bluuebunny/crossref_metadata_2025 huggingface dataset:
Wellhead Pressure Interlock Protection
Authors: Carlson Russell , Wright LaQuayne
Published: June 2014

There are many pressure related issues of concern in petroleum well production. Both high and low pressure conditions are indications of problems that must be addressed to maintain well safety and performance. A flexible and reliable control system for pressure monitoring provides a failsafe interlock which prevents well operation under a variety of unsafe conditions.

Proper operation of a well requires the system be maintained within a specific pressure range. The range can vary from well to well, with offshore pressures typically higher than onshore. The concept remains the same – if pressure is too high, there is a risk of catastrophic failure. If pressure is too low, it may indicate clogging or catastrophic failure at the site.

Well control systems have evolved and become more sophisticated as technology and understanding have improved. Instrumentation is keeping pace and can now provide high integrity monitoring and protection with high efficiency features that increase system safety and reduce maintenance time and effort.
Developments in Marine Gas Hydrate Exploration
Authors: Boswell Ray
Published: June 2014

The evaluation of gas hydrate resource potential continues to spread across the globe. Over the past decade, exploration emphasis has steadily shifted away from the confirmation of the presence of gas hydrate to the more complex issue of prospecting for specific accumulations of highly-concentrated gas. In general, concepts for gas hydrate exploration have evolved from a search for bottom-simulating reflectors to a process much more akin with conventional oil and gas exploration that features the direct detection of gas hydrate accumulations in seismic data supported by integrated geological/geophysical/geochemical studies that address issues of gas supply and reservoir distribution. This report aims to assimilate the lessons learned to date to outline a general exploration procedure for gas hydrate resources and outline remaining research challenges as follows:delineation of the gas hydrate stability zone;the identification and evaluation of strong amplitudes of the same polarity as the sea-floor ("peak" amplitudes) within that interval, as well as intervals of increased acoustic velocity;mitigation of the geologic risk inherent in such prospects via seismic mapping of amplitude distribution along prospective horizons as well as broader seismic facies analyses; andfurther risk mitigation through assessment of evidence of gas presence and gas migration into the gas hydrate stability zone.
Integration into the Sandface Tool System for Gravel and Frack-Pack Installations with a Fiber Optics Wet-Mate Connector System
Authors: Drakeley B.K. , Morrison F. , Grigsby T. , Martinez S. , Perez E.
Published: June 2014

Operators have always sought the capability to monitor pressure, temperature, and flow across the sandface in gravel and frack-pack (and stand-alone screen) completions in real time in order to optimize production, and gain advanced notice of remedial needs.

In most sandface completions, the lower completion contains the screens, and the completion is performed in two stages: the service tool string is run first to perform pack operations, and the second stage "mates" the upper completion string to the lower completion.

The unique capabilities of fiber optics sensing techniques such as Distributed Temperature Sensing, Point Pressure and Temperature, Array Temperature Sensing, and Distributed Acoustic Sensing can provide the desired production and reservoir information across the sandface. However, accomplishing this requires a fiber optics wet-mate connector system to link the fibers in the lower and upper completions.

Weatherford had run a fiber optics wet-mate connector system in Oman in April 2005, and a key driver for the new connector system was to use a lower profile connector to maximize the production flow area with Halliburton's gravel and frack-pack completion technology.

The design essentials for the 9 5/8-in. × 4 ½-in. to 5-in. system, and required field operations for successful deployment are described in the paper along with the development and qualification process performed in laboratory, and test well conditions completed in May 2013. These were to ensure that the two key challenges of alignment and debris management had been successfully resolved. The final System Integration Test (SIT) for qualification was run at approximately 3,000 ft, and witnessed by a major operator. Subsequently, a demonstration SIT in the same well was witnessed by multiple operators in November 2013. The mechanical and optical measurements taken during the qualification process will be presented to demonstrate that the desired production/reservoir information can be provided.
Optimizing Response Strategies to Improve Subsea Equipment Availability
Authors: Pearse J.A. , Botto A.
Published: June 2014

Operators must develop a holistic response strategy to equipment failures that will ensure that effective control is established as quickly as possible in order to safeguard life, protect the environment, ensure containment and control the emergency to minimize damage to assets. This paper will focus on the financial impacts of subsea equipment failure and how real time data improves subsea equipment availability. Failure of equipment must be detected prior to occurrence in order to reduce downtime and increase production availability, i.e. minimize the commercial consequences.

