【作者】 于志超； 刘立； 孙晓明； 曲希玉； 于淼；

【Author】 YU Zhi-chao~1,LIU Li~1,SUN Xiao-ming~2,QU Xi-yu~3,YU Miao~1 (1.College of Earth Sciences Jilin University,Changchun 130026,China;2.Exploration and Development Research Institute PetroChina,Dagang Oilfield Company,Tianjing,300000,China;3.College of Geo-Resources and Information,University of Petroleum,Qingdao 266555,China)

【机构】 吉林大学地球科学学院； 中国石油大港油田分公司勘探开发研究院； 中国石油大学(华东)地球科学与技术学院；

【摘要】 歧口凹陷第三纪以来火山活动十分强烈,凹陷内的火山岩体非常发育,主要以辉绿岩等浅层侵入体的方式产出。本文主要运用岩石学、流体包裹体、有机地球化学等技术手段重点探讨了区内热流体活动的证据及其对储层物性的影响机制。歧口地区第三纪火山岩主要是一套玄武岩-辉绿岩系列的基性的火山岩和侵入岩。玄武岩与碎屑岩接触部位的特征岩性组合主要有五种类型:玄武岩+泥岩;玄武岩+砂、泥岩互层;玄武岩+板岩;玄武岩+砂岩+页岩+泥岩;玄武岩+砂岩。辉绿岩与碎屑岩接触部位的特征岩性组合主要有六种类型:辉绿岩+砂质泥岩;辉绿岩+砂岩（上部）;辉绿岩+油页岩;辉绿岩+砂岩（下部）;辉绿岩+泥岩;辉绿岩+砂岩+泥岩。热流体活动的证据主要体现在碎屑颗粒的热液蚀变;镜质体反射率异常增大;最大热解温度-游离烃-热解烃异常增高;均一温度异常增大;粘土矿物异常转变等五个方面。不管是浅部（<3500m）储层的基性岩浆热液活动还是深部（>3500m）的来自上地幔的富CO₂热流体活动都明显的改善了储层的物性,提高了储层的质量。但是上述两种热流体活动在影响的深度上有着极大的差别:浅部的基性岩浆热液的影响范围较窄,这与侵入体的厚度,就位时的温度和冷却速度有关。侵入体对碎屑岩储层的影响范围约是自生厚度的5倍左右。深部的富CO₂的热流体由于其连通性和持续性都较好,因而持续活动的时间较长,影响范围较广,是区内热流体活动的主要影响因素。更多还原

【Abstract】 The volcanic activity is very strong in Qikou Sag since the Tertiary,so the volcanic rock is very developed in the sag,mainly with in shallow intrusions of diabase and other means output.According to the use of petrography,fluid inclusion and organic geochemical techniques,we mainly discussed evidence of thermal fluid activities and influence mechanisms of its impact on the reservoir properties.The Tertiary volcanic rocks of Qikou Sag is mainly a set of basalt - diabase series of basic volcanic and intrusive rocks.The lithologic characteristics association of contact parts between basalt and clastic rocks are mainly five types:basalt + mudstone,basalt + sand-mudstone interbad,basalt + slate;basalt + shale + sandstone+ mudstone;basalt + sandstone.While diabase have six types:diabase + sandy mudstone,diabase + sandstone（up）,diabase + oil shale,diabase + sandstone（down）,diabase + mudstone,diabase + sandstone + shale.Evidence of thermal fluid are mainly reflected in hydrothermal alteration of the grains;abnormal increased of vitrinite reflectance;abnormal increased of Tmax-S₁-S₂;homogrnization temperature abnormal increase;abnormal changed in clay minerals five areas.Whether the shallow basic magmatic activitives （<3500m） or deep thermal activitives（>3500m） from the upper mantle which is rich in CO₂ fluid both have significantly improved the properties of the reservoir,but their impact depth have a great difference.Influential extent of Shallow mafic magmatic hydrothermal fluid activities is relatively narrow. This is related to the thickness,the temperature of in place and cooling rate of intrusions.The influential extent is about five times thickness of intrusions themselves.Deep CO₂- rich thermal fluids have better connectivity and continuity,therefore their ongoing activities is longer,influential extent is wider,which are the major factors of thermal fluid activities in the region.更多还原