A standard automatic history-matching technique is applied to a Buckley-Leverett solution of laboratory corefloods to obtain oil/water relative-permeability curves. Several laboratory coreflooding examples are included to illustrate the usefulness of this method.
History matching with a simulator has become a very valuable tool in reservoir engineering. Much information can be obtained from production history and well tests that use history matching that cannot be obtained by classic methods because a simulator can model many different situations, while other techniques require restrictive assumptions to obtain a solution. This problem is also evident in laboratory corefloods. Most methods of determining relative-permeability curves assume that irreducible saturation has been attained throughout the core. In the laboratory, however, this is seldom the case. Additionally, inclusion of such effects as capillarity and hysteresis curves between imbibition and drainage relative-permeability and capillary-pressure curves makes analysis with anything other than a simulator almost impossible. One of the drawbacks to using a simulator, however, is that history matching is an iterative process. Many runs must be made before a good match is obtained. A great deal of computer time is used, as well as the time of the engineers involved. Automatic history matching is one possible solution to this problem. The engineer is free to perform other tasks, and the answer is obtained much more quickly because the slow process of obtaining a printout, plotting data, and submitting runs between each iteration has been eliminated. An automatic history matching program will use a lot of computer time, but if a good algorithm is used, it should not use more computer time than a match by hand. In this paper, a standard automatic history-matching method is used to match laboratory coreflood data to obtain relative-permeability curves.