Abstract: The Integration of Geochemical, Geological and Engineering Data to Determine Reservoir Continuity in the Iagifu-Hedinia Field, Papua New Guinea

KAUFMAN, R. L., R. E. FITZMORRIS, and L. I. EISENBERG

In oilfield appraisal and development, the identification of reservoir compartments, whether vertical or lateral, is necessary to understand future reservoir performance. This compartmentalization may develop over geologic or production time frames depending on the characteristics of the seals which isolate the compartments. Frequently, the identification of many reservoir compartments is made only after the field is put on production.

In Papua New Guinea, a series of oil and gas fields, including Iagifu-Hedinia, occur along the leading edge of the Papuan fold and thrust belt. Formed during Pliocene to Recent compression, they are structurally complex, and typically broken into multiple reservoir compartments. The presence of the karstic Darai Limestone at the surface over most of the fold belt prevents acquisition of useful seismic data. Reservoir mapping, and establishment of reservoir continuity, is therefore based solely on 1) surface geologic data, 2) drilling data; initially dipmeter and RFT pressure data, and subsequently well production histories, and 3) geochemical correlation of reservoir fluids. During appraisal of the Iagifu-Hedinia discovery, these complimentary data sets demonstrated that 1) a single hydrocarbon column existed above a flowing aquifer in the main block of Iagifu-Hedinia field, 2) a separate accumulation existed in the Iagifu 3X/8X block, and 3) that two or more separate reservoir compartments existed in the Usano area.

The value of this study was to characterize a structurally complex reservoir in the absence of seismic data. The slight differences in oil composition between reservoirs are likely due variations in the reservoir filling history and multiple phases of oil charging.

AAPG Search and Discovery Article #90942©1997 AAPG International Conference and Exhibition, Vienna, Austria