A Collective Clay Stabilizers Review

Abstract

Oil and gas fields encounter issues associated with clay minerals through drilling and production. Depending on the types of clay minerals, they pose the danger of swelling and migration upon exposure to incompatible water. Drilling introduces water through drilling mud, and production introduces water through different treatments such as acid stimulation and hydraulic fracturing.The recovery of oil and gas from subterranean formations has been troublesome in formations that contain water-sensitive minerals, e.g., water-swellable clays, such as clays in the smectite group, and fines capable of migrating when disturbed, such as silica, iron minerals, and alkaline earth metal carbonates.It has been common practice to add salts to the treatment fluids. The salts adsorb to the clay surfaces in an ion exchange process that can temporarily reduce the swelling and/or migration of the clays. Another method used is to coat the area with a polymer in order to physically block the surface of the clays. This paper will mention the types of clays related to the oil industry, describe the structure of clays, mention the mechanisms behind swelling and migrating, and compare the different developments in the field of clay inhibition.

Insights on Potential Formation Damage Mechanisms Associated with the Use of Gel Breakers in Hydraulic Fracturing

“…When zeta potential becomes highly negative or positive (ζ-potential < −20 or ζ-potential > 20), it produces a significant repulsive force with similarly charged particles in solution. Sandstone formation rocks are negatively charged and having a highly negative zeta potential value causes colloidal induced detachment of fines [ 65 , 66 ]. In other words, this highly negative value of zeta potential will increase the repulsive colloidal forces, which triggers the fines migration cases.…”

Drilling mud with addition of new hydration inhibitor for clay rocks

“…Carried out studies [4] showed that adsorption of quaternary polyamines on bentonite molecules is four times higher than polyacrylamide [5]. Numerous studies carried out worldwide [5,6] as well as authors own studies confirmed effectiveness of ammonium chloride as ionic inhibitor of clay rock hydration. However, application of ammonium chloride in the mud with high pH value is very limited due to possibility of ammonia release.…”

“…Those muds contain in its formula, amine agents, among others: tetra alkyl ammonium salts, polyamine acids, polyhydroxylated alkyl ammonium salts, hexamethylenediamine, polyetherdiamines, lipophilic amines [2] as well as cationic polymers [3]. Carried out studies [4] showed that adsorption of quaternary polyamines on bentonite molecules is four times higher than polyacrylamide [5]. Numerous studies carried out worldwide [5,6] as well as authors own studies confirmed effectiveness of ammonium chloride as ionic inhibitor of clay rock hydration.…”

A Technical Playbook for Chemicals and Additives Used in the Hydraulic Fracturing of Shales

“…Cations are then attracted to the silica surface, leading to hydration or dislodgement. 84,85 This section will discuss the intricacies of the clay structure, testing protocols for assessing clay damage, chemicals used to manage impacts of clay damage, and opportunities for optimizing these chemicals. 5.1.…”

“…86 Pore swelling occurs from surface hydration, cation exchange, and osmotic swelling mechanisms. 85 Migration of clay fines occurs through dislodging and dispersing of clay minerals from the structure caused by fluid movement. 84,87 Crystalline phyllosilicate clay structures consist of alternating SiO 4 tetrahedra and AlO 6 octahedra (i.e., gibbsite) lamina that are stacked in either a 1:1 (i.e., kaolin) or 2:1 (i.e., chlorite, illite, and smectite) ratio to form the unit layer (Figure 5).…”