A BIOSTRATIGRAPHIC ZONAL SCHEME FOR OFFSHORE NEGARA BRUNEI DARUSSALAM

De Leon, M.
Consultant
Fletcher Challenge Energy Borneo Limited (FCE)
COMEXCO, Incorporated

        This paper presents a working biostratigraphic zonal scheme based on calcareous nannofossils and foraminifera for offshore Negara Brunei Darussalam. The scheme was developed based on a study made on FCE/Unocal Joint Venture’s wells in Brunei, some old wells and published information.

        The wells studied consist of very thick succession of mostly Late Miocene to Pleistocene age (NN8?-NN21 of Martini, 1971) sediments composed of sandstones, siltstones and claystones. These sediments were deposited within the paleoenvironment range of littoral to bathyal.

        The study suggests that, by enlarge, standard calcareous nannofossil markers supported by additional species offered better age delineations over planktonic foraminifera. On the other hand, large and small benthonic foraminifera are preferred for paleoenvironmental inferences.