Abstract
Alkaline Surfactant Polymer (ASP) local oil recovery process has shown great potential in enhanced oil recovery (EOR). The recovery percentages are encouraging. The fact that these reagents are locally and cheaply sourced is also advantageous. The technique can be successfully applied in producing oil left in reservoirs after primary and secondary recovery process has been exhausted. The reagents used for this work include Irvingia Gabonensis, Lecithin and Palm Bunch Ash (PBA). Irvingia Gabonensis is granulated wild mango seeds (Ogbono, a biopolymer) used as polymer. It has similar characteristics with the xanthan gum that is already in use. Lecithin is a phospholipid and also a surfactant extract from soya bean. PBA is an alkali, and also an agricultural waste product. The reagents were used individually and in combination. Unconsolidated sand was used in the experiment.
The appreciable oil recovery from the experiment buttresses the essence of lowering interfacial tension by the alkali through in-situ saponification to recover 25% oil in place (OIP). The surfactant in this experiment lowered interfacial tension to release more oil out from the sand pores and thus recovered 23.3% OIP. The polymer used increased the mobility and gradually swept the oil trapped in the pores to increase oil recovery by 22.7% OIP. A combination of the reagents used shows that the ASP flood gave a percentage recovery of 27.7% ROIP and an incremental oil recovery of 17.9% above water flooding.
