A Well Pattern Design Method for Spatial Structure of Fractured-vuggy Reservoir Based on Variation Coefficient

Abstract

The present invention proposes a well pattern design method for spatial structure of fracture-cavity reservoirs based on coefficient of variation. The network design method includes steps: S1): determining a plurality of initial injection-production schemes according to the location of each well or the type of reservoir body of each well; S2): calculating the degree of connectivity between the injection-production wells of each initial injection-production scheme; S3): According to the degree of connectivity between injection-production wells of each initial injection-production scheme, the coefficient of variation of the degree of connectivity between injection-production wells is calculated; S4): The initial injection-production scheme with the smallest variation coefficient is selected as the final injection-production scheme. The method for designing the space structure well pattern of the fractured-vuggy reservoir based on the coefficient of variation of the present invention avoids the one-way effect caused by the channeling of the injected water along the dominant channel, and thus improves the utilization rate of the injected water.

Description

technical field [0001] The invention relates to the technical field of oil and gas exploration and development, and more specifically, the invention relates to an optimization method for water injection and oil recovery of well pattern with spatial structure of fracture-cavity reservoir. Background technique [0002] my country's marine carbonate reservoirs are mainly distributed in the Tarim Basin, mainly of fracture-cavity type. The Ordovician reservoir in Tahe Oilfield is the largest fractured-vuggy reservoir discovered in my country so far. As of the end of 2016, the proven geological reserves of petroleum reached 1.336 billion tons. Water injection began in Tahe fracture-vug reservoirs in 2005. By the end of 2016, unit water injection covered geological reserves of 598 million tons, accounting for 69% of the developed volume. It has become the main supplementary energy development method of Tahe Oilfield. [0003] Spatial structure well patterns adopt different well p...

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Problems solved by technology

On the other hand, the injection-production well pattern of fracture-vuggy reservoirs is constructed on the basis of the initial well pattern through oil well transfer injection. According to the above principles, multiple sets of plans may be obtained. How to further optimize the design is not mentioned.

Therefore, the existing technology cannot meet the needs of fine development

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