洪浩尔舒特凹陷下白垩统热成熟度地震预测

SEISMOLOGIC PREDICTION OF THERMAL MATURITY OF LOWER CRETACEOUS IN HONGHOLSHUT DEPRESSION

刘震 孙强 武耀辉

Liu Zheng Sun Qiang Wu Yaohui

石油大学, 北京 102200 2. 华北石油管理局, 河北 任丘 610041

Petroleum University, Beijing 102200 2. Huabei Petroleum Administration

洪法尔舒特凹陷下白垩统巴彦花样泥岩孔隙度与泥岩干酪根镜质体反射率(Ro)之间存在密切关系。经对比发现该泥岩孔隙度与镜质体反射率之间的关系与幂函数最为接近。本文根据该幂函数关系先由泥岩的地震速度转换出孔隙度,然后从孔隙度计算出镜质体反射率,最终定量地圈定凹陷主力烃源岩的未成熟区和成熟区,为近源圈闭的选择提供评价依据。这种由地震信息直接测定有机质热成熟度的方法,对于勘探程度较低尤其是钻井稀少的盆地,有着较高的使用价值。

There is a close relation between the porosity and vitrinite reflectance(Ro)of kerogen in the mudstones of Bayanhua Group,lower Cretaceous in Hongholshut depression.By a correlation,it is found thatthe relation between the porosity and vitrinite reflectance is most closely approximating to a power function.Based on this power functional relation,porosity was converted from the seismic velocity of mudstones,then the vitrinite reflectance was calculated from the porosity,finally to delineate the immatureand mature areas for the main hydrocarbon source rocks in the sag,and provide evidences for the selectionof near-source targets.The method that measures organic thermal maturity directly from seismic information is of great value for areas with lower exploratory levels,especially for the basins with sparse welldrillings.

https://doi.org/10.11781/sysydz199704371