A methodology will be presented where equipment failure will be assessed based on its operational risk, i.e. probability of failure assessment versus cost of failure analysis. In order to assess the probability of failure, numerous failure data gathering methods should be assessed such as:Condition monitoring? Real time data trending? Operations reports and production trackingFailure management? Integrity management plans (risk-based assessment)? Inspection data? Central maintenance management system? Historical failure data e.g. OffShore Reliability Data (OREDA) or WellMaster / SubseaMaster? Failure Modes Effects and Criticality Analysis (FMECA)? Root Cause Failure Analysis (RCFA)

An efficient comparison and gap analysis of these data sources should be completed recognizing data patterns and identifying trends, so that the risk for equipment failure and production loss can be estimated. In addition, evaluation of the equipment failure's commercial impact based on equipment lead time and spares availability ensures that all probable failures have a response plan in place. A well-planned response plan can reduce the repair time delay significantly and therefore limit the impact on production efficiency.

A case study will be presented; management of risk will be used as a basis for quantifying the risk ranking for different subsea equipment. A response strategy analysis will evaluate the cost benefits of the level of preparedness required for each subsea failure. The case study will demonstrate the value of real-time data monitoring and how data analysis improves production efficiency and possibly influences all future subsea equipment design. In addition, in order to reach a successful repair response strategy, it is imperative that the appropriate information, techniques, materials, spares, and personnel are available to enable an expedited response.
Innovative Positioning of Downhole Pressure Gauges Close to Perforations in HPHT Slim Well During a Drillstem Test
Authors: Al-Nahdi AbdulHakim , Gill Harmohan S. , Kumar Vikash , Sid Imad , Karunakaran Prasad , Azem Wasim
Published: June 2014

An operator successfully tested an offshore, exploration well in a high-pressure and a high-temperature (HPHT) reservoir, where the pressure exceeds 10, 000 psi and the temperature is approximately 400°F. The tested intervals are behind a 4.5-inch liner. Slimhole drillstem test (DST) tools have been considered but not selected due to the restricted internal diameter and limited intervention capability. Instead, a cased hole DST method has been selected in which DST tools are set in a 7-inch liner, and tubing-conveyed perforating (TCP) guns are run in the 4.5-inch liner on the bottom of a long tailpipe.

The first DST has been successfully completed, with the pressure gauges located at the gauge carriers in the 7-inch liner, several thousand feet above the test interval. Pressure and temperature data from downhole gauges have been analyzed and found to exhibit significant wellbore-phase redistribution effects because of gauge location. This has resulted in significant uncertainty in reservoir characterization. Solutions considering the HPHT and slimhole design have been investigated.

We present a unique method of placing the downhole gauges on top of the perforating gun during an HPHT well test operations where formation temperature exceeded 400°F. Five DSTs have been performed using this technique with successful recording of downhole pressure and temperature data, despite the perforating gun shock and hostile environment encountered.

A comparison of pressure transient interpretations as well as a comparison of data gathered by the gauges located above the guns (immediately above the perforations) with the data from gauges in the 7-inch liner will be presented to show the potential for incorrect interpretation due to the gauge placement. We will also discuss the unseen behavior of flowing gas temperature at perforation depth based on actual temperature data recorded.
Investigating Modern Ultra Deepwater Sedimentary Processes in the Central Gulf of Mexico Using High Resolution Geophysical Data
Authors: Prieto Maria I. , Moscardelli Lorena , Wood Lesli
Published: June 2014

A detailed geomorphologic and shallow stratigraphic interpretation was performed in three different geomorphological domains of the ultra-deepwater region of the central Gulf of Mexico (GOM) using a set of high resolution bathymetry and subbottom profiles that were acquired at four major oil fields in the Green Canyon and Mississippi Canyon protraction areas. The seafloor expression of the study areas allowed defining three different geomorphological provinces: Minibasin, Sigsbee Escarpment and Disconnected Canopy Province. The geomorphological expression of these provinces is primarily the result of the dynamic behavior of the underlying salt, in which these regions experienced different degrees and types of substrate deformation. Structural deformation affecting these areas has been very dynamic through time enhancing the occurrence of both regional and localized gravity-induced deposits. Regions of high relief along diapiric slopes (e.g.: Sigsbee Escarpment) are affected by headwall failures and the near seafloor stratigraphy reveals the complex dynamic of eroded and re-deposited sediments that have been affected by both gravity- and current-driven processes. This study seeks to improve our understanding of how local bathymetric variabilities (linked to underlying structural controls) interact with gravity-driven and current-controlled processes in the ultra-deepwater region of the GOM to generate the near seafloor stratigraphic record that is observable in our study areas.
Solubility Study of Magnetite under Extreme High Pressure and High Temperature
Authors: Yan C. , Guraieb P. , Huang J. , Contreras E. , Tomson R. C. , Tomson M.B.
Published: June 2014

With the continued development of offshore production in deepwater wells, a greater understanding of scale formation and corrosion under extreme high pressure and temperature (xHPHT) is needed. In order to better predict scale formation and scale solubility, knowledge of the thermodynamic and kinetic properties of these mineral systems under xHPHT conditions is important. Research to expand the amount of data and models for different types of scales at these conditions will reduce offshore production risk and improve human safety in ultra-deepwater (UDW) production.

