宣汉￣达县地区飞仙关组层序地层与颗粒滩特征

Sequence stratigraphy and grain shoal characteristics of Feixianguan Formation in Xuanhan-Daxian zone

谢圣阳 王兴志 梅秋勇 霍飞 李勇 陈玉巧3

西南石油大学油气藏地质及开发工程国家重点实验室，四川 成都 610500 西南石油大学地球科学与技术学院，四川 成都 610500 中国石化中原油田分公司濮东采油厂，河南 濮阳 457001

State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Chengdu University of Technology, Chengdu 610500, China School of Geoscience and Technology, Southwest Petroleum University, Chengdu 610500, China Pudong Oil Production Plant, Zhongyuan Oilfield Company, SINOPEC, Puyang 457001, China

通过对岩心和野外露头剖面的精细观察，利用地震地层综合解释剖面，结合海平面变化，将川东北宣汉￣达县地区飞仙关组划分为2个三级层序和8个体系域。在此基础上对飞仙关组层序地层及滩体在纵横向上发育特征以及不同体系域内的展布进行研究。结果表明：TSQ1层序发育期，颗粒滩主要发育于高位体系域时期，且以台地边缘滩为主，纵向上具有向上变粗、变厚，但单滩体厚度变化大的特点；横向上滩体分布不稳定，发育层位具有向南爬升的特点，沿台缘带呈北西—南东向展布。TSQ2层序发育期，由于填平补齐作用，PG主体演变为局限台地；颗粒滩主要发育于早期高位体系域时期，为台内点滩沉积，滩体沉积厚度较小，大致呈北东—南西向分布。

Based on the study of precise observation and description of core and outcrops, with the analysis of seismic stratigraphic comprehensive interpretation, the Feixianguan Formation in the Xuanhan-Daxian zone, northeastern Sichuan, can be divided into 2 third-order sequences, eight system tracts in terms of sedimentary facies and sequence interfaces. At the same time, the vertical and horizontal developmental characteristics and the distribution of different system tracts of the sequences and shoal were studied. Results show that, during the development of TSQ1 sequence, grain shoales, mostly platform margin shoales, mainly developed during the highstand system tracts and have the characteristics of thickening and coarsening upward, but the thickness of single shoal varies greatly; the distribution of shoales is unstable horizontally, and migrates upward toward south in developing stratum on the profile, which expands in the direction of northwest-southeast along the platform margin; during the development of TSQ2 sequence, due to the effect of filling, PG area evolved into restricted platform; grain shoals developed mainly in the early of highstand system tract, which are platform inner shoals, and these shoales were thin in thickness and expands in the direction of northeast-southwest.

10.6056/dkyqt201803008