Performance of Equipment Used in High-Pressure Steam Floods

Abstract

Abstract The high temperature and pressures encountered in steam flooding have necessitated the use of premium and, in many cases, unique equipment. Field results from three steam flood installations give an insight as to the performance of high-pressure equipment when subjected to the accompanying high temperatures. Performance of the equipment and factors entering into the selection of equipment for steam flood installations are discussed. Introduction Recovery of low-gravity, high-viscosity crude oil from relatively shallow reservoirs is becoming feasible through the application of steam flooding. Pan American Petroleum Corp. initiated a pilot steam flood with a 5.36 million Btu/hour, 1,500-psi steam generator at the Winkleman Dome field in west central Wyoming in March, 1964. After one year of operation, this steamer was replaced with a larger unit capable of 12 million Btu/hour at 2,500 psi. Two other pilot steam flood projects were started at that time using 12 million Btu/hour, 2,500-psi steam generators, one at the Salt Creek Shannon field and another at the Fourbear field, both in Wyoming. This paper discusses the equipment used in high-pressure steam flooding and reviews some of the problems encountered in the application of the equipment. Where determined, a suggested solution is presented. The discussion follows the conventional flow of water and steam: water treating. steam generation, steam control and transmission, wellhead and subsurface equipment, and instruments and data collection (Fig. 1). The steam generation and transmission equipment discussed in this paper has been designed for 2,500-psi saturated steam service. Maximum operating conditions have been 1,875 psi and 626F. Water Treating Successful operation of steam generation equipment depends primarily upon a good source of water combined with an effective water treating system. Experience gained in the past two years of pilot steam flood operation indicates the majority of steamer down-time is caused by water treating problems. The quality of raw water dictates the amount of treating required; therefore, it is imperative that the best water available should be used. Some criteria for a good quality raw water are:the water should be free of oil or filming amines;dissolved gases such as O2, C2 and H2S, should be absent or at least present only in trace amounts;total hardness should be low; andsuspended solids concentration should be low. Since the quality requirements of water used in a single-pass steam generator are extremely stringent, it is unlikely that the available raw water can be used without some form of treatment. JPT P. 1525ˆ