Supply Waters For Waterflooding In West Central Texas

Abstract

Publication Rights Reserved This paper is to be presented at the 39th Annual Fall Meeting of the Society of Petroleum Engineers on Oct. 11–14, 1964, in Houston, Tex., and is considered the property of the Society of Petroleum Engineers. Permission to publish is hereby restricted to an abstract of not more than 300 words, with no illustrations, unless the paper is specifically released to the press by the Editor of JOURNAL OF PETROLEUM TECHNOLOGY or the Executive Secretary. Such abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Publication elsewhere after publication in JOURNAL OF PETROLEUM TECHNOLOGY or SOCIETY OF PETROLEUM ENGINEERS JOURNAL is granted on request, providing proper credit is given that publication and the original presentation of the paper. 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 considered for publication in one of the two SPE magazines with the paper. Abstract For a nine-county area in West Central Texas, sources of supply waters for water-flooding or pressure maintenance operations are classified in these catagories: Cambrian Sand Water, Fresh or brackish surface waters, and Miscellaneous subsurface brines of varying salinity. As a guide to the selection of a water supply, problems which normally arise from the handling of these waters are discussed, as well as their relationships with produced water. Preventive and remedial control measures which have been employed in the area are described, especially in regard to the primary problems of deposition and corrosion. This paper is intended to assist the waterflood operator in identifying, avoiding, or resolving water handling difficulties not only in the subject area, but in any waterflood project. Introduction In the nine-county area in West Central Texas (Fig. 1) covered by this discussion, a secondary recovery expert may find physical evidence of most of the problems which are likely to be encountered in waterflooding. Many of these problems are directly related to the chemical characteristics of the water. The quality and availability of supply water varies markedly over the area, as does the character of the water found in the producing zones. Most of the flooded formations are sands of relatively low permeability, With either adjacent or interbedded shale stringers. Several massive, naturally fractured reef or lime formations are under flood or pressure, maintenance. Production is relatively shallow in the area, generally less than 6,000 feet and with a maximum BHT of 140 degrees F. The crude oils are of high gravity, generally 38–45 degrees API, and of low viscosity. Severely corrosive waters, occurrings at a depth of 1,000 to 2,000 feet, are responsible for many casing leaks and other difficulties. Typical analyses of two of these waters are shown in Fig. 2. During the past decade, many floods have come, and some have gone, in the subject area. In this period, much has been learned concerning the problems which the waterflood operator faces. This paper is a presentation of some of these problems and how they may be anticipated, or probably solved or overcome. SUPPLY WATER SOURCES One of the primary considerations in selecting a source of water for flooding involves the daily volume required to initiate the project. Requirements in the subject area range from 100 B/D to over 50,000 B/D.