Eventos Anais de eventos
COBEM 2021
26th International Congress of Mechanical Engineering
USE OF MICROCAPSULES TO CONTROL GELATION OF POLYMERS USED TO BLOCK FRACTURES IN OIL RESERVOIRS
Submission Author:
Rubia Bôdas , RJ , Brazil
Co-Authors:
Rubia Bôdas, Marcio CARVALHO, Jorge Antonio Avendaño Benavides
Presenter: Rubia Bôdas
doi://10.26678/ABCM.COBEM2021.COB2021-0063
Abstract
The efficiency of oil displacement is greatly reduced by the presence of fractures and high permeability layers. The injected water phase flows preferentially through low resistance paths, leaving large volumes of the reservoir not affected by the water injection process. An alternative to minimize this problem is to block fractures with a liquid system that forms a gel after some time, forcing the water phase to flow through the porous matrix. Sodium silicate gels is one of the formulations that can be used for this purpose. However, the kinetics of the silicate gel formation process is difficult to control, since it depends on many different variables. This uncertainty of the gelation process may lead to the formation of a gel phase away from the desired position, leading to many different problems, such as loss of injectivity. A liquid formulation using microcapsules is designed to control the release time of the activating agent and, consequently, to improve control over the start of the gelation process. The first step in the development of this technique was to study evolution of the rheology of the gel formed from sodium silicate with hydrochloric acid in order to evaluate the rate of the gel formation as a function of different process parameters, such as the concentration of Na-Si and HCl. The results show that the gelation process is a strong function of the solution pH and that the gelation time is shorter the higher the concentration of hydrochloric acid. In the proposed method, the hydrochloric acid solution is encapsulated and the gelation only starts after the bursting the capsule shell, which is triggered by imposing a gradient of osmotic pressure.
Keywords
sodium silicate, microcapsules, Microfluidics, fractured reservoir, gel systems
