bluuebunny/crossref_metadata_2025 huggingface dataset:
Development and Production of Cascade and Chinook Fields in the Gulf of Mexico: An Overview
Authors: Mattos Deborah M. , Palagi Cesar L. , Ribeiro Orlando J. S. , da Matta Jr. Salvador
Published: May 2013

This paper is based on the work performed during the design, implementation and operation of the Cascade and Chinook fields, located offshore the United States Gulf of Mexico (USGoM) - the first deployment of an FPSO in the region. It presents an overview of the reservoir rock and fluid properties, the design and construction of wells, the design and installation of the subsea system and FPSO BW Pioneer, the oil export system through shuttle tankers, the gas export through pipelines and the regulatory framework of the project. It also presents operational information about the first wells on stream in each field.

The information provided in this paper is a useful reference for petroleum field operators when designing development concepts for ultra-deep water discoveries, not only in the USGoM but also worldwide. It is especially useful for the design of field development and early production systems located far from pipeline infrastructure. It is useful for contractors to identify the technologies which are most suited for application on deep wells and ultra-deep water subsea systems and production platforms.

The initial phase of development, already implemented, consists of two subsea wells in Cascade and one in Chinook tied back, through a field-specific subsea system, to a Floating, Production, Storage and Offloading (FPSO) platform. Oil is transported from the FPSO in shuttle vessels to terminals of opportunity along the USGoM and gas is exported through pipeline. Wells started-up production in 2012. Future phases of development will depend on the performance of the wells.
Cascade and Chinook Subsea Development: A Challenging and Successful Case History
Authors: Cassity Thomas Gus , O'Donnell Michael , Weigle John , Masson Craig , Kochi Kazuhiko , Porciuncula Sergio L.
Published: May 2013

This paper is based on the subsea work performed during the design, implementation and operation of the Cascade and Chinook Field Development Project in ultra-deep waters of the U.S. Gulf of Mexico (USGoM). It describes the engineering, procurement, construction, installation, operation and integrity management phases of the subsea production system. This project required several innovative technologies and solutions that resulted in several " firsts" and records for the industry: first of a kind and deepest subsea boosting system with ESP-Electric submerged pumps installed on the seabed at 8800 ft, non-conventional power umbilicals utilizing carbon fiber rods as the principal tensile strength elements, first subsea pull-in of umbilicals utilizing a submerged winch, deepest and highest pressure rated Free Standing Hybrid Risers (FSHRs), deepest pipe-in pipe flowline and deepest gas export pipeline. This case history paper also describes the procurement strategies employed and the project management systems adopted to mitigate technical, time and cost risks.

Introduction

The C&C fields are located in the Walker Ridge Outer Continental Shelf (OCS) leasing area of the central USGoM. Both fields are situated near the base of the Sigsbee Escarpment on the abyssal plain of the USGoM in ultra deep water. Cascade is located about 160 miles south of the Louisiana coast in 8,200 ft water depth and Chinook is about 15 miles due south of Cascade in 8,800 ft water depth.

The Cascade discovery was made in 2002 and Chinook was discovered in 2003. The C&C reservoirs are in the Lower Tertiary (Wilcox) Ultra-Deepwater trend. After appraisal work the C&C was sanctioned in late 2007 based on a phased development concept. The initial project phase, the subject of this paper, is an early production scenario based on a limited number of wells and subsea infrastructure and the purpose of this initial phase is to gain reservoir information in order to optimize future development phases. The initial phase utilizes a leased, disconnectable, floating, production, storage and offloading (FPSO) vessel located between the fields. Produced oil is transported from the field in shuttle vessels and gas is exported through an export pipeline. The main reason for selecting the FPSO was safety, primarily with respect to hurricanes. The detachable turret mooring buoy provides a mooring point for the FPSO and during the approach of a hurricane the buoy enables the FPSO to disconnect in a short period of time in order to depart the area.

Future phases increase the amount of producing wells and subsea infrastructure and a definitive optimized permanent production facility is to be installed in the last phase. Decisions on the type of and design basis of a definitive facility and number of wells will be finalized in 2013 and 2014.
Cascade and Chinook Fields: Integrated Overview of the Reservoirs
Authors: Syrio Julio Cesar , da Cruz Paulo Sergio , Nguyen Nhom Vince , Navarro Alonso , Becker Mauro , Watkins Elizabeth Ann , Riera Ladimir Alberto , Leite Renato
Published: May 2013

This paper is based on the work performed during the design, implementation and operation of Cascade and Chinook fields and it provides an overview of the Cascade and Chinook fields' reservoirs, part of the emerging Ultra-Deepwater Wilcox Trend in the Gulf of Mexico. A general picture of the structure, stratigraphy, depositional facies, and petrophysics of each field will be given. Reservoir engineering parameters will also be discussed as well as the initial field development.

