Well selection method for repeated fracturing of multi-stage fracturing horizontal wells in low-permeability heterogeneous reservoirs

Abstract

The invention discloses a repeated fracturing well selecting method for a low-permeability heterogeneous oil-reservoir multi-section fractured horizontal well. The method sequentially comprises the following steps of 1, conducting statistics on key factors, affecting repeated fracturing effects, of each fracturing section of a candidate well, wherein the factors comprise physical parameters of a reservoir layer, initial fracturing construction parameters, dynamic production parameters and distribution ranges of the parameters; 2, determining parameter values of the ideal fracturing section with the most repetitive fracturing potential according to the distribution ranges of the parameters of each fracturing section of the candidate well; 3, utilizing a fuzzy system clustering method to calculate the Euclidean distance between each fracturing section of the candidate well and the ideal fracturing section; 4, calculating the average Euclidean distance between each fracturing section of the candidate well and the ideal fracturing section, and preferably selecting a repeated fracturing well according to the average Euclidean distance. Through the adoption of the method, the repeated fracturing well can be preferably selected under the condition that the production capacity of each fracturing section of the horizontal well cannot be obtained, the accuracy of selecting the repeated fracturing well is improved, the risk of engineering construction is reduced, and the method has a good guiding effect on on-site construction.

Description

technical field [0001] The invention relates to the field of petroleum and natural gas development, in particular to a method for selecting wells for repeated fracturing of multi-stage fracturing horizontal wells in low-permeability heterogeneous oil reservoirs in the field of hydraulic fracturing. Background technique [0002] Hydraulic fracturing technology has become a mature and effective reservoir stimulation technology and has been widely used all over the world, especially some low-permeability reservoirs must be hydraulically fractured before being put into production. Most of the low-permeability reservoirs in my country have the characteristics of poor reservoir properties, strong heterogeneity, and low natural productivity. Some of these reservoirs cannot be developed by conventional water injection to form an effective injection-production well pattern. Resilience development of volumetric fracturing technology. However, due to various factors such as geology and...

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Problems solved by technology

This method can only be used for single-stage fracturing well selection in vertical wells, but not for repeated fracturing well selection in horizontal wells with multi-stage fracturing

[0006] (2) Wei Chenji et al. (a method for selecting target wells for refracturing in tight oil and gas reservoirs, patent number: 201510324579.1) determined the completion efficiency of the screening well and the unit reservoir quality of the screening well, taking the unit reservoir quality as horizontal Coordinates, the completion efficiency is the ordinate to make a scatter diagram, and use the horizontal and vertical division lines to divide the scatter diagram into four parts to form an intersection diagnostic diagram, thereby completing the selection of the target well for refracturing, but only considering the physical properties of the reservoir factors and primary fracturing operation factors to select refracturing target wells, ignoring production dynamic factors such as formation pressure

[0008] The above three methods do not comprehensively consider factors such as reservoir physical properties, initial fracturing operation, production performance, etc., and are not suitable for multi-stage volume fracturing horizontal wells in low-permeability heterogeneous reservoirs and well selection for repeated fracturing.

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