Wireless Reservoir Surveillance Using Intelligent Tracers

摘要

Today's field developments are increasingly being characterized by very complex wells in very demanding and costly operating environments. Not only are individual wells challenging, but most are part of a complex reservoir network that must be managed over an extended period. The high cost and risks of acquiring surveillance information using conventional technology, such as production logging tools, is forcing operators to forgo acquisition of fluid inflow distribution information and manage these fields with a blurred understanding of the reservoir. Intelligent chemical tracers are a new technology that consist of smart plastic and unique chemical compounds that are combined into a matrix that resembles strips of plastic. The matrix is designed to be sensitive to either oil or water. For example, when water sensitive matrix is contacted by water, the matrix releases its unique chemical fingerprint (tracer) at a prescribed rate. The water sensitive matrix is dormant when contacted by oil, gas or air. Oil sensitive matrix behaves in the same way. Strips of matrix are easily adapted to any completion configuration including conventional sand screens, ICD sand screens, packers, pup joints, intelligent completions or artificial lift hardware. The matrix can be deployed in any well type including horizontal wells and multilateral wells. Intelligent tracers are economical, easy to deploy and have none of the negative effects of radioactive isotope-based surveillance techniques. Long service life in combination with model-based interpretation techniques of tracer flowback concentrations are the main enablers that tell operators if the entire interval is flowing, where oil is entering the well and where water is entering the well. Samples of produced fluid are analyzed for the concentration of each tracer. This data provides the operator with insight into the relative contribution of well segments and which well segment is the source of water breakthrough. This paper will review how the technology works, recent case histories of intelligent tracer responses and the insight the operator gained from deploying the technology.