The method and system for obtaining absolute unimpeded flow rate of condensate gas reservoirs based on exponential

Abstract

The invention relates to an exponential-based method and an exponential-based system for acquiring absolute open-flow potential of condensate gas reservoir under different formation pressures. The exponential-based method is used for acquiring the absolute open-flow potential on the basis of change of gas components in the condensate gas reservoir and change of gas-phase permeability under the different formation pressures, and includes determining an exponential productivity equation under the different formation pressures; acquiring a relation between a first coefficient and a second coefficient of the exponential productivity equation via a first formation pressure, a second formation pressure, first natural gas viscosity, a first deviation coefficient, first gas-phase permeability, second natural gas viscosity, a second deviation coefficient and second gas-phase permeability according to the exponential productivity equation; and acquiring the absolute open-flow potential of the condensate gas reservoir under the different formation pressures according to the relation between the first coefficient and the second coefficient of the exponential productivity equation, known first absolute open-flow potential of the condensate gas reservoir, the known first formation pressure and the known second formation pressure. The first natural gas viscosity, the first deviation coefficient and the first gas-phase permeability correspond to the first formation pressure, and the second natural gas viscosity, the second deviation coefficient and the second gas-phase permeability correspond to the second formation pressure.

Description

technical field [0001] The invention relates to the field of obtaining absolute unimpeded flow, in particular to a method and system for obtaining absolute unobstructed flow of condensate gas reservoirs under different formation pressures based on an exponential productivity equation. Background technique [0002] Document 1: Chen Yuanqian, Oil and Gas Reservoir Engineering Practice [M]. Beijing: Petroleum Industry Press, 2005, 142-146 The method proposed considers the influence of condensate oil on gas well productivity, expressed as: [0003] P e 2 - P wf 2 = aq sc + bq sc 2 [0004] in: a = TZ μp sc πkh T ...

AI Technical Summary

Problems solved by technology

First, if the pressure changes little, it is considered that the coefficient of the gas well productivity equation is constant during the development process, and the early gas well productivity equation can be directly used; second, the influence of formation pressure changes on gas viscosity, deviation coefficient, etc. The absolute open flow rate of gas wells under different formation pressures is derived from the gas well productivity equation. The composition is constant, i.e. the molecular weight does not change

This assumption is valid for general dry gas reservoirs, but large calculation errors will occur for condensate gas reservoirs

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