Response on Jubilee field fom Tullow.25 Feb 2020 21:09
Dear Tony,
With regards Jubilee there were a couple reasons for production performance being significantly lower than expected in 2019, with water cut being one. So perhaps it would be useful to touch on each one briefly:
•Uptime: our forecast assumptions for uptime in 2019 was 95%, when in reality we were closer to 90%. To mitigate the risk of this in 2020 we are now forecasting 90% uptime.
•Gas offtake: we expected the Ghana National Gas Company (GNGC) to take ~100mmscf/d in 2019, but in reality it was closer to ~50mmscf/d. The result of which was that we had to re-inject more gas into the reservoir than we would have liked, increasing the gas:oil ratio (GOR). So far in 2020 gas offtake has improved to >80mmscf/d.
•Gas handling: with the GOR higher (see above) we have to be able to handle more gas at the surface. In late January 2020 we carried out planned maintenance on Jubilee to increase the gas handling capacity from 155mmscf/d to 174mmscf/d. Furthermore the government have given approval to flare for good reservoir management.
•Water cut: this was again a forecasting issue. In 2019 the water cut we experienced in one well in particular was much greater than expected, this corresponds with a decrease in oil rate. However, this is not a reserves issue, shown by the relative stability of reserves at Jubilee (YE18: 123mmboe and YE19: 121mmboe). So it does not affect our ability to capture the same amount of oil within our Production Licence period.
I was impressed to receive the above on the Jubilee field and thought some of you may wish to read it.