米氏旋回剥蚀量计算方法在泌阳凹陷的应用

利用米氏旋回地层学方法对泌阳凹陷古近系与新近系之间区域不整合面的剥蚀量进行了计算。泌阳凹陷古近系\新近系剥蚀量计算可以分为2段:(1)各井各组(段和亚段)选定现有地层的分层和测井曲线数据进入"旋回地层学研究系统"(Version1.0),寻找0.405Ma周期,求最大优势旋回,计算出现有沉积时间;(2)把现有地层沉积时间以外的剥蚀掉的时间,用0.405Ma周期转化为剥蚀厚度。计算结果表明在凹陷的核心地区,仅廖庄组遭到剥蚀,凹陷东南部安棚一带剥蚀量小于100m,向凹陷西、西北以及北部边缘方向逐渐增大,至廖庄组缺失线附近,剥蚀厚度在650m以上。凹陷边缘附近,核桃园组也遭到剥蚀,核桃园组的剥蚀厚度主要介于4.1～666.5m,总剥蚀量在1000m以上。泌阳凹陷已知油田分布于剥蚀厚度大于200m地区。 

Calculation of denudation amount with Milankovitch cycle method: a case study in Biyang Sag

The denudation thickness of Paleogene—Neogene unconformity in the Biyang Sag has been calculated with the Milankovitch cycle method.The calculation process has been divided into 2 steps.1)Put the strata classification and logging curves of all formations as well as sections and sub-sections into "studies system of cyclostratigraphy"(version 1.0) so as to find the 0.405 Ma period.In this way,the maximum dominant cycle and the sedimentary time for available strata can be calculated.2)Transform the denudation time besides of the above-mentioned sedimentary time for available strata into erosion thickness according to the 0.405 Ma period.It has been concluded that in the center of the sag,only Liaozhuang Formation is denuded.In Anpeng area which locates in the southeast of the sag,the denudation thickness is less than 100m and increases gradually to the west,northwest and northern margin of the sag,and finally exceeds 650m around the missing boundary of Liaozhuang Formation.Hetaoyuan Formation is also denuded near to the sag boundary,mainly 4.1-666.5 m thick,and the total denudation thickness is over 1000m.The known Oil fields in the sag mainly locate in the area with denudation thickness larger than 200m.