First Experience of Use of Detailed Geological-Commercial Model of the Orenburg Oilfield for the Planning of Development of Hard Recoverable Stocks of Gas

By

 M.A. Politykina¹, W.E. Kan², A.M. Tiourine¹

(1) VolgoUralNIPIGas, Orenburg, Russia (2) VolgoUralNIPIGas,

The Orenburg oil field and gas is dated to carbonated adjournment of the Carboniferous-Low-Permian age; in a powerful productive section (the thickness reaches up to 500 <m) it is allocated three operational objects divided by packs of dense practically impenetrable carbonates. Hardly recoverable stocks of gas are concentrated in the first operational object, which permeability of collectors on the average 1-2E10-15 m2. For 20 years of development from it there was recovered less than 30% of initial stocks while from the lower objects it was recovered 66%. The main reason of the weak entrainity of the stocks of the first object in development is neglecting at planning development of its specific geologo-commercial features. Main from them - thin porous structure of collectors, low matrix permeability, high gypsuminity and bituminity, presence of faults and stitolites. One of directions of increase entrainity of stocks of the first object in development is the kickoff of horizontal trunks from low production vertical chinks. Prime for kickoff chinks, directions and structures of horizontal trunks are chosen on the basis of digital geologo-commercial model of a deposit. The model is created in the program "Reservoir Modeling"done by firm "GeoQuest Schlumberger" and contains the parameters necessary for definition of characteristics of a section, an estimation of stocks of gas and predicted efficiency of horizontal trunks.