**5. Desirable changes by addition of polymeric nanoparticles in drilling fluids**

i.Nanoparticles in drilling fluids can improve filter cake quality by both plugging and bridging. Improved, thin filter cake, with non-erodible and impermeable membrane with similar attributes as conventional filter cakes can be achieved. Formation damage is reduced or prevented as a result. Also, due to the thin filter cake, contact between the wellbore and the drillstring is reduced, with resultant reduction of the tendency to experience excessive torque and drag frictional forces while rotating the drillstring and pulling or running in hole respectively. Stuck pipe incidents are reduced due to adequate clearance between the drillstring and the wellbore as a result of reduction of friction.

#### **Figure 8.**

*Barrier creation process with nanofluid with polymeric nanoparticles.*


to their cellulosic nature, the deformable structures enable them to squeeze into the throats. Since the traditional method of switching from water based to oil based to solve shale swelling problem due to water absorption, which can cause environmental problems is prevented by addition of nanoparticles, cost efficiency is achieved.


#### **Figure 9.**

*(a) Film formation with structural disjoining pressure and (b) barrier between the surfaces finally created.*

mainly the barrier properties of the nanoparticles, in association with other attributes that are utilized (**Figure 9**). This is a form of biological treatment.


*Polymeric Nanoparticles in Drilling Fluid Technology DOI: http://dx.doi.org/10.5772/intechopen.106452*

#### **Figure 10.**

*Velocity profiles; with n = 0.42 (highlighted in chain-line) in comparison with other profiles with higher flow behavior index, n.*


on bit can result in low rate of penetration. When polymeric nanoparticles are added to the drilling fluid, films such as nanocellulose biopolymer–based biofilms and starch nanoparticles [20, 32] deposited on the drill bit can help retard development of bit balling for improved drilling efficiency due to their barrier properties. Prevention of clay hydration for hydratable clays in the cuttings would also prevent bit balling.
