New Magnetite Nanoparticles Allow Smart Drilling Fluids with Superior Properties
Authors: Carpenter Chris 
Published: October 2017

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper IPTC 18731, “A Comprehensive Approach for the Development of New Magnetite Nanoparticles Giving Smart Drilling Fluids With Superior Properties for HP/HT Applications,” by Z. Vryzas, Texas A&M University at Qatar; V. Zaspalis, Aristotle University of Thessaloniki; L. Nalbantian, Centre for Research and Technology Hellas; O. Mahmoud and H.A. Nasr-El-Din, Texas A&M University; and V.C. Kelessidis, Texas A&M University at Qatar, prepared for the 2016 International Petroleum Technology Conference, Bangkok, Thailand, 14–16 November. The paper has not been peer reviewed. Copyright 2016 International Petroleum Technology Conference. Reproduced by permission.
This work focuses on using custom-made (CM) magnetite (Fe3O4) nanoparticles (NPs) to improve the properties of bentonite-based fluids. The microstructure qualities and modes of interaction have been identified, helping to optimize the rheological and fluid-loss properties of these drilling fluids. The better performance of the CM Fe3O4 NPs can be attributed to their extremely small size, which leads to stability in suspensions and effective linking with the bentonite particles, thus allowing the formation of a rigid microstructure network.
Introduction
The effects of adding iron oxide NPs on the rheological and filtration properties of aqueous bentonite suspensions have been studied by several researchers. The results showed that the addition of iron oxide NPs at low concentrations significantly improves drilling-fluid-filtration characteristics and maintains optimal rheological properties compared with the base fluid (BF). Moreover, the creation of a thin and impermeable filter cake and its effectiveness depend on the NP concentration.
The main objective of the research detailed in the complete paper is to study the performance of aqueous bentonite suspensions (7 wt%) containing CM Fe3O4 NPs at 0.5 wt% concentration in terms of their rheological and fluid-loss properties. Rheological analysis for the fluid samples with and without dynamic thermal aging identifies the degree of thixotropy of the developed fluids. The study outlines the effect of temperature on the yield stress, presents an integrated approach to characterizing raw materials by use of various methods, and explores techniques used to examine the produced-filter-cake properties and the size of NPs. Combination of such an integrated analytical approach regarding the evaluation of the properties of such suspensions together with the development and use of CM Fe3O4 NPs with made-to-order properties can lead to the development of multifunctional smart drilling fluids. The results of the experiment are discussed in detail in the complete paper.
Experimental
Materials and Sample Preparation. The bentonite, in powder form, had a relative density of 2.6 g/cm3 and was supplied without any polymer additives. It was tan in color with a pH range of 8–10. X-ray-diffraction (XRD) and X-ray-fluorescence analyses confirmed that the bentonite was sodium-based, with small quantities of illite and quartz. The bentonite had a mean particle size of 36 µm.