A novel flow-through apparatus has been developed to perform a scale solubility, dissolution, and precipitation study of minerals under high pressure (up to 24, 000 psig), high temperature (up to 250 °C), and high total dissolved solids (TDS, up to 360, 000 mg/L). This part of research will focus on the solubility study of magnetite and siderite. Studying dissolution and precipitation will improve understanding of the formation of passive layers (Fe3O4 and FeCO3) and their phase transitions as temperature increases, as has been observed in corrosion research. In this work, effects of reaction conditions, including temperature, pressure, pH, and brine composition on solubility of magnetite, have been investigated. Reduction potential is an important parameter which will affect magnetite solubility dramatically and is sensitive to brine composition. Details of the experimental setup and preliminary results of this research will be presented.
A Model Test Ice Resistant Study of FPSO And Yoke Mooring System In Ice Influenced Areas of Bohai Bay
Authors: Li Jianmin , Li Tongkui
Published: June 2014

The ice resistant capacity of a FPSO and its yoke mooring system is one of the critical problems for oil field developments in the ice influenced areas of northern Bohai Bay. A model test study was conducted in the 40m×40m×2.8m Ice Tank of Helsinki University of Technology in Espoo, Finland for evaluating the maximum ice loads acting on the Suizhong 36-1 FPSO and Yoke Mooring System.

The FPSO hull, yoke mooring system, and floating ice packs were simulated for the full-scale processes in miniature. The FPSO hull and the yoke mooring jacket structure are reduced linearly in dimensions and cubic in mass, displacement, and volume, to ensure the geometric similarity. Many factors and properties are of interest when simulating ice in the ice tank. A scale ratio of 1:30 was adopted in the model test. Therefore the ice used must also be 1/30th the thickness and 1/30th the strength. ice pieces flowing, as well as jamming around the FPSO hull and the yoke mooring jacket, are modeled in the ice tank. It is very challenging to correctly reduce the ice properties of interest, thus providing an accurate simulation. The actual environment simulated in a combination of wind, current and ices is of prime concern.

This paper presents the methodology and results of the six model tests which are conducted to simulate various combinations of floating pack ice thicknesses, ice bending strengths, ice flowing speeds, FPSO headings and rotations, etc. The findings include the ice loads acting on the FPSO and Yoke Mooring Jacket at two ice flowing speeds of 0.5m/sec and 1.0 m/sec and three FPSO headings of 0, 90, 180 degrees, respectively. The FPSO model are pulled or pushed through the loose broken ice sheet to simulate the interaction between the ices and the FPSO hull. The ice load and mooring load on the yoke arms were measured by force transducers. The rotation angle of the yoke arms around the mooring jacket were also measured by angular transducers.
The Devil Is In The Details - Lessons Learned From Design Failures in Underwater Monitoring Systems
Authors: Strout J.M. , Sparrevik P.M.
Published: June 2014

Success is of course the most desirable result of any project, but the value of failures in terms of advancing technology should not be underestimated. This paper draws on the experiences of over thirty years of designing and delivering operational monitoring systems for the oil and gas industry, condensed to a short presentation of valuable lessons learned from less-than- successful designs and deployments.

The article covers several principle themes, presenting the failures experienced, evaluation of the root cause of the failure, and subsequently the measures implemented to mitigate similar failures in the future. The insights and solutions presented will be beneficial for organizations planning or executing the design and installation of an underwater monitoring network.

The first theme presented is failure due to corrosion. Corrosion is an insidious process, which if not properly managed in the system design will ultimately result in failure. The obvious culprit is the use of common steel, whereas less obvious culprits include combinations of metal types (including titanium), inadvertent use of alloys, surface treatments and coatings, as well contact with sediments, cements and grouts.

The second theme is barrier philosophy - leaky enclosures, hygroscopic materials, and capillary forces can all contribute to failures. A leaking barrier does not necessarily mean a catastrophic failure, and with the implementation of a few good design details, even a leaky system may be able to operate for long periods before eventually failing.

The third theme examines lessons learned related to deployment and operation of equipment in various environments: in conjunction with permanent infrastructure, as autonomous installations on the seabed, or as moored or drifting floating structures. Each of these operating environments poses challenges, including harsh natural environmental conditions, accessibility, interaction by third parties, and various rules, regulations and company specific practices.

