bluuebunny/crossref_metadata_2025 huggingface dataset:
Design of a Dry Completion Monocolumn Platform Unit Using Optimization Techniques
Authors: Oliveira Allan Carre De
Published: June 2014

Offshore production in ultra deep water may present several technical challenges. New exploration frontiers, sometimes, could provide a very complex scenario for oil production, considering very far fields from the shore, very harsh environmental conditions and the necessity of well intervention, to maximize the recovering factor of the field. Scenarios like that demands functional requirements for production units which can be very hard to achieve considering conventional Production Units.

The MPSO (Monocolumn Production Storage and Offloading) Unit concept has been being developed in recent years to combine small motion requirements and high stability with or without oil storage capability, with good results for oil production scenarios. However, the use of this type of Unit as a drilling Unit or for a dry tree completion scenario becomes a challenge in harsh environmental conditions, due to the very strict constrains required regarding motions and offsets of the unit.

In order to obtain a Monocolumn design with dry completion capability, considering the Brazilian shore pre-salt scenario, an optimization process was set up, evaluating thousands of different configurations considering motion and stability requirements. Mooring analyses were also performed to guarantee a small offset and a small set-down of the unit. As a result, a different platform design was obtained, with very small motions and dry completion capability.

Introduction

For some scenarios considering pre-salt reservoirs, which are located in Santos Basin, in deep water productions fields, the use of dry completion Units could bring some economical advantages, as saving in rigging costs and rigging maintenance, a greater recovering factor of the oil fields and an improved capability of workover of the production wells. In 2008, Petrobras has performed assessments of different types of dry tree unit production platforms, as SPAR and TLP platforms. Besides that, a Monocolumn dry tree production platform concept was already designed for operations in those scenarios.

The Monocolun concept has been being developed for different companies, including Petrobras, which has your own concept, called MonoBR (Masetti et al, 2006), developed in partnership with the São Paulo University, as shown in Figure 1. Besides the Petrobras concept, there are alternative concepts developed by other companies as well (Syvertsen et al, 2004), (Orr et al, 2009). The main idea of the MonoBR was originally designed to be riser friendly considering Steel Catenary Riser subsea systems an the concept combines low motion levels with storage capability and great stability, which are concurrent requirements, in general. To achieve this objective, in general, it is necessary a huge Unit, deep draft and the Use of huge appendages to create vortex damping and added mass effects.
Flexible Subsea Storage Unit Development and Applications
Authors: Kaalstad Jens P. , Kristoffersen Astrid
Published: June 2014

The paper describe the KONGSBERG patented Subsea Storage Unit (SSU) technology and the ongoing Qualification Program. The SSU is characterized by using a flexible bag as oil / fluid storage. It's a gravity based storage unit that differ from conventional gravity storage systems by the flexible bag, which eliminates contact between sea-water and the stored fluid, thus eliminating the problems with emulsion layer and risk of bacteria growth. The bag is further covered by a protection structure, which accommodate the whole volume of the stored fluid thereby providing a second barrier should the bag rupture. There is free flow of seawater into the base of the protection structure and hence no needs to design against the water pressure. The top of the protection structure is designed such that the bag may be retracted separately from the storage tank if necessary for repair or replacement. Different fields would have variable storage needs and the ability to size, combine and manifold multiple SSU's provides attractive flexibility. The number of SSU's could also be varied over the field life and the paper present how the SSU is an enhancer for subsea processing and production in arctic areas and also how it may commercialize development of marginal oil field or tail end production.
Quantile Regression - A Statisticians Approach to the Local Ice Pressure-Area Relationship
Authors: Morrison Tom , Spencer Paul
Published: June 2014

The ISO 19906 local pressure-area relationship represents a deterministic estimate of the failure pressure of massive ice features. For areas < 10 m2 the pressure is represented as a power law on area. For areas between 10 and 40 m2 the pressure has a constant value. In the past, in order to fit the power law, the data were binned and means and standard deviations for each bin were determined. The deterministic value of the local ice failure pressure is the relationship obtained by fitting a line to the values of mean plus three standard deviations so obtained. This implies the probability a local ice pressure exceeds the deterministic relationship is 0.13%, treating the deterministic value as a one-sided upper bound. It is shown herein that a quantitative, repeatable and non-subjective statistical methodology called quantile regression can be applied to this data. Using a nonlinear quantile regression methodology the deterministic relationship can be estimated in one step without the requirement for binning or transformation. Furthermore, the method produces quantile lines for a wide range of quantiles. The nonlinear quantile regression analysis of the local pressure area relationship, fitted to a power law, indicate the deterministic ISO relationship is in fact equivalent to an exceedance of 5% for areas greater than 2 and less than 10 m2. For areas of less than 2 m2 the ISO relationship exceedance decreases from 5% at 2 m2 to less than 1% for areas less than 0.3 m2.

