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Facility operability is the ability of an organization to operate a facility in a safe and efficient manner. The ultimate goal of facility operability is to design and construct a facility that will remain safe, efficient and cost effective throughout its lifetime use. The majority of oil and gas facilities are built and operated successfully, but issues can arise during the design phase and those issues can eventually lead to costly or even detrimental incidents. Proper planning and preparation can enable an organization to adhere to guidelines of licensing organizations and insurance companies. Hazard operations (HAZOP) studies assess the effectiveness of facility operability plans, to identify potential or existing hazards and to evaluate the potential effectiveness of planned changes to a facility.Elements
Abstract For decades, efforts have been made to automate the HAZOP process. The motivation has mainly been to displace expensive manual HAZOP approaches, that are furthermore known to suffer from systemic quality issues related to system complexity, uncertainty, vagueness and level of knowledge completeness. With offset in a review of the main historic arguments for automating the HAZOP analysis, and an outline of the particular benefits of employing Multilevel Flow Modelling (MFM) theory in this context, this paper emphasises the opportunity to redeploy the insights achieved by the HAZOP team to assist an operator facing an abnormal event years later. By means of a detailed analysis of an actual catastrophic failure of a FPSO compression module, the paper demonstrates how MFM enabled HAZOP captures explicitly tacit expert knowledge about the complex interdependencies between process design, equipment design, safety barriers and instrumentation. The paper further describes a methodology to interpret measurements online by means of the MFM analysis, thereby establishing real-time cause and consequence analysis in sufficient time to interrupt the escalation from a benign sensor malfunction to a topside explosion. The paper concludes by outlining a knowledge management framework centred in MFM of the technical, operational and organizational safety barriers, which would make hitherto tacit knowledge explicitly available at all critical decision points during the lifecycle of a process plant, from design and HAZOP to commissioning, operation and decommissioning, as well as in any plant modification required along the way. The MFM theory was adapted and extended to capture the experienced failure mode and thereby facilitate HAZOP automation and subsequent intelligent real-time operator decision support.
Abstract Both Hazard and operability study (HAZOP) and Layer of Protection Analysis (LOPA) are two recognised techniques (or ‘tools') in the Process safety toolkit. Application of these techniques however has historically been restricted to a limited range of operations within upstream. This paper will describe how these tools can, and have been, successfully applied in broader applications. HAZOP was first applied in the heavy organic chemicals division of Imperial Chemical Industries in 1963. The technique was subsequently developed and matured over the following years. Today in the upstream industry HAZOP is typically applied to both existing process operations and new projects. LOPA generally follows after a HAZOP to perform a semi-quantitative assessment of the event likelihood. Application of these techniques however has historically been restricted to a limited number of operations within upstream. The objectives of the paper are to i) describe examples where HAZOP has been successfully applied to novel operations and activities ii) show how LOPA can be applied, not just for determination of Safety Integrity Level (SIL) but to hazards not associated with an instrumented function and iii) demonstrate that broader application of these tools can lead to and improved understanding of risk and, through effective risk reduction, create value for operating companies. An overview of potential challenges associated with implementing this adapted approach towards HAZOP is described, but also possible solutions. Following this the links between HAZOP and LOPA, including the information flows from one study to another are re-capped. This includes highlighting the difference between safeguards and layers of protection and qualitative risk assessment (HAZOP) versus semi-quantitative (LOPA). Current triggers for applying LOPA are compared to other approaches that result in a broader perspective and applicability. The key here is to demonstrate that there are a number of additional hazards that may be identified through HAZOP study, but for which an instrumented function may not be provided. As a result these are currently not always taken forward for further, semi-quantitative assessment. This current approach therefore limits our understanding of the associated risk. In summary, through the use of example scenarios, the paper reveals some of the limitations resulting from restricted application of HAZOP and LOPA. The intent is to raise awareness of how companies are applying these tools to analyse additional operations or activities and, as a result, reduce the frequency of high severity events. The key conclusion is that these existing tools i) with some effort can be readily applied to new / novel areas and ii) can help management understanding of risk and provide assurance that these risks are being adequately managed. In short to fully understand the Process Safety risks associated with our projects and operations we must look to broaden the application of both HAZOP and LOPA tools.
Abstract This paper summarizes a number of the challenges encountered and the common findings in HAZard and OPerability (HAZOP) studies related to the surface gas and mud handling systems on drillships, jackups, semi-submersibles, and land rigs. These HAZOP studies are conducted by experienced multi-disciplined teams that combine the operations, engineering, and process safety personnel from both the oil company and the drilling contractor.
The development and use of the fundamental risk assessment process, the HAZOP (Hazards and Operability Study), was originated in the 1960’s by Trevor Kletz at ICI Industries in Great Britain, and has been a developing process both in its content and the extensiveness of its application during the last 50 years. In particular, the HAZOP process has evolved to be applied at different stages of design and execution such that industry would specifically apply the process to its older (Brownfield terminology) facilities where they can show significant reduction in chemical related incidents with use of the HAZOP process in their mature plants. This demonstrates the existence of a latent risk in these facilities which can occur for several reasons but which is reduced by a HAZOP process. The authors’ use career experiences and recommended practices to advocate the HAZOP in the operations phase which is also known as the OESR, the Operational, Environmental and Safety Review while illustrating through case histories the use of this tool. Conclusions and recommendations are offered for further application and risk reduction in operational facilities.
