Présentations Colloques

Oral Presentation
Session 8.06: Verification of conceptual patterns and expected natural effects of regional groundwater flow by interpretation of relevant field observations
Atin Musti
Hydrochemistry study to determine an active hydrodynamic in hydrocarbon trap system
High water resistivity value in shallow, friable-to-loose sandstone reservoir characteristics below oil-water contact is a rare condition in oil and gas field in Indonesia. Water samples from several wells have been analyzed and showed Na-bicarbonate water type. Low TDS values of the water clearly indicated fresh water characteristic and tritium isotope analysis showed that the water has young age range from 23 to 47 years. These conditions are similar to modern groundwater. Therefore, the water in water zone of the reservoir was not originated from sedimentation process and still affected by modern groundwater movement. The presence of groundwater movement indicated that water in the reservoir could be supplied from recharge area close to study area. Pressure conditions in some wells of the study area are known had a supernormal dynamic pore pressure regime which means that the wells are located in discharge area. All of the analysis yield conclusion that the fresh water from recharge area enter the reservoir and flowing into the wells. The water flow caused the hydrocarbon trapping mechanism in the study area as active hydrodynamic system.