Sound engineering combined with practical experience is the best starting point for a successful design. This article summarizes some of our 'trial and error' experience related to the practical and operational challenges inherent in an underwater monitoring system design and deployment, and these experiences will be useful for others when commissioning, designing and deploying similar systems.
Implementation of Dual Gradient Drilling
Authors: Stave Roger
Published: June 2014

RMR - Riserless Mud Recovery technology is a "first out" commercial Dual Gradient Drilling (DGD) technology. The technology has to date been deployed on more than 200 wells. The majority of wells are in less than 2000ft water depth, and the maximum water depth to date is close to 5000ft.

Initially the development was driven by a zero-discharge demand, but early on the benefits related to Dual Gradient Drilling became the main drivers for the Operators to select the technology. In fact, for only a few of the 200 wells to date, zero-discharge has been the driver. The technology allows weighted and engineered drilling fluid to be used on the top-hole sections and volume control is enabled through circulation of fluid to surface - same as post-Blow Out Preventer (BOP). Borehole quality is significantly improved and planned Total Depth (TD) can be reached without the risk of running out of fluid.

The Managed Pressure Cementing (MPC) technology has been developed as an add-on to RMR. This technology has been used for more than 20 wells to date. Combined with the improved hole quality RMR can deliver, MPC improves the chances of circulating the cements slurry around the well without losses. The pressure is managed and controlled during the circulation time, and monitored during the setting time.

A third development of the core RMR technology has been EC-Drill. EC-Drill has been deployed on 6 jack-up wells and 3 deep water wells drilled from a Semisubmersible rig (SEMI). North Sea and Gulf of Mexico (GOM) deployments are under ways. EC-Drill enables precise control of Bottom-hole Pressure(BHP) through manipulation of the fluid column within the Drilling Riser. Pressure build up due to circulating friction is eliminated and flow rate / Rate of Penetration (ROP) can be increased. By managing Equivalent Circulating Density (ECD), drilling through tight drilling window is enabled. Depleted / low pressure reservoirs can be drilled with conventional / low mud weights. EC-Drill in its present form delivers primarily ECD control and only partial - not full DGD capability.
Project Management, Local Content and Value Delivery
Authors: Idachaba Francis E. , Wokoma Esther
Published: June 2014

The local content policy is enforced by Governments to get local contractors more involved in the supply of services to the Oil industries in their countries so that funds spent on foreign companies for the provision of these services can be retained in the country. This increases the capacities of these companies at providing jobs and reducing unemployment in their countries. The Oil industry in Nigeria spends over $15Billion annually for services such as fabrication, procurement and engineering. These services can be provided by local companies. The main issue with the implementation of the local content policy is in the quality of services rendered by local companies which raises the question as to whether the value delivered is commensurate with the funds spent. Other issues include: Do these companies possess the required expertise to enable them deliver to the required standards? Are these companies being run in such a manner as to grow them into multinational companies capable of providing service to the global oil and gas companies? With the discovery of oil in other African countries, Nigeria should be a source of high quality and low cost alternative for the supply of the required technical expertise in these countries. The local content bill can only be successful if the benefitting local companies grow in terms of technical, financial and managerial capacities to be able to compete globally. For this to happen, the companies must be made to conform to international best practices, the scope of projects to be delivered must be thoroughly understood and the contract terms should include incentives for timely delivery of projects and services within the cost, schedule and quality. The contract terms should also include penalties for slippages by either party and these terms should be adhered to very strictly.
SCORCH JIP - Feedback on MIC and Pitting Corrosion from Field Recovered Mooring Chain Links
Authors: Fontaine Emmanuel , Rosen Jeremy , Potts Andrew , Ma Kai-Tung , Melchers Robert
Published: June 2014

Forensic investigations on severely corroded (pitted) chains recovered from the mooring systems of two FPUs in West Africa and Indonesia are described. During the course of the SCORCH JIP, it became apparent that a similar phenomenon had been experienced by other JIP participants indicating that it may be a common problem deserving attention. The conclusion of the present investigation is that the large pits most likely can be attributed to Microbiologically Influenced Corrosion (MIC). Where pitting occurred, the pit depth growth rate was found in instances to be up to 10 times the uniform corrosion rate, with pits distributed approximately uniformly but randomly around the link and the bar circumference. Destructive tensile tests of the samples indicated residual strength that was at worst 25% below as-manufactured estimated As-new Breaking Load (ABL). The correlation of loss of strength with loss of metallic area due to uniform and pitting corrosion indicated that breaking load cannot be treated simplistically, and requires more sophisticated consideration of the pit geometry and its location with respect to areas of high stress within the link.
New Design Of Lightweight Flexible Pipe For Offshore Oil Offloading Transfer
Authors: Do Anh Tuan , Legeay Sebastien , Pere Jean Marie , Charliac David , Roques Jean Philippe , Karnikian Alexandre
Published: June 2014

Spread moored FPSO (Floating Production and Storage Off-loading) vessels are typically used in the large West African oil fields. The oil from these vessels is transferred to shuttle tankers via an Oil Loading Terminal(OLT). This usually consists of 2 to 3 flexible offloading lines installed between the FPSO and a Single Point Mooring (SPM) with large internal diameter for 24 hour offloading. The final connection between the SPM and the shuttle tanker is made by floating hoses.

