Application of Injection Fall-Off Analysis in Polymer flooding

van den Hoek, Paul (Shell) | Mahani, Hassan (Shell Intl. E&P Co.) | Sorop, Tibi (Shell) | Brooks, David (AAR Energy) | Zwaan, Marcel (Shell Intl. E&P Co.) | Sen, Subrata (Shell India Markets Private Ltd) | Shuaili, Khalfan (PDO) | Saadi, Faisal (PDO)


This has a significant impact on pressure decline signature as exhibited during Pressure Fall-Off (PFO) tests. Therefore, applying a different PFO interpretation method, compared to conventional approaches for Newtonian fluids is required. This paper presents a simple and practical methodology to infer the in-situ polymer rheology from PFO tests performed during polymer injection. This is based on a combination of numerical flow simulations and analytical pressure transient calculations, resulting in generic type curves that are used to compute consistency index and flow behavior index, in addition to the usual reservoir parameters (kh, faulting, etc.) and parameters relating to (possible) induced fracturing during injection (fracture length and height). The tools and workflows are illustrated by a number of field examples of polymer PFO, which will also demonstrate how the polymer bank can be located from the data.