基于GR测井信息的层序细分及砂体预测技术——以鄂尔多斯盆地临兴A地区上石盒子组盒四段为例  

Sequence subdivision and sand bodies prediction technology based on GR logging information:Taking H4 Member of Upper Shihezi Formation in Linxing A area of Ordos Basin as an example

作　　者：王波 齐宇 杜凯 孙乐 李文兰 WANG Bo;QI Yu;DU Kai;SUN Le;LI Wenlan(CNOOC Research Institute Ltd.,Beijing 100028,China)

机构地区：[1]中海油研究总院有限责任公司,北京100028

出　　处：《中国海上油气》2022年第4期164-174,共11页China Offshore Oil and Gas

基　　金：中海石油(中国)有限公司综合科研项目“临兴一体化区石盒子组沉积微相研究与甜点预测(编号:YX-B-KJFZ)”部分研究成果。

摘　　要：鄂尔多斯盆地上古生界致密砂岩气储层沉积厚度薄,岩性及物性横向变化快,地层横向对比多解性强,因此,开展致密砂岩储层层序细分及平面预测至关重要。为厘清研究区段内砂组划分及砂体的平面分布特征,以自然伽马测井曲线信息为载体,纵向上对自然伽马曲线进行最大熵频谱属性分析得到INPEFA曲线,通过分析INPEFA曲线内部不同幅度的趋势拐点来识别不同级次的基准面旋回信息,从而开展段内沉积旋回分析及砂组划分对比;横向上采用地震波形指示反演技术,利用地震波形的相似性约束测井参数进行高频反演得到自然伽马数据体,从而刻画不同砂组的平面展布及其纵向演化特征。研究发现,临兴A地区上石盒子组盒四段自下而上可划分为3个砂层组,河道砂体规模自下而上经历了萎缩期—扩张期—萎缩期的演化过程,其中盒4砂层组河道规模最大,砂体厚度大,沉积物粒度较粗,物性较好,为盒四段内部优质储层的发育层段,且气藏有利区主要位于研究区中部及西部,东部相对不利。The Upper Paleozoic tight sandstone gas reservoirs in the Ordos Basin have thin depositional thickness,rapid lateral changes in lithological and physical properties,and obvious multiplicity of solution for lateral correlation of strata.Therefore,it is very important to carry out sequence subdivision and plane prediction of tight sandstone reservoirs.In order to clarify the division of sand groups and the planar distribution characteristics of sand bodies in the study area,by taking the information in natural gamma logging curve as the carrier,the INPEFA curve was obtained through analyzing the maximum entropy spectral attribute of this curve vertically.The trend inflection points of different amplitudes within the INPEFA curve were analyzed to identify the datum plane cyclicity of different levels,so as to carry out the analysis of sedimentary cycles and the division and correlation of sand groups inside the member.The seismic waveform indicator inversion method was implemented to obtain the natural gamma data volume by constraining the logging parameters with the similarity of seismic waveforms,thereby characterizing the planar distribution and vertical evolution of different sand groups.The study found that the H4 Member of the Upper Shihezi Formation in Linxing A area can be divided into three sand groups upwardly,and from bottom to top,the scale of channel sand body underwent the evolution stages of shrinkage-expansion-shrinkage.Among them,the H4sand group has the largest channel scale,large sand thickness,coarse grain size of sediments and good physical properties.It is the development interval of high-quality reservoirs in the H4 Member,and the favorable gas reservoir areas are mainly distributed in the central and western parts of the study area rather than the eastern part.

关 键 词：临兴A地区 最大熵谱分析 INPEFA曲线 波形指示反演 砂层组 

分 类 号：TE121.3[石油与天然气工程—油气勘探]