oa Sidetracks Drilling Supported by Hydrodynamical Models of Reservoir

In our report we present full cycle of reservoir modelling ending with targets for sidetrack drilling.<br>Many giant oil fields in Siberia started from 70s and still produce more than 1 mln sbl/day. These oil<br>fields are covered by the net of the wells and experience the fast watering of the wells. The operators<br>find sidetrack drilling is a profound way to decrease the drilling costs and to slow down the watering.<br>However, after 40 years of exploitation successful sidetracks in the reservoir require thorough analysis<br>of geology and production. As a service software company Roxar cooperates with operators closely in<br>order to find the best targets for sidetracks. We build a hydrodynamical models of reservoir sector with<br>100-200 wells of 20-40 years of exploitation. It takes about 2-3 months to make history matching of<br>the model. With matched model we get up-to-date and detailed picture of reservoir. Analysis of<br>pressure, mobile reserves and other parameters from the model brings to the precise targets of<br>sidetrack. In practice the model covering 20-50km2 gives immediate solution for 4-10 sidetracks.<br>Firstly we present the typical situations on the oil-field in Siberia and the contribution of modelling to<br>the production process. Next we present the results of sidetracks released after 3D modelling. We<br>demonstrate the whole cycle of modelling on examples from our project with TNK-BP, Samotlor oil<br>field. We compare the real production of sidetracks and our forecasts whose had initiated their drilling.<br>Other problems of reservoir engineering like boundaries of sector models, reservoir pressure matching,<br>implementing hydrofractures into the model and so on are also discussed.