A successful test with subdivision of oil layers and adjustment of water flooding in Gaotaizi oil zone, Daqing Oilfield

Abstract: Gaotaizi oil zone has gone into a high water cut development stage, injecting water easily fingers through high permeability layers, and the conventional adjustments to water injecting projects are no longer efficient. To control the ascending rate of water cut, slow down the production decline and recover the residual oil to the utmost, it is necessary to subdivide oil layers and adjust water flooding. Subdivision is affected by the sublayer number and sandstone thickness in one segment, the variation coefficient between layers, the fingering coefficient in a single layer, and the thickness of interbeds between layers. Since the method is applied, injection profiles between and in the layers have been effectively improved, and the producing degree of the oil zones between connective oil wells increased. The oil output increased 18 t/d, the composite water cut decreased by 0.42%, and the formation pressure decreased 0.46 MPa. Keywords: high water cut stage, subdivision and adjustment, variation coefficient, water flooding, enhanced oil recover