The main result of this work is a consistent integration of all available data, following a recommended workflow process, aiming to build a geologically coherent and realistic reservoir models for these fields. The match of real field production information with the dynamic flow models allows the reduction of uncertainties of the scenarios and better support for the production forecast. From the integration of seismic, logs, fluids, cores and production data has emerged structural models similar for both fields: a faulted salt-cored anticline divided roughly into western upthrown and eastern downthrown blocks, populated with amalgamated-to-stacked turbidite sands. The petrophysical model developed considers the geologic background and supports the dynamic flow model.

The main technical contribution of the work presented in this paper is an overview of the reservoirs that have pioneering production from the Lower Tertiary (Wilcox) Ultra-Deepwater trend (Walker Ridge area). These fields are the first analogues for a mostly untested trend which is still projected to have significant production potential. Currently, numerous oil & gas companies have several Wilcox fields, prospects, and plays in varying stages of development in the area. The information provided and the modeling approach used in this paper can be applied as guidelines for similar Lower Tertiary reservoirs developments in the deepwater Gulf of Mexico.
Large Bore Expandable Liner Hanger provides Reliable, Cost-Effective Solution for Liner Placement in Critical Well Path
Authors: Johnson Michael (Rick) , Ardoin Kevin Wendell , Sweep Miles Norman , Wyatt Nathan Barrett , Benet Paul
Published: May 2013

This document reviews challenges and solution to previously overwhelming issues regarding 14-in. liner placement in the Gulf of Mexico. Necessity and considerable effort are required to deal with multiple mobile/active tar zones, associated with fault zones throughout the sediment sections and below the base of salt. Deploying liners to the desired depth through such hole sections have resulted in costly non-productive time (NPT). The large bore expandable liner hanger drilling/washing capabilities provides a reliable method to assist the operator in reaching their targets.

Advancements in casing connection technology have provided enhanced torque capabilities for some time. Today, the large-bore expandable liner hanger (LBELH) system provides the capability and reliability to deliver torque to the liner shoe. This added rotation and reciprocation capability while circulating is at the heart of NPT reduction.

The running tools to deliver such a system have the capacity to provide 110K foot pounds of torque at top of liner (TOL). Reaming/drilling attachments to the liner shoe have advanced to a point that allows operators to take advantage of the technique to deliver the liner to its target depth.

This combination of equipment allowed a major Gulf of Mexico operator to wash and ream a 14-in. liner through tar and shale, inside their 16-½-in. borehole. Two successful attempts totaling 7-½ hours of reaming resulted in gains of 335 feet. The final effort was to wash and ream the liner down inside the 14-½-in. pilot hole. This was an additional 30 feet of " drilling conditions" to total depth (TD), requiring an additional 45 minutes of torque and vibration.

The liner was cemented and the hanger was set and tested. The operator commented: " Excellent results", [and that he was]"Very pleased to get this critical and difficult section cased off". (Benet, 2012)

Introduction

With proven expandable technology already in place due to problems experienced with traditional liner hangers in difficult well-bore scenarios, the time had come to push toward large-bore expandable liner hangers (Cantu et al, 2004; Nida et al, 2004). The main components of the expandable liner system are an integral liner hanger/packer assembly combining an upper tie-back receptacle with elastomeric elements, which are bonded directly to the body of the hanger.

Figure 1 shows the basic components of the original expandable liner hanger (ELH) system compared to a conventional " casing hanger". The bonded elastomeric elements compress against the internal diameter as the hanger expands which virtually eliminates any leak paths between the liner, liner hanger, and previously run casing, maintaining the pressure integrity of the well bore (Moore et al, 2002).
Mooring System Life Extension Using Subsea Inspection Technologies
Authors: Pederson Tia Anne , deGier Tyler SC , Hall Anthony David , Allan Scott
Published: May 2013

The need for quantifiable inspection methods to evaluate the potential for life extension has become increasingly important for a large number of floating production facilities nearing the end of their design life. This paper discusses the use of a risk-based progressive inspection methodology to identify, quantify and analyze the condition of mooring systems and ultimately determine fitness for purpose.

Due to an increase in mooring system failures and the growing knowledge of failure mechanisms, many operators are moving towards more comprehensive inspection plans in addition to the minimum requirements as set by Class. Using a risk-based inspection plan and focusing on known areas of vulnerability allows for a higher probability that issues are identified before they become catastrophic.

Welaptega's experience with in-service mooring inspection has exposed numerous cases worldwide where mooring systems have been severely degraded due to accelerated and unexpected deteriorative mechanisms. In each case a decision to either replace the moorings or keep them in service had to be made.

Inspection programs using a number of Welaptega's measurement and modelling tools has allowed operators to identify the most severely degraded sections in a mooring system. Data collected makes it possible to produce 3D models of chain links which are used to evaluate the extent of material loss. The application of finite element analysis enables the client to quantify the residual strength of the mooring chain and estimate remaining fatigue life; from here a decision to extend the life of the mooring system can comfortably be made. In the past, finite element analysis combined with break testing has proven that even severely degraded mooring chain may still be fit for purpose in some circumstances.

