shall disconnect existing 69 kV cables and preserve them (for emergency use) at both TPs and connect new 69 kV cables from TP-20.

With the aging of oil wells and the increase in water cut, Saudi Aramco decided to implement artificial lift solutions by installing electric submersible pumps (ESPs) in Safaniya field wells. This solution requires significant power upgrades as each ESP has is designed for 500 horse power (HP), leading the over power requirement to reach 200 MW in the North Safaniya field alone. To support the artificial lift approach, Saudi Aramco designed, procured, constructed and installed dedicated offshore power supply facilities including the world’s longest subsea 230 kV three-core, cross-linked polyethylene (XLPE) cable.

The implementation of the solution has gone through several challenges associated with the high voltage submarine power cable design, supply and installation, and the topside tie-in platform sizing and installation. This paper presents the challenges, the steps taken to overcome them and the unconventional installation technique that was successfully implemented.
Subsea Well Response Project - Simultaneous Operations (SIMOPS) Multi Vessel Operations - Guidance for Marine Based Response to Subsea Well Incident
Authors: Kallaway Kris
Published: April 2015

The Subsea Well Response Project (SWRP) was established in 2011 on the recommendation of the International Association of Oil and Gas Producers as part of its efforts to further improve subsea well capping response readiness and to further study the need for, and feasibility of, global containment solutions. Through SWRP, international oil and gas companies have worked together on an unprecedented scale to share knowledge, expertise and best practices to enhance international subsea well incident intervention capabilities and to minimise the environmental impact in the event of a subsea well control incident.

This paper will present present key drawings that consider 9 phases of work that may or may not be completed during a subsea well response incident which are:

site survey,

debris clearance & removal,

dispersant injection,

capping,

subsea installation,

flaring & incineration,

relief well placement,

offloading,

Containment operations @ three water depths (end game)

SIMOPS is a collaborative, risk based mitigation process using a formal written exchange of information between concerned parties or vessels working in close proximity to each other when responding to a marine based source control event.
Modelling of Wave-Structure Interaction of a Cylinder in Irregular Sea Waves with Vessel Motions Using Coupled Transient CFD and Diffraction Methodology
Authors: Jia D. , Agrawal M. , Schofield P.
Published: April 2015

This paper is a continuation of previous paper (OMAE2014-23225) where a parametric study was performed for wave- structure interaction on a hollow cylinder in regular sea waves without vessel motions, and the effect of waves and current on the motion of the cylinder and the associated forces using a high fidelity methodology (OMAE2013-11569) to couple CFD with diffraction analysis. This approach was demonstrated for predicting the motions and loads of subsea equipment and structures during offshore operations. Instead of relying on simplified equations or empirical formulations to calculate and estimate the hydrodynamics coefficients, or using steady-state CFD simulation on a stationary equipment and structure to predict drag and added masses on submerged structures in traditional approaches, this methodology couples the transient CFD with diffraction analysis. In this paper, we extend the solution to include wave-structure interaction in irregular sea waves and vessel motions. Irregular waves are modelled using a JONSWAP wave spectrum. Simulations are performed to investigate effect of significant wave height, peak wave frequency (time period) of irregular sea waves, and vessel motions on the motion of a hollow cylinder in irregular sea waves. The results are compared with the traditional approach in current practice.

The time domain diffraction simulation is coupled with multiphase CFD simulation of subsea equipment and structures in waves. A transient CFD model with rigid body motion for the equipment and structure calculates added masses, forces and moments on the equipment and structure for diffraction analysis, while diffraction analysis calculates linear and angular velocities for CFD simulation.

