1, The formation of secondary quartz, albitite, calcite and laumontite affected the storage physical properties of sandstone in different degrees.

2, Formation factors and mechanism of the laumontite in upper Triassic Yanchang group of Jingan oilfield are analyzed.

3, However, in the A period of later diagenetic stage, laumontite were dissolved by organic acid which was generated in decarboxylation of kerogen, and a great quantity of secondary pores were formed.

4, Exploration results have proved that newly found reservoirs are largely distributed in the laumontite secondary pore zone.

5, The relative high-permeability zones were resulted from the dissolution of authigenic laumontite on the low-permeability background.