Single-hole type fault solution reservoir well testing interpretation method considering gravity factor influence

Abstract

The invention discloses a single-hole type fault solution reservoir well testing interpretation method considering gravity factor influence. The method comprises the following steps that 1, a single-hole type fault solution reservoir well testing mathematical model considering the gravity factor is built, and a karst cave and crack combined system is regarded as a simultaneous cylindrical region; 2, the well testing mathematical model is subjected to dimensionless processing to obtain dimensionless gravity coefficient definition; 3, solving is performed on a Laplace space after Laplace transformation is adopted, and an expression of the pressure in a stratum hole changing along with time under the gravity factor influence is obtained; and 4, curve parameters and time and pressure fitting values are obtained by adopting a well testing method, and the influence of the gravity factor on well testing curve interpretation is obtained. By adopting the method, the technical problem that some parameters directly serving oil field development cannot be determined by adopting a well testing interpretation method in the prior art is solved, meanwhile the influence of gravity on a well testing curve is analyzed, and technical support is provided for oil field development.

Description

technical field [0001] The invention belongs to the technical field of oil reservoir engineering, and in particular relates to a well test interpretation method for a carbonate rock fault-karst body oil reservoir. Background technique [0002] In a broad sense, "fault-karst body" refers to the reservoir formed by the dissolution of atmospheric water or buried fluid on the surrounding rock along the fault. As an important fluid channel, fractures play an important role in both supergene and burial stages. Fluids will undergo a series of dissolution-filling actions during the process of flowing through faults. Local dissolution will lead to the formation of new reservoir spaces or the dissolution and expansion of pre-existing fractures and pores, and the final formation of reservoirs will develop. The distribution shows the characteristics of being closely related to faults, so it is called "fault-karst body". Shunbei fault-karst reservoirs have strong heterogeneity, large b...

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Problems solved by technology

This technique also does not take into account the effect of gravity on seepage

[0007] However, the theories of the existing interpretation methods are all based on conventional well test interpretation theory. The results based on conventional well test interpretation are parameters such as permeability, storage volume ratio and channeling coefficient. These parameters are only fractures and matrix in the formation. And the average value of cave parameters, using these parameters can not understand the characteristics of fractures and caves, and can not determine the size, number and distance of fractures and caves, etc., which directly serve the development of fault-karst body oilfields

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