Laboratory evaluation to assess the effectiveness of inhibitive nano-water-based drilling fluids for Zubair shale formation

Abstract

While drilling through shale formations, shale hydration, including shale swelling and dispersion, is frequently reported as the main wellbore instability problems, particularly when conventional drilling fluids (water-based) are used. These problems have many adverse effects on the drilling operations resulting in non-productive time. Nanoparticles have been recently introduced as a unique alternative to improve the performance of water-based drilling fluids for shale applications. This paper presents an experimental evaluation to investigate the effectiveness of an inhibitive nano-water-based drilling fluid in reducing the swelling of Zubair shale formation. Well-preserved core samples, which were retrieved from Zubair formation, were characterized using X-ray diffraction, and X-ray fluoresces to quantify the amount of the swelling minerals. Scanning electron microscopy was used to identify the existence of microfractures within the samples. Three different nano-based drilling fluids containing titanium dioxide (TiO 2), copper oxide (CuO), and magnesium oxide (MgO) at two different concentrations (0.5% and 1.5% by vol) were evaluated through a set of tests to assess the shale reactivity in the presence of these nano-based fluids. In addition, the effect of these nanoparticles on the rheological and filtration properties was studied. The results showed that the shale samples contain 41.26% silicon dioxide (SiO 2) and 22.73% aluminum oxide (Al 2 O 3), indicating the presence of smectite and illite. Based on the reactivity tests, fluids containing CuO at 1.5% by vol outperformed the other fluids in terms of reducing the reactivity, where the expansion rate was reduced by 82.7% compared to the reference sample submerged in fresh water. In addition, the addition of nanoparticles resulted in reducing the plastic viscosity, increasing both the yield point and gel strength, and reducing the fluid loss under low-pressure low-temperature conditions.

Nanoparticles in Drilling Fluid

“…According to research, drilling fluid properties can be significantly impacted by nanoclays, including nano-titanium, nano-copper oxide, nano-alumina, and nano-bentonite. Research has indicated that they can decrease permeability, regulate filtration characteristics, improve the mechanical qualities of the drilling fluid, and strengthen shale stability [53][54][55]. Additionally, nanoclays are a promising addition for a variety of drilling operations, including those in sensitive environments, as they can help improve the rheological behavior of the drilling mud and reduce fluid loss.…”

A Critical Review of the Physicochemical Impacts of Water Chemistry on Shale in Hydraulic Fracturing Systems

“…Thus, in natural heterogeneous reservoirs, where it is not intuitively obvious how reactivity and transport are coupled, it is helpful to contextualize the stages of the fracturing process in this dimensionless framework. At present, the majority of shale reactivity studies are conducted under laboratory conditions including batch reaction and flow-through tests of core material. − A present challenge faced in the field is the linkage of these data to reservoir-scale behavior through such nondimensionalized parametrization. In what follows, we review the steps of the fracturing process, while offering a contextualization of the Pe and Da associated with each step using local conditions of reactivity and characteristic length.…”

Recent Advances of Graphene-Derived Nanocomposites in Water-Based Drilling Fluids

“…While addressing the drilling operations in extreme conditions, suitable additives are required to use in WBDF to avoid decomposition and better performance of the drilling fluids during drilling process. Nevertheless, due to the current advances in technology, novel nanocomposites have been selected to utilize as additives for modification of rheological properties as well as the filtration behavior of drilling fluids [ 87 ].…”