The results provide better understanding of structure motion and associated forces in waves using this coupled methodology. The coupled methodology eliminates the inaccuracy inherited from assumed or calculated hydrodynamic properties that are obtained by using simplified equations or empirical formulations, or by using steady - state CFD analyses in traditional decoupled approaches. This coupled methodology has potential applications in analyses of the motions of subsea equipment and structures in waves during offshore operations.
Recent Advances in Soil Response Modeling for Well Conductor Fatigue Analysis and Development of New Approaches
Authors: Zakeri Arash , Clukey Ed , Kebadze Buba , Jeanjean Philippe , Walker Dan , Piercey Gerry , Templeton Jack , Connelly Larry , Aubeny Charles
Published: April 2015

Well fatigue assessment is an important aspect of the design and integrity assurance of deepwater riser-well systems. Fatigue damage arises from stress changes in a conductor due to cyclic loading. In practice, the lateral cyclic soil response is typically modeled using Winkler type springs known as the soil resistance-displacement (p-y) springs. An appropriate soil model for conductor-soil interaction analysis should predict the absolute and incremental magnitudes of stresses and the resulting impact on fatigue. Monotonic p-y relationships (backbone curves) which were originally developed for piled foundations are not appropriate for well conductor fatigue analysis. To determine the appropriate soil response an extensive study involving physical model testing in a geotechnical centrifuge and numerical analyses was initiated. The intent was to develop a robust and comprehensive approach to cover a wide range of seabed soils and loading conditions specifically for conductor fatigue analysis. Soil p-y models were developed for conductors installed in normally consolidated to lightly overconsolidated clays, medium-dense sands and over-consolidated clays. The models rely on the cyclic response of degraded soil at the steady-state condition and provide fatigue life predictions with high accuracy. This paper provides an overview of the past and recent studies that led to development of the fatigue p-y models. It presents the results of two centrifuge test series conducted in normally consolidated clay and medium dense sand. Ultimately, the paper provides recommendations for developing p-y springs specifically for well conductor fatigue analysis.
High Quality and Efficient Seismic Acquisition for Frontier Deepwater Areas
Authors: Cunnell C. , Bloor R. , Biswas S. , Bunting T. , Beasley C.
Published: April 2015

The trend towards frontier deepwater (FDW) exploration plays around the world creates new challenges for seismic data acquisition, processing and interpretation. Technical challenges focus on the need for high-quality seismic data to allow good understanding of geology from seafloor to target - so as well as providing an image of the drilling targets, the seismic survey is must deliver reliable information about the overburden to mitigate drilling surprises. In addition, economic challenges reflect the need to acquire data over large areas in a cost-effective manner, but without compromising data quality.

This paper reviews a new class of marine seismic technology that aims to address these previously contradictory demands. The technology is based on multimeasurement streamers that combine traditional hydrophone (pressure) measurements of the seismic wavefield with densely spaced accelerometer measurements that derive the wavefield gradient in vertical and horizontal directions. These measurements are combined to perform dense seismic wavefield reconstruction. The results provide greater detail of the seismic wavefield between the streamers and build a true 3D representation of the seismic wavefield that is equally and finely sampled in all directions.

In the context of FDW exploration, this offers two main benefits. The first relates to the ability to generate high-resolution earth models of the overburden, where fine-scale isometric subsurface characterization can help define safe and efficient well trajectories. This offers protection against noise and other artefacts in the seismic data, which, despite the typical characteristics of ultra-deepwater environments, may otherwise introduce interpretational uncertainty. It also mitigates inaccuracies and bias in the shallow velocity model impacting the deeper earth model construction.

Secondly, the ability to accurately reconstruct the seismic wavefield between streamers presents options for acquiring data faster, more cost effectively, and with less operational and environmental exposure. For example, using two- and three-boat operations to double or triple subsurface coverage with a single recording vessel. A selection of examples using real and modelled data will be used to illustrate both these key aspects.

Successful seismic imaging for FDW means understanding the pathway to the target reservoir as much as the target itself. A broad technology portfolio is required to provide integrated workflows, and multimeasurement seismic acquisition can be a key component in the solution; addressing aspects of enhanced resolution, wavefield sampling, and 3D deghosting, whilst also providing options to acquire data more efficiently without compromising quality.
Water Injection Pressure Protection System (WIPPS) in Deep-Water Development Offshore Brazil
Authors: Dave Hugg , Murat Kilic
Published: April 2015

This paper presents an overview of the development and implementation of a Topsides safety and control system to mitigate the risk of a downhole caprock breach in the BC-10 Phase 2 waterflood development.

