▁ ▁Qual ifying ▁Draw ▁ ▁Tro fe o ▁Fa ip - Per rel ▁- ▁Singles <0x0A> </s> ▁Ser ia ▁Field ▁is ▁the ▁largest ▁oil ▁field ▁in ▁north west ▁Bor neo , ▁discovered ▁in ▁ 1 9 2 9 . ▁The ▁oil ▁is ▁accum ulated ▁in ▁Upper ▁Mi oc ene ▁sand stone , ▁tra pped ▁in ▁Ser ia ▁Ant ic line ▁that ▁str add les ▁the ▁present ▁day ▁coast line . ▁This ▁field ▁has ▁produced ▁more ▁than ▁ 1   b ill ion ▁bar rel s ▁of ▁oil ▁for ▁more ▁than ▁ 7 5   year s . ▁Br une i ▁Sh ell ▁Pet role um ▁( B SP ) ▁is ▁the ▁operator ▁of ▁this ▁field . ▁ ▁The ▁expl oration ▁of ▁the ▁field ▁started ▁in ▁late ▁ 1 9 2 6 , ▁when ▁F . ▁F . ▁Mar ri ot ▁( B rit ish ▁Mal ay ▁Pet role um ▁Company ▁Field ▁Super int endent ) ▁and ▁T . ▁G . ▁C och rane ▁( General ▁Manager ▁of ▁Sar aw ak ▁O il fields ▁Limited ) ▁sm elled ▁" o il " ▁( H 2 S ) ▁in ▁the ▁K ual a ▁Bel ait ▁area ▁and ▁asked ▁Stra ub , ▁a ▁Swiss ▁ge oph ys ic ist , ▁to ▁do ▁a ▁ge oph ys ical ▁analysis ▁of ▁the ▁area . ▁ ▁At ▁the ▁end ▁of ▁World ▁War ▁II , ▁the ▁Japanese ▁ign ited ▁ 1 4 ▁of ▁the ▁ 2 1 ▁well s ▁in ▁the ▁Ser ia ▁field ▁before ▁ev acu ating . ▁Australian