CX地区含油储层地震反射特征及油气预测效果

Seismic reflectien characteristics and hydrocarbon prediction of oil-bearing reservoirs in the CX area

胜利石油管理局物探公司研究所,东营 257100

Research Institute of Geophysical Prospecting Company, Shengli Petroleum Administration, Donying 257100

CX地区按二段储层为砂泥岩薄互层,埋深在2000～2700m之间,且砂岩速度大于泥岩速度。过去一直认为：砂岩含油气后,速度降低,含油性好的储层在地震剖面上就表现为弱振幅特征。然而,大量的实钻结果证实：“高产井(含油性好的储层)均对应剖面的强反射振幅。”为此,我们从正演模型出发,利用测井、岩芯测试数据,研究了该区的岩石物理特征和沉积相特征,以及产生特殊地震相特征的物理基础和地质基础,建立了正确的油气检测标志,从而使CX地区的钻井成功率从过去的47.6％提高到96％以上。

The reservoir Sa-2 in CX area is a thin sand-shale interbed with buried depth from 2000m to 2700m,and the sandstone velocities are larger than the shale velocities. The previous view was that when the sandstone contains oil,the velocity will reduce,and the well oil-bearing reservoir should show weak amplitude feature in the seismic section. However, many drilling results demonstate that high production wells (well oil-bearing reservoir)all correspond to strong relection amplitude.So,starting from the forward models,we research the petrophysical and sedimentary facies characteristics and the physical and geologic mechanism for producing particular seismic facies using the log and core testing data. The correct signs fot hydrocarbon detection are thus constructed,improving the success rate of drilling from 47. 6% previously to more than 96% now.