The purpose of this paper is to introduce this powerful technique to the ice science and ice engineering communities using the local ice pressure data as an example.
The Role of RADARSAT-2 SAR Data for Ice Seismic Operations
Authors: Staples Gordon , Pierce Ray , Rabus Bernhard
Published: June 2014

In conducting ice-seismic, geophysical ships and icebreakers routinely operate in rigorous ice regimes. As the progress of the geophysical ship must be continuous and without error, operations must be supported with high levels of ice information. Ice-seismic follows a predetermined route where one of the key requirements is to assess and execute a plan to adhere to pre-determined survey parameters. To meet operational requirements for ice-seismic, there are three key elements: ice information, data delivery, and data management. Products have been developed that provide ice information such as ice-water delineation and ice strain. To deal with data delivery bandwidth-constraints data compression was required. For ease of implementation and multi-platform compatibility, a commercial off-the-shelf compression technique was selected and integrated into an automated production chain. A data management system was developed for management of the georeferenced data onboard the ships and the translation of the data into sound operational decisions.
Steel/Concrete Composite Ice Walls for Arctic Offshore Structures
Authors: Wernli Markus , Hjorteset Kare , LaNier Michael W.
Published: June 2014

The oil and gas industry is considering deploying large gravity-based structures (GBS) into the high Arctic seas for year-round production where they will be exposed to multiyear ice loads. Conceptual studies of such structures suggest that the design for the ice load and the low draft requirement during deployment to the Arctic become key design aspects, focusing the attention on force-resisting strategies and ice wall design. A well-designed ice wall in combination with a well-thought-out ice resistance strategy can significantly reduce the cost and construction/installation schedule of a GBS. Ice walls made of steel/concrete/steel composite have the potential to provide significant robustness at a lower weight than typical all-concrete ice walls. Composite ice walls also provide the potential of more robust behavior than all-steel ice wall concepts. Composite walls, thus, promise great value as ice walls for Arctic structures. To validate composite ice walls, a testing program was conducted that applied high-intensity loads to beam specimens 1.8 meters long and 0.3 meter thick with varying degrees of plate stiffening and concrete confinement. Strength, stiffness, ductility, load paths, and failure mechanisms were evaluated. Test variables included temperature, concrete density and strength, load paths, and type of composite load-carrying system. The paper demonstrates the viability of composite ice walls. It presents the results of the testing program, discusses the proposed ice wall configuration and appropriate design procedures, and proposes the steps that have to be taken before composite ice walls can be applied for design and construction of an actual GBS.
Conical Structures in Ice: The Roles Friction, Slope and Shape Play
Authors: Barker Anne , Sudom Denise , Sayed Mohamed
Published: June 2014

Conical structures are often used to ameliorate the action of floating ice. There is a long history of using cone-shaped bridge piers. Moreover, many recent designs adopt downward-breaking cones to further reduce ice forces. The present work aims to clarify aspects of ice interaction with cones that are poorly understood. This work builds on a previous study that employed a numerical model of ice dynamics in order to predict ice failure patterns and forces on a conical structure. Performance of the model was validated against available ice basin tests, and the study examined a test case representing a pier of the Confederation Bridge, Canada. The present tests examine the roles of ice-structure friction and shape of the cone (upward- or downward-breaking) in more detail. Additionally, the effects of ice thickness and embedded consolidated ridges are examined. The results reveal trends of the dependence of the modes of ice failure and the resulting forces on ice-structure friction, slope and the type of the cone (upward- or downward-breaking). For upward-breaking cones, ice-structure friction proved to be more significant for gentler slopes than for steeper ones. For those cones, ice failure appeared to correspond to three-dimensional buckling. Downward-breaking cones displayed a different behavior with downwards bending failure. The value of the ice-structure friction coefficient had a clear influence on the forces for all downward-breaking cases. The results also support the idea that downward-breaking cones correspond to lower horizontal forces than those acting on upward-breaking cones. Concerning ice sheet thickness, peak horizontal ice forces show a near linear dependence on the thickness. For large consolidated ridges, forces increased substantially. The numerical model results are compared with the elastic beam bending approach given in the ISO 19906 Arctic Offshore Structures Standard for ice loading on a sloped structure. In order to use the equations in ISO 19906, assumptions must be made on the maximum accumulated rubble height and other parameters, which affect the calculated load. The peak loads from the model and ISO approach are similar for level ice interactions, although the ISO approach is more sensitive to ice-structure friction. Also, the ISO approach may overestimate the load generated by some ridge geometries.
Temperature Modeling Used to Change Freeze Protection Procedures in North Slope Disposal Wells
Authors: Nofziger Laura , di Lullo Alberto , Hester Keith C.
Published: June 2014

In two disposal wells on the North Slope operating field of Nikaitchuq, diesel was deployed before each brief shut-in period in order to prevent the formation of ice in the tubing due to the presence of water-based fluids.