Currently the flexible off-loading lines (OOL) are designed with steel wire armor, as typically used in the Offshore West Africa Fields. With pipes reaching 23? internal diameter and up to 2300m in length, the steel wires give the pipes a substantial weight generating the need for a large number of buoyancy modules to minimize the tension at the FPSO and OLT. These modules significantly add to both the cost and the installation time.

Carbon Fiber Composite (CFC) is characterized by its light weight and exceptional fatigue performance, with the ability to be manufactured as an armor wire in a long continuous single length (more than 4000 meters). It can be used as an alternative to steel wire armors to design an optimized flexible pipe structure with significant advantages:45% decrease in submerged weightPotential to install in double catenary configuration, without leading to excessive top tensionBuoyancy Modules are no longer required - installation is safer and quickerRiser configuration is no longer impacted by fluid density

These advantages allow greater flexibility in the position of the FPSO relative to the SPM with a fixed length of riser. Because CFC Armor is not susceptible to corrosion, service life of the flexible pipe is unaffected by breaching of the outer sheath and subsequent flooding of the annulus.

This new design of flexible pipe, together with the installation and operational configurations, will be presented in this paper. In order to demonstrate the suitability of CFC, the material performance testing in severe fatigue and ageing conditions will be disclosed. The economic viability will be demonstrated by showing how the material cost is offset by the elimination of buoyancy modules and faster installation. Additionally this technology enables flexible OOL risers to be produced in a long single length.
Operational overview of the first offshore production test of methane hydrates in the Eastern Nankai Trough
Authors: Yamamoto Koji , Terao Yoshihiro , Fujii Tesuya , Ikawa Terumichi , Seki Makoto , Matsuzawa Maki , Kanno Takayuki
Published: June 2014

In March 2013, the world's first field trial of gas production from marine methane hydrate deposits was conducted in the Daini Atsumi Knoll area of the Eastern Nankai Trough off the Pacific coast of Japan as a process to bring gas hydrates under seafloor to valuable energy resource. The technique used to dissociate the ice-like material was "depressurization method" that had been applied in the previous production test in Mallik site, the Northwest Territories, Canada in 2007-2008. Japan Oil, Gas and Metals National Corporation (JOGMEC) as a part of MH21, the Research Consortium for Methane Hydrate Resources in Japan planed and supervised the project with the funding of the Ministry of Economy, Trade and Industry (METI), and scientific supports from the National Institute of Advance Industrial Science and Technology (AIST). One production well with two monitoring boreholes were drilled in the test site for the test. Along with the flow test operation, intensive data acquisition program was planned and implemented to understand behavior of methane hydrate dissociation- bearing sediments against depressurization. To realize high degree of drawdown in relatively shallow formation below deepwater, several downhole devices were designed and installed.

The flow test started in the morning of March 12 and lasted until severe sand production forced to terminate the operation six days later. During the stable production term, gas flow rate was approximately 20,000m3 under atmospheric condition, and gas liquid ratio was larger than 100. A lot of data including formation temperatures, fluid pressure and temperature, and physical property changes in the formation were obtained. The data taken are under studies to verify applicability of the depressurization technique as a methane hydrate production technologies.
Decommissioning Costs Can Be Reduced
Authors: Stokes Alan William
Published: June 2014

Decommissioning Costs can be reduced. Many costs are higher than needed due to decisions made during the initial engineering and construction of an offshore oil or gas field. Five years of decommissioning data, throughout the world have been studied. Key areas have been identified where decisions made during design have affected the eventual decommissioning costs. Examples of possible decommissioning cost savings are listed.

Economics for 60, 000 barrels of oil per day oil field show that a reduction in decommissioning costs of 50% can increase the Project Net Present Value by 13%. The five stages of decommissioning an offshore development are described with the cost percentage split for each stage using North Sea data. The major cost drivers of a decommissioning project are stated. For each of the major cost drivers practical examples are given as how the costs could be reduced during design by changing the design. These changes will increase the choices for removal. The scope of the decommissioning studies during conceptual and detailed design are listed. Finally the missing technologies will be listed as experience has shown that cost reduction and safety can be enhanced if new technology could be developed.

