Worley warns of 'Potential Catastrophe'

Vol 6, PW 10 (17 Jul 02) Exploration & Production

Safety is also an area of major concern for Worley, which makes some startling observations about the state of ONGC's offshore installations on Mumbai High (South).

According to Worley, the lack of "integrity of the primary cementations" leading to migration of gas into the "annuli and near surface horizons" was responsible for two blow outs on the B121 platform and the loss of the platform's wells and jacket. Worley is alarmed by a survey from Cudd Pressure Control of the US that reveals two thirds of 600 wells at Mumbai High (South) have gas flow and pressure build-up in the surface casing.

"Leaks and gas flow paths should be monitored and remedial action plans put in place to avoid an escalation of the situation and potentially catastrophic consequences," says Worley. Another vital safety issue is the "lack of communication across bridge-linked facilities in Mumbai High".

Adds Worley: "A fire or other major incident at one platform may be escalated in its consequence by the lack of immediate response from connected facilities (such as shutting-in oil and gas production). Given the high degree of interconnection between the various major facilities this is a major risk to ONGC." Worley praises ONGC's offshore staff and marvels at their ability "to manage an extremely complicated interconnecting system without the vital online data to optimise the key parameters." Worley advises the introduction of modern 'Distributed Control Systems' to improve communication.

Other recommendations: Reduce number of personnel managing the facilities Slash the time personnel spend in the field Execute remote control and shutdown of unmanned platforms during extreme weather conditions Reduce flared gas by improving process control Reduce unplanned shutdowns by early detection and control of process upsets Improve operational stability of the whole field by enhancing knowledge sharing Provide a central location for managing field production Free up existing control rooms for purposes such as instrument workshops and storage Introduce long term maintenance contracts as in the North Sea to cut costs and free up more time for preventive rather than breakdown maintenance