Nanoscale Laponite as a Potential Shale Inhibitor in Water-Based Drilling Fluid for Stabilization of Wellbore Stability and Mechanism Study

Abstract

Shale hydration is the main reason causing wellbore instability in oil and gas drilling operations. In this study, nanoscale laponite as a shale inhibitor was employed to stabilize wellbores. The inhibition property of laponite suspensions was evaluated by an immersion experiment, linear swelling measurement, and a shale recovery test. Then the shale inhibition mechanism was studied by using capillary suction time (CST) measurement, a thixotropy study, plugging performance evaluation, and related theoretical analysis. Evaluation experiment results showed that laponite had a better inhibition property than widely used inhibitors of potassium chloride (KCl) and poly(ester amine) (PA). The mechanism study revealed that integration of several factors strengthened the inhibition property of laponite suspensions. Laponite nanoparticles could plug interlayer spaces of clays by electrostatic interaction to reduce water invasion; the "house of cards" structure of laponite suspensions enables large CST values and low free water contents; the excellent thixotropy of a laponite nanofluid could allow a nanofilm to form in order to reduce water invasion into the formation; the nanoscale laponite particles could substantially reduce the shale permeability and form less porous surfaces. Furthermore, laponite could considerably decrease the filtrate volume of the drilling fluid, while KCl and PA had negative influences on the properties of the drilling fluid. This approach described herein might provide an avenue to inhibit shale hydration.

Laponite: a promising nanomaterial to formulate high-performance water-based drilling fluids

“…Wellbore instability incidents, such as wellbore collapse, stuck pipe, tight hole, excessive hole, frequently occur. In recent years, the majority of the horizontal sections is drilled by oil-based drilling fluid (OBF) (Li et al 2014;Sun et al 2018) to avoid shale hydration (Huang et al 2018;Jiang et al 2016;Shadizadeh et al 2015) and enhance lubrication property (Sönmez et al 2013). However, the pollution caused by OBF is difficult to handle, which could cause soil contamination and be toxic to marine life.…”

Hydrophobic‐associated polymer‐based laponite nanolayered silicate composite as filtrate reducer for water‐based drilling fluid at high temperature

“…Filtration loss is an important index to the properties of WDF, because the penetration of fluids into the formation resulted in serious wellbore collapse . Therefore, the lower filtration loss, the better the performance of filtration reduction.…”

Ultra-Stable Silica Nanoparticles as Nano-Plugging Additive for Shale Exploitation in Harsh Environments

“…For smaller size pores and holes, the modified silica might be embedded in the pores or laid in the cracks under high pressure to form tight mud cake. For larger pores, the sizes of these pores were larger than the size of modified silica; in that case, the modified silica SiO2-g-SPMA could bridge and stack at the entrance of pores [46]. As the increasing amount of SiO2-g-SPMA, the tubes stacked more tightly, the more compact filter cakes were formed, substantially permeability of filter cakes was decreased.…”