Use of nanoparticles for labelling oil field injection waters

摘要

The present invention relates to the development of tracer fluids, more generally aqueous liquids, intended to be injected under pressure into an oil reservoir, for example from an injection well to a production well. The objective of the invention is to propose a novel process for studying a solid medium, e.g. an oil reservoir, by diffusion of a liquid (e.g. injection waters) containing tracers, through said solid medium, which is simple to implement and economical and which overcomes the drawbacks of known tracers for oil reservoir injection waters. This process essentially consists in injecting, into this solid medium, an injection liquid comprising a tracer based on nanoparticles having mean dimensions between 20 and 200 nm, that can be detected by means of one or more signals S at dilutions of less than or equal to 10-7, and that are capable of forming a stable colloidal suspension in a saline medium; at least one portion of which consists of a core and of a coating provided with an adjustable hydrophilic-lipophilic balance (HLB) and comprising at least one organic and/or organosilicon constituent; in recovering the liquid that has diffused; and in analysing this liquid that has diffused in order to measure the amount of tracer by detection of the signal or signals S.