In-Situ Optical Fluid Analysis as an Aid to Wireline Formation Sampling

Abstract

Summary This paper describes the basic theory of operation for a newly developed wireline tool that uses optical principles for continuous analysis of fluid in the flowline of a wireline formation fluid sampler. The tool has a visible and near-infrared absorption spectrometer for fluid discrimination and a refractometer for free gas detection. The Effective Flow Stream (EFS) model has been developed to interpret the measured data and to estimate the volume fraction of water and oil in the tool's flowline for biphasic flow. For triphasic flow, the technique can give a quantitative estimate of water, along with a qualitative evaluation of the amount of oil and gas. We present an example of showing tool response in the laboratory, introduce applications of the technique for aiding formation sampling, and, finally, illustrate the implementation of this technique with field examples.