Selection of an Adequate Completion Type is the Key to Successful Reserves Recovery. Case History of Horizontal Drilling in the Reservoirs with Different Depositional Settings (by the Example of the Sporyshevskoye Oil Field)

Abstract

Abstract The Sporyshevskoye oil field development started in 1995. In 2002 by the time when all the designed vertical wells had been drilled, practically all the reserves of the main reservoirs within the production targets were put into production. There emerged a necessity to develop the oil-water zones and marginal areas, zones with poor reservoir properties and minor reservoirs in order to maintain the production rates. Application of horizontal drilling allowed achievement of the above tasks. Horizontal completions resulted in not only enhancement of individual well production rates, but also significantly improved the oil recovery. This goal was achieved through optimization of the development system and improved development of oil-water zone reserves and the reserves contained in the zones with poor reservoir properties. The use of the horizontal completion allows development of the reserves, which would have never been possible to produce with vertical wells because of poor economics. Another crucial achievement resulting from horizontal completions was the more efficient use of existing wells. Poor vertical producers were sidetracked; the vertical wells released due to drilling of horizontal boreholes were recompleted; the number of shut-in wells reduced.