A Ryder Scott Calgary team experienced in evaluating western Canadian heavy-oil projects studied the Issaran heavy-oil field in Egypt and issued an independent report last year that served various purposes for operator Scimitar Production Egypt Ltd.

"The Ryder Scott study was critical. It assisted in determining capital requirements to undertake major expenditures for the project. The report also provided the credibility needed for what is considered a simple exploitation project in western Canadian terms of reference," said Peter Lubey, director of exploitation engineering at Scimitar Hydrocarbons Corp., the parent company of the operator.

Establishing Western Canadian analogs to the field was difficult because Issaran has higher reservoir temperatures, lower viscosity oil and thicker net pay zones at relatively shallow depths with slightly lower porosity and water saturations. The main distinguishing feature of the reservoir, though, is the heavy-oil deposits that exist in three carbonate zones, the Upper and Lower Dolomite and Nukhul.

"The historical producing characteristics of the dolomite heavy-oil reservoir do not appear to be all that different from the sandstone heavy-oil reservoirs of western Canada," said Doug Meiklejohn, the Ryder Scott engineer who evaluated Issaran. "However, the Nukhul’s production profile appears to be characteristic of a light-oil, active water-drive reservoir."

Ryder Scott’s geological analysis involved analyzing digital log data and core descriptions from nine existing wells to prepare structure and net pay maps for the Issaran structure, a general north-south trend controlled by five fault blocks and downdip by the water/oil contacts.

Derry MacFarlane, a member of the Ryder Scott geological team, said, "There are very few heavy-oil carbonate fields in the Western Canadian sedimentary basin. The Issaran dolomite is unique and the reservoirs are much thicker. The net pay in the upper dolomite is more than 250-ft thick in some areas."

Ryder Scott reinterpreted existing 2D seismic data to provide a structural interpretation tied to mappable seismic reflectors and then conducted a depth-migration analysis. Based on the volumetric analysis, Ryder Scott estimated the original oil in place.

"The interpretation helped build a clear picture of reservoir parameters, including net pay, water saturation and porosity," said Lubey.

Ryder Scott estimated future production rates from Issaran horizontal wells and laterals by using Canadian sandstone analogies and by reviewing horizontal predictive models. "We know what type of recoveries can be expected from those production mechanisms," said Meiklejohn.

Scimitar plans to acquire 3D seismic data on the field this year. Future analysis of seismic reflections from deeper structures may help delineate the reefal Nukhul reservoir that is not visible on the older 2D data or on a Geoquest seismic model analyzed by Ryder Scott.