Production monitoring of multilateral wells by multivariate dynamic interfacial tension

Abstract

Reliable information about the inflow distribution in a multilateral well is of great importance and an ongoing challenge in the oil industry. In this work, we present a standard method for online monitoring of inflow distribution based on multivariate analysis of the dynamic surface tension (DST) of the produced oil. The method is reliant upon the assumption that the DST of the produced oil is a functional that takes the DST functions of each producing branch or layer as input. We measured the DST of water and crude oils, sampled from the sub-layers of a multilateral well, in ambient conditions. We found that the DST of crude oil samples fit three equations at three intervals which led to easier optimization of the error function of partial least squares (PLS). We, moreover, analyzed the impact of droplet normalization on the accuracy of the predicted results. The developed method was reliably used for an accurate and fast determination of the inflow distribution in a three-lateral well.