Key words: oilfield, geological exploration, development, modeling, horizontal wells.
Oil and gas exploration in the Republic of Bashkortostan has relied on the constantly evolving theoretical perspectives.
Oil and gas exploration in the Republic of Bashkortostan has always relied on the constantly evolving theoretical perspectives.
On the East European Platform the theoretical views on the stacked nature of large swell-like structures of Tuimazinsk-trend down from the Lower Permian setting resulted in the unique Tuimazinskoye oil discovery and a number of big discoveries such as Serafimovskoye, Shkapovskoye and Mancharovskoye oil fields. Extrapolation of these ideas on the other regions within the eastern margin of the platform led to the unique Arlanskoye oil discovery in the Birsk Saddle and Krasnokholmsk group of Arlanskoye-trend oil discoveries on the western flank of the Bashkir Dome. At this stage (1944-1960) virtually the bulk of the hydrocarbon resource base of the Republic
of Bashkortostan was built.
Small discoveries characterize oil and gas exploration in Bashkortostan. Exploration and appraisal of small oil fields is always technologically and economically marginal. That holds true especially for minimal fields with less than one million ton initial recoverable reserves of oil. As the approaches to the exploration and appraisal of such fields developed the main principle of the present technology was defined which implies one exploration well placed at the highest point or crest of an individual seismic prospect and further exploration and appraisal by a cluster of development wells with special emphasis on horizontal completions. 3D seismic acquisition and offset VSP are widely employed.
The foundation for the contemporary science-based oil field engineering and development was laid when developing the unique Tuimazinskoye field. Peripheral water flooding was first designed and implemented then. Contour flooding was introduced on this field to isolate DIFm from DIIFm. Subsequently contour flooding was widely used at Tuimazinskoye, Arlanskoye and other fields to produce from the crestal parts of vast platform reservoirs.
Many engineering solutions for improved oil recovery on the fields in Bashkortostan provided significant and valuable input to the theory and practice of petroleum industry. The theoretical framework was created for engineering and monitoring of the platform fields; over 1000 field development projects have been compiled. Techniques have been developed to reduce the volumes of produced water which at the same time do not affect oil production rates on mature fields, flow deviation or diverter technology being one of them. From 2009 to 2013 Bashneft boosted its current oil production with decrease in water cut from 91.2 % in 2008 down to 90.6 % in 2013 and increase in the average daily rate from 2.0 to 3.0 tons of oil through hi-tech geological and technical field operations.
