塔里木盆地寒武系与蒸发岩相关的白云岩储层特征及主控因素
摘要: 塔里木盆地寒武系广泛发育白云岩,其中中寒武统地层沉积了巨厚的蒸发岩,蒸发岩和白云岩可以构成很好的储盖组合,该领域也是塔里木盆地未来勘探的新领域。萨布哈白云岩和渗透回流白云岩是两种与蒸发岩相关的白云岩,其储层发育的主控因素也都与蒸发岩存在着直接或间接的联系。通过对大量岩芯、薄片、主量元素、稀土元素、碳、氧稳定同位素及锶稳定同位素等地球化学测试和测井资料的细致研究,系统总结了它们的岩石学特征、地球化学特征。萨布哈白云岩储层的岩性以含石膏的泥粉晶白云岩为特征,孔隙类型主要为膏模孔和溶塌角砾砾间孔,萨布哈白云石化作用及伴生石膏的沉淀作用和准同生期大气淡水溶蚀作用是该类储层的主控因素;渗透回流白云岩储层的岩性以保留原岩颗粒或藻(丘)格架结构的粉晶白云岩为特征,孔隙类型主要为粒间孔、铸模孔、格架孔,渗透回流白云石化作用和大气淡水溶蚀作用是该类储层的主控因素。两者主要发育于塔里木盆地干旱气候背景下的中—下寒武统地层,其分布规律主要受沉积相控制。
Main Controlling Factors and Characteristics of Cambrian Dolomite Reservoirs Related to Evaporite in Tarim Basin
Abstract: Massive dolomites are widely distributed in the Cambrian System of Tarim basin, and in Middle Cambrian with thick evaporite, evaporite and dolomite can be good reservoirseal assemblage, so the dolomite strata is a new exploration field of Tarim Basin in the future. Sabkha dolomite and seepage reflux dolomite are the two kinds of dolomite related to evaporite, and the main controlling factors of reservoir are also associated with evaporite directly or indirectly. This article summarized the petrologic and geochemical characteristics of sabkha dolomite and seepage reflux dolomite by analyzing a lot of cores, thin sections, major element, REE and stable isotope (carbon, oxygen and strontium) data. The lithology of sabkha dolomite reservoir characterized by the deposits of gypsodolomicrite, gypsum mould pores and intergravel pores of solutioncollapse breccia are the two kinds of porosity, sabkha dolomitization, gypsum precipitation and dissolution of meteoric freshwater are the main controlling factors of this reservoir; The lithology of seepage reflux dolomite reservoir featured by crystal powder dolomite which has reserved the original grainstone or algae mound structure, intergranular pores, mould pore, framework pores and organism pores are the main kinds of porosity, seepage reflux dolomitization and meteoric freshwater dissolution are the main controlling factors of this reservoir; The distribution law of these tow dolomite reservoirs are controlled by sedimentary facies, and chiefly developed in arid climate background of middle Cambrian, Tarim basin.
塔里木盆地寒武系与蒸发岩相关的白云岩储层特征及主控因素[J]. 沉积学报, 2013, 31(1): 89-98.
引用本文: |
塔里木盆地寒武系与蒸发岩相关的白云岩储层特征及主控因素[J]. 沉积学报, 2013, 31(1): 89-98.
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Main Controlling Factors and Characteristics of Cambrian Dolomite Reservoirs Related to Evaporite in Tarim Basin[J]. Acta Sedimentologica Sinica, 2013, 31(1): 89-98.
Citation: |
Main Controlling Factors and Characteristics of Cambrian Dolomite Reservoirs Related to Evaporite in Tarim Basin[J]. Acta Sedimentologica Sinica, 2013, 31(1): 89-98.
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