渤海湾盆地黄骅拗陷砂岩型铀成矿条件及找矿方向  

Mineralization conditions and prospecting direction of sandstone type uranium in Huanghua Depression, Bohai Bay Basin, China

作　　者：陈长伟[1] 宋舜尧[1] 杨飞[1] 梁传国 邹红丽[1] 王翊超[1] CHEN Changwei;SONG Shunyao;YANG Fei;LIANG Chuanguo;ZOU Hongli;WANG Yichao(Dagang Oilfield of CNPC,Tianjin 300280,China)

机构地区：[1]中国石油大港油田分公司,天津300280

出　　处：《成都理工大学学报（自然科学版）》2022年第6期687-696,共10页Journal of Chengdu University of Technology: Science & Technology Edition

基　　金：中国石油天然气股份有限公司前瞻性基础性战略性技术攻关项目(2021DJ5303)。

摘　　要：研究渤海湾盆地黄骅拗陷浅层放射性异常空间分布规律,探讨该区砂岩型铀矿勘探潜力。利用测录井、地震资料开展放射性异常筛查、归类及成因分析,针对异常区测井异常段开展井壁取心和实测数据验证工作。黄骅拗陷存在港西-港东断裂带、南大港断裂带、羊二庄断裂带和官西-官东断裂带4个浅层放射性异常区,异常层段主要集中在新近系明化镇组和第四系。异常井浅层自然伽马异常分为3种类型,其中I类异常具备工业矿化潜力,是现阶段重点勘查目标。已发现的浅层放射性异常处于曲流河沉积地层,铀聚集成矿与古近系烃源岩排烃作用相关,优势输导砂体内持续的还原性流体与地表含U6+流体补给是研究区砂岩型铀矿聚集并富集的必要条件。曲流河的河道沉积砂体是黄骅拗陷铀聚集的有利载体,精细刻画出的2个放射性异常分布稳定的砂体,预测资源量约13 000 t,黄骅拗陷具备发现中型砂岩型铀矿潜力。There are four shallow radioactive anomaly zones in Huanghua Depression of Bohai Bay Basin: Gangxi-Gangdong fault zone, Nandagang fault zone, Yangerzhuang fault zone and Guanxi-Guandong fault zone, with abnormal intervals mainly concentrated in Neogene Minghuazhen Formation and Quaternary strata. In this paper, the spatial distribution of shallow radioactive anomalies is studied and the exploration potential of sandstone-type uranium in this area is discussed. Logging, seismic data, screening, classification and cause analysis of radioactive anomalies are analyzed, and the coring of borehole wall and the verification of measured data are carried out for the abnormal logging section in the abnormal area. The results show that the shallow natural gamma ray anomalies of abnormal wells can be divided into three types, among which the type I anomaly has the potential of industrial mineralization and is the key exploration target at the present stage. The discovered shallow radioactive anomalies are located in the meandering river sedimentary strata. Uranium accumulation and mineralization are likely to be related to the hydrocarbon expulsion of Paleogene source rocks. The continuous reducing fluid in the dominant transporting sand and the replenishment of U6+containing fluid on the surface are the necessary conditions for the accumulation and enrichment of sandstone type uranium deposits in the study area. It is considered that the channel sedimentary sand body of meandering river is a favorable carrier for uranium accumulation in Huanghua Depression. Two sand bodies with stable radioactive anomaly distribution are carefully delineated, with the predicted resource amount of about 13000 t, indicating that Huanghua Depression has the potential to discover middle-sized sandstone type uranium deposits.

关 键 词：渤海湾盆地 黄骅拗陷 明化镇组 砂岩型铀矿 勘探潜力 

分 类 号：P619.14[天文地球—矿床学]