Sporingsstoff

摘要

The present invention relates to tracer and/or chemical-release materials in the form of particles comprising: a) a partial outer coating comprising at least one resilient material; b) a matrix within said outer coating, said matrix comprising at least one polymeric material; c) at least one porous material encapsulated within said matrix; d) at least one tracer or chemical contained within said porous material. The invention further relates to methods for the use of such materials including methods for assessing the flow of fluids within a subterranean reservoir utilising one or more of such materials. Uses of the material in corresponding methods and also methods of production are further provided.