Productivity prediction model and productivity sensitivity analysis method for multi-section fractured horizontal well in low-permeability tight gas reservoir

Abstract

The invention belongs to the field of tight sandstone gas reservoir development, and discloses a productivity prediction model and productivity sensitivity analysis method for a multi-section fractured horizontal well in a low-permeability tight gas reservoir. The model and method are characterized in that after a variety of factors, such as high-speed non-darcy effect, stress sensitivity, slippage effect, stratum pressure drop, in-fracture linear flow and in-fracture radial flow and shaft pressure drop are comprehensively considered, a steady-state seepage low model of the fractured horizontal well is provided; the influence of the various factors on a productivity calculation result is quantitatively analyzed; through example verification, for the multi-section fractured horizontal wellin the tight gas reservoir, the model can accurately predict the productivity; and a productivity sensitivity analysis result shows that the influences of horizontal well length, fracture half length,fracture number and fracture flow conductivity on the productivity have obvious limits, and a reasonable value should be selected from the perspective of economic development. The model and method have extremely high theoretical and application values for productivity prediction and productivity sensitivity analysis for the multi-section fractured horizontal well in the low-permeability tight gasreservoir.

Description

technical field [0001] The invention belongs to the field of tight sandstone gas reservoir development, and in particular relates to a multistage fracturing horizontal well productivity prediction model and a method for productivity sensitivity analysis applicable to low-permeability tight gas reservoirs. Background technique [0002] With the increase of demand and the continuous reduction of conventional oil and gas resources, the country pays more and more attention to unconventional oil and gas. The permeability of tight sandstone reservoirs is generally less than 0.1×10 -3 μm 2 , and develop natural cracks. On the one hand, the existence of fractures can significantly increase the matrix permeability of low-permeability tight reservoirs, providing seepage channels for fluids, and on the other hand, it can also enhance the anisotropy of reservoir plane permeability by 100 times. This type of gas reservoir generally has no economic production using conventional technol...

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Problems solved by technology

[0054] (4) Before the reserve test, the entire gas reservoir should be shut down. After the formation pressure is basically restored to stability, 1-2 wells should be selected for testing; error

The differential pressure curve method requires the gas well to reach a quasi-stable state before shutting in the well. If the quasi-stabl

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