1. A method for the Integral analysis of inter-well tracer tests in an oil reservoir to measure injection fluid flow behavior and determine physical characteristics in a reservoir between an injection well and an output well, and determine flow parameters of an injection fluid in a fluid injection process for oil reservoirs to improve secondary oil recovery, the method comprising six stages: Stage I, defining objectives and preliminary analysis of geological and physical characteristics of the oil reservoir; Stage II, collecting, classifying and validating data obtained in Stage I; Stage III, design of the inter-well tracer test from data obtained in Stage II by mathematical modeling of tracer flow in a porous media; Stage IV, implementation of the inter-well test from Stage III by injecting a tracer in the injection fluid into the injection well and obtaining tracer test data corresponding to the concentration and amount of the tracer measured for a predetermined period of time at the output well spaced from the injection well by an online measurement system SML in a wellhead; Stage V analyzing the tracer test data obtained by the online measurement system to determine at least one physical characteristic of the oil well from the measured concentration of the tracer at the output well relative to the amount of tracer added to the injection well, and, Stage VI, determining flow patterns and injection fluid behavior in said reservoir from the tracer test data by mathematical modeling and numerical simulation.