Abstract:

Based on the petrologic data of over 40 wells， the characteristics and main controlling factors of the Permian reservoirs in Wuxia area were systematically described. The Permian reservoir in this area is diverse， which mainly includes terrestrial clastic rocks， dolomite or dolomitic rocks， volcanic clastic rocks and volcanic rocks. The reservoir pore space is dominated by secondary pore， and the pore spaces of the clastic reservoir are mainly intergranular solution pore， dissolved pore of interstitial materials，and microfracture. The dolomite reservoir is dominated by fractures; volcanic clastic rock and volcanic reservoirs are dominated by gasreleasing pore. The reservoir  is characterized by  lowmedium porosity and permeability. Its pore texture types include small pore and fine throat， micro pore and tiny throat， and micro pore and mini throat. The reservoir is classified as poor to moderate categories of reservoirs and possess the lowmoderate porosity and permeability. The comprehensive evaluation showed that lithology and grain size， diagenesis and compaction， dissolution and fracturing are the main controlling factors of reservoir quality in this area. Of them， lithology and grain size are the main influencing factors for reservoir property， mechanical compaction is the main controlling factor of porosity reduction which may have caused 2365 percentage points of porosity loss. Dissolution， fracturing and faulting improved the reservoir property effectively. Comprehensively considering the reservoir property and the controlling factors， the reservoirs are divided into five categories， of which， type Ⅲ， Ⅳ， Ⅴare the main types in Wuxia area.

Key words: Junggar Basin, Wuxia area, Permian, reservoir, reservoir property, pore texture, comprehensive evaluation

摘要：

根据40余口钻井的岩石学资料， 较系统地描述了乌夏地区二叠系储集层特征及其主要影响因素。乌夏地区二叠系储集层类型多样，主要包括陆源碎屑岩、白云（质）岩、火山碎屑岩和火山岩4大类。乌夏地区二叠系储集空间类型以次生孔隙为主，碎屑岩储集层以粒内溶孔、填隙物内溶孔、压裂缝最为发育；白云岩储集层主要发育裂缝，火山碎屑岩储集空间类型则主要为气孔和裂缝，火山岩储集层在乌夏地区分布较少，储集空间主要为气孔。二叠系储集层孔隙结构均属小孔细喉、微孔微细喉、微孔微喉，储集性能中等—差，整体为中、低孔渗储集层。研究认为岩性、粒度、成岩压实、溶蚀及破裂作用是本区储集层质量的主要影响因素：岩性、粒度主要影响储集层性质；压实作用是孔隙损失的主控因素，平均压实减孔量高达23.65％；溶蚀及破裂作用则对改善储集层物性起重要作用；断裂活动也使断裂带附近储集层物性发生明显的改善。根据储集层储集性能及其控制因素，将储集层划分为5种类型，乌夏地区以Ⅲ、Ⅳ、Ⅴ类为主。

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关键词: 准噶尔盆地, 乌夏地区, 二叠系, 储集层, 储集物性, 孔隙结构, 综合评价