The ability to provide high quality and quantitative subsea intelligence will continue to allow operators to make risk-based decisions, increasing the economic viability of field life extension without compromising asset integrity.
A Nonlinear Dynamic Substructuring Approach for Efficient Detailed Global Analysis of Flexible Risers
Authors: Dib Michel W , Cooper Philip Adrian , Bhat Shankar , Majed Arya
Published: May 2013

This paper presents a significant methodology advancement that addresses one of the industry's most challenging problems: the accurate prediction of detailed local stresses in unbonded flexible risers. Flexible risers exhibit highly nonlinear dynamic behavior due to the stick/slip interaction between the pipe wall layers in compliant systems that undergo large three-dimensional translations/rotations. Practical, accurate prediction of critical flexible pipe component responses requires an efficient method capable of incorporating detailed flexible pipe models into a global nonlinear dynamic analysis. Current industry practice is a two-step global/local approach involving a global nonlinear analysis with 1D centerline models, which may include bending hysteresis effects, followed by local analysis of a detailed model segment to the global results to predict critical response items such as armour wire stresses.

A Nonlinear Dynamic Substructuring (NDS) framework is developed that expands the classical methods of dynamic substructuring and component-mode synthesis to geometrically and locally nonlinear problems. This evolution/integration of capabilities enables the computationally efficient inclusion of detailed flexible pipe models into, and recovery of detailed response/stress time-histories directly from, the global nonlinear analysis itself. The NDS methodology is benchmarked against published work involving the large deformations static and dynamic global analysis of a flexible riser. The full potential of the method is then demonstrated by efficiently incorporating 3D detailed flexible pipe substructure models, with bending hysteresis, into a global system nonlinear analysis and recovering stress time-histories in tensile armour layers.

Introduction

The accurate prediction of local stresses in flexible risers has been an industry objective for some time. Flexible pipe has a complex structure composed of multiple interacting pipe wall layers (Figure 1). The stick/slip friction hysteretic behavior of these layers is directly coupled to the global large displacements of the overall compliant system resulting in a highly nonlinear problem. A common approach for analyzing flexible risers is to conduct the global analysis with standard line elements utilizing the flexible pipe's unpressurized linear bending stiffness.
Stranded Gas Field Development with Cluster LNG Technology
Authors: Eisbrenner Kathleen , Lee JungHan , Choi DongKyu
Published: May 2013

There are many small scale onshore and offshore gas fields and there are also many diverse small LNG consumers around the world. However, smaller unit of gas fields could not be practically developed due to unfavorable unit price competition with larger ones. Therefore, many stranded gas fields are still waiting for new viable technology for the small unit production. In order to have unit production cost competitiveness, CAPEX and OPEX should be reduced. Cluster LNG technology based on increased pressure liquefaction has distinct advantages in OPEX and CAPEX with inherent high liquefaction efficiency together with superior environmental performance. One of the potential gas consumers for the small capacity LNG would be fuel oil fired diesel engine or gas turbine power plant operators who eagerly attempt to change the fuel source to natural gas due to high fuel oil price. Most of the cases, power plants are located far away from the gas fields, so efficient gas transportation solutions have to be provided. LNG is efficient means of gas transportation between 2 different locations. On the other hand, it requires complicated gas treatment and liquefaction systems which results in high delivery cost. Considered that gas engines need gas as final form not as LNG one, if the interim product of LNG liquefaction is simplified, it would be beneficial to overall project economy. As an application example, extensive economic studies for 0.5 MTPA Cluster FLNG, LNG transportation vessel, and 350 MW capacity LNG power plant have been carried out. Typical distance from the gas field to power plant is 2,000 Km though it can have competitiveness up to around 5,000 Km. The smaller unit LNG production system with high competitiveness would activate developments of stranded gas field, and it would change business paradigm by bringing flexibilities and diversities in the industry.
Gulfstar Spar VIM Responses in Flume Tank
Authors: Antony Arun George , Halkyard John , Huang Ken , Park Young Chan , Islam Mohammed , Moideen Hisham , Herrington Paul
Published: May 2013

The Gulfstar® FPS utilizes a standard Classic spar hull form (full depth, cylindrical hull) with a significantly shallower draft than previous Classic spars. Vortex Induced Motion (VIM) is a well-known but complicated phenomenon for cylindrical hulls and model testing is still the norm to determine the platform's VIM response characteristics.

Towing-type tests are widely accepted and employed for VIM model tests; however this test method only simulates a uniform current profile with depth. In the actual ocean environment, only sheared currents are present so the tow test method over-predicts the loading on the cylinder from current, particularly in the deeper portions of the hull. To achieve more realistic test results for VIM testing, it is desirable to use sheared currents, especially for deep draft floaters, such as a Classic spar.

