Productivity analysis method and system for single-fracture-cavity reservoir

Abstract

The invention provides a productivity analysis method and system for a single fracture-cavity reservoir, and the method comprises the steps: building a fracture-cavity type reservoir physical model of the reservoir according to a connection structure of a fracture and a karst cave in the reservoir, and building a corresponding energy balance equation through comprehensively considering the fracture-cavity type reservoir physical model and force elements which affect the energy balance of fracture fluid; and combining the energy balance equation of the fluid in the reservoir fracture with the established inertia force flow equation, viscous force flow equation and friction resistance flow equation to obtain the pressure gradient in the fracture, calculating to obtain a pressure drop equation from the karst cave to the fracture outlet based on the pressure gradient, and introducing a potential concept to obtain a quadratic term productivity equation of the fracture-cavity reservoir. By adopting the technical scheme to analyze and evaluate the productivity of the fractured-cavity reservoir, the calculation process is simple, the productivity of the reservoir can be reliably described even for the fractured-cavity reservoir corresponding to the abnormal productivity indication curve, and a guidance basis is provided for the development of the fractured-cavity reservoir.

Description

technical field [0001] The invention relates to the technical field of reservoir engineering, in particular to a productivity analysis method and system for single-fracture-cavity reservoirs. Background technique [0002] In the field of reservoir exploration, the effective analysis and evaluation of reservoir productivity greatly affects the effect of development. In the existing research, the determination of the productivity relationship through systematic well testing is one of the important basis for the rational design of production allocation of oil wells. Specifically, the normal production capacity indicator curve presents an arc curve, and the increase rate of pressure difference to production keeps rising; it is approximately a straight line under low production and low pressure difference, reflecting a linear relationship controlled by viscous force, that is, Darcy seepage or laminar flow Features: The curve bends under high pressure difference under large output...

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