Knowledge management includes a library of understanding of the modes of failure such as corrosion, erosion, loss of material properties, cracking, fatigue, other failure modes and related aspects which are critical in deepwater projects. This is due to repair, retrofit, or re-habilitation being costly or impossible. The application of early detection of and an inspection program for potential issues and identification of areas of further study is critical.
Abstract The North East Bab (NEB) Project is currently under construction by Abu Dhabi Company for Onshore Oil Operations (ADCO). It is a grass root field development project. New production facilities are installed to handle oil, gas and water production from three separate oil fields; Al Dabbiya, Rumaitha and Shanayel. In accordance with the project HSE plan, a HAZID (Hazard Identification) study was conducted during the conceptual design phase.HAZOP studies were carried out during the FEED and EPC phases of the project. This paper describes the role of HAZOP in a complex major project involving full field development.Topics covered include: project description, project HSE plan, HAZOP logistics, main HAZOP findings, follow-up and implementation of the HAZOP recommendations as well as the lessons learnt. Finally, the paper concludes by making recommendations on the effective way to implement HAZOP studies for new projects in an E& P environment. Introduction Abu Dhabi Company for Onshore Oil Operations (ADCO) is currently implementing Phase I of North East Bab (NEB) Project, which is a grass root development. New processing facilities will be required to handle oil, gas and water production from three separate oil fields; Al-Dabbiya and Rumaitha and Shanayel. Water and gas injection facilities will also be required to provide pressure support and enhanced oil recovery. Al-Dabbiya is located approximately 50 km south west of Abu Dhabi City. It comprises of a series of low lying islands. The majority of Al-Dabbyia wells, however, are located offshore on existing artificial islands. A network of marine pipelines and power cables will be required to support this arrangement. Rumaitha and Shanayel fields are located entirely onshore in a desert location, some 30 km south of Al-Dabbiya.The location map is shown in figure 1 and the field layout is shown in figure 2. The fields are located in environmentally sensitive areas. Al-Dabbiya presents special concerns because of its proximity to delicate coastal ecologies. The EPC Contract for the project was awarded to an international contractor in May 2003. The project facilities comprise of the following:Central processing plant (CPP) at Al-Dabbiya Central processing plant (CPP) at Rumaitha 15 Clusters (remote stations) at Al-Dabbiya 10 Clusters at Rumaitha / Shanayel The key design parameters of the facilities are as follows:Al-DabbaiyaSustainable oil production rate = 70,000 BPD Peak oil production rate=84,000 BPD GOR= 1000 to 2500 Wellhead closing pressure = 4000 to 1000 psia Two processing trains x 55,000 BOPD H2S contents = associated gas 1% mol, non-associated gas 5% mol, facilities design basis 3% mol. Rumaitha / ShanayelSustainable oil production rate = 40,000 BPD Peak oil production rate=55,000 BPD GOR= 500 to 2000 Wellhead closing pressure = 4000 to 1000 psia One processing train x 55,000 BOPD H2S contents= associated gas 1% mol, non-associated gas 5% mol, facilities design basis 3% mol.
Abstract Many Oil and Petrochemical companies devote considerable resources to hazard identification exercises such as HAZOP studies. A large number of recommendations are generated but progress is often difficult and the amount of work is typically well beyond available budgets. This paper describes an approach to prioritizing HAZOP recommendations and assessing the benefits cost aspects of alternative initiatives. Most importantly the method puts the proposed safety expenditure within the context of existing Risk Management programs including Insurance and alternative investment in other schemes to improve process performance. In this way investment in safer operation is evaluated on the same basis as other business opportunities and within an overall framework of Corporate Risk Management.
The paper will provide an insight into the role of HAZOP in a complex North Sea project involving three significant new subsea developments - Lyell, Staffa and Strathspey - operated by third parties and tied back to two existing Ninian platforms, Central and Southern. Major platform modifications were required involving both new process systems and the revamping of existing facilities, all whilst maintaining existing production. This presented substantial technical, project and safety related challenges of a type not hitherto encountered by North Sea operators. An integral part of the project plan was the comprehensive use of HAZOP as a core activity in ensuring that corporate safety and project operability objectives were met. HAZOP was seen as an important element in Chevron's Ninian Safety Case as the primary tool for hazard identification. The successful application of HAZOP in this complex ‘brown field' development required a range of measures, some often overlooked and some involving innovative HAZOP methodology and these are detailed.
The Ninian field operated by Chevron on behalf of the Ninian Field Group, is a mature North Sea producer with the Ninian Central Platform acting as a strategic gathering point for oil from Unocal's Heather, BP's Magnus and Total's Alwyn North fields. Rationalisation of the topside facilities and declining production rates had left spare equipment and capacity in the production systems of two of the three platforms. This spare capacity, coupled with Ninian's strategic location in the Northern North Sea makes it an ideal candidate for tie-in of satellite fields in the area. [Ref 1]
Staffa, Lyell and Strathspey, operated by Lasmo, Conoco and Texaco respectively are three such third party subsea developments using Ninian topsides facilities.
