脉冲中子全谱测井碳氧比资料在南堡钙质砂岩储层的应用

Application of PNST C/O Log to Calcareous Sandstone Reservoir in Nanpu Oilfield

南堡油田馆陶组至东一段主力开发层系的砂岩储层富含钙质,造成应用常规测井资料和碳氧比测井资料识别储层流体存在困难。针对性地研究与应用了PNST碳氧比测井资料的钙质校正方法。按照PNST测井仪和当地套管井实际结构建立模型,通过MCNP数值模拟,获得了碳氧比和俘获钙产额测井值随地层岩性和孔隙度变化的规律。可利用俘获钙产额曲线校正钙质含量对碳氧比曲线影响,提高含油饱和度解释准确性。应用钙质校正方法后,PNST含油饱和度测井解释成果为南堡油田制订堵水、补孔方案提供了有效依据,90%以上的井措施后增油明显。测井实例显示,PNST测井资料在南堡油田能够准确识别油水层。

The calcium-rich sandstone reservoirs in the main development zone from the Guantao Formation to the first interval of the Dongying Formation in Nanpu Oilfield bring challenges to identify formation fluids using conventional logging data and carbon-oxygen ratio logging data. To address the issue, the calcium correction method for PNST carbon-oxygen ratio logging data was studied and applied. Model was established according to the PNST logging tool and actual wellbore structure. The variation of carbon-oxygen ratio and capture calcium yield logging with lithology and porosity of the formation was obtained by MCNP numerical simulation. The capture calcium yield curve can be used to correct the influence of calcium content on the carbon-oxygen ratio curve and improve the accuracy of oil saturation interpretation. By applying the calcium calibration method, the PNST oil saturation logging interpretation results provide an effective basis for the development of water blocking and infill perforating schemes in Nanpu Oilfield. More than 90% of the well showed significant oil recovery after stimulation. Well logging case study showed that PNST logging data can accurately identify oil and water layers in Nanpu Oilfield.