川东北地区上三叠统须家河组沉积特征及其演化  

Sedimentary characteristics and evolution of Upper Triassic Xujiahe Formation,northeastern Sichuan Basin

作　　者：胡绍吉 张航[3] 宋东昇 孙海涛[1,2] HU Shaoji;ZHANG Hang;SONG Dongsheng;SUN Haitao(College of Geosciences,China University of Petroleum(Beijing),Beijing 102249,China;State Key Labora-tory of Petroleum Resources and Engineering,China University of Petroleum(Beijing),Beijing 102249,China;Northeast Sichuan Gas District,PetroChina Southwest Oil&Gasfield Company,Dazhou,Sichuan 635000,China)

机构地区：[1]中国石油大学(北京)地球科学学院,北京102249 [2]中国石油大学(北京)油气资源与探测国家重点实验室,北京102249 [3]中国石油西南油气田公司川东北气矿,四川达州635000

出　　处：《天然气勘探与开发》2024年第4期15-27,共13页Natural Gas Exploration and Development

基　　金：国家科技重大专项(编号:2016ZX05002-004-011);中国石油西南油气田公司科技项目(编号:20210301-22)。

摘　　要：川东北元坝、通南巴地区上三叠统须家河组致密气勘探开发不断获得储量和产量的稳定增长,但相邻的南部地区却鲜有重要突破,其主要原因是勘探程度低,缺少系统、精细的沉积相研究。为此,基于测井识别、录井岩性分析、野外露头考察、钻井岩心观察,对川东北地区须家河组沉积特征及其演化开展系统研究。结果表明:(1)川东北地区须家河组为辫状河三角洲平原亚相,可进一步划分为分流河道微相和分流河道间微相,分流河道间微相以发育沼泽沉积为主,沉积物粒度细,主要为泥、页岩,分流河道微相以发育心滩沉积和河道充填沉积为主,沉积物较粗,以中细砂岩为主;(2)须家河组物源主要来自南东方向,沉积相带展布受物源方向控制整体具有呈纺锤状或条带状沿北西—南东向展布的特征;(3)须二段、须四段属于高物源供给辫状河三角洲,在川东北地区以发育分流河道微相为主,心滩沉积大规模发育;须三段、须五段属于低物源供给辫状河三角洲,在川东北地区以发育分流河道间沉积为主。The exploration and development of tight gas for the Upper Triassic Xujiahe Formation in the Yuanba and Tongnanba areas of northeastern Sichuan Basin have achieved stable growth in production and reserves.However,there have been few important break-throughs in the adjacent southern area,due to the low exploration level and lack of systematic and detailed research on sedimentary fa-cies.Based on logging identification,logging lithology analysis,field outcrop investigation,and drilling core observation,a systemat-ic study was conducted on the sedimentary characteristics and evolution of the Xujiahe Formation in northeastern Sichuan Basin.The results are shown as follows.(i)The Xujiahe Formation is a braided river delta plain subfacies,which can be further divided into dis-tributary channel microfacies and distributary interchannel microfacies.The latter is dominated by swamp sediments with fine grains,which are mainly mudstones and shales.The former is chiefly composed of channel bar and channel filling sediments with coarse grains,which are mainly fine-medium sandstones.(ii)These sediments mainly came from the southeast provenance.And controlled by the provenance direction,the sedimentary facies zone shows a spindle or banded distribution along the NW-SE direction.(iii)In the northeastern Sichuan Basin,the Xu2 and Xu4 Members belong to the braided river delta with high material supply,which dominatly develops distributary channel microfacies with extensive channel bar sediments;the Xu3 and Xu5 Members belong to the braided river delta with low material supply,which mainly develops distributary interchannel microfacies.

关 键 词：川东北地区 须家河组 辫状河三角洲平原 分流河道微相 沉积演化 

分 类 号：P618.13[天文地球—矿床学]