CAJ | 학술논문

黄骅坳陷板桥地区古近系沙河街组沙二段具有典型的湖泊滩坝沉积特点，其砂体内部主要发育泥质、钙质和致密粉砂质3种类型的隔夹层。利用构型分析法，将滩坝砂体分为复合坝、单一坝和坝内增生体3个构型要素，将内部隔（夹）层分为单一坝间隔层和单一坝内夹层2个级别。单一坝间隔层具有3种成因机制：（1）基准面波动造成单一坝叠置区分布的细粒沉积；（2）风暴作用形成的滞留泥砾沉积；（3）坝后水动力低能区域形成的泥质沉积。单一坝内夹层则是波浪能量衰减形成的细粒沉积，岩性以粉砂质泥岩、泥质粉砂岩为主。通过分析夹层的井上识别特征，结合青海湖、岱海现代沉积的原型地质模式，对单一坝进行内部构型解剖。结果表明，夹层厚度为0.1～1m，靠近岸线近水平分布，向湖中心方向以低角度倾斜，倾角为2°～5°。不同级次与成因的隔（夹）层在滩坝砂体中都有特定的发育部位，其分布规律和空间配置关系不仅可以反映不同隔（夹）层的沉积时间顺序，还可以依此来推测滩坝的沉积规模与展布形态。隔（夹）层会导致含油气性的差异，认识隔（夹）层分布规律是提高滩坝储集层油气采收率的关键。
황화요함판교지구고근계사하가조사이단구유전형적호박탄패침적특점，기사체내부주요발육니질、개질화치밀분사질3충류형적격협층。이용구형분석법，장탄패사체분위복합패、단일패화패내증생체3개구형요소，장내부격（협）층분위단일패간격층화단일패내협층2개급별。단일패간격층구유3충성인궤제：（1）기준면파동조성단일패첩치구분포적세립침적；（2）풍폭작용형성적체류니력침적；（3）패후수동력저능구역형성적니질침적。단일패내협층칙시파랑능량쇠감형성적세립침적，암성이분사질니암、니질분사암위주。통과분석협층적정상식별특정，결합청해호、대해현대침적적원형지질모식，대단일패진행내부구형해부。결과표명，협층후도위0.1～1m，고근안선근수평분포，향호중심방향이저각도경사，경각위2°～5°。불동급차여성인적격（협）층재탄패사체중도유특정적발육부위，기분포규률화공간배치관계불부가이반영불동격（협）층적침적시간순서，환가이의차래추측탄패적침적규모여전포형태。격（협）층회도치함유기성적차이，인식격（협）층분포규률시제고탄패저집층유기채수솔적관건。
The Member 2 of Paleogene Shahejie Formation in Banqiao area of Huanghua Depression developed typical lacustrine beach-bar deposits with three kinds of inter (inner)-layer in sand bodies, i.e.,muddy,calcareous and compact silty inter (inner)-layer.The beach-bar sand bodies can be divid-ed into three architecture elements using the reservoir architecture analytical method:Compound bar,sin-gle bar,and the inner accretion of single bar.The inter (inner)-layers in the beach-bar reservoir can be subdivided into two hierarchieInter-layer between single bars and inner-layer in single bar.There are three genetic mechanisms of inter-layer between single bar①Fine-grained sediments developed in a re-gion superimposed by two-phase single bars sand bodies caused by base-level change;②Retention mud-gravels drawn by storm activities;③Mud deposit in a low wave energy behind bars.The fine-grained in-ner-layers in single bar are formed by the attenuation of wave energy, and mainly consists of silty mud-stone and argillaceous siltstone.Further research is to dissect architecture inner single bar through well-log facies recognition and modern beach-bar prototype geological models in Qinghai Lake and Daihai Lake.It is found that the muddy inner-layers in single bar with thickness about 0.1~1m are nearly horizontal close lakeshore and inclines in low angle towards the center of the lake,with 2°~5°dip angle.Each hierarchy and genetic inter (inner)-layer is found in a certain region in a single bar sand body.The relative posi-tion and distribution pattern of each inter (inner)-layer can not only reflects the order of deposition in a single bar,but also be used to predict the scale and morphology of beach-bar.The inter (inner)-layers can lead to the diversity of oil-bearing properties,therefore it is important to reveal the distribution of inter (inner)-layers in beach-bar reservoirs,which is the key to raise oil and gas recovery ratio.