Design and Evaluation of a Water-Based Drilling Fluid Formulation Using SiO and Graphene Oxide Nanoparticles for Unconventional Shales

Abstract

Unconventional shale reservoirs have become a key player in the oil and gas industry to cover the world's energy demands. Traditionally, oil-based drilling fluids (OBM) are preferred to drill shale plays due to negligible chemical interactions. Nevertheless, strict environmental regulations have motived the industry to design water-based drilling fluids (WBM) capable to control the shale-water interactions, improving their performance. Still, conventional additives are too large to plug shales’ micro-fractures and nanopores. Thus, nanoparticles due to their unique size, shape, and properties can provide a solution for the WBM. This study focus on the design and evaluation of a customized nanoparticle water-based drilling fluid (NP-WBM) using silica nanoparticles (SiO2-NPs) and graphene nanoplatelets (GNPs). The main objective is to identify the optimal NP concentration to improve the rheological and filtration properties of the NP-WBM and evaluated its inhibition benefit. The NP selection was based on the characteristics of the Woodford shale obtained through x-ray diffraction (XRD), cation exchange capacity (CEC), and scanning electron microscopy (SEM). NPs’ colloidal stability was analyzed in an alkaline environment with zeta-potential measurements. The concentration of NPs was evaluated below 1 wt.%. Laboratory measurements for the NP-WBM included API filtrate test (LTLP) and high-temperature/high-pressure (HTHP) test using a static filter press and rheological analysis with a rotational viscometer. To evaluated the inhibition benefit, the NP-WBM was tested against the Woodford shale by performing immersion and cutting dispersion tests. The results showed zeta-potential values below −30 mV for both nanomaterials, indicating good dispersibility of the NPs within the WBM. Also, significant improvements in the filtration properties were observed when adding 0.5 wt.% of SiO2-NPs with 0.25 wt.% of GNPs to the base fluid with no spurt-loss and minor effects on the rheological parameters. Higher concentrations did not show further improvements; thus the previous combination was selected as the optimal. Chemical interactions tests indicated that the Woodford shale might develop micro-fractures when exposed to water for long periods of time. However, no micro-fractures were observed when the rock was exposed to NPs. Furthermore, the NP-WBM reduced the cutting dispersion by 35.61% compared to the base fluid, showing superior inhibition properties even in high illitic shales that are prone to experience cuttings disintegration. NPs’ stability and benefits at low concentrations, indicates their potential to improve the design of WBM for unconventional shales, reducing the environmental impacts linked to the drilling operations.

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

“…Nanomaterials have been found roughly in the size of 1 to 100 nm, provided many advantages upon their applications. In recent years, the effect of GO at HPHT and LPLT conditions have reported high-performance fluid loss control [ 128 ]. Upon the discovery of graphene back in 2004 [ 88 ], it was proved to be a promising material for many applications.…”

“…Recently, the role of GO in featured rheology was analyzed such as an examination of GO-SiO 2 nanoparticles for unconventional reservoir shales to reduce cutting dispersion [ 128 ], suspension of cutting fluids using GO [ 133 ], improved thermal stability and inhibition capabilities of WBDF in Woodford shale [ 134 ], the effect of GO functionalization to improve heavy oil recovery [ 135 ], clean swelling inhibitor in WBDF [ 97 ], and GO as an additive to improve filtration, thermal conductivity, and rheological properties of drilling fluids [ 116 , 136 ].…”

Nanoparticle-based drilling fluids as promising solutions to enhance drilling performance in Egyptian oil and gas fields

“…Adding NPs were also reported to improve YP and PV at the studied conditions. [4] checked both SiO2 and Graphene-NPs (GNPs). A significant improvement in the filtration properties were observed when a mixture of 0.5 wt.% of SiO2 and 0.25 wt.% of GNPs with a neglect effect on the spurt loss, PV, and YP.…”

“…They also reported improved-rheological profiles with less effect on the fluid loss properties. A mixture of both SiO2 and GNPs was also investigated to explore the NPs' potential to enhance the inhibition of woodford shales [4]. The immersion and cutting dispersion tests showed good NPs' stability, which indicating less cutting dispersion and good inhibition even in high illitic shales.…”

Nanomaterial-Based Drilling Fluids for Exploitation of Unconventional Reservoirs: A Review

“…Nanosize additives with enhanced characteristics are actively being investigated in regards to drilling of HPHT wells [33,50]. Several nanomaterial have been investigated such as nano silica [51], graphene oxide [52], graphene nanoplatelets [43,53], multi-walled carbon nanotube [51,54,55], single walled carbon nanotube [54,56], nano ZnO [57,58], TiO 2 [59], CuO [60], and Fe 2 O 3 , nano-cellulose, nano-silica polymer grafted polymer [61], ZnO polymer nanocomposite [43], TiO 2 /polymer nanocomposite [62], TiO 2 /clay nanocomposite [63], and several others [64].…”