A Research On Reservoir Physical Texture Lower-bound Of The Second Zone Of Xujiahe Formation Of South Area Of West Sichuan

By the use of the data of core testing, logging well.drilling well and production ,make a synthetical research on reservoir physics lower-bound of Second Zone Xujiahe Formation of South Gas reservoir of West of Sichuan.The studies of physics lower-bound of compact pore sandstone reservoir are as follows:By the use of the experimental date of the laboratory,such as gas-water capillarypressure.gas-water relative permeability,mercury-gas capillary pressure.and so on , achieving the upper-bound of the bondage water-saturation.the lower-bound of the porosity and permeability. .And then, by the use of the interpretative result of the the logging well,accounting the the lowest porosity and the correspondenced water-saturation in the pay formation.achieving the lower-bound of the logging well porosity and the upper-bound water-saturation.The studies of physics lower-bound of compact sandstone reservoir in the place are as follows:After Statisticing the experimental data of the helium gas porosity, kerosene porosity, porosity of the big diameter core and the small core.the porosity on the condition of the changed pressure.gaining a formula which can transform the surface porosity into the subsurface porosity.Oh the base of the result,achieving the lower-bound of the subsurface reservoir porosity The studies of gassy lower-bound of compact sandstone reservoir are as follows: By the use of calculation formula of the gassy pore-laryngic semidiameter, , analyzing the data of the gas-water capillarity pressure again on the base of the theory of the second migratation.And then,achieving the lowest gassy pore-laryngic semidiameter and the lower-bound of the porosity on the basis of the relation plan between the water-saturation and the capillarity pressure.The studies of productive gas lower-bound of compact sandstone reservoir are as follows: First,by the use of the interpretative result of the productive logging well and conventionallogging well, achieving the lower-bound of the logging well porosity and the upper-bound water saturation of the compact sandstone reservoir.Second.by the use of the experimental data of the productivity simulation , achieving the lower-bound of the porosity and the permeability of the pay formation.Third,by the use of the productive data of the gas well and the calculation of permeability of the gas quantity formula on the condition of pay formation, achieving the lower-bound of the permeability and the pay formation coefficient (KH=0.8 × 10-3μm2.m).At last ,on the base of the above conclusions,, gaining the lower-bound of the reservoir physical texture that maybe as a reference when calculating the gas reserves by the use of cubage formula.