裂缝孔隙型火山岩储层特征及物性主控因素——以准噶尔盆地陆东-五彩湾地区石炭系火山岩为例

火山岩储层具有裂缝-孔隙型双重孔隙结构特征，其岩性识别和物性主控因素分析是研究工作中的难点。为此，以准噶尔盆地陆东-五彩湾地区石炭系火山岩为例，通过岩心、薄片、常规测井和FMI成像观察，对火山岩岩性、物性特征以及成岩作用等进行了分析，结果表明：① 中基性熔岩主要分布在五彩湾凹陷东部，酸性熔岩和火山碎屑岩主要分布在滴南凸起西部和东部，进而总结了不同类型火山岩岩性测井响应的特征；② 该区火山岩储层孔隙类型可分为3大类9小类，孔隙组合有4类，包括原生孔隙型、次生溶孔（洞）型、次生溶孔-裂缝复合型以及裂缝型；③中-基性熔岩以斑晶溶孔为主，酸性熔岩和各种凝灰岩以基质溶孔为主，裂缝以溶缝和风化缝为主，其中酸性熔岩中的基质溶孔与溶缝、风化缝组合物性最好；④该区火山岩物性影响因素包括岩性、构造地形和后生改造作用。结论认为：依据孔隙度、渗透率相对高低可将火山岩储层分为4种类型，靠近火山口的火山岩储层物性较好，构造高地易形成各种裂缝，油气产量大，盆地中心以各种溶孔为主，以产油为主，含气量较少；次生溶蚀和交代充填对该区火山岩储层影响较大，前者对火山岩储层物性起到了主要的贡献作用。

Characteristics of fractured and porous volcanic reservoirs and the major controlling factors of their physical properties: A case study from the Carboniferous volcanic rocks in Ludong-Wucaiwan area,Junggar Basin

Volcanic reservoirs have characteristics of fracture pore dual porosity, so the relevant studies will focus on the identification of their lithology and the major controlling factors of their physical properties. Taking the Carboniferous volcanic rocks in the Ludong Wucaiwan area of the Junggar Basin as an example, we analyze the lithology, poroperm characteristics and diagenesis of the volcanic reservoirs through observation of cores, thin sections, regular logging and FMI imaging. The following conclusions are obtained: (1) The neutral basic lavas are mainly distributed in the eastern Wucaiwan sag, while the acidic lavas and volcaniclastic rocks mainly occur in the western and eastern parts of Dinan salient, and volcanic rocks with different lithologies have different logging responses. (2) The pores of the volcanic reservoirs can be grouped into 3 categories and 9 types, and there are 4 types of pore combinations, including primary pore type, secondary dissolution pore (cavity) type, secondary dissolution pore fracture hybrid type, and fracture type. (3) The intermediate basic lavas are dominated by dissolved fractures and weathered fractures, and the physical properties are the best in acid lavas with the combinations of matrix dissolution pores dissolved fractures and/or weather fractures. (4) Factors controlling volcanic reservoir quality mainly include lithology, tectonic landform and epigenesis. According to relative values of porosity and permeability, volcanic reservoirs can be divided into 4 types. Volcanic reservoirs close to volcanic vents have relatively good quality and fractures may be highly developed on structural highs, thus, oil and gas production are high, and the volcanic reservoirs in this central basin are dominated by dissolution pores and contain mainly oil and less gas. Secondary dissolution and metasomatism filling are the major factors influencing volcanic reservoir quality in the area, and the former contributes a lot to the reservoir quality.