三塘湖盆地马朗凹陷上石炭统卡拉岗组中基性火山岩储层地质特征及主控因素  

Geological characteristics and influencing factors of intermediate basic volcanic reservoirs in Kalagang Formation of Upper Carboniferous in Malang Sag, Santanghu Basin

作　　者：张桓 陈亚军 伍宏美 马强 ZHANG Huan;CHEN Yajun;WU Hongmei;MA Qiang(519 Team of North China Geological Exploration Bureau,Baoding,Hebei 071051,China;Furuisheng(Chengdu)Technology Company Limited,Chengdu,Sichuan 610095,China;China United Academy of Petroleum Sciences,Beijing 100101,China;Research Institute of Exploration and Development,Yumen Oilfield Company,PetroChina,Jiuquan,Gansu 735019,China)

机构地区：[1]华北地质勘查局五一九大队,河北保定071051 [2]福瑞升(成都)科技有限公司,四川成都610095 [3]北京中科联华石油科学研究院,北京100101 [4]中国石油玉门油田分公司勘探开发研究院,甘肃酒泉735019

出　　处：《东北石油大学学报》2022年第3期25-44,I0002,I0003,共22页Journal of Northeast Petroleum University

基　　金：中国地质调查局西安地质调查中心综合地质调查项目(DD20190143)。

摘　　要：利用岩心观察、元素地球化学、岩石薄片与铸体薄片鉴定、成像测井等方法,结合储层物性、含油性及地震资料等,研究马朗凹陷上石炭统卡拉岗组中基性火山岩储层地质特征与主控因素。结果表明:卡拉岗组火山岩储层岩石成岩古地理环境为陆上喷发陆上地表强氧化环境和频繁水(湖)陆过渡弱氧化环境,岩石整体蚀变较强,尤其是蚀变形成的沸石(浊沸石、钠沸石)、方解石类矿物发育层段,是较好的储集层;线状裂隙群控制的脉动式或缓慢溢流喷发机理形成火山机构内部多相带与复杂岩性组合,限制火山岩储层发育的有效性。火山岩储层物性受埋深影响不大,有利储层分布于距离风化顶面18~63 m;风化淋滤及蚀变作用对火山岩储层改善明显,遭受较强风化淋滤及蚀变作用改造的熔岩相和爆发相岩石平均孔隙度高于油层有效孔隙度下限6.00%,为有效储层;受断层、裂缝和喷发间断不整合或构造不整合面控制,有利储集层分布在主断层影响的1.5 km半径范围内,以及卡拉岗组顶界不整合面以下270 m范围内。该结果为研究区石炭系火山岩储层地质研究及火山岩储层综合评价与勘探提供参考。Based on core observation,element geochemistry,thin section identification of rock and pore cast thin section,imaging logging and other methods,combined with physical property,oil content and seismic data,the geological characteristics and main controlling factors of intermediate basic volcanic rock reservoir in Kalagang Formation of Upper Carboniferous in Malang Sag are studied.The results show that,the petrogenetic palaeogeographic environment of volcanic reservoirs in Kalagang Formation consists of land eruption land surface strong oxidation environment and weak oxidation environment with frequent water(lake)land transition.The overall alteration of the rock is strong,especially the altered zeolite(laumonite,sodium zeolite),calcite mineral development layer,which is a better reservoir.Pulsating or slow overflow mechanism controlled by linear fissure group results in the existence of multiphase belts and complex lithologic assemblages in volcanic mechanism,which enhances the heterogeneity of volcanic rocks and limits the effectiveness of volcanic reservoir development.The physical properties of volcanic reservoirs are not affected by burial depth,and the favorable reservoirs are distributed in the range of 18-63 m from the weathering top surface.Weathering leaching and alteration obviously improve the volcanic rock reservoir.The average porosity of the lava and eruptive facies rocks subjected to strong weathering leaching and alteration is 6%higher than the lower limit of effective porosity of oil reservoir,which is an effective reservoir.Controlled by faults,fractures,and eruptive discontinuities,or structural unconformity,favorable reservoirs are distributed within a 1.5 km radius of the influence of the main fault and 270 m below the top unconformity of the Kalagang Formation.This study is expected to provide geological theoretical basis for comprehensive evaluation of volcanic reservoir and optimization of favorable reservoir zones in this area.

关 键 词：中基性火山岩 储层地质特征 成岩环境 喷发机理 主控因素 卡拉岗组 石炭系 马朗凹陷 三塘湖盆地 

分 类 号：P581[天文地球—岩石学]