Unlocking New Upside Potential Kujung-I Carbonate PHE WMO

Abstrak

"Elemel" field is located in the northern block of PHE WMO. The field is starting to produce gas and oil from Kujung-I formation in 2014. The biggest problem in this field is gas in place calculation with static reef model approximately 46 BCF, but the current in place calculation using MBAL shows gas in place 68.7 BCF which is much higher than the static model. By 2017, one of the reef (Reef B) has produced 110% of the gas from the total gas in place, while the pressure is only decrease 25% and still in production today. Therefore, the static model for the reservoir should be revised based on the actual production data.
Kujung-I formation consists of limestone units with reefal characters and limestone units with carbonate platform characters interbedded with shale. Based on bio stratigraphic data, these two units have different geological ages, reefal limestones have an older age than the above carbonate platform limestones.
Static reservoir model on "Elemel" field was originally constructed based on the geological concept of reefal limestone with boundary reef was defined using variance and the reservoir property distributed using AI seismic attribute. This attribute has correlation coefficient on porosity of 90%.
Potential addition is believed to come from play upside that has been ignored; the Kujung-1 Carbonate Platform is formed spread and onlap against top Kujung-1 Reef. The presence of HC is proved from the data wells that penetrate the interval.