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克拉通盆地深层白云岩是中国陆上未来天然气勘探的重要领域。通过统计分析四川、塔里木、鄂尔多斯等中国主要克拉通盆地,明确深层白云岩主要类型为颗粒白云岩、微生物白云岩及结晶白云岩,孔隙类型以裂缝—孔洞型和裂缝—孔隙型为主。指出有利沉积微相是孔隙形成的物质基础,早期溶蚀作用是孔隙形成的必要条件,准同生—浅埋藏期等早期白云石化作用有利于准同生期形成的孔隙保存,表生岩溶及构造破裂作用起到改善储层物性的作用。明确了深层优质白云岩储层仍具有相控性,深层白云岩储层继承性大于改造性,其纵向分布不是受深度控制而是受早期沉积旋回控制,横向分布不是受岩溶作用控制而是受高能沉积相带控制。认为未来深层优质白云岩储层的勘探主要为“台内裂陷两侧”及碳酸盐岩缓坡之内缓坡—中缓坡。
Deep craton in the craton basin is an important area for future exploration of natural gas on land in China. Through statistical analysis of major cratonic basins in China, such as Sichuan, Tarim and Ordos, the main types of deep dolomites are particulate dolomite, microbial dolomite and crystalline dolomite. The types of pores are mainly crack-hole type and fracture-pore type. It is pointed out that favorable sedimentary microfacies are the material basis for pore formation. Early dissolution is the prerequisite for pore formation. Early dolomitization, such as quasi-shallow burial, is beneficial for pore preservation, epikarst formation and epikarst formation Fracturing plays a role in improving reservoir physical properties. It is clear that deep-quality dolomite reservoirs are still facies controlled. Deep dolomite reservoirs are more inheritable than reworkable ones. Their longitudinal distribution is controlled not by depth but by early sedimentary cycles. Horizontal distribution is not controlled by karstification but by High energy sedimentary facies control. It is considered that the prospecting of deep-seated dolomite reservoirs in the future is mainly “gentle flats” on both sides of “intra-platform rifts” and gentle brasses within carbonate rocks.