水合物海脊ODP204航次天然气水合物测井评价

在天然气水合物勘探中,地球物理测井是一种重要的资源评价方法。针对卡斯凯迪亚大陆边缘水合物海脊的天然气水合物储集层,利用ODP 204航次的测井数据,对水合物脊天然气水合物储层常规测井响应特征进行总结,并采用密度法和标准阿尔奇公式对储层孔隙度和水合物饱和度进行评价。结果表明,ODP 204航次的水合物测井响应以高电阻率、高声波速度异常最为明显,密度测井和自然伽马测井出现小幅度的低异常。密度法和标准阿尔奇公式的初步计算结果显示,ODP204航次1247B和1250F孔天然气水合物储层孔隙度分别介于51.6%-58.9%和53.2%-60.6%,水合物饱和度分别介于0-18.0%和0-33.0%。

Logging Evaluation of Gas Hydrate at Leg 204 of ODP in Hydrate Ridge

Well logging is a very important method to prospect gas hydrate. In order to survey the gas hydrate reservoir of Hydrate Ridge on Cascadia continental margin, by the logging data from leg 204 of ODP, summarizing the logging response characteristic of gas hydrate at Hydrate Ridge, then evaluating the reservoir porosity and the gas hydrate saturation by density method and Archie equation. From result, among the logging response characteristic of gas hydrate at Hydrate Ridge, high resistivity anomaly and high wave velocity anomaly are the most obvious. And there is little amplitude negative anomaly at density log and gamma ray log. The result indicates preliminarily by Density method and Archie equation, the reservoir porosity is between 51.6%-58.9% and the gas hydrate saturation is between 0-18.0% at hole 1247B of leg 204, and the reservoir porosity is between 53.2%-60.6% and the gas hydrate saturation is between 0-33.0% at hole 1250F of leg 204.