The task to bring on production fluids from these three fields and process them using the existing infrastructure became known as the Ninian Third Party Project (NTPP). The project presented a number of unique technical and safety related challenges. It involved subsea tie-in via existing risers and J-tubes, extensive modification and upgrade to existing facilities, as well as the installation and hook-up of new gas processing modules. New "state of the art" equipment was required to be interfaced with that of a mid-70's design. These major operations were to be performed in a staged approach whilst Ninian continued to operate. In keeping with most modern projects there was a demanding schedule requiring careful project management.
NTPP objectives included ensuring that potential hazards were identified and addressed, as well as affirming the facilities would be fit for purpose, operable and safe. The design team also had to satisfy the requirements of the offshore Operations group and contractual obligations to Lasmo, Conoco and Texaco.
The NTPP was conceived and started during the compilation of Lord Cullen's Report and accompanying recommendations following the Piper Alpha tragedy. Consequently Chevron were required by these circumstances to interpret their obligations under the evolving legislative and goal setting regime. Corporately Chevron committed to producing Safety cases, as defined by authoritative industry opinion at the time, for their facilities.
Environmental Review Using Structured Analysis Technique (ERUSAT) provides a method to comprehensively review the environmental regulatory requirements that would affect the engineering design of an offshore drilling and production platform. It is used to identify scenarios/issues which could result in environmental non-compliance and provide a means of addressing potential design modifications which would alleviate the environmental concerns.
The method is qualitative, requiring an experienced multidisciplinary team to identify scenarios/issues from the review of all pertinent environmental legislations, development and design conditions, previously conducted HAZOP studies and third party studies that could potentially affect the platform design and to discuss potential design modifications leading to a recommendation for further task force/contractor review. The study is meant to be an integral part of the engineering process of the project, similar to the other safety studies performed on the platform design.
The approach is similar to other structured analysis techniques, such as Hazard and Operability (HAZOP) studies, but requires the identification of issues/scenarios rather that potential causes of undesired events. The review requires several steps:
Step 1: Identification of potential issues/scenarios;
Step 2: Critical review of identified issues/scenarios;
Step 3: Recommendations (where warranted) for changes in practices or design or for a more detailed study to determine solutions.
The ERUSAT study document thus produced, will now be a living document for the operating company to be updated regularly in response to environmental legislative changes, technological advances in pollution abatement equipment, operational experience, etc..
The paper outlines the ERUSAT approach, explains the customizing of a commercially available HAZOP software package to facilitate the documentation of the study, summarizes the results of the review sessions, and highlights the potential application of the technique to the current development project and other future onshore/offshore complex industrial projects.
The project consists of a concrete Gravity Based Structure (GBS), a topsides consisting of five super modules and two drilling rigs, a crude loading system with offshore loading facilities, purpose-built shuttle tankers, and support vessels. This facility will be located on the outer continental shelf of the Grand Banks on the east coast of Canada.
Environmental requirements have historically played an important part and prominent role in the project's development due to the environmental sensitivity of the Grand Banks, one of the richest fishing grounds in the world.
Responsibility for process safety may start with the facility designer, but it ends up with the production operator. A process facility, no matter how well designed and protected, is unsafe unless its operators are thoroughly trained. This paper describes an operator training program for a Unocal Thailand offshore gas compression and conditioning platform that was structured around the HAZOP analysis technique. The program proved to be efficient and effective, and was unexpectedly popular with the operators. This training structure solves many of the intercultural problems that have limited the effectiveness of technology transfer in the ASEAN region.
In February 1992, Unocal Thailand commissioned an eight-pile central processing platform designed for 170 MMscfd of natural gas and 15,000 barrels per day of condensate from the Funan Field in its Gulf of Thailand concession. The processing facility supports two trains of gas compression, glycol dehydration and hydrocarbon dew point control, and a condensate processing system that sends stabilized product directly to a storage tanker.
A thorough HAZOP study of the facility was conducted by the design team in June 1991. The study uncovered no serious deficiencies. This was not a surprising result for a proven design that had evolved from three similar process facilities brought on-line during Unocal's twelve years of offshore production in Thailand. All potential catastrophes were well covered by automatic safeguards, design conservatism and application of industry standard practices. The design did not, however, provide automatic coverage for every minor problem.
The Funan design-validation HAZOP study revealed a principle common to many normally- manned process plants: the operators themselves are the safeguards against escalation of "routine" upsets. Small process upsets, each with their potential for product contamination, plant shutdown and minor equipment damage, are left to the operator to handle. Automatic safeguards do not take over until the event escalates, in most cases by initiating some level of process shutdown.
On Funan, the operator would be the first-line safeguard against escalation of minor operating upsets. Automatic devices were provided to back up the operator if he failed, or was unable, to react correctly.