“2+3”组合提高采收率技术在濮城低渗油藏的研究与应用

濮城油田沙三中1-5油藏属于低孔低渗裂缝型油藏,层间非均质性强、渗透率级差大,使得油藏层间动用状况差异大,主力油层采出程度高、水淹严重,非主力层水驱动用低,采出程度低,油藏递减大,开发效果变差。针对此油藏以前调剖存在的难点,研究改进并应用了"2+3"组合提高采收率技术,即NAL可控无机凝胶调剖技术与ZY微生物驱油组合技术。应用效果表明,该技术不但能在纵向上改善吸水剖面,还可大幅提高洗油效率,经济效益明显。

Study and application of the combination technique of secondary oil recovery with tertiary oil recovery in low permeability reservoirs

The study found out that 1-5 zones of the midland third section of Shahejie in Pucheng oilfield is fracture type reservoir with low porosity and permeability.Be- cause of strong heterogeneity in interlayer and high per- meability contrast,the producing condition in interlayer is quite different:the waterflooded area in major layer is big with high recovery,while the situation in non-essential layer is on the opposite.Therefore,the development effi- ciency is poor.In order to solve the difficulties occurred in profile control,the combination technique of secondary recovery with tertiary recovery is studied and adopted, namely the combination technique of controlled NAL gel and ZY microbial flooding.The application proves that the technique not only improves water absorbing profile in vertical but also enhances displacement efficiency,and it has brought great economic benefits.