ONGC’s offshore operations - Application of Floating production systems

ONGC’s major share of oil & gas production comes from its offshore fields in water depths ranging upto 100m with facilities mainly confined to fixed wellhead platforms with dry trees, fixed processing platforms and subsea pipelines. This approach is economically viable only for fields having high production potential and long field life, being high capital intensive. ONGC has discovered few offshore marginal fields located at considerable distance from existing processing facilities with peak production potential of the order of 25000-50,000 BOPD and short production plateau period. Development of these fields with fixed platform and pipeline architecture will not be cost effective. Further Fixed platforms have limitations in terms of water depth and are not suitable for the discovered fields in the deeper waters. Therefore, ONGC started examining the development with alternative technologies like FPSO, MOPU, FSO/FPU combination, etc. for last couple of years.

Each of the alternative solution has its own advantages over the other. Decision to select a particular development option depends on many aspects besides technology and economic viability. The decision has to be weighed on considerations like company’s strategy to own asset/facility or to take asset/facility on hire, operational philosophy (by company itself or hire from contractor), company’s experience / position on learning curve for the selected technology. The decision process is necessarily iterative and involves tradeoffs.

The first technology considered for development of a marginal offshore field is by deploying a hired FPSO for processing and export of hydrocarbons. All possible options were examined and weighed against each other wherein hired FPSO approach was found to be most attractive. The exercise carried out for one field (X) has established that FPSO as a viable alternative for consideration for development of marginal fields offshore. While the contract for hiring FPSO for X field has been awarded and FPSO is expected to be mobilized in Dec 2012, ONGC requires another FPSO for Y field development.

The paper will discuss the Technological & Contractual issues, the acquisition strategy and the lessons learnt in hiring a FPSO for development of marginal fields in western offshore and to master the technologies to regain confidence to operate in deep water in east coast in future.

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