Although thermal heavy oil recovery methods are extensively used, no unified and standardized basis exists for selecting materials and configuring intermediate (production) casing/connection systems for these extreme-service applications. Thermal intermediate casing systems must accommodate a wide variety of mechanical and environmental loads sustained during well construction, thermal service at temperatures exceeding 200°C, and well abandonment. Numerous operator- and field-specific designs have been used with good success and only a few isolated challenges, but industry's use of its operating experience to calibrate tubular design bases for future wells has been limited.
This paper identifies the benefits and components of a unified casing system design basis for thermal wells, aimed to be technically comprehensive, inclusive of the available elements of industry's collective knowledge and experience, and adaptable to technological advancements. The technical element of the unified basis broadly relates to the engineering foundation used to make three primary design selections: material, pipe body, and connections. For each design selection, the paper provides an overview of the associated technological challenges and the current state of the industry in addressing those challenges, including the commonly-adopted design approaches. Key performance considerations include integrity during well construction, connection thermal service structural integrity, pipe thermal service integrity and deformation tolerance, connection sealability, and casing system environmental cracking resistance. Where applicable, the paper identifies interdependencies that exist between design selections (for instance, the impact of pipe material selection on the thermally-induced axial load that must be borne by the tubular and connection), and discusses mechanisms for accounting for those added complexities in the design.
Ultimately, the intent of this paper is to provide a framework for referencing existing technical knowledge and for considering further development and field benchmarking work that will reduce the technological uncertainty and increase simplicity in thermal casing system designs. Industry will benefit from a unified engineering approach that offers operators sufficient flexibility to accommodate application requirements and prior experience.
A low oil price challenges the Operator's field economy for development of deepwater marginal fields. Using typical development solutions proposed in the past 10 years regime with high oil price such developments may not be economically viable to develop, therefore operators call for cost-effective solutions that enables development with today's oil price.
In response to this request a production floater for development of marginal fields has been developed. Equipment vendors were involved in the design process to ensure use of their preferred standard solutions. The target was a processing capacity of 60 000 barrels of liquids with a requirement of a not to exceed topside weight of 6000 tonnes arranged on one deck level. This weight was used in sizing the hull giving the topside designers an early layout area limitation. Conventional proven solutions were used as platform building blocks. The standard Aker un-manned hull (Blind Faith) and a flat top deck with wet truss (Njord A) were combined to form the basis for the topside design using skid-based low weight modules with standardized equipment. A process on removing "nice to have" and heritage from other projects gave a strict project design focus for the equipment selection needed to fulfill safety and functional requirements.
The standard Aker un-manned hull with a flat top deck is used in the design considering 100 to 400m water depth. Typical North Sea functionality and redundancy requirements have been challenged using conventional standardized low weight equipment modules with a campaign based maintenance and repair philosophy. The concept has its base as a product to be used for fields with characteristics in proximity of the proposed design basis, hence, the Operator will have a platform which offers a low CAPEX and OPEX cost compared to a tailor made solution, but with some limitation as compared to a tailor made solution. The design process resulted in a concept with 60 000 barrels of liquids capacity having a topside operating weight of 6000 tonnes designed according to Norsok safety requirements. When comparing to a traditional North Sea platform with similar production capacity 30% weight reduction of the topside was achieved. The cost estimate performed, including the vendor equipment cost, show a further cost reduction. The product type combined with such lean design process inspired the name for the product; the Lean Semi.
The study method represents a different method to do concept studies where the topside weight is constrained and focus is on designing for a highest possible production capacity given this limit. The paper presents this process and the resulting design.
Floating Offshore Wind Turbines (FOWT), Current and Tidal Turbines (CTT), Wave Energy Converters (WEC) and Ocean Thermal Energy Converters (OTEC) are promising Marine Renewable Energy (MRE) technologies. Considering the emerging stage of development of MRE technologies, no dedicated certification scheme has been developed so far by international organizations. Technical specifications are under development in the framework of the International Electrotechnical Commission (IEC) Technical Committee (TC) 114 and IEC Renewable Energy (IECRE) has been recently created. Within IECRE, the Marine Energy Operational Management Committee (ME OMC) is in charge of the development of a conformity assessment system dedicated to MRE. In this context, Bureau Veritas (BV) has issued a Guidance Note NI631 Certification Scheme for Marine Renewable Energy Technologies to support technology developers and speed up commercial phases. The note NI631 covers different types of technology for energy conversion from wind, wave, tidal or temperature gradients at sea. This paper presents the Guidance Note NI631, which purpose is to provide an overview of the certification schemes applicable to MRE technologies, addressing prototype, component, type and project certification. Main objective, scope, intermediary steps to be completed and resulting certificates will be detailed for each certification scheme, as well as their interactions. Finally, focus will be made on a riskbased approach developed by Bureau Veritas to define the reference set of standards used as a basis for certification.
