Production surveillance in the producing wells has been an important task for many years in oil and gas development since it provides relevant information useful for the effective management of the HC production. The main objective pursued by operators is to increase the production volume and enhance the oil recovery rate, which often requires some additional well interventions in the existing producing wells. For this purpose, it is necessary to understand how and where to perform stimulations and properly select adequate EOR technologies in order to avoid the risks associated with premature complications of well operation. Usually, production surveillance can be performed using standard logging methods (PLT complex), aimed at the inflow profile monitoring in a well. There are many factors, however, that may complicate the data recording and affect the reliability of the study results. In addition, it is not always possible to shut down the well for production logging purposes. As an alternative approach, it is proposed to consider a technology that involves the placement of special marker-reporters in the bottom-hole zone of the well . The inflow tracers are gradually washed out in the course of production, thus providing the possibility to directly assess the current flow rate, while different codes of productive intervals enable quantification of the production with a phase-wise analysis (hydrocarbon and water) .
This paper presents the results of the analysis of reserves recovery in a multi-layer reservoir characterised by relatively low porosity and permeability parameters by means of a tracer-based technology designed for production profiling in directional wells. Surveillance of each productive interval's performance over time was conducted by taking reservoir fluid samples from the mouth of several wells during stable production without well shut-down.