磷灰石裂变径迹的分析在石油勘探中的初步应用

本文根据东濮凹陷文留地区的三口探井取得的13块岩芯,系统地做了磷灰石裂变径迹的测试。确定文留地区的磷灰石径迹衰退带的上限为2,000m,下限为3,500m。其温度范围为70℃～125℃。通过换算得到该区的古地温梯度,并取得区域的平均古大地热流值。根据测试资料,编制了径迹长度频谱图、绝对年龄与深度关系图。这些基础图对区域的古地温场的解释提供了较可靠的依据。

THE PRIMARY APPLICATION OF APATITE FISSION TRACK ANALYSIS IN OIL EXPLORATION

The core samples were collected from three oil-prospecting wells in Dongpu Depression of North China Basin and various parameters of fission track of apatite wells systematically measurad. The results show that the fission track zone of apatite in Dongpu Depression appears in the well interval from 1700 to 3300 m. Thus, the paleogeothermal gradient of different strata formed since Eogene in this region is obtained. To determine the ancient tectonic heat flow value in Dongpu Depression, 360 core samples have been gathered from 21 prospecting wells in the region, and systematic measurements of rock heat conductivity have been done. With substitution of the rock heat conductivity in the formula, the ancient tectonic heat flow value of this region is yieled. On the basis of paleogeothermal parameters, the geothermal history of Dongpu Depression of North China Basin has been revealed and the geothermal maps of Eogene have been made.