학술논문
松辽盆地南部长岭断陷蚀变火山碎屑岩储层质量评价 / Quality evaluation of altered volcaniclastic rock reservoirs in the Changling fault depression of the southern Songliao Basin
Document Type
Academic Journal
Author
钟高明; 石磊; 赵向原; 毛永强; 李永刚; 郭宇航; 吴冷; 郑天龙; ZHONG Gaoming; SHI Lei; ZHAO Xiangyuan; MAO Yongqiang; LI Yonggang; GUO Yuhang; WU Leng; ZHENG Tianlong
Source
天然气工业 / Natural Gas Industry. 43(12):25-36
Subject
Language
Chinese
ISSN
1000-0976
Abstract
火山碎屑岩普遍存在蚀变现象,蚀变直接影响火山碎屑岩储层储集性能的定量表征和准确评价.为此,以松辽盆地南部长岭断陷下白垩统火石岭组火山碎屑岩为研究对象,采用岩心观察、薄片鉴定和扫描电镜等手段对储层岩性进行识别,分析储层微观特征,明确储层主要蚀变类型,通过测井曲线建立岩性识别交会图版,并建立蚀变指数计算方法,定量识别储层蚀变程度,再结合储层质量因子对储层质量进行综合评价和分类.研究结果表明:①研究区火山碎屑岩主要蚀变类型包括玻屑脱玻化蚀变、长石溶蚀蚀变和黏土化蚀变3类,其中黏土化蚀变对储层的测井响应和识别影响很大,脱玻化蚀变和溶蚀蚀变对增加孔隙起到了建设性作用,黏土化蚀变既可以形成黏土矿物晶间孔,也可以堵塞原有孔隙,其作用随蚀变程度的增加,孔隙度呈现先增加再减小的变化趋势.②火山碎屑岩储层的测井响应受蚀变影响明显,其中自然伽马、电阻率、声波时差、密度、补偿中子和元素测井曲线为黏土化蚀变敏感曲线,通过常规曲线和元素测井确定蚀变指数,可以定量识别储层蚀变程度.③研究区火山碎屑岩储层可分为3类,其中Ⅰ类储层以粗粒晶屑岩屑凝灰岩为主,钠长石次生溶蚀作用较强,黏土化蚀变程度较弱,蚀变指数低;Ⅱ类储层以中粒晶屑岩屑凝灰岩为主,黏土化蚀变程度中等,蚀变指数较低;Ⅲ类储层包含细粒含泥凝灰岩和极细粒泥质凝灰岩,黏土化蚀变程度强,蚀变指数高.
Alteration is common in volcaniclastic rocks,and it has a direct effect on the quantitative characterization and accurate evaluation of the capacity of volcaniclastic rock reservoirs.Taking the volcaniclastic rocks of the Lower Cretaceous Huoshiling Formation in the Changling fault depression of southern Songliao Basin as the research object,this paper determines reservoir lithology,analyzes microscopic reservoir characteristics and clarifies the main reservoir alteration types by means of core observation,thin section analysis and scanning electron microscopy.Then,the lithology identification cross plot is established on the basis of logging curve,and the alteration index calculation method is developed to quantitatively identify the degree of reservoir alteration.Finally,reservoir quality is comprehensively evaluated and classified based on reservoir quality factor.And the following research results are obtained.First,the main alteration types of volcaniclastic rocks in the study area include vitroclastic devitrification alteration,feldspar dissolution alteration and clay alteration,among which,clay alteration has a great impact on the logging response and identification of reservoirs while devitrification alteration and dissolution alteration play a constructive role in increasing porosity.Clay alteration can not only form clay mineral intercrystalline pores,but also block the original pores.And with the increase of the alteration degree,the porosity increases first and then decreases.Second,the logging response of volcaniclastic rock reservoirs is affected greatly by alteration,and natural gamma,resistivity,acoustic travel time,density,compensation neutron and elemental logging curves are sensitive to clay alteration.The alteration index can be determined by conventional curves and elemental logging,so as to realize quantitative identification of the degree of reservoir alteration.Third,the volcaniclastic rock reservoirs in the study area can be classified into three types.Type Ⅰ reservoir is mainly composed of coarse-grained crystal lithic tuff,and is characterized by stronger secondary dissolution of albite,weaker clay alteration and low alteration index.Type Ⅱ reservoir is lithologically dominated by medium-grained crystal lithic tuff,and is characterized by medium degree of clay alteration and low alteration index.Type Ⅲ reservoir is composed of fine-grained mud-bearing tuff and very fine grained argillaceous tuff,and is characterized by strong clay alteration and high alteration index
Alteration is common in volcaniclastic rocks,and it has a direct effect on the quantitative characterization and accurate evaluation of the capacity of volcaniclastic rock reservoirs.Taking the volcaniclastic rocks of the Lower Cretaceous Huoshiling Formation in the Changling fault depression of southern Songliao Basin as the research object,this paper determines reservoir lithology,analyzes microscopic reservoir characteristics and clarifies the main reservoir alteration types by means of core observation,thin section analysis and scanning electron microscopy.Then,the lithology identification cross plot is established on the basis of logging curve,and the alteration index calculation method is developed to quantitatively identify the degree of reservoir alteration.Finally,reservoir quality is comprehensively evaluated and classified based on reservoir quality factor.And the following research results are obtained.First,the main alteration types of volcaniclastic rocks in the study area include vitroclastic devitrification alteration,feldspar dissolution alteration and clay alteration,among which,clay alteration has a great impact on the logging response and identification of reservoirs while devitrification alteration and dissolution alteration play a constructive role in increasing porosity.Clay alteration can not only form clay mineral intercrystalline pores,but also block the original pores.And with the increase of the alteration degree,the porosity increases first and then decreases.Second,the logging response of volcaniclastic rock reservoirs is affected greatly by alteration,and natural gamma,resistivity,acoustic travel time,density,compensation neutron and elemental logging curves are sensitive to clay alteration.The alteration index can be determined by conventional curves and elemental logging,so as to realize quantitative identification of the degree of reservoir alteration.Third,the volcaniclastic rock reservoirs in the study area can be classified into three types.Type Ⅰ reservoir is mainly composed of coarse-grained crystal lithic tuff,and is characterized by stronger secondary dissolution of albite,weaker clay alteration and low alteration index.Type Ⅱ reservoir is lithologically dominated by medium-grained crystal lithic tuff,and is characterized by medium degree of clay alteration and low alteration index.Type Ⅲ reservoir is composed of fine-grained mud-bearing tuff and very fine grained argillaceous tuff,and is characterized by strong clay alteration and high alteration index