For the water injection development in deep water offshore Brazil (SS-BC-10 Phase II), there is a strict operational pressure envelope for the water injectors. Excessive pressurization of the sand can lead to fault reactivation and/or a breach of cap rock (shale) integrity. A breach in turn can lead to out of zone injection, propagation of the injected water to the seabed and release of hydrocarbons to the environment. The efflux of reservoir fluids to the seabed constitutes a major HSE hazard with potentially significant impact to environment and company reputation.

Current subsea pressure measurements cannot be utilized in any Safety Instrumented Function (SIF), as these measurements are transmitted by equipment that is not rated for use in safety systems. Instead, we derived a relationship between the pressure of the water injection distribution header (WIDH), and the subsea pressure. From this relationship, we calculate a maximum pressure for the WIDH as the trip setting for a high pressure SIF.

To implement this we have designed a Water Injection Pressure Protection System (WIPPS) that includes a safeguarding function as well as control funtion. The safeguarding function will provide a dynamic trip setting and will stop the water injection pump, and will close an isolation valve on the water distribution header. The control function consist of an override pressure controller for each water injection well, which will limit the flow of injection water if any injection well's pressure exceeds a specified setpoint.

We concluded that the safeguarding and control system are compliant with our requirement for a Safety Integrity Level 3 (SIL3) safeguarding system. The safeguarding system requires regular testing and calibration to maintain this SIL. The WIPPS has been commissioned succesfully without any HSE incident and to date there has been no demand on the safeguarding function.

We realize that it would be better to safeguard the injection wells by using direct measurements that are close to the injection point. However, this will require us to have a means to securely communicate subsea pressure measurements to the Safety Logic Solver (SLS). For this purpose we are developing new instruments that make use of a secure communications framework called Black Channel Communications.
Integrating Onboard DP Systems into Model Test Facilities and Offshore Bridge Simulators
Authors: Voogt Arjan , Hallmann Rink
Published: April 2015

After the first model tests confirmed station keeping performance for Dynamic Positioned (DP) drilling units, many research projects have helped improve the positioning accuracy. Universities and research institutes developed their own closed loop dynamic positioning systems and started Joint Industry Projects to study the efficiency and interactions of thrusters. These models continue to challenge the state of the art, but are less suited to study operations with existing DP systems. Therefore, an alternative setup is developed in which the DP system to be used on board of the vessel can be coupled to the model tests or bridge simulations.

The new setup has been successfully applied to confirm station keeping offset limits and power utilization at model scale for the actual onboard DP system. Due to the applied Froude scaling the onboard DP system needs to respond faster than real time, but this proved feasible. The setup provides the best of both worlds: The model tests help to account for the hydrodynamic interactions correctly, while the onboard DP system ensures that all functionality in the control is identical to the actual operation. In addition, this setup allows institutions to study possible improvements to the onboard DP system in reproducible environmental conditions and in a safe and manageable manner. The paper describes the integration of an onboard operational system into a model test facility and a bridge simulator. It also discusses the main findings from the model tests and simulations thus far.
Subsea Membrane Water Treatment Progresses Towards Application
Authors: Hegdal T. , Pinchin D.
Published: April 2015

Treating seawater on the seabed for injection into reservoirs will deliver a new and significant capability to the industry's expanding subsea toolkit. This paper will describe the latest developments in the Subsea Water Intake & Treatment (SWIT) system and its ability for long lasting production on the seabed of ‘tailor made’ water for any IOR & EOR application.

In addition to ‘normal’ waterflooding, adding membrane treatment can adjust the chemical composition of injection water to suit specific demands of any reservoir. The injection of low salinity water in many reservoirs has shown significant increases in recovery factor of the oil in place, whereas removal of sulphate ions from injected seawater will prevent scaling and provide the ultimate protection against reservoir souring.

This paper will discuss the findings of a 2012-2013 JIP that showed that the SWIT technology, when coupled with membrane systems, has the ability to deliver ‘tailor made’ water quality, reliably and for several years without intervention directely on the seabed. The success of this JIP has raised enthusiasm for a technology qualification program with Oil Majors and many other companies. The paper will present status of this (already started) program and include technology gaps identified and measures required to close them. In addition to the ‘ready to go’ SWIT system, membrane treatment of seawater on the seabed is making significant progress towards becoming a qualified process in the subsea tool-box.

