Method for evaluating volume transformation capacity of vertical well of fractured tight oil reservoir

Abstract

The invention discloses a method for evaluating the volume transformation capacity of a vertical well of a fractured tight oil reservoir. The method comprises the following steps: forming a transformation fracture network near a well bore, wherein the transformation region is divided into two parts, namely an inner area and an outer area, the inner area is an artificial main fracture transformation region, and the flow conductivity of an artificial main fracture is much higher than external supply, so that the region is assumed to have limited artificial main factures during a model derivation process, the attribute parameters of all factures are consistent, and the seepage of the fluid in a main fracture is linear seepage and follows the Darcy law; under the combined action of artificial fracture extending and reservoir rock brittle shear, the artificial fractures, shear fractures and natural fractures are criss-cross, so that the seepage mode of the region is changed into fracture conductivity primarily; a semi-analytical two-region comprehensive mathematical model which can be used for evaluating the volume transformation capacity of the vertical well is established. The method is applicable to evaluating multi-fracturing of the vertical well of a closed boundary fractured reservoir and the volume transformation of the vertical well of the fractured tight oil reservoir; reference is provided for reasonable development of the tight oil reservoir.

Description

technical field [0001] The invention belongs to the field of fractured tight oil reservoirs, in particular to a productivity evaluation method for vertical well volume stimulation in fractured tight oil reservoirs. Background technique [0002] Under the general background of China's energy unconventional oil and gas reservoir main replacement strategy, tight oil (gas) reservoirs with abundant resources are bound to become one of the main forces in the continuous resources. The successful exploitation of such resources has become an important part of the field of “increasing production and increasing reserves” of domestic oil and gas. [0003] Tight sandstone reservoirs have pores, narrow roar radius, and poor fluid flow ability. It is usually necessary to perform fracturing operations on the reservoir to maximize the micro-fractures with very small conductivity, induced fractures and large fluid conductivity. The artificial fractures are connected together, the effective f...

AI Technical Summary

Problems solved by technology

Although the fractal model can better describe the spatial distribution of fractures, it cannot objectively describe the behavior of pressure propagation and realize the optimization of artificial fracture parameters.

So far, there is no unsteady-state productivity evaluation model that can be used for volume stimulation of vertical wells in fractured tight oil reservoirs

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