Evaluating an Offshore Oilfield

Imagine an offshore oilfield that spans across 15,000 acres that was discovered more than 60 years ago. The field has 3 productive formations between depths of 3,000 meters to 3,500 meters. A total of 50 wells have been drilled in the field; 20 are currently active, 20 are shut in, and 10 have been plugged and abandoned.

With more than 50% of the wells currently inactive, what should one do?

A National Oil Company (NOC) allowed iStore to intervene with their Quick Value Assessment (QVA®) software and consulting services to evaluate the field and give recommendations to help the company achieve the greatest return on their investment. After just 3 months, the study yielded deep insight into the subsurface.

The findings of the study found that the field was larger than currently mapped, therefore the original oil and gas in place values and remaining reserves were larger than originally projected. The study also found that many wells were not drilled through the entire formation, leaving vast amounts of reserves in the lower areas of the reservoirs. A shallower formation with significant reserves potential was also identified, which could give way to even more production opportunities. A few recommendations were made to recover the oil in the tighter portions of the producing formation by implementing hydraulic fracturing with proppant and horizontal wells and a few recompletion opportunities were identified in the majority of the shut in wells.

In addition, the study found that the primary producing formation was faulted. A few blocks experienced pressure support due to natural water drive from an active aquifer and a few more blocks were experiencing pressure drawdown. Maintenance programs were needed due to reservoir pressure nearing bubble point pressure.

The assessment also resulted in a few findings related to data management quality control. After a thorough evaluation of the NOC’s data, recommendations were made to integrate seismic data with subsurface data. Additional recommendations were also made to achieve better data quality and completeness for analysis and ongoing operations in the field.

After viewing the results and taking the recommendations into consideration, the NOC decided to offer the entire field to a service contract to qualified operators. The field study findings also greatly assisted the NOC during the contract negotiation process.