延长油田低温低渗油藏空气泡沫驱矿场实践

Field practices of air foam flooding in low temperature and low permeability reservoirs of Yanchang Oilfield

延长油田T区块油藏具有低温低渗的特点,注水井和油井大多经过重复压裂,水驱开发过程中存在沿裂缝或优势通道水窜的问题,进而导致注水开发效果差。针对T区块水驱开发存在的问题,结合空气泡沫驱油的优势,2007年开始实施空气泡沫驱矿场试验,探索低温低渗油藏空气泡沫驱可行性,并取得了一定的效果。鉴于前期试验效果,研究区于2011年后陆续扩大空气泡沫驱矿场应用规模。目前,经过多年的空气泡沫驱矿场实践,延长油田低温低渗油藏空气泡沫驱见到了较好的效果,并形成了完整的配套工艺技术及安全保障措施。矿场应用表明:约有70%的单井见效,区块单井月均产油增加了2.2 t、综合含水降低了25个百分点,提高阶段采出程度达1.21%,延长油田低温低渗油藏空气泡沫驱见到较好效果。

The oil reservoirs in Block-T of Yanchang Oilfield have the characteristics of low temperature and low permeability.Most of injection wells and oil wells have been fractured repeatedly,and the effect of water injection development is poor because of the water breakthrough along fracture or dominant channels.In order to solve the problems existing in the water flooding development of Block-T,combined with the advantages of air foam flooding,its field test was carried out in 2007 to explore its feasibility in low temperature and low permeability reservoirs and certain effects had been obtained.Based on the effects of the preliminary tests,its site application scale expanded after 2011.After years of field tests,the air foam flooding shows good effects in the low temperature and low permeability reservoirs now,and the complete supporting technology and safety guarantee measures have been formed.The field test shows that the measures applied in about 70%of the single wells are effective,the average oil production per month of single well increases by 2.2 t,the comprehensive water cut reduces by 25%,and the oil recovery improves by 1.21%.The air foam flooding has a good effect in low temperature and low permeability reservoirs of Yanchang Oilfield.