Shell Oil Company conducted an oil shale thermal conduction pilot in the Piceance Basin of Colorado during 1997 and 1998. Six heaters and one producer were arranged in a single unconfined hexagonal seven spot pattern to test the viability of the Shell's proprietary in-situ conversion process (ICP) in oil shale under field conditions and to substantiate the in-house experiments that produced high quality crude. The pilot succeeded in meeting all of the intended objectives. The history match of the production data, however, encountered some technical challenges and hindered the full interpretation of test results.
This paper presents the results and findings of a new history match study of the pilot. This simulation succeeded in achieving a good match of the production data by the identification of (1) borehole reflux heat loss, and (2) production impairment from scale build-up and the proper adjustment of well skin effects in the model. It also confirmed that the ICP performance observed in laboratory could be used as a good proxy for ICP in field.