A temperature model was built to determine if the use of diesel as a freeze protection fluid could substituted with an available briny waste water stream. In particular, the model was used to determine how long the waste water fluid would provide freeze protection with respect to the operational requirements. The temperature model was also checked against the data acquired by distributed temperature sensing fiber optic technology deployed in similar wells of the same field.

The paper will review the model, the temperature data retrieved from an injection well in the same field using DTS technology and discuss the cost benefit deriving from the avoidance of the diesel batches formerly used for freeze prevention.
The Sensitivity of Ice Keel Statistics to Upward Looking Sonar Ice Draft Processing Methods
Authors: Ross E. , Fissel D. , Mudge T. , Kanwar A. , Sadowy D. , Ekeberg Ole-Christian
Published: June 2014

Upward looking sonar (ULS) instruments have been used for several decades to provide continuous measurements of ice draft. The time resolution of the ice draft observations is typically 1–2 seconds. When fused with ice drift speed observations, a high horizontal spatial resolution can be realized. Such a high resolution allows for the identification of individual ice keel features and an analysis of their spatial characteristics. Many methods are available for transforming the ice draft series from an equispaced time domain to an equidistant spatial domain. This paper analyzed the sensitivity of ice keel statistics to three transformation methods applied to ULS sea ice measurements in the Beaufort Sea and North Chukchi Sea. Although differences were found between the methods, these were related to episodes when the sampling frequency is not high enough to profile an ice draft feature travelling with a high drift speed. Knowledge of maximum drift speeds in the region of a measurement location along with the enhanced power and storage capacities of modern ice profilers enable sampling configurations which avoid this scenario.
GPU-Event-Mechanics Evaluation of Ice Impact Load Statistics
Authors: Daley Claude , Alawneh Shadi , Peters Dennis , Colbourne Bruce
Published: June 2014

The paper explores the use of a GPU-Event-Mechanics (GEM) simulation to assess local ice loads on a vessel operating in pack ice. The methodology uses an event mechanics concept implemented using massively parallel programming on a GPU enabled workstation. The simulation domain contains hundreds of discrete and interacting ice floes. A simple vessel is modeled as it navigates through the domain. Each ship-ice collision is modeled, as is every ice-ice contact. Each ship-ice collision event is logged, along with all relevant ice and ship data. Thousands of collisions are logged as the vessel transits many tens of kilometers of ice pack. The GEM methodology allows the simulations to be performed much faster than real time. The resulting impact load statistics are qualitatively evaluated and compared to published field data. The analysis provides insight into the nature of loads in pack ice. The work is part of a large research project at Memorial University called STePS2 (Sustainable Technology for Polar Ships and Structures).
Cable and Pipeline Detection Methods for the Arctic Environment
Authors: Nash Jim
Published: June 2014

This paper describes the application of new proprietary methods for the detection and location of submerged power cables and pipelines that can be applied in Arctic and subarctic regions, as well as beneath unfrozen ground. The methodology and results of the technology are presented. It demonstrates the proven use to locate and position these assets horizontally and at depth. Originally developed for power cable detection and precise positioning of assets located in the Gulf of Mexico, the technology penetrates ice in the same manner as water, while also working successfully on land.

Introduction

The precise location of assets such as cables and pipelines is critical to safety, reducing environmental impact, maintaining compliance with various agencies, and reducing risk. Conventional methods, such as probing, diving, jetting, and access by environmentally intrusive vehicles, may not be practical or possible in the arctic environment. TerraSond's proprietary system can be towed by a vessel, or operated on land or ice by an individual surveyor.
The Question of Ice Management and Some Associated Realities
Authors: Browne R. , Wright B. , Connelly D.
Published: June 2014

Over the past few years, questions surrounding the ice management topic area have become of higher priority for many oil companies who are interested in the Arctic offshore. A key impetus stems from the fact that many of the new Arctic offshore areas of interest lie in moderate to deeper waters, where floating drilling and production operations will be required. In keeping with this "priority theme", an ice management working group has recently been formed under the auspices of the current ISO/TC67/SC8 initiative. The objective is to build upon the foundation of Ice Management Standards included in the Arctic Offshore Structures – International Standard ISO/DIS 19906, to include several identified subject areas and develop a philosophy and logic, covering all potential ice management scenarios, leading to effective, efficient and safe ice management operations.

