元素俘获谱测井在长庆天然气勘探中的应用

Application of Element Capture Spectroscopy Logging in Changqing Gas Exploration

在砂泥岩剖面中,泥岩往往比砂岩具有较高的自然伽马值,从而可以利用自然伽马测井将砂岩储层划分出来。但是由于储层中泥质类型发生变化,或砂岩储层中含有某些放射性较强的矿物,造成储层伽马值较高,往往造成将高伽马砂岩储层误解释为泥岩。在这种情况下,元素俘获谱测井通过测量地层不同元素的俘获谱,可以较准确地识别高伽马砂岩储层。

Based on the features of mudstone with higher gamma ray than sandstone in sandstone -mudstone section,we can distinguish sandstone reservoir from the drilling profiles with gamma ray log.But this method is not reliable ,for instance,when the clay types change or sandstone reservoir contain some high radiation elements ,the gamma ray value of the reservoir is usually high,resulting in mistaking the sandstone reservoir with high gamma ray for mudstone one.ECS (Element Capture Spectroscopy)logging can effectively distinguish this kind of sandstone reservoir through measuring different elements capture spectroscopy of strata.