Investigation of sweep efficiency in surfactant-polymer flooding with an existing barrier between wells by using CMG (STARS) simulator

Abstract

The effects of a single barrier existing between two wells on the chemical flooding are investigated with the assumed various shapes and sizes of the barrier by 3D numerical studies in STARS (CMG) software. The same injection schemes of surfactant and surfactant-polymer (SP) flooding are utilised for all barrier cases and the no barrier case. The simulated results show that in surfactant flooding, the small type barrier might give the positive effects on the flooding performances compared to no barrier case and bigger barrier cases, while the existence of a barrier completely influences negatively to the sweep efficiencies in SP flooding. However, for all barrier cases, the combined surfactant-polymer injection scheme always gives higher oil production than using single surfactant injection although the obstructive level by a barrier is higher in SP flooding. The changes of well configurations in terms of well locations and well patterns point out the unsuitable of installing horizontal wells in any case of barrier compared to vertical wells, instead the vertical injector should be installed closer to barrier than the vertical producer for achieving the better flooding performances. [Received: May 12, 2016; Accepted: October 21, 2016]