The work will benefit from the tremendous experience base with real-life ice management activities in the Canadian Beaufort Sea, on Canada's East Coast, offshore Sakhalin Island, in the Caspian Sea and off West Greenland in recent years.
Unmanned Aircraft Systems in Alaskan Civil Research
Authors: Cunningham Keith , Hatfield Michael , Philemonoff Ron
Published: June 2014

In Alaska, unmanned aircraft systems (UAS) have garnered much attention, largely due to ongoing research at the University of Alaska Fairbanks (UAF). This research has focused on a multitude of civilian applications suitable for support by the technology. UAF has long held an advantage in this competitive research by virtue of its status as a non-profit research institution, a requirement for approval by the Federal Aviation Administration (FAA) to operate UAS. In addition, UAF has a long history in this field, managing airspace since the 1960's as part of its duties as the only university-operated rocket range in the world. These factors have led many commercial entities to partner with UAF to conduct UAS research over the years.
A Fresh Look at Pipeline and Riser Bundles: Combined Experience and Practice
Authors: Seguin B. , Goodlad M.
Published: June 2014

The paper presents the synergies between two proven Bundle systems:Pipeline Bundles and Riser Bundles, based on extensive track records: 70 Pipeline Bundles over 35 years and 6 Riser Bundles over 15 years.

Despite the two Bundle systems being developed independently, the synergies between the design requirements, the components and the towing requirements are remarkable. This shows that despite the different applications the technology has been developed with the same technical understanding and demonstrates how the merging of different technologies can bring benefits to the industry.

The paper includes a general description of the two Bundle systems, including fabrication and installation methods. A review of the similarities and differences between the two systems is presented.

The benefits of synergies are discussed, based on practical examples of new developments:–Design: Pipeline Bundle design adapted to Riser Bundle for enhanced thermal insulation performances and bundle section simplification.–Fabrication: feasibility of fabrication and launching of a Riser Bundle from a Pipeline Bundle fabrication site (Wester Site, Scotland).–Installation: development of methods for installation of Pipeline Bundles in deepwater and long-distance towing of Riser Bundle in shallow waters.

The synergies discussed in the paper result in enhanced capabilities for Bundle systems, including: improved system operating performance, increased systems applicability extent (allowing development in deeper waters and new areas). These systems can thus be considered for new geographical areas.
An Innovative Approach of Revival for Damaged Wells in High Erosive Environment Using Ceramic Sand Screens
Authors: Gaurav Kumar , Nadeem Asaf , Megorden Mike , Ivanova Svetlana , Wheeler Josephine , Sultan Shreen
Published: June 2014

Oil and gas companies struggle with high rate wells failing due to down hole sand screen failure. If those wells are completed with a dry tree there is an opportunity for revival by installing a robust and durable sand preventive system using ceramic sand screens. These work-over jobs can be made cost effective by using wire line / coil tubing, avoiding high costs and lead time associated with rig-operation. This paper is the first documented work on a through tubing intervention plan for a high rate gas well with ceramic sand screens.

One of the biggest challenges is incorporating ceramic sand screen in wells where existing sand prevention has already failed. These cases not only require specific ceramic screen design but are also limited by the existing completion profiles and status of the damaged well. The workover operation is challenged by effectiveness of the well cleaning and the installation of ceramic screen to ensure a safe return on investment.

This paper details the plan for the revival of a high rate gas well with a currently damaged screen due to erosion. The study incorporates the selection of screen length, size of screen slots, support assemblies and installation sequence for an actual field case. A detailed sensitivity analysis was carried out to optimize well production in different reservoir conditions and results were utilized to construct the bottom hole assembly. The ceramic sand screen size was selected after series of retention tests and it was compared with the performance of metallic screens to ensure safe differential pressure and flow profile across the screen.

In conclusion this paper documents an innovative approach for workover operations in highly erosive environment using ceramic sand screens. The design procedure presented coupled with sensitivity analysis provided a long term, cost effective revival of damaged wells.
Active Heating for Life of Field Flow Assurance
Authors: McDermott Paul , Sathananthan Ratnam
Published: June 2014

Development of thermal management strategies in the design of subsea oil and gas production systems is critical for prevention of solids deposition such as hydrates and wax formation during turndown and shutdown scenarios. Passive insulation provides no control of fluid temperature and forces the operator to depressurise the pipeline following a shutdown and ‘no touch’ period i.e. time after which the fluid falls below the hydrate temperature. For deep water and ultra-deep water applications this approach would be ineffective as the large riser static head would prevent the pipeline pressure being reduced below the hydrate formation pressure. In these cases there is a requirement for active heating or dead oil flushing.

Active heating provides the capability to monitor and control the fluid temperature during start up, shutdown and turndown operations. Several electric and hot fluid circulation active heating systems are in operation as part of bundle or pipe in pipe systems.