Free from all topsides restrictions, this technology enables new levels of flexibility in reservoir drainage strategy. Reservoir engineers will have the ability to significantly increase recoverable reserves and production rates in a cost effective and environmentally friendly manner.
Design and Manufacture of a Harsh-Environment Riser System
Authors: Burke R , Botros T , Stoica V
Published: April 2015

BP have worked with Wood Group Kenny (WGK) since 2010 to design a robust riser system which will service a harsh-environment FPSO for the next 25 years, in some of the most hostile environmental conditions in the world. Quad204 is located approximately 130 km west of Shetland in 400 m water depth.

In order to deliver hardware which would match the expected facility uptime, and to provide a best-in-class toolbox for integrity management of the riser system during operation, a design program was set up with heavy emphasis on learning from operational experience in the region, and incorporating more onerous Metocean conditions for the new production platform, the turret moored Glen Lyon FPSO, which is significantly bigger than her predecessor, Schiehallion.

A detailed review of BP's West of Shetland (WoS) and Northern North Sea (NNS) operational experience, including previous riser system designs and integrity concerns was carried out in 2010-11. This led to the specification for the Quad204 dynamic riser system which incorporated several unique features to address the location and platform constraints, as well as the restricted construction season.

These particular features were identified as value-adding early in the process, and built into the specification, and subsequent detailed design process, to enhance the system integrity over a lifetime operating in this environment: additional layers of tensile armour to extend riser corrosion fatigue life; double outer sheaths to obviate the consequences of installation damage; autonomous annulus monitoring; enhanced turret/end-fitting venting capacity; turret motion response monitoring; riser I-tube inspection facilities and pipe specimen retention. An extensive program of inspection and dissection of recovered Schiehallion hardware was also carried out to confirm the integrity of the retained brownfield infrastructure. The design, qualification and manufacture of the biggest bend stiffener produced by the supplier transpired to be a significant risk for the project and the program to address this is described herein.

The final riser system - a combination of bespoke hardware and supporting integrity management tools - is believed to be state of the art for harsh-weather floating production systems.
Kick Detection at the Subsea Mudline
Authors: Toskey E.D.
Published: April 2015

On land or offshore, kick detection is primarily achieved by means of measurement and observation at surface of the drilling fluid and drilling equipment. A kick, if not controlled, will progressively grow in the wellbore until it becomes a blowout. Control of a kick is dependent upon time-to-detection. Kick detection in a subsea well is more problematic because the subsea well contains a large volume of drilling fluid between the wellbore and the surface kick detection – the volume of mud in the riser – which can mask a kick or delay detection. This additional volume in the riser may be up to twice as much as the volume in the wellbore. In any case, control of a kick in a subsea well can be improved if detection of the kick can be made sooner.

In this work an investigation was made to develop kick detection sensors that could work at the subsea mudline. By detecting kicks just above the wellhead, at the base of the subsea riser, the time for corrective action can be increased by as much as a factor of three. Two sensors, ultrasonic and hydrostatic, were tested to detect changes in the fluid density caused by the presence of oil, gas, or water in the drilling fluid.
Developing an Innovative Deepwater Riser System: From Concept to the Full Production of Buoy Supporting Risers (BSR)
Authors: Hiller Daniel , Karunakaran Daniel , Cruz Ivan , Tadeu Marcus
Published: April 2015

