Authors

Najeh Alali, MSc; Mahmoud Reza Pishvaie, PhD; Hadi Jabbari, MSc

Abstract

Thermal recovery by steam injection has proven to be an effective means of recovering heavy oil. Forecasts of reservoir response to the application of steam are necessary before starting a steam drive project. Thermal numerical models are available to provide forecasts. However, these models are expensive and consume a great deal of computer time. An alternative to numerical modeling is to use a semi-analytical model. The objective of current study was to investigate thermal applications of horizontal wells for displacement and gravity drainage processes using analytical modeling as well as reservoir simulation. The main novelties presented in the paper are entailed as; a) the transient temperature distribution ahead of the moving oil-steam interface is formulated, instead of classic assumption of quasi-steady distribution, b) New drainage oil rate calculation, c) Estimation of interface position while advancing into the reservoir towards the pattern boundaries, d) Introduction of new equations to place the interface curves into the reservoir, e) New "Type-Curves" are set up for approximating the interface velocity while propagating beyond the horizontal wells to the side boundaries, f) introducing an indirect formulations for evaluating the oil-steam interface velocity into the reservoir. Many cases were run on the classic approaches and proposed approach for comparison and verification purposes. The
proposed methodology outperforms the previous and most recent models in view of precision and consistency

Keywords

Steam Assisted Gravity Drainage; SAGD; In-Situ Steam Heating, Thermal Oil