The guidance for project design reviews is provided to direct designers and engineers so they can consider decommissioning as part of their work.
Challenges and Solutions of an Ultra-deepwater Dry Tree System for Drilling and Production in the Gulf of Mexico
Authors: Zeng J. , Smith D. , Wu W
Published: June 2014

This paper discusses the key challenges associated with the design of a Dry Tree Semi (DTS) global configuration with robust performance and easy execution, as well as the integration of the topside facilities with hull at quayside. The authors will address the issues associated with a safe wellbay design in order to satisfy all functional requirements of simultaneous drilling and production operations, and compensation of riser stroke. More importantly, the authors will present technically robust and cost-effective solutions to overcome these challenges through extensive engineering assessment, computer simulation, and model test verification.

The authors focus on improving functional and operational safety of the DTS system while minimizing project execution risks. Through innovative design, engineering analysis, and model test verification of the DTS system, important and valuable results will be presented in this paper, which include overcoming various conflicting issues associated with wellbay arrangement and functional performance under simultaneous drilling and production operations; compensating for the most challenging issue of riser performance on a DTS utilizing long stroke riser tensioner technology; and deriving a hull-mooring-riser global configuration that not only carries robust performance during operation, but also offers the benefits during project execution.
MWCC's Expanded System: Enhancing Well Containment in the U.S. Gulf of Mexico
Authors: Massey Marty
Published: June 2014

This paper will include a technical overview and progress update on Marine Well Containment Company's (MWCC) expanded containment system (ECS), which is being constructed to further enhance industry's containment capabilities in the deepwater U.S. Gulf of Mexico. In support of that mission, MWCC established two shore base locations in strategic Gulf Coast communities that will house, test and maintain the ECS equipment. The shore bases – located in Ingleside, Texas and Theodore, Ala. – provide MWCC with the ability to respond to a well control incident safely and effectively.

Together, the ECS and shore base locations enhance MWCC's deployment capabilities and allow the company to keep pace with its members' needs. The ECS will provide greater containment capacity in deeper water depths and enhance SIMOPS and controls capabilities. The expanded system will be able to cap and flow a well in depths up to 10, 000 feet and has capacity up to 100, 000 barrels of liquid per day (and up to 200 million standard cubic feet per day of gas).

The shore base locations will house topsides processing equipment for modular capture vessels (MCVs) and subsea equipment. The providers were selected because of their ability to meet MWCC's operational and technical requirements, thus creating a unique infrastructure for comprehensive and integrated support that allows MWCC to carry out its mission to be continuously ready to respond.

Construction is underway on the ECS, under the direction of the Marine Well Containment System project team, and delivery of key components to the shore base locations has already begun. The established shore bases signify an important milestone in the delivery of the ECS, which is scheduled for completion in 2014.

The availability of the ECS – which represents an investment of more than $1 billion by MWCC's ten members – demonstrates unprecedented industry collaboration and allows MWCC to keep pace with its members' needs. The ECS, together with the established shore base locations that will house this equipment, will enhance MWCC's ability to respond to a deepwater well control incident in the U.S. Gulf of Mexico.
Enhancing Well Control Through Managed Pressure Drilling
Authors: Gabaldon Oscar , Culen Martin , Brand Pat
Published: June 2014

In addition to enhancing drilling safety and performance, MPD offers new options for well control. Because MPD allows rapid changes in bottom hole pressure, the response to an unwanted influx during MPD operations is not necessarily to shut-in and weight-up. Instead, the required overbalance can be regained dynamically to stop an influx, as well as circulate it from the wellbore. This fundamental difference from conventional drilling allows components of the primary barrier envelope to be used without having to activate secondary well control equipment, as the MPD system is designed to handle influxes to a maximum size. Most commonly in MPD operations, this can be achieved by closing an MPD choke, while circulation is maintained. The advent of dual gradient drilling offers further variation in dynamic well control practices.

MPD is a deviation from traditional drilling practices and the technique is relatively new to industry. MPD systems are designed to detect and control influxes of a certain size, however, many MPD operations revert quickly to conventional shut in procedures when confronted with an influx regardless of the size. Effectively, all influxes are treated as kicks.

Inconsistent definitions and misunderstandings of MPD systems' equipment and capabilities amplify the problem of determining when dynamic operations are appropriate. The switch from influx management with the MPD system to conventional well control is governed procedurally through the definition of operational decision points based on influx indicators and surface backpressure during drilling. Quantification of manageable influx size is not standard. The onus is on the operator to define these decision points such that influxes are safely managed by the MPD system, while the rig handles kicks. Further, the use of MPD equipment can also be used to limit the resultant size of an influx that has become a kick, demonstrating that MPD equipment can ultimately enhance drilling safety, in most cases.

