With the easy conventional oil in Argentina having been produced, one remaining way to find new oil in existing fields is to convert fields from primary or secondary production to secondary or tertiary production, respectively. For the Cerro Fortunoso field, the high costs required to develop the field, combined with an ambiguous log response that suggested that sand was predominantly disconnected, resulted in secondary production not being implemented. To reduce the risk, a waterflood pilot was necessary to demonstrate that waterflooding has potential and to provide water-injection and production data to constrain the history-matching process.
Fig. 1 shows the location of Cerro Fortunoso in Mendoza province, approximately 1200 km southeast of Buenos Aires. Most large fields in Mendoza province were exploited by waterflood decades ago. For waterflooding not to be initiated, the nature of the reservoir had to be unclear or the capital expenditure required had to be high. In the case of Cerro Fortunoso, a substantial investment is required to cover the cost of drilling infill wells and for the construction of a pipeline to provide injection water from a river 15 km away.
To minimize the risk associated with converting the field to waterflooding, an integrated study was sanctioned that aimed to characterize the field initially and then to determine if waterflooding would, in fact, be economically viable.
Modeling of a Complex Reservoir Where the Normal Modeling Rules Do Not Apply
01 July 2016