Recent advancements in generating good quality sheared currents involve using a Flume Tank where the model is stationary and the water flows past with its velocity varied with depth. This paper describes a recent test program using this technology in a Flume Tank to explore effects of sheared currents on the VIM response characteristics of the Gulfstar® FPS. In addition to the capability of generating sheared currents, the Flume Tank, completely removes the constraints of towing tank length and the number of realizations for each test case. For benchmarking purposes, a uniform current is also generated in Flume Tank.

Distinct VIM responses have been observed in both types of current profiles. These findings are presented and discussed in this paper.

The value for the offshore industry from better predictions of VIM responses using model tests would be hard to overestimate. Being able to test using sheared currents is a valuable step toward obtaining more accurate test results for VIM type responses.

Introduction

The Gulfstar FPS® is a standard floater solution for the Gulf of Mexico region. The Gulfstar hull has a diameter of 25.9m (85ft) and a draft of 159.7m (524ft) making it much smaller as compared to other classic Spars in the Gulf of Mexico. Cylindrical structures such as Spars are known to exhibit Vortex Induced Vibration (VIV) or Vortex Induced Motions (VIM). VIM has increasingly become critical to the design of riser and mooring system. Low frequency fatigue in mooring system and risers due to VIM often drives the design of riser and mooring systems. Even though VIV has been investigated extensively over past three decades, prediction tools for VIV/VIM response of various systems are still very limited. Model testing is still the industry standard for determining the VIM performance of floaters. VIM is also observed on column stabilized units such as TLPs and Semi-submersibles [18], though not as significant as Spars.
Exploitation and Production of Gas Condensate Reservoirs
Authors: Vega Riveros Gina
Published: May 2013

Latin America countries have shown a great interest for increasing the reserves of gas and gas condensate reservoirs in mature fields. However, the production per well in some cases is very low with an elevated cost of production. It has pushed in some countries to adopt a long work strategy to handle multi-research studies oriented the enhancement of the field production in pre-selected mature fields.

In the Eastern Venezuela, gas reserves are concentrated in Anaco area, Anzoategui State. Anaco has been one of the most important operational districts and it has a high number of gas condensate reservoirs. However, a good portion of the remaining reserves are still trapped due to inefficient drainage and low production. Due to the importance of exploitation in these fields, it is fundamental the development of new technologies that allow their exploitation and production.

This paper presents an analysis method to accelerate production, as well as, recover additional reserves based in the detection of connected pay sands known as hydraulic units. The integration of the geology, seismic, petrophysic, geochemical study, fluids and reservoir properties identified the existence of hydraulic units through both areal and vertical communication. The reserves were evaluated using analytical methods, volumetric analysis, empirical correlations, P/Z material balance and probabilistic analysis. From static model, well correlations identified stratigraphic coalescence between G and H sands. The dynamic model detected that the four reservoirs are hydraulically connected showing an increase of gas condensate in place GCIP of 231.99 BCF in comparison official data. Based on the analysis of well spacing, there was a good opportunity to increase the daily production rate via adopting infill drilling.

The development strategy proposes the exploitation of several sands by hydraulic units, fracturing, pumps, workovers, infill drilling, well highly inclined and horizontal well in order to contact higher reservoir volumes and accelerate the operational process. A compositional simulation study was recommended to evaluate the factibility of injection EOR fluids, recycling gas and water-flooding as a secondary recovery project. This will increase the recovery factor and help to maintain the reservoir pressure.

Introduction

Many of the fields of the traditional areas of eastern Venezuela still contain important gas reserves but the majority is not economically viable for production because the principal productive sands are partially depleted. As it is well known, government regulations have established that each reservoir should be completed and produced individually. However, the production of some wells of gas condensate reservoirs is very low (between 40 and 60 STBD per well) with an elevated cost of production.
Projecting Shuttle Tanker Fleet for Gulf of Mexico FPSOs: Discrete Event Simulation
Authors: Majhi Sai , Feng Jeffrey , Kulkarni Makarand , Fales Raymond
Published: May 2013

This paper will present a Discrete Event Simulation (DES) based solution for an optimum shuttle tanker fleet to serve the present and future FPSO based Gulf of Mexico (GoM) production. The simulation takes into account average ‘field lifecycle’ based production rates of specific developments and the sensitivity of ‘offloading availability’ to variables such as shuttle tanker size, loading rate, distance to market etc. A probabilistic representation of downtime associated with wave, wind, currents, maintenance etc. at the FPSOs and random weather and non-weather delays at the receiving terminals have also been considered in this effort.

Despite the impressive pipeline infrastructure available in the GoM, none of it currently reaches some of the newer fields being discovered in over 5000ft water depths in the lower tertiary trends. The high cost of pipeline extensions in ultra-deep water (UDW) and uncertainty in the producibility of reservoirs has multiple operators considering an FPSO - Shuttle Tanker (ST) based solution for production export. This paper would help operators considering this option to understand the limitations and potential options in using shuttle tankers in serving the field(s).

The assessment of offloading availability for shuttle tankers to serve multiple fields would be made on the basis of production rate, loading rate and tanker size using a Discrete Event Simulation (DES) model subject to threshold and offloading operational downtime.