In this paper, differentiation between appropriate MPD operations using the primary and secondary barrier envelopes is proposed. The work explores the key factors that must be considered in determining when the appropriate initial response to any influx is dynamic or conventional. A common understanding throughout industry of the safety related aspects of MPD may lead to the use of such systems on every rig, defining the new normal.
A Gyroscope Guidance Sensor for Ultra-Deepwater Applications
Authors: Richardson D. A.
Published: June 2014

The Laserlith team designed an inertial guidance system for ultra-deepwater drilling. The system was based on micro-electro-mechanical systems (MEMS) gyroscope technology; with a demonstrated gyroscope mechanical sensor design integrated with robust readout circuits that can operate in the down-hole environment, i.e., high temperature and high vibration/shock. MEMS gyroscopes enable this inertial guidance system to be positioned next to the drill bit, which is a significant improvement over existing magnetometer guidance systems that must be installed 50 to 80 feet behind the drill bit. The shortened reaction reduces drilling time and drilling cost. The system could potentially enable a greater volume of the reservoir to be accessed from a single surface location, decreasing costs and environmental impact.

The three main components to the work included high temperature circuit design, optimization of the MEMS sensing element, assembly and test.

The successful development of this technology can substantially reduce response time of drilling measurements by providing the ability to install the inertial sensor next to the drill bit. Improved accuracy and reduced drilling time accelerates the rate of commercial production, as well as exploration in emerging plays. A MEMS gyro can significantly reduce drilling time for casing window cutting applications, intermediate radius re-entry applications and steering applications.
Subsea Well Response Project enhances international well incident intervention capabilities
Authors: Lewis Keith , Kaczmarski Andrzej , Lowery Rock , Stanga Heather , Kallaway Kris
Published: June 2014

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 a summary of the key results from the Project, including the research and technological advancements that will benefit the whole industry.

SWRP has undertaken extensive studies into existing technologies and capabilities and the availability of components already stored around the world, in order to design a well intervention toolbox, including capping and dispersant injection capabilities that can be used in different offshore regions around the world. The first elements of this integrated intervention system are now available to the industry, including four subsea capping stack systems and two subsea incident response toolkits for debris clearing and the subsea application of dispersant.

Furthermore, SWRP developed a concept for a subsea well containment solution which relies extensively on existing drilling rigs and commercially-available well-testing equipment to capture fluids from an incident well and flow them to the surface for processing and disposal (in the unlikely event of a well capping operation being unable to completely stop uncontrolled flow of hydrocarbons to the sea).

Based on this concept, SWRP carried out further engineering and modelling studies to develop a technically feasible subsea well containment template system. This template system consists of a combination of (i) items of long-lead equipment referred to as the containment toolkit, and (ii) existing capture vessels and various items of industry standard well testing equipment.

SWRP is collaborating with Oil Spill Response Limited to make this advanced capping, dispersant and containment equipment available to the wider industry, on a commercial basis.

The subsea well owners/operators will benefit from planning in advance in order to prepare appropriate contingency response plans for a well control incident and potential emergency deployment of the integrated subsea well intervention system.
Ultra Deepwater Reel and Flexible Pipelay Vessel for Pre-Salt Field Developments
Authors: Christiani Erik
Published: June 2014

Reeled & flexible pipelay has normally been utilized in fully developed and matured offshore oil and gas field areas with close proximity to onshore support, onshore logistics and short offshore transit distances to onshore spoolbases for loading the pipeline stalks or flexibles onto the reels. This is normally an activity that requires comprehensive planning both onshore and offshore and is often on the critical path of the overall pipelay campaign.

New discoveries in remote locations such as the Gulf of Mexico deep water field developments often have long transit times from established spoolbases and port facilities, hence rendering certain reeled-lay scenarios uneconomical. This paper will discuss the advantage of the next generation of pipelay vessel suitable for remote offshore locations in hostile environment. This new generation of multi-lay vessels utilizes portable reels to eliminate critical path activities at the spool-base, which often causes delays and other problems. In addition to this, these vessels, when configured correctly, allow installation of in-line structures conveniently and safely together with integrated touch down monitoring. As a bi-product or complement to the portable reels, these vessels also feature significant offshore lifting capabilities, which further enhance their flexibility as a full field development vessel. In addition flexible and umbilical products can be combined with-in the pipelay vessel on the vertical reels or the carousels with-in the pipelay vessel hull, i.e. avoiding multiple vessel mobilizations for a reeled and flexible pipelay campaign.

