Engineering Study of Water Reinjection for Geothermal Systems. Section I. Water Injection Well Fundamentals. Section II. The Injection Well Model. Section III. Sources of Water Contaminants. Section IV. Simulating the down-Hole Behavior of Injectors. Section V. The Overall Influence of Damage Near the Well Bore

摘要

Information related to the effects of suspended solids and, to some extent, vapor bubbles on injection well performance is presented. The means of evaluating the tolerable amounts of solids in injected water are presented, and all necessary derivations, equations, test procedures and correlations are explicitly described. Methods of determining whether surface filtration of solids, deep bed filtration of solids, or solids pass-through occurs in the well, and two sets of correlation parameters are presented. An injection well typical of those expected in Gulf Coast geopressured energy recovery systems is described, and optimium injection tubing sizes are calculated. It is concluded that the predominant sources of suspended solids in a system not containing atmospheric, uncovered ponds will be corrosion products and scale particles. Trace oxygen causes a devastating type of pitting corrosion. A technique is used to simulate injection well performance and provides data which illustrate the danger of injecting waters which contain finely divided, flocced solids, and demonstrates that injection problems caused by rigid particulates in the low micron size range will be minimal if the process system is designed to produce and handle treated injection water containing specified limits of particulate content, size, and texture. The effects of well damage over a wide range of conditions is presented in a graph which demonstrates that continuous invasion of the reservoir by trappable particulates should be avoided. (ERA citation 03:039929)