琼东南盆地YLA区花岗岩潜山风化壳地质模型  

Geological model of weathering crust of granite buried hill in YLA area of Southeastern Hainan Basin

作　　者：郭原草[1] 郭建华[2,3] 李智宇 余烨 黄俨然[3] GUO Yuancao;GUO Jianhua;LI Zhiyu;YU Ye;HUANG Yanran(School of Civil Engineering,Hunan University of Science and Technology,Xiangtan 411201,China;School of Geosciences and Info-physics,Central South University,Changsha 410083,China;School of Earth Sciences and Spatial Information Engineering,Hunan University of Science and Technology,Xiangtan 411201,China)

机构地区：[1]湖南科技大学土木工程学院,湖南湘潭411201 [2]中南大学地球科学与信息物理学院,湖南长沙410083 [3]湖南科技大学地球科学与空间信息工程学院,湖南湘潭411201

出　　处：《中南大学学报（自然科学版）》2022年第9期3462-3473,共12页Journal of Central South University:Science and Technology

基　　金：国家科技重大专项(2016ZX05026-002);中海油湛江分公司外部协作项目(CCL2018ZJFN1603)。

摘　　要：为揭示花岗岩潜山油气藏的发育机理与成藏规模,需深入研究花岗岩风化壳地质模型。首先,基于风化作用及砂化作用的原理,将前人提出的土壤带、极强风化带、完全风化层等归入残积−坡积层;将前人提出的砂化层、风化淋滤层、次风化带等归入砂化层;将砾质风化带、半风化层、风化崩解带等归入风化裂缝层;其次,基于水文地质学原理,将前人提出的裂缝层分为风化裂缝层和水平潜流缝洞层;据此提出适用于琼东南盆地YLA区的风化壳垂向5层地质模型,从上到下依次为残积−坡积层、砂化层、风化裂缝层、水平潜流层、基岩层;第三,通过对典型风化壳露头踏勘与鉴定,识别出风化壳模型中出露于地表之上的3个层,并分别解析风化壳各层形成机理及特征;最后,依据提出的风化壳地质模型,基于古生物鉴定资料、钻井−测井资料对工区内YLA-11井风化壳进行分层识别,在井震对比剖面图上标定出3个界面并识别出对应4层;以YLA-11井为例分析风化壳各项测井指标特征;研究结果表明:地震相、测井指标随深度的变化规律与风化壳各层岩性、物性及电性特征基本吻合。研究成果验证了前述风化壳地质模型的合理性,可为YLA区风化壳储层预测、评价及下一步勘探部署提供参考价值。In order to reveal the development mechanism and reservoir forming scale of granite buried hill oil and gas reservoirs,it is necessary to study the geological model of granite weathering crust deeply.Firstly,based on the principles of weathering and desertification,the soil layer,extremely strongly weathered layer and completely weathered layer proposed by predecessors were classified into eluvial-deluvial layer.The sandy layer,weathered leaching layer and sub weathered layer proposed by predecessors were classified into sandy layer.The gravelly weathered layer,semi weathered layer and weathered disintegration layer were unified into weathered fracture layer.Secondly,based on the principle of hydrogeology,the fracture layer proposed by predecessors was divided into weathering fracture layer and horizontal subsurface flow fracture cave layer.Based on this,a vertical 5-layer geological model of weathering crust suitable for YLA area of southeastern Hainan basin was proposed.From top to bottom,it was successively residual-eluvial layer,sandy layer,weathering fracture layer,horizontal subsurface flow layer and bedrock layer.Through the survey and identification of typical weathering crust outcrops,three layers exposed on the surface in the weathering crust model were identified,and the formation mechanism and lithologic characteristics were analyzed respectively.Finally,according to the proposed geological model of weathered crust,the weathered crust of well YLA-11 in the work area was identified by layers based on paleontological identification data,drilling and logging data,three interfaces were marked and the corresponding four layers were identified on the logging-seismic correlation profile.Taking the YLA-11 well as an example,the characteristics of various logging indexes of weathered crust were analyzed.The results show that the variation law of seismic face and each single index with depth is basically consistent with the lithology,physical properties and electrical properties of each layer.The research resul

关 键 词：花岗岩潜山 风化壳 地质模型 分层识别 琼东南盆地 

分 类 号：TE122[石油与天然气工程—油气勘探]