This paper will review current active heating system designs in pipe-in-pipe (PiP) and bundle systems. In light of recent projects that have employed hot fluid circulation systems, the flow assurance challenges and subsequent design to ensure complete system functionality across the life of field will also be discussed.
New Technology Application for Fast Recovery of a Typhoon Damaged oil Field in South China Sea
Authors: Jiayou Mao , Yiyong Liu , Zuan Yue
Published: June 2014

Huizhou oil field is located at the Pearl River Mouth in South China Sea. Water depth 117m. The oil field main facilities include 8 fixed jacket platforms, two subsea production well heads and one FPSO "NANHAI FAXIAN". The peak production is around 70,000BPD of crude oil. In September 2009, after strong typhoon "Ju Jue", the FPSO permanent mooring was broken. The production was shutdown. In order to resume the production in a fast track manner, several engineering cased were studied and screened. Finally, the DP FPSO concept was adopted. After 5 months offshore operations, the field was back to production. The DP FPSO system operated for over 18months and proved safe and effective. This is a world record for FPSO operate in DP mode for such a long time.
Deepwater Development Strategy
Authors: Dekker Martijn , Reid David
Published: June 2014

The risks and uncertainties related to deepwater oil and gas reservoirs, development concepts, lifecycle reservoir management and ultimate production continue to increase substantially as the oil and gas industry pushes into deeper water, more complex environments and frontier unproduced plays/areas. Given the technical and non-technical risks related to these developments, it is more important than ever to integrate and align stakeholder expectations and the view of project risks by agreeing on the overall field development strategy early in the project maturation cycle.

This paper details the importance of defining early in the project maturation process the overall field development strategy which encompasses project phasing, the reservoir development approach and the application/deployment of new technology. A framework is proposed as a starting point in setting the development strategy based on both project complexity and overall schedule drivers.
Effects of Fiber Rope – Seabed Contact on Subsequent Rope Integrity
Authors: Ayers Ray R. , Del Vecchio Cesar J. , Devlin Paul V. , Head William J.
Published: June 2014

A 15-month research project was initiated in September 2012, funded by the Research Partnership to Secure Energy for America (RPSEA) and industry partners, with the goal of investigating the effects of polyester mooring rope segments contacting the seafloor prior to installation as part of a deep-water mooring system. It is possible for some soil particles to bypass the particle filter, become embedded in the rope core, and intensify normal fretting wear damage as the installed ropes respond to the cyclic loads resulting from extreme weather forces (such as hurricanes).

Potential soil ingress into rope due to accidental contact with the seabed may affect the long-term integrity of the mooring system and increase the risk for failure. This situation, in turn, places nearby subsea and surface infrastructure at risk. This investigation may also provide the ability to qualify particular rope designs for pre-installation on the seabed prior to hook-up. This option would greatly reduce overall risk by reducing the time required to attach mooring lines to a floating facility, thereby reducing time to reach a safely moored condition before arrival of severe weather.

This paper is a 2014 continuation of the 2013 OTC paper on the same subject, OTC 24027, and describes:results from extraction of subropes from seabed-soiled full rope 15-meter inserts,laboratory experiments on water and soil particle ingression and migration, andthe initial full-scale subrope cyclic wear testing to determine the impact of seabed soil contact on the long-term performance of a mooring system.

In summary, all of the experimentation and testing performed to date are showing that with multiple layers of filtering material and with the one alternative filtering system we evaluated, the tentative conclusion is that the rope designs tested can completely protect the mooring ropes from soil ingression, and thus there is no reason to avoid having such ropes drop to the seafloor or be laid on the Gulf of Mexico seafloor. This tentative result assists in working toward the important project goal of reaching agreement between industry participants and U.S. regulatory agencies to qualify polyester mooring ropes for incidental seabed contact and seabed pre-installation.
Extending Wealth Creation Through Effective Project Management Strategy In The Oil And Gas Industry
Authors: Ibe Prince Ikenna
Published: June 2014

This treatise is created to expose the opportunities that abound in the oil and gas industry. Have you ever faced a situation where a project owner shows little or no interest in the success of the project involving large scale amount of resources? Imagine a project engineer in a large oil and gas organization working twenty years on several projects having only one regret – that he cannot recall any one project that was successfully concluded with good return on investment (ROI). The phrase "failed project" is nothing new to the engineer who is deflated having nothing to boast about on leaving the establishment. This paper provides insight on the root cause of these colossal waste in resources and directs the world's focus on how reducing these losses can result in the creation of wealth for not only the establishment but for numerous suppliers, original equipment manufacturers (OEMs) and governments. The paper presents a solution based upon the enforcement of appropriate project management methodologies.

This paper applies primarily to government owned oil and gas establishments in developing nations. However the effect of the wealth creation will benefit manufacturers and stakeholders the world over.

