Enhanced-Oil-Recovery Injection Waters

Publication Rights Reserved, U.S. Government Publication Rights Reserved, U.S. Government This paper was prepared for the 1977 SPE-AIME International Symposium on Oilfield and Geothermal Chemistry, held in La Jolla, California, June 27–28, 1977. Permission to copy is restricted to an abstract of not more than 300 words, Illustrations may not be copied. The abstract should contain conspicuous acknowledgement of where and by whom the paper is presented. Publication elsewhere after publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is usually granted upon request to the Editor of the appropriate journal, provided agreement to give proper credit is made. Discussion of this paper provided agreement to give proper credit is made. Discussion of this paper is invited. Abstract A survey was made of the types of waters, chemicals, and water-treatment methods used in enhanced-oil-recovery operations. The study indicated that numerous types of waters, chemicals, and water-treatment methods are used. Chemical and biochemical reactions can occur when different types of waters are mixed, or when enhanced-oil-recovery chemicals are added. Stringent quality control is needed in all operational phases related to injection waters in order to produce optimum amounts of oil and to prevent irreparable damage to equipment, wells, and oil reservoirs. Standard methods are needed to assure adequate quality control. Introduction In this report, enhanced oil recovery is defined as the additional production of oil resulting from the introduction of artificial energy into the reservoir. Primary oil recovery is defined as the oil and gas produced by natural reservoir energy or forces. Therefore, by this definition enhanced recovery includes waterflooding, gas injection, and other operations involving fluid or gas injection whether for secondary or tertiary oil recovery. Tertiary recovery is any enhanced-recovery operation applied after secondary recovery. The ERDA research program on enhanced oil recovery does not include waterflooding. Enhanced recovery is applied to an oil-containing subsurface reservoir for the purpose of dislodging oil from the reservoir rock pores and moving it to a production well. Many subsurface petroleum reservoirs contain sufficient energy because of internal pressures to push oil and gas to the surface when first penetrated by a drill bit. However, as the penetrated by a drill bit. However, as the internal pressures become low because of the removal or production of oil, gas, and water at the wellhead, the residual oil in the reservoir cannot be recovered without the application of external or artificial force. Secondary recovery is any enhanced-recovery operation first applied to a reservoir. Often it follows primary recovery, but it can be conducted simultaneously with primary recovery. The most common secondary-recovery process is waterflooding.