oa Beneath the Surface: Unearthing Low Resistivity Pay Zones in the Balingian Province

The Balingian Province, situated offshore Sarawak, Malaysia, has recently emerged as a focal point of intrigue in the hydrocarbon exploration sector due to the newfound discovery of concealed low-resistivity hydrocarbon reservoirs, challenging conventional wisdom. This paper presents a rigorous methodology for the evaluation of these low-resistivity zones, underlining the necessity of a holistic approach. Traditionally, high resistivity has been regarded as indicative of potential pay zones, but recent revelations have complicated this interpretation. The methodology involves precise resistivity measurements, shaliness estimation, and water saturation calculations based on variations of Archie’s law. Nevertheless, challenges arising from limited vertical resolution of logging tools and mineralogical complexity in reservoirs are addressed. Through a case study of Well X-1, which exhibited low resistivity readings in carbonate-clastic intervals, we demonstrate how elevated gas readings and Nuclear Magnetic Resonance (NMR) logs played a pivotal role in revealing the presence of hydrocarbons, subsequently validated through fluid sampling and analysis. The reassessment of these previously underestimated hydrocarbonrich zones in the Balingian Province has not only enhanced our geological understanding but also inaugurated a new era of exploration, offering promising untapped hydrocarbon potential in a once-deemed mature basin.