Reservoir fracture prediction method and apparatus

Abstract

The invention discloses a reservoir fracture prediction method and apparatus, and belongs to the field of oil and gas exploitation. The reservoir fracture prediction method comprises the steps of 1: randomly generating a plurality of fractures in a work area range, and obtaining initial feature parameters of the fractures; 2: building a discrete fracture mesh model; 3: performing production history numerical simulation to obtain a production dynamic parameter simulation value; 4: obtaining a covariance matrix of an error between the production dynamic parameter simulation value and an actual production dynamic parameter, and then obtaining Kalman gain; 5: adjusting the initial feature parameters to obtain new feature parameters, and calculating a variance of the new feature parameters; and 6: judging the convergence of the new feature parameters, and if the new feature parameters are not converged, repeating the steps 2-5, or otherwise, taking the new feature parameters as final feature parameters of reservoir fractures. According to the method and the apparatus, the reservoir fracture prediction is performed based on the discrete fracture mesh model and the Kalman gain, so that the reservoir fracture information can be predicted more accurately.

Description

technical field [0001] The invention relates to the technical field of oil and gas exploitation, in particular to a reservoir fracture prediction method and device. Background technique [0002] In the field of petroleum exploitation technology, in the process of water injection, gas, polymer development and other enhanced recovery factors, reservoir fractures have a great impact on fluid flow and directly affect the development effect: the natural main fractures of the reservoir often become water channeling, gas Inaccurately predicting the location of natural fractures in the reservoir will lead to a decline in the effect of water injection and gas injection, and even force the production well to be shut down. [0003] At the same time, for the development of unconventional oil and gas resources such as shale oil and gas, accurate prediction of fracture location and flow conductivity is more necessary. Because shale reservoirs are characterized by low porosity and low per...

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Problems solved by technology

[0005] However, the inventors found during research that the existing crack prediction techniques based on the ensemble Kalman filter method are all based on conventional structured grids (orthogonal grids or corner grids, etc.). When dealing with fractured reservoirs, grids can only do simplified processing, and the conductivity of fractures must be equivalently incorporated into the matrix grid, so it is impossible to accurately and easily simulate fractured reservoirs, and the corresponding fracture inversion results are also Not accurate enough

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