LOWER LIMITS OF PHYSICAL PROPERTIES OF EFFECTIVE CARBONIFEROUS IGNEOUS RESERVOIR IN SU13 WELL BLOCK OF WEST JUNGGAR BASIN

The determination of lower limits of effective reservoir physical properties is an important basis for effective thickness statistics, reservoir division and reservoir reserve estimation. The carboniferous igneous rock in the study area is characterized by multi-period diagenesis, multiple rock types and strong heterogeneity, and the lower limits of effective reservoir physical properties lack systematic research. The distribution function curve method and the physical oil test method are used to study physical property lower limits and the results of two methods are mutually compared to avoid the randomness of a single method. On this basis, the lower limit values of physical properties of different strata in the study area are obtained, and the fitting equation of lower limit value and buried depth of reservoir is established. The results show that the reservoirs in the study area are mostly low-porosity and medium-low-permeability reservoirs, with relatively high porosity and permeability in the central area and good physical property, and the physical properties gradually become worse in the north and south. The effective reservoir porosity of the carboniferous system in the study area from 1500 meters to 1900 meters and from 1900 meters to 2300 meters is 5.09% and 4.93%, respectively, and the lower limit of permeability is 0.252 mD and 0.198 mD, respectively. The lower limit of the effective reservoir property of the carboniferous igneous rock in the study area is negatively correlated with the buried depth of the reservoir.