细分调整措施在高台子油层初见成效

高台子油层已进入高含水水驱开发阶段,注入水易沿着已形成的注水通道在高渗层单层指进,常规的注水井方案调整收效甚微.为了控制高台子油层含水上升速度,减缓产量递减,最大限度地挖掘剩余油,需采用细分调整措施,即尽量将油层性质相近的小层放在一个段内注水.细分调整以井区含水为依据,段内小层数、段内砂岩厚度、层间变异系数、单层突进系数以及夹层厚度对细分调整效果都有一定的影响.在高台子油层实施细分调整以来,有效改善了注水井区层间、层内吸水剖面,调整了注水结构,连通油井的油层动用程度有所增加.日产液量稳定,日产油增加18 t,综合含水率下降0.42%,沉没度稳定.同时,油井地层压力下降,异常高压层得到有效缓解.高台子油层细分后地层压力下降了0.46MPa,东西部地区层系间压力更趋向于平衡.图4表5参10

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

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 slow down the ascending rate of water cut, control 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.