In recent years

an important break-through has been achieved in Ansairegion based on the theory of deltaic hydrocarbon exploration. Numerous small but rich oil pools with high productivity which are controlled by marginal bank sand bodies are discovered in distributary channels of delta plain. In delta-front sandbars

abundant oil reserve of Chang-6 reservoir has been detected. The diagenesis of the sand bars may either produce networks of secondary pores

or form diagenetic traps. As for the exploration of deltaic subtle oil pools

we should not only pay attention to the distribution and variation of facieszones

but also study the important role of diagenesis in the formation of the oil pools.