The Ymer Platform

Ymer is a semi-submersible production, drilling and living quarters (PDQ) platform, Eigure 27.1. The platform is located directly above the subsea 

The platform deck is built as an integrated deck structure. This is located on the top of a substructure, consisting of four columns and a rectangular pontoon. The platform is fixed to the seabed by sixteen anchor chains. 

The drillfloor and the derrick (drilling tower), with pipe handling systems and the flare tower on the top, are located in the centre of the platform. In this area, we find the remaining systems, for drilling and mud treatment. Subsea equipment such as valve assemblies (X-trees) and blow-out preventer (BOP) are stored and handled in the moon-pool area below the drill floor. 

The aft of the integrated deck is dedicated to the process systems. There is an oil- and gas-processing train with three-stage separation for production of 15000 Sm stabilised crude per day. All gas is compressed and re-injected during the initial production phase. 

The living quarters are built as a separate module at the front end of the platform. Here we find the accommodation areas and the offices. Most of the utility systems for electricity, water, air, etc. are located in the integrated deck below the living quarters. There are two main generators adjacent to the derrick. 

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The manning level of the Ymer platform is lower than on other comparable platforms. This is obtained by simple and functional design and by letting machinery suppliers take more responsibility for maintenance of their own... 

According to Norwegian risk-analysis regulations, oil companies have to develop acceptance criteria for the risk of losses due to accidents. Risk analyses should be used to verify that new design solutions meet these criteria. Norskoil applies the following acceptance criteria for the Ymer platform ... 

In a Comparison analysis, the number of accidents per year of operation is estimated for the Ymer platform. Accident statistics for the two reference installations serve as a basis for these estimates. Three different teams representing the different areas of the platform make the estimates. All teams consist of project and operations personnel with thorough knowledge of the area. Results show that the total number of accidents per year is expected to decrease somewhat compared to the reference platforms. Reductions in the number of accidents in maintenance in particular contribute to this decrease. This has to do with improved equipment handling during maintenance, improved equipment reliability and improved maintenance plans. 

Norskoil has documented its SHE management system for the operation of the Ymer platform. It is not collected in a handbook but is integrated into the total platform-management system that is available via Intranet. It covers the following elements ... 

Implementation is ensured through the Ymer platform organisation as defined by its responsibilities and qualifications. There are yearly SHE action plans that break down the policy and goals into tangible actions. 

Figure 27.11 Control chart for the Ymer platform, showing the upper control limit (UCL) and the lower control limit (LCL).

Control chart for the Ymer platform, showing the upper... 

Permit-to-work systems should ensure that work is planned and carried out under adequate safety precautions in cases where the exposed persons do not have personal control of the involved hazards (Section 7.6). At the Ymer offshore platform, modifications of one of the compressor trains must take place while the platform is producing. This work has been subcontracted to an installation firm, BCC Installations. At the start of this work, the platform manager wants to be confident that the established work-permit-system is adequately designed and implemented. Your group is assigned the responsibility for the planning and execution of an audit. Its scope is the implementation of the work-permit-system for this particular modification work. Your tasks are to ... 

This Part illustrates different applications of SHE information systems. Chapter 27 is built around a case, the Ymer offshore platform with Norskoil as operator. The case is fictive, but it draws experiences from a number of real field developments on the Norwegian continental shelf. We will look into how experience feedback is accomplished in different phases of a platform s Ufe cycle, i.e. design, construction and operation. The purpose is to demonstrate the use of different methods presented in previous sections of this book as integral parts of a SHE management system. We will illustrate both the prevention of occupational accidents and the prevention of major accidents. 

SHE is a central issue in all activities in connection with the development and operation of offshore fields. We will here demonstrate how the different tools described in Parts HI to V may be put into a system for use in SHE practice during the different phases of an offshore platform s life cycle. We will concentrate on design, construction and operation. The selected case, the Ymer field with Norskoil as operator, is fierive. It draws experience from real installations in operation and project work. 

Norskoil decides to select a semi-snbmersible platform concept for further development of the Ymer field. At the second decision gate (DG2), Norskoil s board of directors makes the project go decision. To pass this gate, the investment plan has to show adeqnate profitability. This impHes that the capital and operational expenditures as well as the revenues from production of oil and gas are known with adequate certainty. It is here necessary that the project s scope has been adequately defined. The platform concept and the subsea and pipeline installations must be defined at an adequate level of detail. 

Example The Comparison analysis indicates that there will be a small increase in the frequency of drilling accidents from on average S.8 accidents per platform year at the reference platforms to 5.9 at Ymer. This increase is mainly explained by increased drilling activities, whereas the probability of accidents per activity has been reduced. Due to expected improvements in other areas, the acceptance criteria are met. 

Example The Ymer contract is a EPC contract, where one contractor will be responsible for the design and fabrication of the complete platform. This contractor will in turn sub-contract parts of the work to other contractors. One of the potential bidders for the Ymer contract had allied itself with other yards to be able to tender for the complete contract. One of the yards in this alliance did not perform well on SHE management and performance in the pre-qualification audit. The Ymer project management decided to accept this bidder alliance in order to achieve adequate competition for the contract. 

Ymer s platform management faces a number of SHE challenges, especially dnring the first period after start-np. The organisation is new and unfamiliar with the platform and the management system. Construction work on the platform has not been fully completed at start-up and continues in parallel with production and drilling. It is of major importance to avoid construction work on systems that have not been de-energised. Here, the permit-to-work system plays an important role. 

We here choose to describe and analyse the SHE management principles applied at Ymer during the operation phase in relation to the well-known quality control loop. Figure 27.9. We view safety against occupational accidents as a quality aspect that platform management has to satisfy. 

Norskoil s overall SHE policy has been implemented in Ymer s SHE management system. In addition, Ymer s management has defined goals for the SHE performance of the platform. 

Ymer practices one-on-one rounds at the different levels of the platform organisation. Approximately twice a year, Norskoil s assistant director for production makes a one-on-one round with the platform manager. They are not notified in advance and the focus is on safe behaviour and housekeeping. The platform manager and the department managers make such rounds on a monthly basis. 

Ymer has implemented coarse and detailed job-safety analyses as a systematic measure to control the hazards at the workplaces. All employees are involved in these activities. They participate in the listing of all activities on the platform. Each activity is assessed and documented with respect to ... 

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