泌阳凹陷付湾—张厂地区砂坝微相沉积特征

付湾—张厂地区位于泌阳凹陷北部斜坡带的中部，由于正向构造不明显、断块构造发育、砂岩岩性较为发育，具有潜在隐蔽油气藏的聚集条件。以核三段 IV—VI 油组为例，从岩芯、测井、粒度等资料入手，结合区域地质背景，通过砂坝微相沉积特征分析及平面相、剖面相展布规律分析，进一步建立了滩坝沉积模式。研究发现：（1）本区砂坝微相岩性以细砂岩、粉砂岩、泥质粉砂岩为主；测井曲线为宽指型和反旋回漏斗型；粒度概率曲线多为滚动组分不发育的两段式；沉积构造以波状和交错层理为主；沉积相序列主要为反相序；滩、坝共生，发育部位一致性强。（2）砂坝微相在 IV—VI 油组均有发育，IV 油组发育规模最大；滩微相在 V 油组局部井发育，规模较小。

Sedimentary Characteristics of Beach-bar Sandbodies in Fuwan and Zhangchang Area in Biyang Depression

Fuwan and Zhangchang Area is located in the center of north clinoform zone in Biyang Depression,which is of possibility to become a subtle reservoir,as a result of inconspicuous positive structure,growth of fault block architecture and fairly growth of sandstone lithology.Taking reservoir group IV—VI for example,combining with core observation,well logging,grain size and areal geology information,this paper establishes a model of beach-bar in study area,when sedimentary characteristics and dimensional distribution discipline of beach-bar facies is determinate.First,the main lithology is fine sandstone,siltstone and pelitic siltstone in study area,and logging trace is like egg with symmetric transition and funnel with converse circle,and grain probability curve is two-stage with no roll components mostly,and the main sedimentary structure is wave bedding and cross bedding,many biological burrows and much commotion structure included,and depositional sequence is mainly adverse facies sequence,besides,beach facies and bar facies are symbiotic,and vegetal area has strong compatibility.Second,bar facies grows in IV—VI Group,especially in IV Group.Beach facies just grows in a few wells in V Group in a small way.