Integrated Interpretation of C-8 and G-61 Sandstones at Badak and Nilam Fields in Sanga-Sanga Block of East Kalimantan, Indonesia

W. C. Ade, W. Suwarlan

Huffco's Badak and Nilam fields are giant gas fields that together currently produce more than 1.0 bcf of gas per day from sandstones within the Miocene Balikpapan beds. The reservoir sandstones were deposited within a thick regressive deltaic sequence that includes coals, shales, and occasional limestones. Wells typically encounter multiple stacked pay sandstones at depths ranging from about 5,500 ft to more than 13,000 ft. Individual sandstone thicknesses can vary from several feet to more than 20 ft. Abrupt lateral stratigraphic variations in sandstone thickness are the rule rather than the exception.

Sandstone reservoir interpretations are based on an integrated approach by incorporating the study of well logs, cores, seismic sections, normal moveout-corrected gathers, amplitude variations with offset (AVO) graphs, and pressure and reservoir performance data.

AAPG Search and Discovery Article #91022©1989 AAPG Annual Convention, April 23-26, 1989, San Antonio, Texas.