Characteristics and Evolution of the Provenance Systems from the Paleogene Shahejie Formation in the Jiangjiadian Area,Huimin Sag
[Objective]Low understanding on the provenance system exists in the upper part of the Fourth member to Third member of the Paleogene Shahejie Formation(i.e.,E2ss4 and E2s3,respectively)in the Jiangjiadian area,in-creasing difficulties in the prediction of sand bodies and high-quality reservoirs.The characteristics and evolution of the provenance system are system natically studied,so as to lay a foundation for prediction of sand bodies and reser-voirs.[Methods]Characteristic elements analysis,Q-type cluster analysis of lithological components,and percent-age statistics of sand-conglomerates are performed to identify the provenance system and transport routes of clastic matter,subsequently build evolutionary model of provenance,and discuss its significance to petroleum exploration.[Results and Conclusions]Distributional patterns of the characteristic elements in sequence Ⅰ to Ⅴ,i e.,E2ss4 and E2s3,are in agreement with those of Mesozoic formations,displaying obviously high Mg/Mn and Al/Mg ratios along with relatively high Al/Na and Ba/Mn ratios.Five QFR assemblages,extracted from Q-type cluster analysis results of all lithological components reveal that 3 prodominant provenance regions exist:across the Xia27-Xiaxie98,Xia37,and Xia222-Xia223-Xia225 well blocks.During development of sequence Ⅰ and Ⅱ,the provenance system,located in the Luxi uplift located in the southeast of the study area,supplied abundant clastic matter to the sedimentary region,forming a large scale of sandstones.The provenance systems recede during sequence Ⅲ,causing the scale of sand-bodies to decrease.Subsequently,the provenance systems advance during sequence Ⅳ and Ⅴ,allowing the sand-bodies to develop.
characteristic elementcluster analysisprovenance systemShahejie FormationJiangjiadian areaHuimin Sag
万方数据
维普
