Effective Enhancement of Wellbore Stability in Shales with New Families of Nanoparticles

Abstract

Traditional water based fluids tend to penetrate into shale formations, and interact with clay minerals, which results in clay swelling and wellbore instability. The larger content of clay in some deep water shales compared to regular onshore shales generates more wellbore instability problems. To reduce shale-fluid interaction, we need to reduce water invasion by sealing the pores and micro-fractures in shales. Therefore, the objectives of this study are to conduct pore pressure transmission (PPT) tests with test fluids that contain two new families of nanoparticles and to evaluate the major factors that affect pore pressure transmission. For the first time, Mancos Shale and Eagle Ford Shale have been investigated with PPT tests using fluids that contain nanoparticles in different sizes (10 nm, 20 nm, 30 nm, 40 nm), types (aluminum oxide, magnesium oxide) and concentrations (3%, 10%). Results show that nanoparticles of 10 nm size can delay the time needed to reach the equilibrium state to 48.2 hours, compared to 27.8 hours needed for Eagle Ford Shale treated with suspensions that contain 40 nm nanoparticles. Based on the test matrix, the better combinations to decrease pore pressure at the equilibrium state are 10% 10 nm Al2O3 for Eagle Ford Shale and 10% 30 nm Al2O3 for Mancos Shale. This relatively new plugging technique using nanoparticles has great practical potential for successful application in deep water drilling. A decrease in pore pressure transmission and the delay of the time to reach the equilibrium state will reduce problems of hydration and swelling in shale formations. This study can also help to define water based drilling fluid properties for the purpose of improving wellbore stability in deep water drilling.

MoS2 Nanoparticle Effects on 80 °C Thermally Stable Water-Based Drilling Fluid

“…The quality of filter cake with respect to fluid loss and mechanical strength depends on the additives in the drilling fluids such as fluid loss control polymers as well as the packing of solids deposited in the mud cake. Several investigators have reported the impact of nanoparticles that reduce the filtrate loss such as (Fe 2 O 3 , [ 15 ], SnO 2 [ 17 ] MWCNT, Al 2 O 3 , CuO, TiO 2 [ 16 , 19 ], MWCNT, Graphene, [ 18 ], Fe 2 O 3 , [ 20 ]) and silica reduce the permeability of the shale by plugging the pore spaces [ 21 , 22 , 23 ].…”

“…The impact of the nanoparticle on the drilling fluids depends on the atomic structure, the morphology, the concentration, and the surface chemistry interaction with the base fluid’s chemical ingredients both physically and chemically. Among the documented research results, the blending of nanoparticles with water-based drilling fluid enhances the rheological properties of drilling fluid [ 15 , 16 , 17 , 18 ], reduces filtrate loss and the filter cake thickness [ 15 , 16 , 17 , 18 , 19 , 20 ], reduces the permeability of the shale by plugging the pore spaces [ 21 , 22 , 23 ], reduces the coefficient of friction [ 16 , 17 , 24 , 25 , 26 ], increases the wellbore strength [ 27 ], enhances the electrical conductivity and thermal conductivity of the conventional drilling fluids [ 28 , 29 , 30 , 31 , 32 ], and inhibits shale swelling [ 20 , 33 , 34 ].…”

Experimental investigation of fracture-based wellbore strengthening using a large-scale true triaxial cell

“…However, we still lack a comprehensive thermo-hydro-mechanical-chemical (THMC) understanding of wellbore strengthening. For instance, limited success has been achieved on shale wellbore strengthening (Guo et al 2014;Gao et al 2016). On the other hand, disregarding pore pressure and lack of temperature control are common problems due to manufacturing difficulties.…”

Application of nanofluids for treating fines migration during hydraulic fracturing: Experimental study and mechanistic understanding

“…Moreover, NPs have found many applications and have been used as gelation materials, foaming agents, stabilizer of water-in-oil emulsion, filter cake additives, and fluid loss control agents (Binks, 2002;Zakaria et al, 2012;Contreras et al, 2014aContreras et al, , 2014bContreras et al, , 2014cBorisov et al, 2015;Dai et al, 2015). Furthermore, they have been used as additives for promoting wellbore stability in shales (Gao et al, 2016). Recently, Hoxha et al (2017) explained the physical mechanism by which shales and nanoparticles interact, and also they described the way that this interaction might actually benefit shale stability.…”