This paper describes the evolution of Buoy Supporting Risers (BSR), from inception to successful deployment and full production in the Santos Basin development, offshore Brazil. It was a process that started with the early engagement of the operator and contractors on concept and feasibility studies, through identification of potential application scenarios and into a fast track development of basic engineering, bidding, detailed design and construction. The process involved the early selection of development partners and the joint management of R&D and engineering in order to identify and develop existing and emerging technologies, as well as managing the construction of assets and identifying methodologies, all under a single commercial structure. Then, the specifications and work scopes were jointly developed and fixed lump-sum prices were agreed, under a competitive bidding. This model avoided the going back-and–forth and eliminated most of the delays, introducing a great deal of collaborative spirit and transparency. In this case, following an initial feasibility engagement some 20 years before and the identification of a real application scenario, through the above process, it has been possible to develop the major BSR decoupled riser technology from concept selection to full production mode in about five years. The major portion of such period is related to the complete execution of the largest EPIC SURF project executed in Brazil up to that date, where several world-first technologies were implemented in a harsh weather environment, allowing the operator to achieve the production ramp-up plan. In this journey, it took a lot of focus and tenacity from all involved parties to overcome major challenges and ensure that pioneer technology is implemented and available for further applications.
Technical Challenges of the CLOV Oil Loading Terminal
Authors: Brinkhuis H. , Dormans K. , Jones A. , Ming M.T.
Published: April 2015

This paper considers the key technical challenges experienced by Bluewater Energy Services BV during the design, fabrication and load-out of a deep water buoy, also referred to as the Oil Loading Terminal (OLT) for Total E&P Angola, acting as Operator for and on behalf of a Consortium.

The OLT buoy was contracted for the Cravo, Lirio, Orquidea, Violeta (CLOV) Field Development Project, located offshore Block 17 in Angola, about one nautical mile from the Floating Production Storage & Offloading (FPSO) unit. The preferred way for offloading will be through the Oil Loading System (OLS), comprising of two Oil Offloading Lines (OOLs), two Fibre Optic Cables (FOCs) and one OLT.

Bluewater Energy Services BV entered into an Engineering, Procurement and Construction (EPC) contract for the OLT buoy including mooring lines, mooring hawser system, floating hose system and suction piles. During the execution of the work, the key technical challenges may be summarized as follows:

The impact of the deep water environment (ranging from 1,100 to 1,400 meters) on specific mechanical equipment. The design of the double pivoting chain stoppers, extensively tested at full scale. The interface with the Oil Offloading Lines (OOL) resulting in two large steel structures (the OOL receptacles) underneath the bottom plate of the buoy body. This in combination with the available lifting capacity at the fabrication yard in Angola, imposed limitations on the way the OLT buoy could be placed into the water.
ACG Field Geohazards Management: Unwinding the Past, Securing the Future
Authors: Hill Andrew W. , Hampson Kevin M. , Hill Andrew J , Golightly Chris , Wood Gareth A. , Sweeney Michael , Smith Martyn M.
Published: April 2015

The super-giant ACG field lies in the Azerbaijani sector of the south Caspian Sea. The significant complexity of the geohazards setting over the field was realized in 1993 when negotiations for the PSA to develop the field were still ongoing.

This resulted in the need to understand geohazard risks being recognized in the Minimum Obligatory Work Program terms set out in the "Contract of the Century" in September 1994.

Over the last twenty years work to define and refine understanding of the multiple geohazard issues has been ongoing. Work started in early 1995 with the completion of two deep geotechnical boreholes and a PSA contract area wide geophysical and geological geohazards campaign that delivered an early, first pass geohazards stop-light map and supported delivery of the Early Oil Project (1997).

The results of these two initial pieces of work formed the basis of the first PSA contract area wide integrated geohazard study that addressed the threats of individual sources of geohazard to Full-Field Development planning. These included, amongst other issues: slope instability, mud volcano stand-offs and fault risks, all being included in the first integrated geohazards risk map of the PSA's contract area in 1999.

Since this time, direct experience, in drilling and facilities installation, has driven the need for an ongoing update of data and improvement in geohazard understanding. New sources of hazard, such as the implications to riser-less drilling from super-saline soils, have had to be assessed and new data acquired to assist in mitigation of the risks identified.

Most recently HR3D data has been acquired across the entire PSA which, tandemed with AUV seabed and shallow profiler imagery has been used to guide a further series of geotechnical campaigns. These results have been used to drive an update to the geohazards zonation addressing, in particular, slope instability in field areas previously considered too sensitive for development.

