Highly Stabilized Foam by Adding Amphiphilic Janus Particles for Drilling a High-Temperature and High-Calcium Geothermal Well [component]

unpublished
Fabricating Janus particles that consist of two distinct functional regions is an intriguing research topic. In this study, Janus particles with both hydrophilic and hydrophobic regions are fabricated and innovatively applied in foam drilling fluids as anti-high temperature and anti-calcium foam stabilizers. First, silica particles (approximately 500 nm) are partially covered by wax colloidosomes using the Pickering emulsion method. Then, amino-containing hydrophilic modifiers and a series of
more » ... s and a series of hydrophobic modifiers with different carbon lengths are successively utilized to adjust the hydrophilic-lipophilic balance (HLB) of the particles. The results show & These authors contributed equally to this work that the (3-aminopropyl) triethoxysilane-SiO 2 -dodecyltrimethoxysilane (NH 2 -SiO 2 -12C) Janus particles possess the best foam stability. Due to their suitable contact angle of 80°, high positive zeta potential and good surface activity, these foams display the characteristics of low surface tensions, high dilational elasticities, nonspherical shapes, large sizes and thick films, which together result in the extension of the drainage half-life from 448 s to 778 s in comparison with the foam of pure foaming agent solutions. Moreover, compared with a foam with no stabilizer or those stabilized by a soluble foam stabilizer and homogeneous hydrophobic-modified silica particles, NH 2 -SiO 2 -12C-stabilized foam can extend the drainage half-life to 668 s after hot rolling for 16 h at 280 °C and resist CaCl 2 concentration of 0.8 wt%. Benefiting from their excellent thermal stability and salt tolerance, these Janus particles are expected to be promising candidates for use as foam stabilizers in high-temperature and high-calcium conditions, including drilling, enhanced oil recovery, "waterless" fracturing and, especially, in geothermal wells.
doi:10.1021/acs.iecr.9b01714.s001 fatcat:ieggaqarjvek3mae6rhuui5vfu