Sand Stabilization with Hydroxy Aluminum Solutions

Abstract

This paper was prepared for the 43rd Annual California Regional Meeting of the Society of Petroleum Engineers of AIME to be held in Bakersfield, Calif., Nov. 8–10, 1972. Permission to copy is restricted to an abstract of not more than 300 words. Illustrations may not be copied. The abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Publication elsewhere after publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is usually granted upon requested to the Editor PETROLEUM ENGINEERS JOURNAL is usually granted upon requested to the Editor of the appropriate journal, provided agreement to give proper credit is made. Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers Office. Such discussions may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines. Abstract In many oil producing reservoirs, sand and other fine-grained rock materials migrate into wells. This influx may decrease oil production by plugging gravel packs, production by plugging gravel packs, eroding well equipment or completely sanding up wells. In many such problem formations, the principal problem formations, the principal natural cementing agents are clay minerals, which are relatively weak and may be further weakened by changes in formation fluid chemistry. When these clay minerals expand and disperse, the coarser silt and sand in the formation rock may also move in with flowing fluids and damage the well. This paper describes a procedure for treating such formations with hydroxy-aluminum to stabilize clay minerals and thereby prevent sand and silt production. production. Hydroxy-aluminum is a relatively inexpensive and commercially available chemical that very effectively inhibits clay damage in normally water sensitive formations. An aqueous solution of hydroxy-aluminum is injected and is desirably followed by an aqueous overflush and a short shut-in period. Hydroxy-aluminum cations adsorb very tightly on clay mineral surfaces and stabilize them by decreasing dispersive forces and eliminating structural expansion. Laboratory flow studies show that after treatment many selected friable natural formation sands can withstand considerably higher flow rates without sand production. The effectiveness of the chemical treatment is related to the clay mineral content and cation exchange capacity of the rock. The process has been applied successfully in California and Gulf Coast fields. Introduction Movement of formation materials into wells is a serious problem in many oil-production areas around the world.