Method for predicting production effect of shale reservoir after size modification

Abstract

The invention discloses a method for predicting production effect of a shale reservoir after size modification. The method mainly includes following steps: collecting basic parameters of the reservoir, fluid and a horizontal wellbore; dividing a heterogeneous gas reservoir into at least two vadose zones along the length direction of the horizontal wellbore, wherein each vadose zone contains artificial fractures; building a vadose unit simulation model for each vadose zone; building vadose simulation models of at least two vadose units; coupling the vadose simulation models of the vadose units, and predicting the production effect of a heterogeneous gas reservoir fractured horizontal well in a stable state; discretizing time, and repeating the steps 1-5. By the technical scheme, the defect that only prediction on homogeneous shale reservoirs can be realized without considering starting pressure gradient and stress sensitive effect is overcome, and comprehensive evaluation on the production effect of the shale reservoir after size modification can be realized.

Description

technical field [0001] The application belongs to the field of oil and gas field development, and in particular relates to a method for predicting the production effect of shale reservoirs after volume reformation. Background technique [0002] With the rapid development of the global energy industry and the increasing demand for energy, more and more low-permeability oil and gas reservoirs have been put into development and utilization. Ultra-low permeability gas reservoirs are characterized by extremely low reservoir permeability, plane heterogeneity, starting pressure gradient, and stress-sensitivity effects. Fracturing horizontal well technology is one of the key technologies for increasing reserves and production of ultra-low permeability gas reservoirs and economically and effectively developing them. However, the stimulation mode of conventional fracturing to form a single fracture cannot effectively communicate with the reservoir, and it is difficult to achieve effic...

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Problems solved by technology

[0003] At present, the production prediction models for volumetric fracturing of horizontal wells mainly include dual-linear flow, tri-linear flow, and five-linear flow and other seepage models. None of the above models considers the heterogeneity of ultra-low permeability gas reservoirs and ultra-low permeability gas reservoirs at the same time. Combined effects of threshold pressure gradients in the presence of fluid flow and reservoir stress-sensitivity effects in pressure drops

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