Companies adopt different facets of project management strategies. The intent ranges from compliance to standards and regulations to being regarded as world class organizations. Some corporations even have an established Project Management Office. Regrettably, the top management may just be keeping the company running without appreciable growth. This paper aims at rekindling the desire for excellence and call for patriotic evaluation of intents and desires thereby reducing wastage of funds and other resources in the oil and gas industry.

Due to "failed projects", OEMs are blacklisted by organizations. New OEMs and service companies are then engaged only to be also blacklisted when the projects do not produce the right results even when the faults are not from the OEMs or service companies. This paper will bring to light the actual causes of failed projects and attempt to exonerate the OEMs and service companies while providing the right platform for achieving ROI on every project undertaken.
Pressure balanced Telescopic Riser Safety Joint
Authors: Tømmermo Bernt-Olav , Tandberg Geir , Carlsen Hans-Paul , Carlsen Tor-Øystein , Muff David Anthony , Løvland Arne Thor , Orekåsa Ronny , Sundkvist Arild , Sørensen Arvid , Lerstang Joakim
Published: June 2014

Safe operation is fundamental and a prerequisite for all subsea well operations including drilling, completion and well intervention. With an intensified demand for well interventions on mature and live wells globally, there is an increased need for improved system and component safety functions. It shall be known which barriers are established and which function they are intended to fulfill. The pressure balanced Telescopic Riser Safety Joint (TSJ) will become a critical safety element within these systems and replace the traditional Weak Link(s). The TSJ can be configured in a drilling- or workover riser system and is designed to increase the safety and operating envelope of well interventions and drilling operations in the case of unintended operational event. There is no overloading due to accidental excessive top tension, while containing well bore fluids, solving the following fundamental risk elements;Protection of well barriersProtection of rig and personnel andProtection of environment.

This newly developed TSJ is the first system which significantly reduces operational risk from severe accidents due to loss of rig station-keeping or top compensator lock-up. The TSJ enables an automatic overload protection system based on the following functions; Tensile bolts with predefined capacity control the activation. In an accidental event, the bolts get overloaded (rupture) and the TSJ starts telescoping while maintain pressure balance. The telescopic length is longer than the rig heave movements to avoid riser separation. The TSJ will also prevent spill to sea after activation. It includes a bore membrane separating clean hydraulic control fluid from dirty bore fluid for pressure compensation. Once the Safety Joint is activated as a result of excessive top tension, it will provide sufficient time to safely shut in the well and perform a controlled riser disconnect. The Safety Joint can be instrumented and included in a Safety Instrumented Systems (SIS). A full scale workover riser prototype has been built and tested to validate the fundamental principles. This paper provides an overview of the development and testing performed on the pressure balanced Telescopic Safety Joint.
Wave Energy Converter (WEC) - Formulation of Numerical Method to Predict Fluid-Structure Interaction and Wave Energy Potential
Authors: Gullaksen Jóannes
Published: June 2014

Cost of energy is a critical factor to the success of Wave Energy Converters (WEC), in order for wave energy converters to compete with other forms of renewable and fossil-fuelled power generation. Essentially, the energy converted into electricity by a WEC is a function of the resource the converter is placed in, the converter's prime mover, and the converter's power take- off system. This is a dynamic system and changes to one aspect can have a significant influence on another.

Kinematics and kinetics are fundamental in fluid-structure interaction and design for optimizing wave energy camture performance, as well as loadings for mooring and structural analysis. The following analysis domains are covered in this paper:physical description of variables affecting wave energy capyure performancethe kinematics of wave energy converter motion, i.e. the geometrical aspects of motion (variables, reference frames and transformations,the kinetics of wave energy converter motion, i.e. the study of the forces acting on the wave energy converter and the motion they produce,combining the wave energy converter kinematics and kinetics to obtain a dynamic model and 5) description of numerical solution method.

The paper presents the mathematical formulation with numerical method which can be used together with laboratory testing of a WEC. The combination of numerical computations and laboratory testing can be used to produce results to predict how the WEC responds to real wave conditions.
Assessing Well Integrity Using Numerical Simulation Of Wellbore Stability During Production In Gas Hydrate Bearing Sediments
Authors: Long Xiaoyan , Tjok Ko Min , Wright Christopher S. , Witthoeft Alan F.
Published: June 2014

Well integrity during hydrocarbon production from an oil or gas well drilled through naturally occurring gas hydrate bearing sediments (HBS) may be problematic due to hydrate dissociation during well production. Assessment of well casing integrity is complicated because of the many variables involved such as:character, distribution and volumetric concentration of gas hydrate habitat;physical characteristics, in-situ stress-strain history along with thermal and engineering properties of the sediments overlying, within and vertically adjacent to hydrate bearing zones;specific design and installation details of the production well(s) including well tubular depths, sizes and the undisturbed formation temperatures;thermal characteristics of the various well components including tubing, casing, packer fluids, cement, anddetails of produced hydrocarbons including production flowrates over time, reservoir pressures over time, duration of production, produced fluid composition over time and well temperature profile during production.