This paper provides a timeline of geohazards activity on the ACG PSA over the past twenty years as a background to other papers being offered in the technical session that discuss how specific geohazard data acquisition and analysis issues have been addressed.
GIS-Based Probabilistic Slope Stability Assessment Using Shear Band Propagation
Authors: Rushton David , Gray Thomas , Puzrin Alexander , Hill Andy
Published: April 2015

This paper describes a GIS-based application of shear band propagation to model slope instability that combines rapid analysis over large areas using pixel-based analysis with an approach capable of modelling the observed slope failures.

Slope instability modelling can be performed over large study areas through application within a GIS. This approach typically involves calculating the limit equilibrium factor of safety using an infinite slope geomechanical model for a dense grid of pixels covering the study area. The result is a quantitative and spatially resolute estimate of susceptibility to slope failure representative of the seabed gradient, sediment strength and density, and other conditioning or triggering factors. For input to a spatial risk assessment, factor of safety can be converted into annual probability of failure using a Monte Carlo assessment to capture the uncertainties in the inputs and the modelling approach.

Shear band propagation offers an alternative to limit equilibrium and provides a simple approach to modelling to the long and relatively thin slope failures typically observed in the offshore environment. This method is applied probabilistically, resulting in a numerical map of annual probability of slope failure through shear band propagation. The complexities of applying a two-dimensional model within a three-dimensional spatial framework are explored in this paper.

This GIS-based probabilistic slope stability assessment using shear band propagation has been successfully employed as part of a landslide risk assessment of the Azeri-Chirag-Gunashli (ACG) development, Caspian Sea, where pixel-based annual probability of failure estimates contribute to a landslide risk score for each geohazard province within the area.
Managing Obsolescence Risk for Subsea Production Control Systems Through the Implementation of a Proactive Obsolescence Management System
Authors: Akbar Iqbal , Bertmand Trond , Broadbent Paul , Cotton Mark , MacKenzie Rory , Smith Harvey
Published: April 2015

Obsolescence can be a significant cost driver and impacts equipment at all stages of the whole life of field. The life cycle of parts within major long life products can be significantly shorter than the life of the products they are within.

Obsolescence risk when installing and maintaining existing and future Subsea Production Control Systems (SPSs) is therefore of significant concern to the industry as there is an ever increasing demand to extend the operating life of equipment. Whilst the largest risk is with electronics and electro/mechanical items, the requirement is to manage all types of parts used in the design, manufacture and support of SPSs and associated topside equipment.

A Subsea Obsolescence Management Joint Industry Project (JIP) was established to address the significant obsolescence issues being experienced by Oil & Gas operators as they attempt to upgrade ageing infrastructure or repair failures.

The objective of the JIP is to make available a recommended practice that could be freely used by any/all operators in the industry, as required. The intention is that a common practice used by all would minimise the different types of methods employed within the major suppliers to manage obsolescence. To help in this respect the JIP has produced a Recommended Practice (RP) for Subsea Obsolescence Management. This recommended practice relates directly to the requirements of a Joint Operator Specification (JOS) that was collaboratively developed by a group of operators and released in 2012.

This paper will present the key activities undertaken by the JIP and show how they have implemented, and are continuing to improve, a proactive obsolescence management capability into the Subsea Systems supply base.
Creating Sustainable Offshore Developments in the Ultra-Deep Water
Authors: Rijtema Saskia , de Haas Ramon
Published: April 2015

The continuous drive to increase oil and gas production requires fields to be developed under challenging circumstances such as deeper water, harsh operating & environmental conditions and remote areas all while adhering to strict HSE requirements. At the same time, investment decisions for an increasing number of projects have been postponed because the increasing costs have resulted in reduced shareholders return.

In order to overcome the technical challenges within the changing environment, funding needs to be created by improving the cost effectiveness of the adopted solutions. This can be achieved by optimizing and standardizing the current concepts and by using the research in and outside our industry, to benefit from innovations, which can reduce risks and save costs. At the same time, lessons captured in the past decade need to be imbedded within the organizations which requires retaining, training and guidance of the engineers and building on the technical relations within the supply chain.

