塔里木盆地蓬莱坝组层状白云岩储层发育规律  

Development and Exploration Direction of Bedded Massive Dolomite Reservoir of Lower Ordovician Penglaiba Formation in Tarim Basin

作　　者：乔占峰 张天付[1,2] 贺训云 熊冉[1,2] Qiao Zhanfeng;Zhang Tianfu;He Xunyun;Xiong Ran(PetroChina Hangzhou Research Institute of Geology,Hangzhou 310023,China;Key Laboratory of Carbonate Reservoir,CNPC,Hangzhou 310023,China)

机构地区：[1]中国石油杭州地质研究院,浙江杭州310023 [2]中国石油天然气集团公司碳酸盐岩储层重点实验室,浙江杭州310023

出　　处：《地球科学》2023年第2期673-689,共17页Earth Science

基　　金：中国石油基础性前瞻性科技项目“海相碳酸盐岩有效储层形成与保持机理及分布预测研究”(No.2021DJ0503)。

摘　　要：塔里木盆地蓬莱坝组油气勘探潜力巨大,但勘探对象上存在“断溶体”和层状白云岩的争议.在露头与钻井储层特征认识的基础上,岩石学与碳氧锶同位素和激光U-Pb定年等地球化学分析相结合,探讨了蓬莱坝组白云岩的成因机制及层状规模储层发育潜力与发育规律,进而根据白云岩储层分布预测讨论了塔里木盆地蓬莱坝组的勘探方向.取得3点认识:(1)蓬莱坝组发育孔隙-孔洞型白云岩储层,平均孔隙度2.81%,最高可达13.91%,具备发育优质储层的潜力;(2)白云岩储层以准同生白云岩叠加浅埋藏云化作用形成的埋藏白云岩为主,具有相控性和规模性,可层状发育,主要分布于内缓坡-中缓坡准同生云化滩;(3)塔北南缘和塔中北斜坡为层状规模优质白云岩储层发育有利区,是该领域值得探索的勘探方向.PenglaibaFormation of Tarim Basin has huge potential of hydrocarbon exploration, however, with unclear exploration target of either “fault dissolved geobody” or bedded massive dolomite reservoir. Based on the analysis ofreservoir features on the outcrops and drilling data, integrated with petrography and geochemistry examinations including C, O, Sr isotopes and laser ablation U-Pb datingetc., the origin and development of dolomite and the potential of bedded massive dolomite reservoir of Penglaiba Formation of Tarim Basin has been discussed, and furthermore, the exploration directionwas analyzed based ont the prediction of massive dolomite reservoir. Three aspects of results achieved include:(1) Penglaiba Formation hosts porous-vuggydolomite reservoir with the average porosity of 2.81% and the maximum porosity of 13.91%, with thepotential of constituting high quality reservoir;(2) It’s proposed that the dolomite reservoir is made of mainly the burial dolomite formed by penecontemperanous dolomite modified and recrystallized by shallow burial dolomitization, whichis controlled by sedimentary faciesand could be developedmassively and bedded, mostly within the inner-to middle ramp penecomtemporaneously dolomitized shoal;(3) It’s predicted that south margin of Tabei uplift and north slope of Tazhong uplift are the favorable zone for the bedded massive dolomite reservoir, constituting worthwhile exploration targets.

关 键 词：白云岩 埋藏白云石化 规模储层 蓬莱坝组 塔里木盆地 石油地质 

分 类 号：P624[天文地球—地质矿产勘探]