Method for determining cavity flux in stratum of fracture-cavity type reservoir stratum test well

Abstract

The invention discloses a method for determining the cavity flux in a stratum of a facture-cavity type reservoir stratum test well, and relates to the technical field of fracture-cavity type reservoirstratum test wells. The method comprises the steps that a model of the fracture-cavity type oil reservoir test well is built, and karst caves in the stratum are taken as point sources; the real spacebottom hole pressure solution in the infinite formation is acquired according to the test well model; the real space bottom hole pressure when the multiple caves exist simultaneously in the stratum is acquired by adopting a superposition principle according to the real space bottom hole pressure solution; and the numbers of the caves and the distances from the caves to the well are acquired by conducting matching on the real space bottom hole pressure solution and the really measured bottom hole pressure data. The method can directly explain the number and the distances of the karst caves inthe fracture-cavity type oil reservoir by providing a matched interpretation means for calculation of the fracture-cavity type oil reservoir parameters and calculation of reserves, and provides technical support from making the oil field developing scheme. The analytical solution can be given in the laplace space, and the calculation speed is high. The number and the flux of the karst caves can bedirectly obtained from the interpretation result after matching is conducted.

Description

technical field [0001] The invention belongs to the technical field of fracture-cavity reservoir well testing, and in particular relates to a method for determining the flow rate of a cave in a formation through well testing of fracture-cavity reservoirs. Background technique [0002] The matrix of carbonate fracture-cavity reservoirs basically contains no oil, and the storage spaces are mainly fractures and caves. The flow of crude oil in fractures and caves has pipe flow and seepage. When crude oil flows in deep fractures and caves, the vertical flow is obvious. The current well testing analysis methods are mainly based on the theory of triple medium and equipotential body. Based on these two theories, it is impossible to judge whether there are caves in the formation and give the flow provided by the caves. [0003] The triple medium is based on the macro-statistical theory to divide the oil storage space of the fractured-vuggy reservoir into three types of media (caviti...

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Problems solved by technology

[0006] The object of the present invention is to provide a kind of fracture-cavity reservoir well testing method to determine formation medium-cavity flow rate, by using the fracture-cavity reservoir test interpretation method based on the combination of energy conservation law and karst cave fluctuation, through the pressure recovery test curve Interpretation, obtaining the number of caves in the formation and the flow parameters provided by the caves, which solves the existing problem of not being able to determine the size, number and distance of fractures and caves, etc., which directly serve the development of fractured-cavity oilfields

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