Publications

Handil Field is located in Kutai Basin, comprises of multilayer and highly compartmentalized reservoirs of the Miocene Mahakam Delta complex. As a mature oil and gas field, detailed reservoir characterization is required to optimize production and field development schemes. This paper presents an integrated reservoir modeling workflow to define better reservoir compartment and to know the geology factor that cause it. The analysis will be based on sedimentology concept and dynamic reservoir behavior. The methods used consist of facies analysis, well correlation using sequence stratigraphy concepts, geological modeling, and reservoir connectivity analysis using reservoir pressure data and fluid map. The Handil Deep Zone interval comprises of delta environment deposits of the Mentawir Formation. The development of channel facies complex is northwest-southeast trending and bar geometry (mouth bars and splays) are perpendicular to channel sedimentation. Normal fault and 4-way dip anticline structures were established during the compression phase of Middle Miocene. The normal fault acts as seal fault, restricting connectivity of reservoirs in between where it shows different fluid contacts across the fault. This divides the field into two major compartments: north and south. Reservoir heterogeneities at the scale of facies differentiation of a delta environment has also affected reservoir compartmentalization. Integrated reservoir connectivity analysis using reservoir pressure data, fluid map, and sedimentological concepts, help in defining reservoir compartments and provide a better perspective of understanding sedimentological factors. Reservoirs of R28 interval at region B-4 in the north part of the field is presented as an example of performing this compartmentalization analysis. As the result, two region of accumulation are identified, B-4.1 and B-4.3 which may resulted from rapid channel abandonment restricting the connectivity between sidebar channels. Volumetric estimation for each accumulation is carried out from geological modeling and is then validated with volumetric estimation from material balance analysis to confirm the interpretation of reservoirs compartments. This provides a higher level of confidence for field development purposes.