A method for optimal design of injection-production well pattern in spatial structure of fractured-vuggy reservoir

Abstract

The present invention proposes a method for optimal design of injection-production well pattern with spatial structure of fractured-cavity reservoir, wherein there are multiple wells in the oil field block, and the optimal design method for spatial structure of injection-production well pattern of fracture-cavity reservoir includes Steps: S1): Determine multiple initial injection-production schemes according to the location of each well or the type of reservoir body in each well; S2): Calculate the degree of connectivity between injection-production wells for each initial injection-production scheme; S3): According to Calculate the Gini coefficient of the connectivity between injection and production wells for each initial injection-production scheme; S4): Select the initial injection-production scheme with the smallest Gini coefficient as the final injection-production scheme. The injection-production well pattern optimization design method of the spatial structure of the fracture-cavity reservoir of the present invention avoids the one-way effect caused by the channeling of the injected water along the high diversion channel, and improves the sweep coefficient 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 optimal design method for well pattern water injection and oil recovery of 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 patt...

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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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