青海柴达木盆地大地热流测量与统计热流计算

TERRESTRIAL HEAT FLOW MEASUREMENT AND CALCULATION OF STATISTICAL HEAT FLOW IN CAIDAM BASIN

１９９１年６—８月对青海柴达木盆地２１个石油勘探孔进行了钻孔温度测量，其中８个用于热流计算；从油田已有的测温资料中选取了１４个孔用作热流研究．为解决线性温度段与采样段的不匹配，对１７６块岩样的实测热导率与岩样的埋藏深度及地层年代之间的相关性进行了系统分析，求出热流计算段的加权平均热导率，共获得２２个热流值，其变化范围３２—７５ｍＷ／ｍ２，平均约５３ｍＷ／ｍ２．为阐明全盆地热流分布趋势，采用网格化方法计算统计热流．实测和统计热流一致表明，柴达木盆地热流值呈西高东低的分布特征．

Temperature logging in 21 oil-exploring wells was conducted in Caidam Basin in the summer of 1991.Among them eight were selected for heat flow study.In addition,14 available temperature logging data were chosen from abundant reserve information for heat flow calculation. To solve the unmatching between linear temperature section and sampling interval a systematic analysis was carried out for the correlation between the rock thermal conductivity(K) and the occurrence depth and between K and the stratum age of 176 rock specimems collected, which resulted in obtaining average weighted thermal conductivity of the depth-interval for heat flow calculation. All together 22 heat flow values were actually measured ranging from 32 to 75mW/m2 with an average value of 53 mW/m2. An approach of evaluating statistical heat flow using griding network technique was employed to clarify the general tendency of heat flow distribution in the Basin. The observed and statistically evaluated heat flow all indicate the heat flow distribution potttrn of 'higher in the West and lower in the East'.