The other side of the deep-water challenge is the current technical limitations, which need to be overcome. Equipment that is currently available and their applications need to be revised to deliver the step change to the ultra-deep water.

This paper will focus on the areas, which combine our extensive installation experience with our more recently gained SURF EPCI insights and the ongoing technology developments with the intent to create practical solutions for the industry. It will describe how we intend to use real time simulators to identify and manage risks during the offshore construction. Also, topics such as lowering capabilities for the ultra-deep water, flexibility in field developments, smart design which incorporates vessel capabilities, coating & welding developments for the high pressure, high temperature fields and the implications of remote areas will be addressed.
Process Safety KPI's - Wells and Drilling Activities
Authors: Carvalho F. A. F. , Lopes M. T.
Published: April 2015

An essential element of any improvement program is the measure of existing performance needs, as well as identification of new and future needs. This paper presents Process Safety KPI's (Key Performance Indicators) for Wells and Drilling activities, created by a committee in a Brazilian Energy Company comprised by experienced professionals with expertise in those activities. The continuous improvement of Process Safety Management in this company leaned on four steps: accidents (definition of process safety anomalies), competence, diagnostics and implementation of effective leading and lagging process safety metrics. The company understands that said continuous improvement can be achieved through the definition of accidents, incidents and Process Safety deviations, awareness promotion, process safety training (developed in cooperation with the Corporate University), definition of Process Safety Management elements at corporate level and development and implementation of effective leading and lagging process safety metrics with periodic critical analysis.

Monitoring and analysis of results derived from Process Safety Indicators provide inputs to the continuous improvement process in Safety Management. In fact, these results make it possible to focus efforts on the weaknesses identified and to determine potential opportunities for improvement. Furthermore, throughout the maturation time of these indicators, it is possible to verify those that are most representative for the process under analysis and the need for reformulation or exclusion of some metrics during the trial period.
Overview of BC10 Deepwater Development - An Effective and Efficient Phased Approach
Authors: LeBlanc Jeanne-Marie , Soares Andre , Boyd-Gorst John , Stingl Kent
Published: April 2015

The Parque das Conchas BC-10 deepwater development is a combination of several distinct small to mid-size fields that allow for phasing. The fields are off the coast of Brazil in 1800+/- meter water depth. This series of successfully phased projects started with the deployment of the Espirito Santo FPSO, 11 wells and subsea boosting equipment in Phase 1 which came on-stream in July 2009. Phase 2 followed on-stream in October 2013 with an additional 11 wells (including water injection), subsea boosting equipment, and brownfield topsides upgrades on the FPSO. The Phase 3 investment has already added 7 wells and will come on-stream in early 2016 after the subsea and topsides scopes are completed. The success of this phased development is attributed to rigorous standardization, rapidly applied learnings, and strategic deployment of new technologies.

Maintaining the cost competitiveness and economic value of each new investment phase was more difficult, given the decreasing size of the fields developed. Leveraging contractual partnerships and using standardization of well design and subsea hardware led to improved quality, competitiveness and delivery schedule (corrected for market factors).

Technologies deployed during the project included mudline boosting through Electrical Submersible Pumps (ESPs) (and later, in Phase 2, multi-vane pump inserts to increase gas handling capacity), transmission of high voltage electrical power through subsea umbilicals, real-time geosteering and permanent reservoir monitoring technology. A 6th generation Bully Class rig was successfully used in Phase 2, and after replication efficiencies, coupled with focused improvements to the drilling scheme, the rig and crew performed flawlessly for the Phase 3 wells, delivering the scope several months ahead of schedule.

Another challenge was committing to pre-investment for the later phases. For example, water injection facilities were pre-installed with the Phase 1 project, for use on Phases 2 and 3. Taking this investment decision early had risk attached, but this has paid off. This paper highlights the advantages of a phased approach, as well as how the learnings can be used in successive phases to improve overall project value.

The strategy of a phased approach to the development of BC10 enabled quality business decisions, and optimized the ullage utilization of the FPSO. Continuity of resources to continuously learn and rapidly apply learnings proved highly successful.