Experimental Investigation of a Novel Nanosilica for Blocking Unwanted Water Production

Abstract

Nanotechnology is the design and application of engineered nanoparticles with one minimum dimension in the range of 1 to 100 nanometers. To achieve a specific target, innovative methods are highly required to overcome the challenges in the oil and gas industry, such as undesired water production. Herein, we present an advanced nanosilica, a new eco-friendly, cost-effective, and promising approach to control undesirable water production. The objective of this work is to evaluate our nanofluid system that can be used for water management in different water production mechanisms, including: high permeability streak, wormhole, and fractured reservoirs. A systematic evaluation of novel nanosilica/activator for water shut-off application requires an examination of the chemical properties before, during, and after gelation at given reservoir conditions. The placement of this water shut-off system is highly dependent on gelation time and viscosity. Therefore, we emphasized in this study on investigating these gelation kinetics by conducting extensive rheology experiments at varied temperatures and activator concentrations. We have looked into evaluating the optimum breaker for the gel as a contingency plan for improper placement. Measurements of the nanosilica fluid’s initial viscosity exhibited a low viscosity, less than 10 cP at normal temperature and pressure (NTP) conditions; this provides significant benefit for mixing at surface and pumping requirements for pilot testing. The nanosilica gelation time can be tailored by adjusting activator concentration to match field job design at a given temperature, which is more than 200°F. The gelation time revealed an exponential relationship with temperature and reversible proportionality. The nanosilica gel proved to be a thermally stable fluid system along with different activation ratios. For breaker tests, the gellant fluid showed complete breakdown at altered temperatures to mimic downhole conditions. Our lab observations conclude that nanosilica fluid is verified to be acceptable as a water shut-off system for field applications. This novel nanofluid system is a promising technology to control water production from oil wells. The system has low initial viscosity that can be injected in porous media without hindering the injectivity and getting at risk of fracking the sand. In case of inappropriate placement, the fluid can break down entirely using a non-damaging chemical breaker instead of using mechanical approaches that might damage the completion.