A New Environmentally Friendly Clay Stabilizer

Abstract

Clay stabilizers are means to prevent fines migration and clay swelling, which are caused by the contact of formation with low salinity or high pH brines. Previous clay stabilizers including: Al and Zr compounds and cationic polymers have several drawbacks. Al and Zr compounds can be removed by acids. Cationic polymers can cause formation damage in some cases, and their environmental impact is questionable. There is a need to develop new clay stabilizers that can work following acid treatment and are environmentally acceptable.Laboratory studies were conducted on newly developed Al compound. Zeta potential and particle size measurements were used to determine surface charge of four types of clays: kaolinite, illite, montmorillonite, and chlorite; and to optimize clay stabilizer concentration. Coreflood experiments were conducted on Berea sandstone cores (1.5 in. diameter and 6.0 in. length) to assess the effectiveness of the new compound and determine the impact of acids on its performance. Atomic absorption was used to measure the concentrations of Al, Mg, Ca, and Fe in the core flood effluent.The new clay stabilizer was very effective in mitigating fines migration. Zeta potential indicated that the isoelectric point at which complete shields of surface charge of clay particles was achieved at a stabilizer concentration of 0.2 wt%. Coreflood tests showed that this new chemical was effective, and unlike previous Al compounds, it did not dissolve in acids. In addition it is environmentally friendly compound, and also worked very well at 200 o F. The behavior of the new stabilizer was much better when it was prepared in DI water than in brine.

Experimental investigation of colloidal silica nanoparticles (C-SNPs) for fines migration control application

“…In principle, the ion exchange process between stabilizers and fines minerals that release during acidization will keep them in aggregated form to prevent migration (Fink 2013). Among the fines or clay stabilizer developed to control and prevent the fines migration are chemical stabilizers, such as inorganic salts, cationic inorganic salts, cationic organic polymers, anionic organic polymers nonionic organic polymers (Ali and Hinkel 2000;Fink 2013;El-Monier et al 2013;Maley et al 2013;Gomez et al 2015;Clarke and Nasr-El-Din 2015;Karpiński and Szkodo 2015).…”

Performance of cationic β‐cyclodextrin as a clay stabilizer for use in enhanced oil recovery

“…During the past decades, many water‐soluble polymers have been used as clay stabilizers in drilling fluid systems to inhibit clay swelling and migration. The water‐soluble polymers used so far include inorganic polymers , uncharged polymers , anionic polymers, cationic polymers , and zwitterionic polymers . These fluids have several drawbacks in inhibiting clay swelling and migration on drilling operations.…”