中国主要克拉通盆地深层白云岩优质储层发育主控因素及分布

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。

Main controlling factors and distribution of high quality reservoirs of deep buried dolomite in typical craton basins in China

Deep dolomite in craton basin is an important field for future natural gas exploration in China.Through statistical analysis，it is clear that the main types of deep dolomite are granular dolomite，microbial dolomite and crystalline dolomite，the pore types are mainly fractured fissure cavity and fractured pore type.It is pointed out that favorable sedimentary microfacies are the material basis for pore formation，early dissolution is a necessary condition for pore formation，dolomitization is beneficial to preservation of early pores，epigenetic karstification and structural fracture improve reservoir property.Definite，the deep quality dolomite reservoirs are still facies controlled，the deep dolomite reservoir is more inherited than transformed，the vertical distribution is not controlled by depth，but controlled by early sedimentary cycles，the lateral distribution is not controlled by karstification，but controlled by high-energy sedimentary facies belts.It is considered that the exploration of deep quality dolomite reservoirs in the future will be mainly “both sides of the inner rift of platform” and carbonate ramps.