All good equipment & system designs include certain margins to deliver operational flexibility, mechanical integrity and high availability under unforeseen variations in operating conditions. However, the adequacy & veracity of these margins has long been an issue of discussion. Project facility design goes through many cycles of reviews & updating during which, margins are added resulting in equipment or facilities that are difficult and expensive to operate & maintain. Reasons for over-design include working in silos, incorrect input-data, inappropriate simulation correlations and/or assumptions, non-linear incremental cost for upsizing, large project-cycle-time, lack of precedence, avoiding penalties etc. and last but not least, regional culture. This paper discusses the problems & root-causes associated with over-design, its evolution through various project stages & possible opportunities to limit over-design in up-stream oil & gas industry through real-life examples. This philosophy was utilized in recent projects and led to capex & opex savings besides delivering technically efficient systems. As majority of over-design cases relate to green-field projects, brown-field projects will not be discussed. Though over-design bias & its pitfalls apply globally to all sectors of the oil & gas industry, discussion will be focused around surface gas handling facilities (compressors mainly & brief references to pipelines, gas treatment units).
As engineering companies and operators further define the scope of project engineering efforts, the facilities engineer is being phased out of operations. This role is being replaced with a combination of project engineers, package engineers, and other specialists, leading to an increase in complexity in upstream projects. The SPE Gulf Coast Section Project, Facilities, and Construction Study Group’s fall lecture series, “The Role of the Facilities Engineer in Upstream,” defined the role of facilities engineers and the contributions they make to successful project execution. In the first presentation of the series, “The Value of Facility Engineers,” James Deaver spoke about the skills facilities engineers need to develop in order to complement and support the project manager. Deaver is an engineering adviser at Oil Field Development Engineering.
Every operation site, oil and gas drilling, shipping , pipelines and loadingfacilities, need a design basis to be properly planned. Also monitoring of theenvironment when the operation has already started is of utmost importance.This became noticed already in late 1960ies during the Manhattan voyages. Eversince ice data has been collected around various projects both in the westernand eastern Arctic. In Canada the heat was on during the Polar Gas and ArcticPilot Project in the 1970ies and 80ies. The discoveries in the Russian Arcticlaunched systematic arrangements to collect ice data in the in thePechora Sea, Barents Sea, Kara Sea, Ob Bay and offshore Sakhalin Island duringthe last 25 years. This paper describes the main features of typicalarrangements made for a successful data collection expedition, how arrangementsworked and also difficulties met during the execution of such anexpedition.
Chevron has recently developed and improved tools to promote consistency in environmental designs across the company. The objectives of the tools are to leverage institutional knowledge and best practices in environmental engineering design; to select the most appropriate treatment/control equipment; and to provide design recommendations that can be incorporated into engineering specifications. The tools are: 1) the Environmental Basis of Design (BoD) Template; and 2) the Environmental Design Manual.
The purpose of an Environmental BoD is to identify key design requirements related to environmental performance that must be addressed in pre-Front End Engineering and Design (pre-FEED), FEED and included in the final detailed design. The Environmental BoD Template includes company internal standards, and references to international conventions, codes, standards, project-specific compliance requirements and best practice design considerations.
The Environmental Design Manual promotes consistent design of environmental technologies and complements the BoD Template as a bridge between the Health, Environment and Safety (HES) and Facility Engineering (FE) functions by helping HES staff set appropriate design targets and helping facilty engineers design equipment to meet those targets. The Environmental Design Manual is incorporated into the Company's Engineering Standards and is comprised of individual guidelines on specific environmental effluents, emissions or management technologies. The guidelines summarize environmental requirements and provide suggestions on the best engineering designs to meet those requirements. The Environmental Design Manual builds engineering excellence by sharing company experience, lessons learned, and key design recommendations. The Environmental Design Manual now includes guidelines for sanitary wastewater, incinerators, drilled cuttings, and stationary point source control technologies. Guidelines for produced water, onsite waste storage, and flaring are in development. Existing guidelines will also be refreshed periodically to remain current on best-available technologies and company expectations.
