以钻井、测井资料为基础,以高分辨率层序地层学为指导,通过层序界面和层序地层的测井响应特征研究,对宁东煤田中侏罗纪延安组含煤岩系进行了精细划分与对比.结果表明,宁东煤田中侏罗纪延安组层序地层界面位于测井曲线基值发生明显改变的转折点上,大型河道冲刷面、湖泛面以及进积(加积)与退积的相互转换面也是层序界面的发育位置;层序地层的测井响应特征中,进积类型测井曲线呈现漏斗型,退积类型测井曲线呈现钟形,加积类型测井曲线呈现箱型；宁夏宁东煤田中侏罗纪延安组可以识别出3个三级层序,共识别出9个层序组,并可进一步详细划分为9个四级层序.%Based on drilling and well logging data, guiding by the high resolution sequence stratigraphy, studied sequence boundary and sequence stratigraphic well logging response characteristics, carried out refined division and correlation of middle Jurassic Yanan Formation coal-bearing strata in the Ningdong coalfield. The result has demonstrated that the Yanan Formation sequence stratigraphic boundaries used to be on the abrupt turning points of logging trace basic values; switching planes between surfaces of large sized channel scouring, lacustrine flooding, prograding (aggrading) and retrograding also the developing places of stratigraphic boundaries. In sequence stratigraphic well logging response characteristics, prograding typed logging traces present infundibuliform, while retrograding campaniform and aggrading box-form. 3 third-order sequences, 9 sequence sets can be identified in middle Jurassic Yanan Formation in Ningdong coalfield in Ningxia, and then can be further subdivided into 9 fourth-order sequences.
展开▼
