Effect of a modified nano clay and nano graphene on rheology, stability of water-in-oil emulsion, and filtration control ability of oil-based drilling fluids: a comparative experimental approach

Abstract

During the past decade, researchers have used different Nano-Particles (NPs) due to their unique characteristics for improving formulation of Oil-Based Drilling Fluids (OBDFs). This study is the first research that investigates the effect of a Modified Nano Clay (MNC), namely CLOISITE 5 and non-functionalized Nano Graphene (NG) on rheology, electrical/emulsion stability, and filtration control ability, as the main properties of OBDFs. Initially, five concentrations of both NPs (0.25, 0.5, 1, 1.5, and 2 wt%) were added separately into an NP-free OBDF (the base fluid). Then, rheological properties and electrical stability of all prepared fluids were measured at three 90, 140, and 180 °F temperatures. Moreover, filtration test was carried out under 500 psi (3447 kPa) differential pressure and exposed to 300 °F temperature for all fluids. Since experimentally measured shear stresses followed well both Herschel Bulkley (shear-thinning) and Bingham Plastic models, effects of temperature and the NPs concentration on both model parameters are investigated more deeply in the paper. Activation energies calculated from Arrhenius model showed that MNC is more effective than NG on reducing the dependency of apparent and plastic viscosities of the base fluid on temperature. MNC, due to its amphiphilic structure, significantly stabilizes water-in-oil emulsion at all temperatures and concentrations, but NG with high electrical conductivity reduces the emulsion stability. The nanofluids containing 0.5 wt% MNC and 0.25 wt% NG which have respectively 32.6% and 43.5% fewer filtrate volumes than the base fluid, were considered as the optimal nanofluids from controlling filtration into formation aspect. Finally, MNC is applicable to enhance the formulation of the OBDF through supporting its commercial viscosifier, emulsifiers, and fluid loss control agent, but the negative effect of NG on emulsion stability limits its application.

Investigating the efficacy of novel organoclay as a rheological additive for enhancing the performance of oil-based drilling fluids

“…The Bingham plastic model is used to describe the rheological behavior of the two drilling fluid samples with R 2 values of 0.9773 (Claytone-IMG 400) and 0.9803 (MC-TONE). Several studies have provided support for the applicability of the Bingham plastic model in characterizing the flow properties of OBDFs 10 , 15 , 56 , 60 . Werner et al 56 demonstrated the effectiveness of the Bingham plastic model in capturing the viscoelastic properties and flow behavior of OBDFs, particularly under HPHT conditions.…”

Applications of Emerging Nanomaterials in Drilling Fluids

“…The best nanofluids for regulating filtration into formation were those containing modified nanoclay and nanographene, which had ∼32 % and ∼43 % smaller filtrate volumes than the base fluid, respectively. Furthermore, modified nanoclay can support fluid commercial loss control agents and emulsifiers to improve the formulation of the oil‐based drilling fluids, although its use is restricted because of the nanoparticles detrimental impact on emulsion stability [125] . In another work, nano enhanced WBDF were generated employing the synthesized ZnTiO 3 nanomaterials in a solution as a base fluid, which was then employed as an additive.…”

“…Furthermore, modified nanoclay can support fluid commercial loss control agents and emulsifiers to improve the formulation of the oilbased drilling fluids, although its use is restricted because of the nanoparticles detrimental impact on emulsion stability. [125] In another work, nano enhanced WBDF were generated employing the synthesized ZnTiO 3 nanomaterials in a solution as a base fluid, which was then employed as an additive. It was proven that the inclusion of one 1 wt% ZnTiO 3 nanomaterial to drilling fluid reduced the volume of fluid loss by around ∼ 8 %.…”

pH-Responsive Drilling Fluid With High-Temperature and High-Density Performance

“…Conventional oil-based drilling fluids typically have high emulsion stability and strong oil-wetting properties, which render contact drilling pipes, formation, and drill cuttings oil-wet (Nooripoor and Hashemi, 2020). In drilling procedures, strong oil-wetting properties are beneficial for improving shale formation stability and reducing downhole accidents.…”