In this paper, assessing well integrity using numerical modeling of wellbore stability in a natural deepwater offshore environment in the face of in-situ gas hydrate dissociation due to heating is performed and described in detail herein. The simulation includes thermodynamic stability analyses of the hydrates, assessment of fracture development and soil movement prediction considering seepage and soil consolidation effects followed by soil-well interaction modeling to determine potential stresses in the well components. Fracture models of crack dimensions are premised on either (1) development of a pattern of laterally expanding horizontal fractures evenly spaced vertically throughout the hydrate-bearing zone and centered on the wells, or (2) development of vertical fractures which will intersect the seafloor to allow gasses from hydrate dissociation to vent into water column.

For this study, hydrate accumulation (character, saturation and distribution) for field development area is interpreted using seismic inversion and rock physics transform along with available geophysics seismic data and offset well log data. Sensitivity analyses with parametric variations of sediments and wells indicate that well design (in terms of insulation) and an increase in soil capacity for fluid flux will have a distinct impact on reduction of soil motions and casing stresses.

With computational efficiency, the numerical simulation can provide bounding estimate of gas hydrate dissociation effects around producing wells. The model is very useful for a sound understanding of key parameters that determine HBS response to hydrocarbon production and the well integrity.
Using Generalized Linear Regression Of Multiple Attributes For Modeling And Prediction The Formation Permeability In Sandstone Reservoir
Authors: Al-Mudhafer Wathiq J.
Published: June 2014

In this paper, we present an efficient flexible algorithm for modeling the formation permeability with respect to other well and core petrophysical properties for a well in sandstone formation in West Africa.

In Generalized Linear Regression, the monotonic link function, glm, has been used to generate the relationship between the core permeability and the explanatory variables such as caliper log (CCL), deep induction log, medium induction log, gamma rays, neutron porosity, core porosity, deep resistivity, medium resistivity, spontaneous potential (SP), density & corrected density, in addition to rock facies.

Meanwhile, the glm function has been adopted for attaining normal distribution for the continuous variables and multinomial distribution for the discrete (rock facies). The link function relates the expected value of the distribution to the predictor variables. Fitting of a GLM model was achieved through optimization of maximum likelihood estimates by an iteratively reweighted least-squares mechanism.

The Root mean square errors (RMSE) is not a sufficient indicator of bias for an estimate because RMSE could be changed due to a change in variance, with no change in bias. Consequently, variance, analysis of deviance, and RMSE have been considered for model comparisons. In GLM results, a significant overall reduction in model deviance with less variance, residual deviance, and RMSE that reflects the reduction in both variance and bias and the validity of the fitted linear model.
Need For Industry Ready Education: Flow Assurance Course - A Case Study
Authors: Kondapi Phaneendra
Published: June 2014

Subsea developments continue to escalate in quantity and complexity as the exploration and production companies ramp up exploration of deepwater and ultra-deepwater reservoirs with complex formations in harsh environments with increased challenges. Overcoming these challenges is the job of subsea engineers. Hence there is an immediate need to train and enhance their skills through practical education to enable them to manage and take ownership responsibility of these larger and complex fields at greater depths. In this "Great Crew Change" phase, the subsea industry is looking for people who are not just bright and smart but also be able to do productive work right away the moment they are hired. The challenges and expectations of both the subsea industry and academia are very high in terms of knowledge. So, in this highly competitive world, the need for practical subsea engineering knowledge at the college level is very much increasing in order to prepare the next generation of technical professionals.

In order to meet the subsea challenges and industry needs a new and effective course has been developed to teach flow assurance at University of Houston, the first three credit-hour university level industry-ready course in the US that has been designed to meet direct subsea applications with academic standards. The motivation of this course is to make students acquire the ideas and solution strategies necessary to figure out an industry problem in a classroom setting and hence train the prospective subsea engineers for work in industry by successfully learning the concepts. The flow assurance course provides an understanding of multiphase flow fluid dynamics and analyses, overview of flow assurance and the fundamentals of flow management for subsea production systems. The course benefits include an understanding of basic sciences, engineering and flow assurance principles, as well as their application in the assessment, prevention, mitigation and remediation of flow assurance issues encountered in deepwater subsea systems using state of the art prediction tools.
Live Well Display & Automated Data Analysis To Improve Timely Well Control & Drilling Optimization Decision-Making In MPD Operations
Authors: Gumus Ferhat , Pobedinski Ilia , Hannegan Don , Valiullin Khaydar , Simpkins Douglas R.
Published: June 2014

A state-of-the-art MPD system should have not only highly accurate sensors measuring critical mud flow data and PLC automated chokes to precisely maintain desired annular pressure, but also the ability to aggregate, analyze and display this real-time information on monitors on the rig floor and in remotely located centers. In the past, this flow monitoring and detection capability that was primarily based on mass flow balance has helped safe and effective drilling of complex wells through early identification and interpretation of critical events such as kicks vs. ballooning and has enabled the safe drilling of prospects deemed un-drillable using conventional technology.

