鄂尔多斯盆地F油田延7、延8油层组夹层分布特征及其对开发效果的影响

Interlayer Distribution Characteristics and Their Influence on Development Results of Yan7 and Yan8 Oil Reservoirs in Oilfield F,Ordos Basin

侏罗系延安组延7、延8油层组作为鄂尔多斯盆地F油田主力生产层位,储层内夹层广泛发育,开发效果表明夹层已对油藏油水运动规律产生影响。由于开发前期缺乏对目的层段储层非均质性的系统研究,直接制约了后期精细油藏开发工作。利用研究区测井资料解释成果以及岩心观察资料,全面总结研究区夹层类型、夹层规模及其电性特征。并在此基础上结合生产实例分析夹层对油藏开发效果的影响。研究认为,F油田延7、延8油层组夹层类型以泥质夹层和钙质夹层为主。其中,延8油层组夹层规模多属相对稳定夹层,延7油层组属较稳定夹层。不同夹层其电性特征差异较大,是实际生产中确定油藏夹层类型的重要依据。油藏开发特征表明,夹层可以通过抑制砂体的吸水能力降低油藏水驱动用程度,同时能够减缓边底水油藏底水锥进的速度,避免生产井过早见水。

Yan 7 and Yan 8 oil reservoirs of Jurassic Yan′an Formation are the major productive formations of the Oilfield F in Ordos Basin,and the interlayers in the reservoir are widely developed.The development results indicate that the interlayer has an impact on the oil-water movement law of the reservoir.Later fine development of oil reservoir was restricted for lacking systematic research on the heterogeneity of target zones at early stage.The type,scale and electrical characteristics of the interlayers of the studied area were analyzed systematically according to the interpretation results of logging data and the core observation data.The impact of interlayers on the reservoir development was analyzed combined with the cases.The interlayers in Yan 7 and Yan 8 oil reservoirs in Oilfield F are mainly argillaceous and calcareous according to the research re-sults.The interlayer scale of Yan8 oil reservoir is relatively stable,and Yan7 is less stable.Different interlayers have different electrical characteristics,which is the basis for determining the type of interlayer.The characteristics of reservoir development indicate that the production of oil reservoir by water drive may be reduced through inhibiting the water absorption capacity of the sand by the interlayer,and the speed of bottom water coning may also be slowed down in the edge and bottom water reservoir to avoid early water breakthrough in the production well.