The development of the Cascade-Chinook field at the US GoM has established its viability using dedicated shuttle tankers. However, potential of synergy in using a common fleet of shuttle tankers exists subject to further FPSO based developments in the near future. This paper explores the technical and logistical feasibility of such a possibility.
Operational Experience With a Cylindrical Floater Design Demonstrating the Feasibility of Safe Permanent FPSO/FSO Mooring in Areas With Tropical Cyclones
Authors: Major Fredrik
Published: May 2013

Sevan Marine has successfully pioneered the cylindrical floater concept to the market with 3 FPSOs and 2 MODUs in operation and an additional 4 FPSOs and 2 MODUs in construction. The paper will present these units and the operational experience in harsh environments in the UK Central North Sea. Through studies supported by major oil companies, a concept for safe permanent mooring of a floater through the typical design tropical cyclone in areas like NW Shelf Australia, South China Sea or Gulf of Mexico is demonstrated to be feasible. The paper will present the analysis, model tests and full scale motion recordings, supporting this conclusion. Finally some new methods for offloading to export tankers will be presented, also including systems relevant for LNG offloading to standard LNG tankers from an FLNG unit.

Introduction

Operation of FPSOs in areas exposed to tropical cyclones is today largely based on disconnect-able ship-shaped units. The disconnect requirement has several disadvantages such as production downtime, complexity of disconnect system, requirement for the unit to operate as a navigable ship.

Yearly production downtime will be based on number of disconnects and duration of production downtime due to disconnect. The additional downtime will vary from one area to another, but an additional downtime of 5–10% can be seen in many cases.

Added complexity for the mooring and riser system in order to allow for safe disconnects and re-connects of mooring lines and riser bundle will add in the order of magnitude 30–50% to the turret mooring system.

For operating the FPSO as a navigable ship, a marine crew as well as propulsion and navigation systems have to be in place, adding significantly to both FPSO construction cost as well as cost of daily operation.

Based on the operational experience with the world's 3 first cylindrical FPSOs as well as extensive analysis and model tests carried out, it has been possible to demonstrate that a cylindrical FPSO can be designed for safe permanent mooring in areas exposed to tropical cyclones.
Development of a Monobore, High-Flow, ROV Operable Connector for Gas Lift and other Applications
Authors: Krohn Dan , Kamdar Prashant , Cunningham Michael Thomas
Published: May 2013

The Monobore, High-flow, ROV Operable Connector is a male and female connector and seal system designed for use subsea in small bore gas and fluid piping applications. This system's principle attribute over traditional methods is its ability to be installed in " free fly" fashion, by a typical work class Remotely Operated Vehicle, similar to hydraulic flying leads in production control system applications.

Latching of the type of connector is similar to conventional hydraulic junction plate technology. The tooling required for this operation is also similar to the make-up of hydraulic junction plates utilizing an API 17D class 4 torque tool, flying lead orientation device, and any other easily attachable and detachable stability aides or weights.

To meet these operational scenarios, the connector must be light, made of corrosion resistant materials, and have an extremely reliable sealing mechanism. This system must also be easily configured into a " flying lead", where the tubing or piping is both strong and compliant. This paper describes just such a connector system that is designated as the M5.

For the matter of this paper, the removable half of the connector will be referenced as ‘removable connector’ and the fixed half of the connector will be referenced as ‘fixed connector’.
3D Seismic Spectral Decomposition: An Emerging Tool for Deepwater Geohazard Assessment
Authors: Cauquil Eric Charles
Published: May 2013

Introduction

Spectral Decomposition refers to any method that produces a continuous time/frequency analysis at each time sample of a seismic trace. This allows the interpreter to see amplitude and phase tuned to specific wavelengths. This tool is based on the fact that a reflection from a specific geological thin body (levee, channel, debris flows …) has a characteristic signature in the frequency domain. Thus, spectral decomposition is able to separate features with subtle petrophysical differences. It allows to quantify amplitude variation with frequency, thereby gaining insights into the distribution of sedimentary bodies, faults and fractures. Since the high-frequency response of a reflector can be attenuated by the presence of compressible fluids, spectral decomposition can also assist in the direct detection of shallow gas accumulations. Spectral decomposition, to date, has been a conventional approach for lithological interpretation of thin reservoirs. With the high-frequency content in the shallow part of a seismic cube, it may provide an additional tool for geohazard assessment at or near seabed.

This paper will review the additional value of spectral decomposition for the geohazard assessment of deep-water seabed areas.
A New Approach to Pipeline Inspection Using Autonomous Underwater Vehicles
Authors: Courbot Anne , Nasr Amin , Gilmour William , Biedermann Caitlin
Published: May 2013

Autonomous Underwater Vehicles (AUVs) have successfully been introduced into Oil and Gas operations for Geophysical and Environmental surveys, replacing the traditional vessel based and towed system approaches. AUV development continues to advance rapidly, with the majority of the technology growth stemming from the defense industry's requirements. Total and Chevron have been working collaboratively to understand, influence, and adopt these advances in technology to enable sonar and visual pipeline inspections using AUVs. Together, the companies are developing a comprehensive approach to AUV pipeline inspection.

