柴达木盆地西部地区第三系温度压力和油气分布相互关系探讨

TEMPERATURE, PRESSURE AND RESERVOIR DISTRIBUTION IN TERTIARY, WESTERN QAIDAM BASIN

根据实测和理论计算得到柴达木盆地西部地区第三系各层底界的温度，同时利用测井和录井资料及实测压力数据分析了４０多口井的地层压力状况，进而分析了第三系各层的温度和压力分布特征．在此基础上对温度和压力的相互关系进行分析，井对其与油气藏分布关系进行探讨．研究表明现今油气藏分布与温度压力状况有密切的关系，现今异常高压区是油气藏保存的有利地区；异常高压区上方的次生油藏往往分布于压力正常带，但与下方的异常压力有密切关系．这种次生油藏是由下方异常高压区的原生油藏脉冲式运移的结果，沸腾包裹体的发现为此提供了有力的证据，这也是柴达木盆地西部地区典型的油藏分布特征．

Temperatures in Tertiary layers in Western Qaidam Basin were obtained bytheoretical calculation and measured data. Pressure data of more than 40 wells wereanalyzed using logging data at the same time. Based on these data. the distributioncharacteristics of temperature and pressure in four Tertiary strata were obtained, whichwere the basis to study the relationship between temperature-pressure and reservoirdistribution. There exists a close relation in the present-day's temperature-pressurestate and reservoir distribution. The abnormal high-pressure regions are more favorablefor reservoir preservation. However, the secondary pools are distributed in the normalpressure regions related with the abnormal high-pressure below. This hydrocarbonaccumulation model is typical in Qaidam Basin and the existence of 'boiled fluidinclusion' provided an evidence for this model.