Method for predicting dynamic open-flow capacity of fractured horizontal wells for tight sandstone gas reservoirs

Abstract

The invention relates to the field of gas field development research, in particular to a method for predicting dynamic open-flow capacity of fractured horizontal wells for tight sandstone gas reservoirs. The method includes coupling gas reservoirs, fracture and wellbores to obtain gas and liquid two-phase flow productivity equations for optional fracture locations of the fractured horizontal wells; building corresponding fractured horizontal well numerical models on the basis of reservoir stratum parameters and fracture parameters to obtain relation curves and fitting relational expressions of non-dimensional gas release boundaries and gas test time; computing gas release boundaries of the fractured horizontal wells at production phases by the aid of dynamic reserves inverse processes; solving the gas and liquid two-phase flow productivity equations on the basis of phase permeability curves obtained by rock core tests so as to obtain the dynamic open-flow capacity of the fractured horizontal wells at the different production phases. The method has the advantages that influence of difference of physical parameters of reservoir strata, change of the fracture parameters, difference of gas well open-flow test time, external fracturing fluid and movable water of formations on open-flow capacity is taken into consideration, accordingly, the open-flow capacity of the fractured horizontal wells at the different production phases can be predicted by the aid of the method, and the prediction practicality and reliability can be improved.

Description

technical field [0001] The invention relates to the field of gas field development and research, in particular to a dynamic unobstructed flow prediction method for fracturing horizontal wells in tight sandstone gas reservoirs. Background technique [0002] Horizontal well multi-stage fracturing technology is an important means to achieve economical and effective development of tight low-permeability gas reservoirs, and has been widely used in the development of low-permeability tight gas reservoirs. There are a lot of journal documents published at home and abroad about the method of gas well open flow prediction. Among the various open flow prediction methods currently reported in the literature, whether it is the well test method or the productivity formula method, almost all of them are calculated based on gas single-phase seepage flow. Even if there are open flow prediction methods that consider gas-liquid two-phase flow, None of them considered the impact of open test ...

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Problems solved by technology

Among the various open flow prediction methods currently reported in the literature, whether it is the well test method or the productivity formula method, almost all of them are calculated based on gas single-phase seepage flow. Even if there are open flow prediction methods that consider gas-liquid two-phase flow, None of them considered the impact of open test time, the impact of external fracturing fluid, movable water in formation and fracturing operation itself on the average permeability of the matrix in the fracturing stimulation area of ​​the gas well, and all of them are calculated for the open flow in the gas test stage. Less useful and less reliable

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