AUVs have advantages and disadvantages compared to more conventional towed systems and remotely operated vehicle (ROV) systems with respect to pipeline inspection approach. In order to take full advantage of AUV attributes while minimizing the effect of AUV drawbacks, a change in the current pipeline inspection philosophy will need to be adopted. This change will require improvement of sensors, autonomy software, and data processing and management, as well as further development of technology gaps such as AUV navigation, real time 3D mapping, feature recognition, and communications between the AUV and intelligent sensors.

The deliverables for the Total/Chevron collaboration effort will be new specifications for AUV pipeline inspection surveys that will help guide AUV suppliers and operators as they enhance their current capabilities to meet both companies' requirements for pipeline inspection. Included in the deliverables will be an in-depth analysis of the current AUV technology gaps in relation to internal integrity management systems for both companies.

The new AUV-specific approach to pipeline inspection will provide better data quality and result in improved integrity management of subsea pipeline assets. The ability of AUVs to successfully perform pipeline inspections will also provide a stepping stone toward acceptance of AUVs as capable tools for additional inspection and light intervention programs, and will eventually lead to the development of field resident AUV systems.

Introduction

The goal of the TOTAL/Chevron Technology Co-operation agreement for global AUV pipeline inspection is to gain alignment in our global requirements for AUV pipeline inspection and to define these requirements in an AUV pipeline specification document. This pipeline specification document considers the limitations of AUV's compared to ROV's and towed platforms, without compromising the key requirement to assess the integrity of our offshore pipeline assets.

The specification covers periodic inspection of pipelines and is categorized into sonar or visual inspection or a combination of both approaches. This specification provides a basis to discuss a business case for introducing AUV pipeline inspection to each of our different business units in order to fully comply with existing regulatory standards and industry best practices.
Interstitial Light Hydrocarbon Gases in Jumbo Piston Cores Offshore Indonesia: Thermogenic or Biogenic?
Authors: Bernard Bernie Boyd , Orange Daniel L. , Brooks James M. , Decker John
Published: May 2013

Interstitial light hydrocarbon gases were measured to 12 m below seabed in two Jumbo piston cores acquired in deepwater sediments offshore Indonesia. Determinations were made for dissolved methane, ethene, ethane, propene, propane, iso-butane, n-butane, iso-pentane, and n-pentane, as well as for carbon dioxide. Stable carbon isotopic ratios of methane and ethane were also measured. Such gas measurements are typically performed in deepwaters around the world as elements of surface geochemical exploration programs for the purpose of distinguishing biogenic from thermogenic sources in seep gases. Various gas source models have been developed in the literature to aid in accurate interpretation for systems that have been biodegraded, fractionated, and/or mixed during migration. In these models, assumptions are made about the ranges of composition of the end-member gas types and maturities. The compositional ranges of the thermogenic and biogenic end members have been empirically derived from a large database of drilled-hole gas data and various theoretical considerations. In addition to this literature base, tens of thousands of near-surface marine sediment cores have been acquired worldwide and analyzed for interstitial gases on a proprietary SGE basis over the last 35–40 years. Interpretation of these results has helped to fine-tune the accepted end-member compositions of the source models. However, essentially all of the SGE sediment cores have reached a maximum 5 m below the seabed. Our acquisition and analysis of cores down to 12 m has revealed information about gas compositions not apparent from the former SGE coring efforts. In particular, ethane concentrations are in the accepted thermogenic range, but their stable carbon isotopic compositions are not. Near-surface gases formerly interpreted to have an unambiguous thermogenic component are here shown to be purely biogenic. Our conclusions may change the boundaries of the biogenic end member used for the indication of thermogenic gas traces in near-surface sediments.
BOP MUX Control System: Comparing Embedded Computer Based Versus PLC Hybrid System for Maximum Reliability
Authors: Sacco John , Tinney Lynn , Whitney Charles , Johnigan Robert , Shanks Earl F , Boyle Greg
Published: May 2013

Description of the Proposed Paper:

Deepwater BOP Control Systems are typically a Multiplexed Electro-Hydraulic (MUX) System for water depths greater than 5,000 ft. There are currently two dominate hardware philosophies in the industry; Embedded Computers (EC) and Hybrid Personal Computer (PC) and Programmed Logic Controllers (PLC) based systems. This paper presents Oceaneering International's Embedded Computer technology, and compares it to PLC/PC Hybrid Systems.

Application:

There are several different EC based and Hybrid PC/PLC based OEM systems in the market today, each somewhat different. Each must be evaluated individually, based on its unique hardware and software design and implementation. Information in this paper will explain the system architecture and philosophy of the EC based system and gives a comparison with Hybrid PC/PLC based systems. This system information can be used by interested parties to perform a more detailed comparison of other OEM systems.

