Improvement of black oil delumping method applied to an offshore oil field

Abstract

Black oil delumping, also known as a stream conversion method, converts a black oil wellstream into a compositional wellstream. This procedure ensures consistent flowrate allocations and monitoring of well’s performance. This method requires volumetric oil and gas flowrates given in well-test reports, an equation of state model, and additional black oil information reported in the Well Test, PVT Analysis, and Gas Chromatographic Analysis. This work proposes an improvement on the method to convert black oil data into compositional wellstream. The method’s performance was tested using data of three wells of a platform from an offshore oil field. This improvement significantly increased the accuracy of the method by decreasing the maximum percentage relative error from 16.50% to 4.44% when comparing the calculated and measured oil and gas properties for Well 1, for example. The method also preserves the gas and oil ratio reported in the well tests.