Experience of Thermo-Hydrodynamic Studies of Wells in Combination with Noise Logging and Quantitative Interpretation of Data Based on the Simulator
Authors: Vlasov Stepan , Kruchatov Dmitriy , Podberezhnyy Maxim , Azamatov Marat , Valiullin Rim , Sadretdinov Alexander , Ramazanov Ayrat 
Published: October 2019

The purpose of the report is to share with experts some of the accumulated experience in the planning and interpretation of thermohydrodynamic data of multilayer injection and production wells in combination with noise measurement.

The description of the mathematical model of thermohydrodynamic processes in the system "wellbore – jointly operated reservoires", which takes into account convective heat transfer, thermal conductivity and barothermal effect in the reservoir, is given. The temperature model of the well takes into account the convective heat transfer, heat transfer with the environment. Annular flows and modify properties of wellbore zone are simulated.

The article describes the geological properties, the technology of production well logging, mathematical models of thermohydrodynamic processes, algorithms of proccesses and quantitative data interpretation that tested in practice. Geological and technological measures to increase oil production are recommended based on the analysis of the results.

The quantitative interpretation of thermohydrodynamic data based on the use of the simulator is demonstrated by the example of one injection well of SPD. There are results of production logging on several modes of injection and transient pressure and temperature.

Production well logging (PL) was performed by several combined tools, such as different types of flowmeters, noise meter, temperature, pressure and composition sensors. The first research was carried out by a standard production logging unit, in the second case, an additional noise tool with fixed frequency windows was used, in the third one a broadband acoustic noise toll was used.

The results of the interpretation of the standard production well logging, additional information on the noise data are analyzed. The temperature and pressure fields in the wellbore and in the reservoir are numerically simulated. As a result of the inverse problem solution, the contribution of each layer to total injection was determined, including the contribution of the overlapped tubing interval.

The following results were obtained: The injectivity profile of the well at two different injection modes.Behind-the-casing flows of fluid above and below the perforated zone. A quantitative assessment of behind the casing flow contribution in two different injection modes is made.The location of casing leakage above the perforated zone is revealed, as well as a quantitative assessment of the contribution of fluid inflow from this location in two different modes of injection is made.The internal fluid circulation between the casing leakage point and the perforation zone is determined.

As a result of simulating it was established: Behind-the-casing flow down is insignificant and repair and insulation works are not required.Behind-the-casing flow upwards is insignificant, but its effect is associated with long-term injection into an undeveloped formation. When the injection pressure decreases, this formation begins to push the perforated reservoir. Repair and insulation works are required.

Thus, the combination of a standard production logging unit, acoustic noise measurement and simulation of thermohydrodynamic processes allowed to eliminate uncertainties in the interpretation of data and to give clear recommendations for repair and insulation works.