超压盆地热演化及其对油气勘探潜力的影响——以南海北部陆缘盆地为例

在南海北部陆缘盆地中,油气田分布与现今地温异常区有密切关系,该现象通常与油气藏形成过程中地下热流体活动及油气层的隔热作用有关。沉积盆地的热演化对生烃窗口的深度范围有较大影响;超压作用对镜质体的演化有抑制作用,在用EasyRo法计算镜质体反射率及热史恢复时应考虑超压作用对计算结果的影响。模拟计算表明超压抑制作用增加了生烃窗口的存在深度,扩大了油气勘探的范围。 

Thermal evolution and its impaction on exploration potential in overpressure sedimentary basins-a case study on continental margin basins of the northern South China Sea

It's observed that oil/gas fields distribution is distinctively connected with the geothermal abnormal areas in continental margin basins of the northern South China Sea.This phenomona is basically due to the geothermal fluid vertical movement and the lower thermal conductivity of oil/gas beds during the process of oil/gas reservoir formation.Thermal evolution of sedimentary basin has significant impaction on the range of oil/gas window,and also the maturity of vitrinite reflectance can be restrained as a result of overpressure.Therefore it has been taken into consideration in this paper when the vitrinite reflectance is calculated with EasyRo model.The simulated result indicates that the fact of overpressure has expanded the range of oil/gas window and exploration scope as well.