Double lower limit low permeability-compact sandstone reservoir classification method

Abstract

The invention relates to a double lower limit low permeability-compact sandstone reservoir classification method, comprising: calculating physical property lower limit of reservoirs of different depths, obtaining a changing curve of the physical property lower limit long with depth change; identifying day economy capacity lower limit and a function thereof changing with the depth, determining a relation between the day economy capacity lower limit and the porosity and permeability of the reservoir; obtaining an economic capacity curve of the porosity and permeability of the reservoir changing with depth according to the relationship between the function and the relation; respectively establishing a relational graph of the day economy capacity porosity lower limit with the effective reservoir porosity lower limit and the depths, and a relational graph of the day economy capacity permeability lower limit with the effective reservoir permeability lower limit and the depths. The classification method provided by the present invention effectively solves application of reservoir physical property lower limit changing with depths in reservoir evaluation, combines drilling and economy capacity in production, and helps to establish an objective, accurate, intuitive and easy reservoir classification evaluation program.

Description

Technical field [0001] The present invention involves the geological field, especially the reservoir classification method under a double lower limit constraint. Background technique [0002] The basis of reservoir classification is the physical properties of the reservoir, that is, the pore degree and penetration of the reservoir.For conventional sandstone reservoirs, the classification of the material nature of the reservoir and the fairy pressure characteristics is commonly used as a common reservoir classification evaluation method. It is generally divided into Class I ~ IV reservoirs. Most of the III and IV reservoirs belong toLow osmosis -dense reservoir.For low osmosis -dense reservoirs, due to its low ~ extremely low pores and penetration rates, it is divided into different reservoirs or even non -reservoirs in conventional reservoir evaluation. [0003] With the improvement of oil and gas exploration and the improvement of process technology, the huge amount of oil and g...

AI Technical Summary

Problems solved by technology

However, the low-permeability-tight characteristics of such reservoirs also determine that conventional reservoir classification methods and schemes are difficult to meet the evaluation requirements, and it is urgent to develop corresponding classification schemes.

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