Results, Observations, and Conclusions:

It has been found beneficial to use components that comply with MIL Specifications whenever possible. The electronics which are not purchased are designed in-house and built to IPC Class 3 requirements (Electronics for Life Support and Safety Critical Systems).

This strategy gives maximum reliability and allows flexibility in form factor to develop optimal subsea electronic packaging.

The EC system allows programming in an object oriented language which allows creating software objects once and reuse them in many places without copying the code.

An EC based system has high data rates between surface and subsea for very high bandwidth for solenoid control, status readback, and diagnostic capabilities when using Fiber Optic Communication. The EC type system also allows for more robust and flexible communications options than other types of system architecture.

Significance of Subject Matter

What makes a system reliable is the complete understanding and control of the hardware/firmware/software design, manufacturing process, and testing procedures.
AUVs and ROVs: Supporting Offshore Renewable Technologies
Authors: O'Halloran William , Elvander Joshua
Published: May 2013

The presentation will show how Bluefin Robotics' capabilities in the ROV and AUV space provide effective survey, observation and light-work technologies that will support marine renewable technologies markets by enabling a wide variety of both broad area survey and underwater intervention tasks in the high-current, low-visibility environments associated with marine renewable installations. In addition, the ROVs and AUVs provide a cost-effective footprint, low infrastructure support and operational flexibility.

Installation of marine renewable energy structures such as offshore wind turbines and marine hydrokinetic devices will require a variety of visualization and monitoring equipment to properly survey the sea floor for initial installation, cable lay, and post-installation, monitoring, and maintenance tasks. Such activities can be challenging due to the shallow water environments where these installations are located, with high ocean currents and tides necessitating remote systems that can execute station-keeping in water flows above five knots. In addition, the visibility is such that traditional optical solutions such as divers or cameras are not feasible, necessitating forward-looking sonars, laser imaging or similar tools.

Bluefin Robotics recently acquired Hawkes Remotes, Inc. (HRI), a spinoff of Hawkes Ocean Technologies that develops advanced Remote Operated Vehicles (ROVs). The Hawkes ROV designs offer scalable, modular solutions including a thin, armored fiber-optic tether and on-board high-energy-density batteries that will reduce the total cost of ownership and operating costs while simultaneously outperforming existing ROV technology. The rollout vehicle is the U-4000, a hydrodynamic light-work-class ROV designed for the inspection, repair and maintenance (IRM) market and capable of speeds of two to six knots. Bluefin is leveraging their autonomy and subsea experience to add hybrid capabilities to the Hawkes ROVs and offer them as an extension of their current autonomous underwater vehicle (AUV) product line. AUVs and ROVs fill different niches within the underwater intervention task spectrum: while workclass ROVs such as the Hawkes vehicles can provide inspection, repair and maintenance capabilities in high-current environments, AUVs provide the capability for subsea inspection and survey on a variety of range scales and with multiple sensors, including sidescan and synthetic aperture sonar, sub-bottom profiling, multi-beam echosounding, and still and video photography.
Introduction to FLNG FEED Study
Authors: Kim Jae Shin , Nam Kiil , Park Jinsang , Kim Tae Jin , Kim Yoon Choon
Published: May 2013

With depletion of conventional oil and gas fields, offshore installations have become complex and capital extensive, requiring the development of new processes that should be able to operate satisfactorily and economically even for nonconventional environments. The FLNG (Floating Liquefied Natural Gas) is introduced to develop stranded gas fields that have been considered as uneconomical in the past. The FLNG enables natural gas to be produced and liquefied on a floating vessel and offloaded directly onto a carrier without touching onshore facilities. However, there are many challenges that have interrupted the realization of the FLNG project. The installation needs gas purification and liquefaction processes which are completely new in the offshore industry though they are proven technology in the onshore LNG sector. During the conceptual design of such a new process, the selection of the best among the candidates is a formidable task due to the intrinsic features of offshore plants which are characterized by being uncertain, safety-critical, independent and motional. This study proposed a new economic evaluation with the production availability expenditure taken into account for comparative evaluation of offshore process options at their conceptual design stage. The production availability expenditure accounted for the production loss and the maintenance expense due to equipment failures. It was demonstrated that the new economic evaluation was capable of playing the role of a process selection basis in choosing the best of the liquefaction process options including the power generation systems for the FLNG. In addition, the study represented the design basis, the layout-safety study and the findings & observations from FEED study of 2.5 MTPA (Million Ton Per Annum) for generic design approach.
Shape Memory Alloy: Low-Cost Manufacturing for the Oil and Gas Industry
Authors: Lewis Peter , Vasquez Myrone
Published: May 2013

Tube to tube joining and tube to fitting assembly are among the most time consuming aspects of the manufacturing cycle for offshore equipment due to the large number of tube connections the equipment requires. Conventional methods of performing these tasks are costly and frequently constitute a manufacturing bottleneck. For these reasons alternative methods of manufacturing are being sought.

