This paper introduces a novel wireless well inflow/outflow profiling technique and illustrates how operators may gain from its use. Results from well-scale multiphase flow loop tests are presented.
A system has been realized, based on tracing of heatwaves induced in the well fluid by wireless heat sources embedded in the completion string or otherwise deployed along the reservoir section of hydrocarbon-producing wells. The heatwaves are subsequently registered as temperature anomalies as they flow past one or more downstream temperature sensor(s). The data will be available through an existing SCADA system for real time analysis and interpretation.
Heatwave travel times and the Residence Time Distributions (RTD) in different parts of the well system are derived using flow models. This forms the basis for estimating "what is flowing where and how much?".
Extensive tests were carried out at SINTEF's flow laboratory. Single- and multiphase (oil-water) fluid compositions were produced through a well-scale horizontal flow loop with multiple inflow points, and across a range of flow regimes from laminar and up to fully turbulent regimes. Based on theoretical work and the laboratory results models were developed to accurately represent the transport of heat from heat sources to temperature sensor placed downstream. For the simplest case of turbulent single-phase flow, heatwaves are well defined for the whole tubing length and flow rates at various inflow points can be accurately determined. Also, for cases of multiphase and laminar flows, valuable flow information can be extracted from the downstream sensors. Models are being developed for all these cases.
A brief comparison to alternative monitoring techniques is made. The technique described in this paper is basically a tracer technique and similarities with flow monitoring by chemical tracers can be observed. Unlike traditional tracer technologies heatwave applications are not limited to production cases. It will also be a tool for water injector wells and wells for CO2 sequestration.