Water breakthrough time prediction method and device for low permeability bottom water gas reservoir

Abstract

The invention provides a water breakthrough time prediction method and device for a low permeability bottom water gas reservoir. The method comprises the following steps of building a water breakthrough time computing model based on a gas phase plane radial flow throughput model and a hemispherical centripetal flow of the lower part of a perforated zone according to a gas phase non-Darcy flow effect influence factor and a stratum skin effect influence factor; acquiring actual production data of the low permeability bottom water gas reservoir; and predicting the water breakthrough time of the low permeability bottom water gas reservoir according to the actual production data of the low permeability bottom water gas reservoir based on the water breakthrough time computing model of the low permeability bottom water gas reservoir. The scheme comprehensively considers the influences of the gas phase non-Darcy flow effect and the stratum skin effect, and builds the dynamic water breakthroughtime computing model fitter for the fracturing well water cone of the low permeability bottom water gas reservoir, so that the water breakthrough time of the low permeability bottom water gas reservoir can be accurately predicted, and the guiding significance and practical value are provided for improving development benefit and reasonable production allocation of the low permeability bottom water gas reservoir.

Description

technical field [0001] The invention relates to the technical field of water breakthrough risk prediction of natural gas wells, in particular to a method and device for predicting water breakthrough time of low-permeability bottom water gas reservoirs. Background technique [0002] Unlike conventional gas reservoirs, low-permeability gas reservoirs have poor reservoir physical properties and low natural productivity of a single well. Stimulation measures such as fracturing are usually required in oilfields to obtain industrial productivity. Under the effect of high production pressure difference, the bottom water continuously coning into the bottom of the well. Because the reservoir physical properties of this type of gas reservoir are poor, the bottom water tends to stay in the formation void after coning, which reduces the seepage area of ​​the gas phase. As a result, the productivity of gas wells will decrease, and even the gas wells will be scrapped. Therefore, accuratel...

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Problems solved by technology

However, the previous productivity prediction models for fracturing wells did not consider the influence of gas phase non-Darcy effect and formation skin effect near the bottom of the well, which did not conform to the real seepage conditions of fracturing wells in low-permeability bottom water gas reservoirs, resulting in inaccurate prediction of water breakthrough time. precise

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