System to determine existing fluids remaining saturation in homogeneous and/or naturally fractured reservoirs

A system to determine a remaining saturation of existing fluids in naturally fractured and/or homogeneous reservoirs, comprising:

• a) an active oil well head, under study configured to receive an injection of tracers;
• b) a pressure and temperature sensor with background resolution;
• c) sensors for a continuous and real-time measurement of a non-partitionable radioactive tracer concentration, a partitionable tracer concentration, and a secondary tracer concentration, the secondary tracer being a product of a chemical reaction of the partitionable tracer, in a well discharge line;
• and
• d) a processor configured to:
• continuously monitor concentrations of the non-partitionable tracer, the partitionable tracer, and the secondary tracer in the well discharge line,
• continuously monitor a flowing bottomhole pressure in the well discharge line,
• generate a breakthrough concentration curve of the non-partitionable tracer and the partitionable tracer and a flowing pressure curve of the flowing bottom pressure in the well discharge line:
• and
• e) a collection of samples of fluids produced in the active oil well head for storage and subsequent chromatographic analysis in a laboratory.