Steam stimulation results have been given "glamorous" coverage in the oil and financial press in recent months. One article spoke of steam injection as a "tonic" for tired oil fields, a "thermal Geritol" which thins down viscous crude and helps stimulate the production of oil. Some isolated spectacular results have indicated very large initial increases in production.
An attempt has been made to collect well performance data of steam soak operations for economic appraisal. Twelve operators were contacted and I am grateful and appreciative of their cooperation. Not all those contacted furnished data, but they were helpful in their encouragement to prepare the paper. Some producers have kept their steam injection operations quiet while learning the technology of steam stimulation. However, for this paper, the operators who made available their stimulation results furnished well performance data of the heavy oil fields of the San Joaquin Valley of California. The attached map, Plate I, shows the location of thermal steam projects in California together with the names of the operators in each field.
In evaluating the economics of steam "soak" recovery, there is no escaping the uncertain task of peering into the future based on available past performance. A detailed forecast is a massive job and falls outside the scope of this paper because much of the available data on performance has not been released by operators; nevertheless, it is intended to treat the subject in the broadest of terms with the limited operational data in order to identify the main economic considerations.
Successful operations are dependent on initial and repeated productive response to steam injection, productive trends after each steam soak, optimum spacing and steam costs.
At this time steam flooding will be briefly described and defined. There are three primary methods of using steam to increase oil production. Plate II shows these three induced production methods by steam injection.