One such option for tube joining uses a Shape Memory Alloy (SMA) coupling which has been in use in the aerospace industry for over 40 years. SMA couplings, unlike other mechanical couplings, have a metal-to-metal seal which exerts a continuous high force on the tubing being joined, effectively " following" any movement from flexure, vibration or thermal cycling. As the product has been developed for medical, telecommunications, marine and nuclear applications it has become evident that the greatest cost benefits of Shape-Memory-Alloy Technology are to be gained on small diameter tubes such as instrumentation and hydraulic lines.

SMA couplings require no tooling or training investment, no additional manufacturing space and are quicker and less costly to install than traditional welding methods of pipe joining. Installation of an SMA coupling can be easily and swiftly achieved, in densely packed, tight access areas due to the unique tool-less package. Not only is the installation phase much quicker than welding, but the inherent properties of SMA make radiographic inspection redundant. The fact that the preparation, installation, and inspection of an SMA joint takes only seconds has the potential for dramatic reduction in cycle times and increased production throughput for any facility manufacturing instrumentation or fluid tube assemblies in the Oil & Gas industries.

Introduction

SMA Fittings & Couplings were originally developed in the late 1960s and early 1970s to fill the needs of Military Aerospace programs such as the F14 Tomcat. In the 1970s and 1980s there was some use of the technology in military marine applications, notably in UK Royal Navy nuclear submarines, and at the Ingalls shipyard in Pascagoula, MS. Some investigations into the suitability for offshore applications were also carried out at this time, although these seem to have focused on larger diameter pipe applications.

As SMA coupling technology has been developed, it has become evident that the greatest cost benefits of SMA Technology are to be gained on complex assemblies of small diameter lines such as instrumentation and hydraulic assemblies where large numbers of welded joints are typically required.
Irenaeus’s knowledge of the Gospel of Judas: Real or false? An analysis of the evidence in context
Authors: Van Oort Johannes
Published: May 2013

This study discusses Irenaeus of Lyon’s testimony of the famous Gospel of Judas, offering both a historical and, in particular, linguistic analysis and retranslation of Against Heresies 1.31.1. On the basis of a detailed philological commentary and textual analysis it is – contrary to most current opinions – concluded that Irenaeus, in all feasibility, had first-hand knowledge of the Gospel and its contents. In other words, Irenaeus appears to have read the text as we now have it (‘a composed work’) and he summarises it in his treatise. According to Irenaeus’s testimony, the Gospel was produced by a group of 2nd century Gnostics who positively venerated Judas as a fellow Gnostic in the same way that they positively venerated Cain. It was because of his particular knowledge of the redeeming act of Sophia as well as the negative characteristics of the creator God in contrast to the superior God that Judas accomplished the ‘mystery of his (= Jesus’) betrayal’, so that ‘through him (= Judas) all things, both earthly and heavenly, have been dissolved.’
Clinical, ultrasonography and haematology of aglepristone-induced mid-gestation pregnancy terminations in rabbits
Authors: Özalp Gözde R. , Temizel Ethem M. , Özocak-Batmaz Elçin
Published: May 2013

Aglepristone is a safe abortifacient in cats, dogs and rabbits. Although no serious side effects have been reported, there is no information available about the effects of the medicine on haematological parameters. For the first time clinical and ultrasonographic features and haematological profiles were evaluated in rabbits treated with aglepristone 15 and 16 days after mating. Ten healthy 10–14 month-old New Zealand White female rabbits were mated with fertile bucks and pregnancies were conﬁrmed by ultrasound 15 days later. Of these, 5 does were treated with aglepristone (test group, n = 5) whilst the remaining five (control group, n = 5) were treated with a saline solution (0.9% NaCl). The treatment dose was 10 mg⁄kg body weight, administered subcutaneously once daily on two consecutive days (day 15 and 16 post mating). Ultrasonographic, clinical and haematological assessments were performed daily. Aglepristone treatment induced embryonic fluid resorptions without foetal death in mid-gestation terminations. Following ultrasonographic and haematological examinations, it was established that aglepristone is a safe abortifacient in rabbits.
Efficacy and Safety of Remifentanil as an Alternative Labor Analgesic
Authors: Devabhakthuni Sandeep
Published: May 2013

The objective of this review was to evaluate the clinical efficacy and safety of remifentanil in the management of labor pain. Although neuraxial analgesia is the best option during labor, alternative analgesic options are needed for patients with contraindications. Using a systematic literature search, clinical outcomes of remifentanil for labor pain have been summarized. Also, comparisons of remifentanil to other options including meperidine, epidural analgesia, fentanyl, and nitrous oxide are provided. Based on the literature review, remifentanil is associated with high overall maternal satisfaction and favorable side-effect profile. However, due to the low reporting of adverse events, large, randomized controlled trials are needed to evaluate maternal and neonatal safety adequately and determine the optimal dosing needed to provide effective analgesia. While remifentanil is a feasible alternative for patients who cannot or do not want to receive epidural analgesia, administration should be monitored closely for potential adverse effects.