利用自然电位与自然伽马测井曲线划分沉积相带及储层分布

自然电位、自然伽马测井曲线形态和特征与沉积相带及其储集砂体关系密切,它们对不同岩性地层特征响应十分敏感.利用自然伽马、自然电位同步减小的较大幅度评价识别渗砂层,指示划分水下分流河道主体沉积微相带;利用自然伽马、自然电位减小的幅度差评价识别低渗砂、致密砂层,指示划分水下分流河道堤泛(侧翼)沉积微相带;并以自然电位比自然伽马减小幅度的相对细小差异识别油水层.在安塞油田沿河湾地区长6自然伽马、自然电位曲线划分沉积相带及储层的应用中,建立了自然伽马、自然电位划分储层的下限标准,有效地评价了特低渗透储层沉积微相带及储层类型,提高和扩大了测井曲线的应用及效果.

Dividing sedimentary facies and reservoir distributions by using natural potential and natural gamma ray logging curves

The curve shapes, characteristics of self-potential logging curves and natural gamma ray logging curves are related with sedimentary facies and reservoir rocks.They are sensitive to different lithology formation characteristics. Penetrative sandstone is valuated by using highly reduced amplitudes from self-potential and natural gamma ray borehole logging.They indicate and divide underwater channel deposits of body sedimentary micro-facies. Low and tight penetrative sandstone is valuated by using reductive amplitude deviation of self-potential and natural gamma ray. They indicate and divide underwater channel flank sedimentary micro-facies.We have identified water/oil beds using small amplitude differences of self-potential and natural gamma ray. Bottom criterion of self-potential and natural gamma ray is established to divide reservoirs by means of the application of the Chang6 reservoir in the Yanhewan area in Ansai oilfield.The evaluation of low-permibility reservoirs in this area has enhanced and broadened application and effect of logging curves.