Treatment of Injection and Producing Wells with Monomer Solution

Abstract

American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc. This paper was prepared for the Oklahoma City SPE Regional Meeting, to be held in Oklahoma City, Okla., March 24–25, 1975. 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 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. 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 discussion may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines. Abstract This is the application of a process whereby a monomer solution is mixed at the wellsite and pumped into the well. Once the solution is within the formation, the well is shut in to provide time for the monomer to polymerize. The process can be used in polymerize. The process can be used in producing and secondary recovery waterflood producing and secondary recovery waterflood injection wells. The process is applicable to either single wells or multiple wells in a waterflood system. The purpose of the process is to place a polymer solution within the formation without polymer solution within the formation without the shear degradation caused by passing the solution through restrictions. Mixing problems due to dissolving high molecular weight polymers are avoided. Viscosities of 10,000 to 1,000,000 cp have been created in simulated formations. These viscosities would be difficult to handle with surface mixing of polymers. The polymer can be formed immediately around the wellbore or in a theoretical annular ring by overdisplacement with water. The concentrated polymer created is spread by normal injection of polymer created is spread by normal injection of flood water. Well-treatment histories are tabulated and discussed. Production well responses to treating injection wells indicate that the polymer formed in the formation may be acting both as a diverting agent and as a means of improving mobility ratio. Mobility ratio improvement should affect production eventually. The process is flexible enough so that both process is flexible enough so that both diverting effect and polymer flood front may result in the same system. Increased oil production or decreased water production will production or decreased water production will result more quickly from diverting effect. Successful results have been obtained after treating producing wells with the monomer. The number of treatments was not extensive, but they indicate that better response can be achieved with improved treatment technique. Introduction As formation pressure declines, primary recovery of oil will reach a rate that is no longer economical. There are several methods of re-establishing some formation pressure such as natural gas injection, carbon dioxide injection, steam injection, fire floods and water injection. The main concern of this paper is some problems afflicting waterfloods. paper is some problems afflicting waterfloods. When water is injected into a well with the intention of sweeping oil into adjacent wells, there are a number of commonly occurring conditions that may interfere with efficient displacement of oil by water. Among these are cracks and fissures in the formation, permeability variations within the producing permeability variations within the producing interval, the geometry of sweep patterns, and fingering of water into viscous oil (unfavorable mobility ratio). These conditions often occur simultaneously.