Borehole
stability is one of the crucial success elements of the
drilling operation, which is partially dependent upon the chemistry
of the drilling fluid. Nanoparticles are emerging as one of the most
significant additives for improving the major properties of drilling
fluids. Thus, SiO2/KCl/xanthan nanocomposites (NCs) was
synthesized from Euphorbia condylocarpa extract in an eco-friendly and environmentally friendly way. The
synthesized NCs was used to prepare nanoinhibitive drilling fluids
(NIDFs) at different concentrations to improve the rheological, filtration,
and inhibition properties of the drilling fluid. All of the required
experimental tests related to the rheology, filtration, and swelling
measurements were performed at the ambient and high temperature and
high pressure (HTHP) conditions. The obtaining results revealed that
the rheological properties of the drilling fluids (plastic viscosity,
yield point, and gel strength) were improved from 4 cP, 10 lb/100
ft2, and 27 lb/100 ft2 to 19 cP, 17 lb/100 ft2, and 46 lb/100 ft2 (with adding 4000 ppm of KCl)
and 19 cP, 62 lb/100 ft2, and 54 lb/100 ft2 (with
adding 4000 ppm of synthesized NCs), respectively. In addition, the
filtration properties of the base drilling fluid were increased by
adding 4000 ppm of KCl at HTHP (fluid loss from 25.85 to 36.38 mL
and thickness of the filter cake from 3.4 to 5.1 mm), while the synthesized
NCs was more effective in lowering the fluid loss and filter cake
thickness from 25.85 mL and 3.5 mm to 2.5 mL and 0.33 mm, respectively.
Moreover, NIDFs were favorable in decreasing shale swelling that was
52.2%, but conventional inhibitive drilling fluids could lower shale
swelling by 41%. It can be stated that NIDFs are highly applicable
toward the successful drilling operation as a result of their abilities
in reducing shale swelling, improving rheological properties, and
decreasing the filtration properties.