Method for simulating pressure of gas reservoir finite diversion asymmetric fractured well in any shape

Abstract

The invention provides a method for simulating the pressure of a gas reservoir finite diversion asymmetric fractured well in any shape. The method comprises the following steps that the boundary condition in a fracturing fracture is coupled to a gas reservoir mass conservation equation, and a seepage differential equation is export; definite solution conditions are wrote, and combine with the seepage differential equation to form a stratum seepage mathematical model without dimensionality; an intra-domain differential equation is converted into an integral equation on the boundary and discretization is carried out, a finite flow guide fracturing fracture seepage mathematical model is established, and integrating and dispersing are carried out; matrixes obtained by the discrete boundary integral equation and the discrete fracturing crack equation is simultaneously solved; and a dimensionless bottom hole pressure curve and a derivative curve are drawn, and the influence of the position,a skin coefficient of the fractured well in the complex-shape gas reservoir, a dimensionless flow conductivity coefficient of a fracturing crack and the asymmetry of fracturing crack two wings on thecurve are analyzed. According to the method, an unstable well testing mathematical model of a gas well is established, a transient state of the bottom hole pressure of the gas well is accurately calculated, which is a theoretical basis for well testing interpretation to obtain important stratum parameters.

Description

technical field [0001] The invention belongs to the well testing technology of oil and gas wells, in particular to a method for simulating the pressure of an asymmetrical fractured well with limited conductivity in an arbitrary shape gas reservoir. Background technique [0002] Well testing technology of oil and gas wells is a very important technology for understanding oil and gas reservoirs, and is praised as "the eyes of oil and gas reservoir development" by the petroleum industry. Through well testing, we can obtain some important dynamic parameters of deeply buried oil and gas reservoirs (such as formation permeability, wellbore pollution coefficient, etc.). Establishing a reasonable unstable well test model (the unstable well test model is one of the unstable seepage models) and accurately simulating the transient bottomhole pressure of oil and gas wells is the theoretical basis and necessary premise of well test analysis technology . [0003] Conventional analytical...

AI Technical Summary

Problems solved by technology

The model built by Kryuchkov and Sanger has two deficiencies: the first one is that the model only considers the case where the lengths of the two wings of the fracture are symmetrical, but the actual fractures are often asymmetrical; the second deficiency is that their research is It is carried out in the real time domain, so there will be many infinite series in the model solution results, which is extremely unfavorable for the fast calculation of the computer

However, up to now, the establishment of well testing models and the accurate and efficient calculation of bottomhole pressure in some complex situations have not been well resolved.

For example, a system that can not only comprehensively consider the complex shape of the gas reservoir, the conductivity of the fracture, the asymmetry of the two wings of the fracture, and the asymmetry of the flow distribution of the fracture, but also accurately (reach the precision required for well test analysis) and efficiently The boundary element well test model for calculating and describing the bottomhole pressure dynamics of fractured gas wells and the corresponding accurate simulation method for the transient state of bottomhole pressure have not yet been seen.

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