Much more still needs to be done at Mumbai High

Vol 8, PW 2 (21 Apr 04) Exploration & Production

Without doubt ONGCs redevelopment of the Mumbai High has halted the worrying decline in production.

But the GCA-led review believes more needs to be done. The current production rate is less than forecasted in the feasibility reports, it states.

This is attributed to, lower number of wells drilled, project delays and recent unplanned facility downtime. For instance, production from Mumbai High Norths LII reservoir in October 2003 was 11,000 b/d against 14,400 b/d projected in the feasibility report.

Luckily, ONGC is already working to rectify this and, a new geological model for LII has been prepared and a simulation study is being carried out to firm up redevelopment and augment production. No different is the story at Mumbai High South where, post-revamp, cumulative production till 31st March 2003 was 19.4m tonnes against the feasibility report target of 20.3m tonnes.

By end-March 2004, production would have reached 27.2m tonnes 3.5% below the feasibility report forecast of 28.2m tonnes. At Mumbai High North, cumulative production since redevelopment till 31st March 2003 was 9.1m tonnes, while the feasibility report had forecast 9.9m tonnes.

By end-March 2004, cumulative Mumbai High North production would have reached 12.9m tonnes 6.5% below the 13.8m tonnes forecast in the feasibility report. The ONGC-GCA report is candid in its analysis of why production is below target.

Procurement and installation of platforms, pipelines and facilities are behind schedule. Much of the delay has been caused by slippage in tendering and award of contracts.

Because of these, ONGC has had to carry out, alternate drilling plans to use existing free slots, install additional clamp-on slots and complete more sidetracks. More, overall drilling is behind schedule.

By October 2003, as against the 93 redevelopment wells to be drilled, only 86 had been drilled. Why Changes in development planning, underperformance of some of the rigs and implementation of new drilling technologies.

Drilling costs were also higher than forecast.