Steam Simulation for Secondary Recovery

This paper describes the steam stimulation process, and discusses where itis applicable, and why it succeeds and fails. Field data for three separateprojects in California are presented. Oil recovery from a single cycle ofinjection and production is discussed and a theoretical method of calculatingoil recovery is shown with an example. The major components of steamstimulation costs are listed. A generalized correlation of reservoir oilviscosity versus temperature is presented in a form convenient for use in steamstimulation work. Introduction Steam stimulation has caught the fancy of the petroleum industry. The ideais not new, because the effect of temperature on crude oil viscosity has beenknown since the days of Colonel Drake. Early-day patents concerned theinjection of steam to reduce viscosity and clean up paraffin deposits aroundthe wellbore. There has been a cloak of secrecy surrounding steam stimulation activities, motivated by the hope of acquiring producing properties susceptible to thesteam stimulation technique. Many of the reasons for secrecy are now gone. As amatter of fact, many of the sellers have a fear of missing out on something andare asking prices that may be over and above the actual worth of theproperty. It is important that the oil industry break through the darkness andmysticism surrounding steam stimulation. This paper is presented as an encouragement to others to publish and exchange information, and to put steamstimulation in its rightful place as a valuable means of improving the recoveryand profitability of our more viscous oils. What Is Steam Stimulation? Steam stimulation is the addition of thermal energy to a reservoir by steam injection. The same well is used for injection and production. The primary object of the steam injection is to get heat to the bottom of the hole andlower oil viscosity. The rock at the bottom of the well acts as a heatexchanger and permits storage of heat from the injection cycle, to be usedeffectively as the oil is produced back into the well.