Traditional deepwater pipelay vessel types will be compared to the multipurpose reeled and flexible lay vessel with and without onshore facilities and logistical infrastructure support close by. This will validate the robustness of installing deepwater pipelines and flexibles in remote locations using this new type of reeled pipelay vessel.
ECD Management Toolbox for Floating Drilling Units
Authors: Godhavn John-Morten , Hauge Espen , Molde Dag Ove , Kjøsnes Ivar , Gaassand Sturle , Fossli Statoil Børre , Stave Roger
Published: June 2014

This paper presents ongoing work as well as plans and ideas for future development of a toolbox of managed pressure drilling systems that solves major challenges when drilling in both mid- and deep waters. The toolbox contains three applications based on field proven Controlled Mud Level (CML) technology. Additional benefits can be achieved by combining controlled mud level technology with other technology elements such as a fast closing annular or a sealing element in the riser, usually referred to as a rotating control device (RCD).

The first application is called CML. A subsea pump module (SPM) is used to pump the mud returns to surface in a separate mud return line (MRL). The SPM is used to regulate and manage the bottomhole pressure by adjusting the mud level in the riser. High bottomhole pressure or Equivalent Circulating Density (ECD) due to friction and other effects can be avoided by reducing the mud level in the riser accordingly. One of the objectives with this technology is to avoid or reduce losses both during drilling and other operations such as cementing.

In the second application called ECD-Management, CML is combined with a fast closing annular installed in the riser just above the SPM. This enables extending the operating envelope of the technology to a point where loss of circulating capability could potentially cause an underbalance scenario in the well. The hydrostatic pressure from the drill string or MRL can be trapped within a few seconds by closing the fast closing annular element, e.g. on unplanned rig pump stops or formation pack off situations. A second annular will also be installed to be used during connections in order to save time filling up the riser to compensate for the ECD effect (friction losses in the annulus).

The third application in the toolbox is called ECD-Control. Here a subsea RCD or a sealing element is installed in the riser and the SPM can then be used to manipulate the pressure below the RCD to compensate for ECD variations. The riser is always topped up with mud and hydrostatic overbalance is maintained.

The paper will present simulation results comparing the different technologies and address benefits and challenges with the different methods.
Assessment of Ultra Deepwater Riser Concepts for High-Motion Vessels
Authors: Royer Brian S. , Power Thomas L. , Ayewah Daniel O. , Head William
Published: June 2014

The paper presents the results of the second half of a study funded by Research Partnership to Secure Energy for America (RPSEA) under project 10121-4401-02 Ultra-Deepwater Riser Concepts for High Motion Vessels. In the first half of the study, candidate riser systems consisting of alternatives to the steel catenary riser in both geometry – for the purpose of isolating the fatigue-critical riser touchdown zone from the motions of the vessel – and material were identified then down-selected to meet the constraints of high motion vessels like the conventional semi-submersible or a ship-shape floating, production, storage, and offloading vessel (FPSO). In addition to water depths approaching 10,000 feet, the present-day challenges of high pressure, high temperature, and sour well product are incorporated into the problem being framed.

Results from dynamic analyses of riser concepts passing through the down-selection process are used to assess both utilization of strength capacity and fatigue performance. Comparisons of dynamic responses highlight the differences of each riser concept's behavior and provide understanding of the limitations of riser concepts. Assessments to other criteria such as cost, failure modes, and installation considerations are also used to ascertain safe riser systems that meet the performance demand of high-motion vessels.
Subsea Compact Separation: Control System Design
Authors: Li Z. , Olson M. , Rayachoti V. , Gupte P. , Pierre F. , Gul K.
Published: June 2014

This paper summarizes key results of the development and verification for a subsea compact separation control system based upon a literature review, control system design, dynamic simulations, and an integrated system test. The compact separation system being considered is designed for applications in water depths up to 3,000m. The control system is a key technology element of the compact separation system, and its satisfactory performance is critical to ensure stable operation of the overall system. A thorough literature review was conducted to evaluate the control system designs for comparable subsea separation systems in industry, to understand the technical challenges, and to incorporate the key learnings into the development of this control system design.

From this work, best practices were identified and were used as guidelines. A preliminary control system was developed, and the robustness of its design was assessed through dynamic simulations. Later, an integrated system test was performed with real crude and methane at realistic operating conditions to evaluate the performance of the compact separation equipment and to validate the model of the control system. The dynamic simulations and integrated system test results demonstrated the control system response following transient events, such as slugging, and provided insight into the system dynamics that then led to further modifications of the control system design and enhanced the overall system performance.

This paper also delineates challenges associated with the design of a control system for a subsea compact separation system consisting of multiple, closely integrated gas-liquid and oil-water separation units. For example, the relatively small control volumes in compact separation equipment and the interaction between the different components can both add complexity to the control system design. Lessons learned from the modeling and implementation of such a sophisticated control system are discussed with the intent to serve as a reference for future subsea separation projects in the oil and gas industry.