Plug and perforation technique is the predominant method for multistage horizontal completion widely usedin unconventional or tight reservoir applications.Perforation quality in such circumstances has a significantinfluence on completion efficiency.However,perforation performance is often described with an API RP19B Section 1 test and not always analyzed thoroughly during the actual application.In this paper,wepresent several examples that qualitatively analyze perforation performance via operation data.In the plug and perf method for multistage completions,the purpose of the perforation is to create a fluidentry point for hydraulic fracturing of each stage after the previous lateral section is isolated by plugs.Inmany fields,the initiation and extension of the fracture could be a critical issue and significantly slow downoperations onsite.Theoretical analysis shows that perforation penetration and the effective hole numbercan lower the fracture pressure significantly,particularly in tectonic regions where stress anisotropy isat a high level.A novel perforation technique with consistent holes and deep penetration was tested andevaluated in several projects and it showed unique features applicable to reducing fracturing challenges.Three examples were reviewed to demonstrate that downhole perforation performance can be analyzedquantitatively through breakdown pressure comparison,pressure standard deviation analysis,and fractureextension hardness.This approach clearly showed that the novel perforation technique has advantages overtraditional perforations.Better perforations with consistent hole size and deep penetration are valuable for multistage completionsin unconventional or tight reservoir applications.All the case studies in the paper show improved efficiencyduring multistage fracturing and completion execution.The analytical method introduced can also be easilyadapted to evaluate and compare perforation quality in most multistage completion conditions.
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