大庆油田超前注水储层物性界限研究

大庆油田近年新增储量渗透率低、品质差,未动用储量开发难度大,而低渗透油田投产后,如果能量补充不及时,地层压力会大幅下降,油田产量迅速递减。为提高开发效果,大庆油田对天然能量小的低渗透油田,开展了保持地层压力的超前注水开采试验。超前注水技术能够尽快建立有效的压力驱替系统,及时补充地层能量,提高地层压力,减小应力敏感损害,降低油井初始含水率,避免流体性质变差,从而改善油田开发效果。在大庆油田已投产的超前注水试验区块中,储层物性较差的扶杨油层超前注水效果较明显,储层物性较好的葡萄花油层单井产量提高不明显。利用室内试验、现场开发数据及数值模拟等手段确定了超前注水储层界限:大庆油田渗透率小于10mD的储层采取超前注水效果较好。这为超前注水技术在低渗透油田难采储量开发中的应用提供了有效依据。

The Threshold Research about Reservoir Physical Property Advanced Waterflooding in Daqing Oilfield

It is difficult to develop the new proved reserves and unproduced geologic reserves in Daqing oilfield in recent years for its low permeability and poor quality.If the energy can not be supplied timely for the low-permeability oilfield,the formation pressure and oil production will drop significantly after putting into production.In order to enhance the development effects,advanced waterflooding is carried out to maintain for- mation pressure for the low-permeability oilfield with less natural energy.Advanced waterflooding can establish an effective pressure displacement system as soon as possible ,replenish the formation energy ,improve the for- mation pressure ,reduce stress sensitive damage and initial water cut and avoid deterioration of the fluid prop- erties so as to improve the development effect of the low permeability oiffield.Among those tested blocks,the testing effect of Fuyang oil layer with poor reservoir physical properties is obvious ,while the effect is not ev- ident for the Putaohua layer with better reservoir physical properties.At last,the threshold value of permeabili- ty is 10mD for Daqing oilfield by means of laboratory experiments,field data,numerical simulation and other means.That is to say,the development effect of the advanced waterflooding is better for the reserves of permeability less than 10roD ,all of which can provide a valid basis for the development of trouble reserves in the low-permeability oilfields.