Matching Calculated With Actual Waterflood Performance by Estimating Some Reservoir Properties
Authors: Higgins R.V. , Leighton A.J. 
Published: December 2007

The Higgins-Leighton mathematical model was tested by comparing predicted with observed performance in a mature Southern California waterflood for which accurate reservoir data were not available. By using successively revised estimates for interstitial water and permeability distribution, an excellent history match was achieved.

Introduction
The use of mathematical models to predict the future performance of petroleum reservoirs is a valuable tool that has developed rapidly in recent years. However, the number and complexity of methods available for numerical simulation continue to increase with bewildering rapidity. As the complexity of the models increases, the cost of engineer and computer time also increases. The first problem of the engineer, then, is to decide which method to use in each case. Sometimes the problem is resolved by using a simple model first and then deciding whether the accuracy of the basic data and the expected use of the results justify using a more complex model. The Higgins and Leighton method is one of the shorter methods developed to predict reservoir performance. Although the method can be used for several types of predictions, it is most often used to predict the future performance of waterfloods. There are many indications that the method is widely used by industry, but only a few direct comparisons of predicted with actual performance have been published. More such comparisons are needed to prove that the theoretical model accurately predicts performance, and if it does not, to determine what improvements should be made either in the model or in the quality of input data. The easiest and best way to test the method is to find a field where a successful waterflood has been completed, then make the calculations and compare the predicted with the actual performance. The results of four either partial or complete performance. The results of four either partial or complete comparisons have been published. None of the fields in those comparisons were in California where thick sands, faulting, and other reservoir characteristics pose different types of problems. The Dominguez field (Southern California), where a waterflood had been almost completed is such a field, and with the cooperation of the operator, Union Oil Co. of California, we collected all the pertinent field data, made the predictions, and compared the calculated performance with the actual performance.

Field Information

The Field
The Dominguez oil field, one of the important ones in the Los Angeles Basin, is situated 14 miles south of downtown Los Angeles. The field was discovered in 1923 and to the end of 1971 had produced more than 250 million bbl of oil. The structure, a faulted produced more than 250 million bbl of oil. The structure, a faulted anticline, has been produced from at least eight zones, ranging in depth from about 3,000 to 8,000 ft. The sequence of sedimentation is remarkably consistent, and in many instances thinner beds can be traced without difficulty. There are only minor changes in the character of sediments within the oil zones; this applies not only laterally, but also to the vertical column.