Volumetric Flow Rates from Impedance Tomography in Oil/Gas Flows

Gijs Fehmers

Shell International Exploration and Production

Box 60, 2280 AB Rijswijk, The Netherlands, gijs.fehmers@shell.com

ABSTRACT

In the oil industry, we want to determine volumetric flow rates of the individual components of oil/gas/water flows in underground production tubing. The local conditions are such that (complex) impedance tomography is one of the few feasible methods. This paper presents progress we have made to actually derive these volumetric flow rates from dual plane tomography data. The paper focuses on oil/gas flows and on two aspects of the problem: (1) regularization of the inverse problem, and (2) how to obtain oil and gas volume flow rates from velocities obtained form cross correlation.

We apply our method to dual plane capacitance data taken in a multiphase flow loop, and compare the results against flow line conditions. For bubbly and slug vertical upward flow, we can estimate oil and gas volume flow rates with 25% accuracy. For single component and non-vertical flow, as well as for

other flow regimes (stratified, annular, etc.), we can only determine volume fractions.

Keywords Oil production, Volumetric flow rates