COMPILATION OF DOWNHOLE MEASUREMENT DATA OBTAINED BY OCEAN DRILLING PROGRAM AND PRECISE DETERMINATION OF IN-SITU PHYSICAL PROPERTIES

井下测量网在海洋钻井项目中发挥着重要作用。由于最近计算机性能和通信技术的进步，井下测量数据可以很容易地获得，并且可以在单个基础上进行深入分析。为了准确估计海底沉积物的物理性质，我们通过互联网或亲自收集了尽可能多的ODP井下数据集。(1)采用一致性数据处理方法对ODP地热数据进行了重新估计和修正；例如，降低地层温度的数据间隔对于所有测量都是相同的。与以前的结果相比，重新处理的热流数据差异高达10-20%。(2)通过实测热导率和孔隙率估算颗粒热导率。颗粒电导率与颗粒密度的交叉图显示，ODP得到的海底沉积物具有轻微的正相关。(3)将实测孔隙度与测井孔隙度进行对比。(4)为了获得高分辨率水合物饱和度剖面，对ODP Leg 164地层微扫描仪图像进行了半定量分析。FMS图像被转换成电阻率，然后使用阿奇公式转换成水合物饱和度。含水层段的平均饱和度估计为5-10%。

Downhole measuremanets play a significant role in the Ocean Drilling Program. Due to recent improvements in the computer performance and telecommunications, downhole measurement data can be easily obtained and an intensive analysis can be carried out on an individual basis. In order to provide precise estimates of the physicalproperties of seafloor sediments, we collected as many ODP downhole datasets as possible through Internet or personally.(1) ODP geothermal data have been reestimated and revised by applying a consistent data processing; e.g. intervals of data to reduce formation temperatures are set equal for all measurements. Reprocessed heat flow data are found to be different by up to 10-20% as compared with previous results.(2) The grain thermal conductivities were estimated from measured thermal conductivities and porosities. A crossplot of grain conductivity vs. grain density revealed a slightly positive correlation for seafloor sediments obtained by ODP.(3) Porosities measured on individual samples were compared with logging porosities.(4) A semi-quantitative analysis of the Formation Micro Scanner image was carried out for ODP Leg 164 in order to get a high-resolution profile of hydrate saturation. FMS images were converted to resistivity, then to hydrate saturation using Archie's formula. The average saturation at the hydrate-bearing interval was estimated to be 5-10%.