This paper describes a number of enhancements including the system's ability to display and analyze not only the critical parameters of drilling hydraulics, but also other information that allows looking at the totality of the closed-loop system from different perspectives. It provides just-in-time engineering that improves the decision making process in time sensitive scenarios by increasing awareness and decreasing reaction time. It does this by utilizing a user friendly "live well display". The real-time MPD automation software platform that has been developed allows the conducting of advanced well hydraulics and drilling dynamics simulations, providing engineering calculation tools and customizable plug-in controls for multiple hardware components.

By employing real-time models such as hydraulic, well control, swab-surge and T&D, the system displays information from different perspectives and aids in understanding what are the real limits during a drilling operation. The expandable database structure allows capturing more valuable data while continuity of data streams is secured with implementation of "heart beat" technology. The ability to control not only chokes but multiple components such as RCD, PRV, remote valves etc. provides further automation possibilities and minimizes the possibility of human errors. Finally, putting engineering and operational analysis, real time drilling process control and even automated reporting on the same software platform maximizes operational efficiency and increases safety for people and rig equipment during well control events and MPD applications.
Development of High Temperature Telemetry Systems for Long Term Borehole Monitoring Systems in Riser Holes
Authors: Namba Yasuhiro , Kyo Masanori
Published: June 2014

In the present study, some component evaluation tests, unit integration tests, system integration tests, environmental life tests and land tests have done with using the experimental prototype (EXP) mockups of the telemetry system for the long term borehole observatory system (LTBMS). This paper describes some issues on the development of telemetry system and reports some test results. The telemetry system being developed in the present study is intended to apply especially for the deep riser holes in Nankai, Japan. Analog to Digital Converters (ADCs), voltage controlled crystal oscillators (VCXOs), and the other major components in the telemetry systems have been evaluated and their life-times have been estimated as more than five years in 125 °C. The life time of the EXP itself has been estimated as five years in the environment of 100 °C. The case study about the power distribution in the EXP of 8 downhole modules and 1 subsea module has shown that the assumed power supply of total 45 Watts from a submarine cable network, so-called DONET, can't maintain the versatile power supply for the sensors. This means we need to consider more specified power supply for the sensors after defining the sensor configuration. The shock and vibration tests on the telemetry system have shown some of modules being failed. Some anti-vibration measures have been conducted. The present study identified some issues to be resolved to realize the deep riser hole long term observations.
How to Execute a Successful Petrotechnical Data Donation Project
Authors: Thomson James A. , Thorn Barbara , Tucker Julieta
Published: June 2014

This paper describes the methodology used to design and execute a project for donating multiple high-resolution datasets simultaneously to a number of university geoscience departments. A step-by-step process shows how an integrated, multidisciplinary team consisting of data specialists, geoscientists, attorneys, administrators and others verified that the datasets were sound, eligible for distribution and consistently delivered to recipient universities. The steps include obtaining permissions from four internal BP asset teams and four external data co-owners, and assuring ownership and distribution rights through the data acquisition contractor.

Efficiencies in the data donation process were achieved by batch issuing the data to a group of universities under a single round of permissions granted by internal BP data owners and a Letter Agreement executed between BP and each of the data co-owners. The permissions and agreements put in place will cover additional qualified research and teaching institutions that may be identified in the future, allowing subsequent data donations without the need for supplementary rounds of approvals.

After executing Confidentiality Agreements and distributing data to a group of 15 targeted U.S. University Geoscience Departments, additional universities have applied for, and received, the datasets, with selected universities outside the U.S. also receiving data. Originally, data were delivered on a physical disk drive however, more recently, a digital data download system has been enabled.

The BP Data Donation Project met the initial goal of delivering high-resolution geophysical datasets from four BP deep-water developments in the Gulf of Mexico to multiple universities in 2011. BP have seen that these universities are using the data in teaching and research and that expertise in using these data types is developing in the recipient Geoscience Departments. Research results based on the donated datasets have enhanced our understanding of seafloor and shallow subsurface geology. The data donation effort has enabled graduate research projects and the first manuscripts based on research using the data are beginning to be published.

The data donation project will eventually be shut down, with one potential trigger being a drop off in demand for the high-resolution datasets. However, alternative datasets may become eligible for donation in the future, possibly including a collection of proprietary, high-resolution 3D seismic data.