Method for optimizing low-permeability reservoir intermittent mining working system based on model coupling exhaustion method

Abstract

The invention discloses a method for optimizing a low-permeability reservoir intermittent mining working system based on a model coupling exhaustion method. Aiming at the input and output characteristics of a low-permeability and low-yield well, through the combination of the flow-in dynamic characteristics of the low-permeability reservoir, the liquid level change rule of an intermittent mining well shaft and the pump efficiency analysis, and based on the relation between the stratum liquid supply capacity and the pumping and suction capacity, a stratum flow-in dynamic model and a well shaftoutflow dynamic model are established, a coupling model is established through the coupling parameters of the bottom flow pressure and the pump efficiency, a computer solution model is established onthis basis, and the optimization of the low-permeability reservoir intermittent mining working system determination method is carried out by means of an exhaustion method. The method can accurately describe the low-permeability reservoir seepage law, realizes the real-time dynamic changes of the bottom flow pressure and the pump efficiency during the intermittent mining, and realizes the accuratequantified intermittent mining limit. The exhaustion method has better optimization precision, and the program calculation efficiency is high.

Description

technical field [0001] The invention belongs to the technical field of intermittent production of low-permeability oil reservoirs, and in particular relates to a method for optimizing the intermittent production system of low-permeability oil reservoirs based on a model coupling exhaustive method. Background technique [0002] The two basic processes of the continuous decline of the liquid level of the production wellbore and the continuous rise of the wellbore liquid level of the shut-in and restoration are the two basic working systems of the intermittent production well. The establishment of the intermittent oil production system is completed by determining the change range of the fluid level in the wellbore and the period of intermittent production. The entire intermittent mining system is optimized through the optimization of the range of dynamic liquid level and the cycle of intermittent mining. [0003] Due to the large difference between foreign oil reservoirs and d...

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Problems solved by technology

[0012] Although many experts and scholars have completed the establishment of the intermittent production system, the establishment method is not accurate enough. The inflow dynamic equation generally adopts the general vogel equation or some simplified productivity formulas, which cannot accurately describe the seepage law of low-permeability reservoirs; the intermittent process cannot realize bottom hole flow. The real-time dynamic changes of pressure and pump efficiency; the interval range is delineated by qualitative analysis or economic limit as an upper or lower bound, which lacks rationality and cannot be accurately quantified to determine the interval limit

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