Filter cake formation process by involving the influence of solid particle size distribution in drilling fluids

Sodium alginate as an eco-friendly rheology modifier and salt-tolerant fluid loss additive in water-based drilling fluids

“…The reasonable particle size distribution was conducive to plugging pores, in which the large sized particles play a key bridging role, whereas smaller sized particles enter into the internal voids and ll the pores between the large particles without percolation. [61][62][63] It is reasonable that SA is able to maintain a wide particle size distribution, which effectively prevents water from penetrating pores in the formation and improves the integrity of the borehole.…”

Transient response of near-wellbore supercharging during filter cake growth

“…cake has not formed yet at this moment. With increasing time, the drilling fluids continue to filter into the formation, and because of irregular protrusion on the inner wall of the wellbore, some solid particles in the drilling fluids will gradually adhere to the borehole wall and form the filter cake (Fisher et al, 2000;Ma et al, 2020). During those time, the invaded small sized particle will block the pore throat, which will result in a smaller permeability of filter cake as time increasing.…”

“…where k e (t) is the equivalent filter cake permeability, mD; k 1 is the real situation with time-dependent filter cake permeability, mD; w o is the constant filter cake thickness, m; w(t) is the real situation with time-dependent filter cake thickness, m; and r w is the filter cake inner radius, m. During drilling, many factors such as drill-string rotational speed, annulus velocity, drilling fluid type, solid particle size, formation temperature, formation pressure, and formation permeability, can influence the time-dependent properties of the filter cake (Jaffal et al, 2018;Ma et al, 2020;Ribeiro et al, 2017;Veisi et al, 2020;Yao et al, 2014). Some experimental and mathematical models have been conducted to study the filter cake growth process (Fisher et al, 2000;Hashemzadeh and Hajidavalloo, 2016;Jaffal et al, 2017;Ma et al, 2020;Rabbani and Salehi, 2017), and their results showed that both the thickness and permeability of filter cake obey the exponential changing modes. Some previous researchers have utilized the empirical equations with the exponential changing modes to investigate the time-dependent filter cake effects on wellbore stresses (Feng et al, 2018a;Tran et al, 2011), but the coefficients of their empirical equations are constant, which can only be used in some special cases.…”

“…The supercharging phenomenon in the vicinity of the borehole is significant because it is a prerequisite for analyzing wellbore stability, reservoir damage, and formation testing while drilling; thus, numerous works have been conducted on this topic. It should be noted during drilling that the pressure differential between the wellbore and the formation causes the mud filtrate to invade the formation while depositing solid particles at the wellbore wall to form a filter cake (Banerjee et al, 2006;Ma et al, 2020); a schematic description of the pressure profile with supercharging in the vicinity of the borehole is provided in Figure 1, which shows that the pressure in the wellbore is at hydrostatic pressure (p w ) but falls quickly across the filter cake (p a ) and then slowly decreases in the formation to the original formation pressure (p i ) some distance away from the wellbore (Banerjee et al, 2006;Hadibeik et al, 2012).…”