The development and application

A great deal of attention has recently been focused upon "enhanced oil recovery"; that is, the application of recently developed processes for recovering oil that would normally remain in a reservoir following depletion by conventional techniques. Since this heretofore unrecoverable remaining oil amounts to about 300 billion barrels in the U.S. alone (see Figure 1), one can see why enhanced recovery is getting so much attention. Among the broad class of enhanced oil recovery processes are processes called chemical flooding. These chemical flooding processes are extremely complex and really not completely understood. For example, a chemist in the laboratory can design a process which will recover 80 to 100 percent of the oil-in-place from a representative piece of reservoir rock; however, when these same systems are applied in the field, recoveries have ranged from 15 to 65 percent. This implies that there are interactions which sometimes occur in the reservoir that are sufficiently off design relative to laboratory work, to result in near or total process failure. To this technical uncertainty, add the problems of selecting a specific process for a given reservoir and the tremendous economic uncertainties that still exist; we see why chemical flooding is not projected to recover substantial amounts of oil for this country by the year 1985. One way to accelerate the amount of oil recovery from chemical flooding is to obtain a better understanding of what takes place in a chemical flooding project. This understanding can be achieved through the interaction between mathematical models, laboratory results and actual field experiments. Much work is going on in the laboratory, and much work is going on in the field. However, until very recently there did not exist a mathematical model which could be used to better evaluate and understand the complex physics involved in all these processes and be used to scale the laboratory results to the field. INTERCOMP has developed such a chemical flooding model, and the development and . application of this model is the subject of this paper.