Summary In the current energy transition era, oil exploitation and especially the development of heavy oil reservoirs are facing big challenges to overcome the possible limitations in terms of economy (oil price), energy efficiency, and carbon footprint. Particularly, thermal enhanced oil recovery processes need to be re-evaluated in an attempt to harness the injected and produced energy. In that sense, Ecopetrol is evaluating new strategies to optimize the current steam injection process using different hybrid technologies from laboratory to field scale. One of the most attractive initiatives is evaluating the in-situ steam generation using mist water-air injection. This process involves simultaneous air and water injection into the formation through a set of nozzles. It looks to use part of the in-situ oil as a fuel, using the reservoir not only as a tank of energy but also as a steam generator. The main contribution of the technique concerning conventional steam generation is the use of the heat from the combustion of the residual oil to generate an in-situ steam front to transfer the uncontacted oil. This is reflected in reduced carbon dioxide (CO2) emissions, reduced fuel and water requirements, and increased oil production and net energy recovery. This article describes the methodology, results, history matching, and kinetic modeling of experimental evaluations and the upscaling of the experimental observations to a representative sector model from a Colombian heavy oil field. Results are described in terms of incremental oil recovery, energy efficiency, and carbon intensity compared with the baseline (a traditional steamflooding scenario). The technology of in-situ steam generation using mist waterair injection led to benefits in terms of better energy use and reducing the external fuel dependency for steam generation at the surface. Additionally, it was possible to identify improvements in incremental oil recovery (around 90%), energy efficiency (about 10 times less energy required to produce 1 m3 of oil), and reduction in carbon intensity (up to 91%) considering as baseline a conventional steamflooding scenario. These results will be key input parameters for designing and commissioning future applications in the Colombian fields.

Objectives/Scope: To determine quality, mass and volumetric flows in each sands where steam has been injected using well completions with selectivity elements under critical regime. From pressuretemperature logs and ILT run in wells, were used to estimate density, volumetric and mass flow of steam, and heat injected at each distributor element which wells are completed. Methods, Procedures, Process: When steam is injected into a well, the quality and mass flow at the well head is usually known. With the logs of pressure and temperature, together with the ILT and flow control devices in critical regime, it is possible to know the conditions of the steam (saturated, sub-saturated and over-saturated), and speed of flow, it is possible to determine in function of the completion of the well, diameter of tubing for injection and diameter of the throat, the following variables or properties, like volumetric flow, mass flow, quality and density of the steam, in each point or element for distribution of the well. Results, Observations, Conclusions: The methodology developed has allowed to determine the steam mass flow and injected energy that flows in each distributing element and how much is injected in each selected sand, obtaining that the highest mass flows are obtained where the lower qualities of the steam exist and vice versa, as well as the total energy injected in each sand looks almost independent of the steam quality in a range of 15% to 90%. This is due to the behavior of the mass flow and the latent heat of vaporization and their relation to the quality of the steam in throat under critical regime. As the steam quality increases, the mass flow through the throat decreases, and by the contrary the latent heat of vaporization increases. So the combination of both generates a total heat injection is almost independent of the quality of the steam, and the total amount of heat injected being a direct function of the diameter of the throat and the number of devices used for steam distribution. Novel/Additive Information: The novel combination of flow equations in pipes, critical flow in throat and flow through the spinner used in the ILT, allowed to estimate the mass flow and the energy injected into the reservoir with wells using selective completions in critical flow conditions. It was determined the existing differences in the conditions used during the design of the well completion and those existing during the steam injection. With this new methodology, the steam injector well completion is optimally designed, as well as obtaining the efficiency of the steam injection by sand, through a better estimation of the SOR and the oil incremental recovery during the continuous steam injection process.