Аggregation of 2D and 3D Approaches in Planning and Geological Monitoring of Drilling Horizontal Wells and Sidetracks in Llc «Bashneft-Dobycha»

Summary One of the most effective methods for brown-field development optimization is drilling horizontal wells or sidetracking with the purpose to involve into development remaining recoverable oil reserves.Conventionally, analytic approach (2D) based on initial and remaining oil thicknesses maps is used for evaluation of remaining recoverable oil reserves when planning new wells and sidetracks. In this case production rates are calculated with following assumptions: reservoir properties are homogeneous, pressure, volume and temperature fluid properties are constant, reservoir pressure and oil saturation also are constant in well drainage area.It should be noted that, planning and implementation of well drilling projects in PJSC Bashneft Oil Company are based on complex approach, including:- analytical evaluation (2D) of remaining recoverable oil reserves,- 3D - reservoir simulation for reliable calculation of remaining recoverable oil reserves and determination of well drilling efficiency, - geological monitoring of well drilling in real time. Complex approach application consisting of 2D-analytical and 3D - numerical methods improves evaluation reliability of remaining recoverable oil reserves and allows to perform multivariate well predictions of oil production taking into account all existing geological risks.The detailed description of algorithms application for planning and implementation well drilling projects and obtained results will be considered in this work.