B.H.P.-Esso upgrades oil reserves

Press, Volume CXIV, Issue 33563, 18 June 1974, Page 20

B.H.P.-Esso upgrades oil reserves

f.V.Z. Press Association—Copyright) SYDNEY. B.H.P. has increased by 22.1 per cent its estimated initial recoverable reserves of oil from Bass Strait. Total initial estimated recoverable reserves of oil, condensate and liquid petroleum gas now stand at 2510 million barrels.

However, since production began in 1969, B.H.P. and Ess j have extracted 422.4 million barrels, leaving estimated net recoverable reserves of 2087.6 million. The release of new oil reserve figures has been sparked by a downgrading of the biggest Bass Strait field (Kingfish) and an upgrading of the second and third biggest fields, Halibut and Mackerel respectively.

The revision of oil reserves is by no means new to B.H.P. and Esso. The chairman of B.H.P. (Sir lan McLennan) pointed: out at the annual meting last j September that the estimation: of total recoverable reserves is a continuing exercise. I

“Given the great number

of variables involved in such calculations, it is understandable that the estimates are likely to vary substantially from time to time as new data becomes available.” B.H.P. in the latest statement, says the new and more precise seismic analyses conducted over the last 18 months have resulted in an increased estimate of oil-in-place. Calculation of recoverable reserves has been helped by four years of reservoir performance by -Halibut and three years by Kingfish. “This, together with studies of water-oil displacement, S gives rise to a higher recovery efficiency estimate, i “Analyses and study of oil.

field performance are a continuous process and periodic revisions, upwards or downwards, are to be expected until a field is virtually depleted.” The recovery rate for Bass Strait is believed to be about 50 per cent of the oil-in-place. Further increases in recovery technology could lead to a significant rise in recoverable reserves and prolong the life |of the fields.

j In addition, LPG and condensate reserves have been released for the first time. ■Total initial estimated re‘coverable reserves of LPG are 387 million barrels and of condensate 181 million barrels.