Experiments were made on the porosity

permeability and the compaction regularity of the reservoirs of Ponglaizhen shallow gas pools in Luodai Gasfields.The results indicate that the porosity and permeability decreased with the increasing of confining pressure.When the confining pressure increases to 10 MPa

the porosity and permeability would decrease maximally to 7.39% and 80% respectively as compared with those measured at normal temperature and pressure.The variation of reservoir porosity is closely related to the contents of calcium and anhydrite.A mathematical relational expression is established according to core data.The description of textural parameters suggest that

the main peak of throat radiuses of Ⅰ～Ⅲ type reservoirs of the gas pools are distributed between 0.4～4.0 μm;more than 90% of the cumulated permeability are distributed in those the throat radiuses greater than 1.0 μm.This shows that large throat radius dominats gas mgration.