Slotted liners used for primary heavy oil recovery support relatively minor operational loads at the depths and pressures common in Western Canada. In such applications, installation loading is the primary concern, and load limits can be defined using an elastic design basis to support running operations. In thermal operations, the installation limits need to be more stringent, because of the impact of residual stresses and deformation on the operating response. Furthermore, the high axial loads induced by confined thermal expansion can place the liner into large-scale yield, where localization resistance is virtually eliminated and a variety of deformation failure mechanisms can become manifest. A prudent design takes the deformation mechanisms into consideration, balancing the mechanical requirements for supporting thermally-induced loads against the inflow requirements to generate the final design.
Commercial Steam Assisted Gravity Drainage (SAGD) projects currently under development in Northern Alberta typically use slotted liner for both injectors and producers. Reservoir sand grain size distributions and inflow requirements require slot densities as high as possible without compromising the structural integrity of the wells. Therefore, a design assessment was required to determine the relationship between slot geometry and density, thermal and production loading, and post-yield material properties. A variety of possible failure mechanisms were considered, and failure limits in terms of these controlling parameters were evaluated. The outcome was an allowable slot density, slot geometry and post-yield material description required for the liner to operate reliably, and corresponding quality assurance programs to ensure the slots and material satisfy the requirements for reliable operation.
The paper addresses how the difficulties of designing the fire protection on a new offshore project using fire assessment as the basis of project using fire assessment as the basis of design can be overcome. It suggests how the layout, process and protection design can proceed in parallel when they are interdependent. It examines the stages at which fire assessment should take place, the level of detail required and the decisions which should be taken.
The size and duration of process fires with respect to platform scale are addressed. This introduces the question of the maximum tolerable fire size. This, in turn applies constraints to process design, inventories and layouts.
It identifies process design and layout measures which can be used to minimise the scale and duration of possible fires. It shows how the fire analysis method can be used to highlight those process sections creating the greatest fire risks process sections creating the greatest fire risks and those with insufficient inventory to cause significant damage or escalation.
Overall it directs designers to integrate process and fire protection design so that the optimum protection strategy can be achieved. protection strategy can be achieved
The Inquiry report into the Piper Alpha disaster (1) recommended that the prescriptive legislation requiring the provision of an array of active fire protection equipment should be repealed and protection equipment should be repealed and replaced with "goal setting" regulations. This would allow designers to use all the tools at their disposal to minimise and counteract fire hazards. It should also allow due credit to be given by the protection designer and the approval bodies for the protection designer and the approval bodies for the inherent safe design features. This has not always been the case in the prescriptive era. These features include process design, control measures, layout and drainage and are addressed by different discipline engineers on a project. It is important that each of these disciplines understands the contribution it can (make to the reduction in fire hazard. A process fire hazard analysis method (2) has been developed to quantify the size and duration of credible fire hazards. This requires input from the various disciplines and can be used to show how variations in design can affect the potential consequent fires. This would allow all potential consequent fires. This would allow all disciplines to work together with the protection designers to provide an integrated, cost effective design.
THE TRADITIONAL OFFSHORE PROTECTION DESIGN PROCESS
Traditional offshore design methods have been dominated by compliance with the regulations (3) which are centred around the provision of equipment such as firepumps, deluge systems etc. As designs have progressed, loss control engineers have endeavoured to provide safer platforms by increasing the levels of protection or have added novel features to the systems. This is reflected in, for example, the use of higher deluge application rates, pressure controlled deluge systems or automatic loadweigh halon systems. This concentration on equipment has resulted in better protected, but not necessarily safer, platforms. protected, but not necessarily safer, platforms. The design process has been dominated by material "deliverables", with particular emphasis on long lead items such as firepumps. These have been sized on a water demand figure originating from the largest "reference area". This is a process or wellbay area bounded by firewalls. The water quantity is based on the floor area multiplied by a water application rate with contingency factors for shadow effects and hydraulic balancing. In some cases, an allowance is also made for application on to the surfaces of vessels.
The primary criticism of this approach is the lack of any assessment of the fire hazards or of their consequences. This was highlighted in evidence to the Piper Alpha Inquiry.