Production Analysis on Wells Producing with Flow Thru Plugs to Optimize the Usage of HPCT Milling Operations

Abstract

One of the main used completion techniques in the gas wells Plug and Perf for proppant or acid stimulation, where the flow through frac plugs are commonly installed to provide isolation between the planned stages to be stimulated. Once the stimulation is completed, the well is flowed back where gas is produced thru the internal diameter restriction in those frac plugs, then all plugs are milled to clear any downhole restriction. The objective of this paper is to evaluate the need of milling frac plugs by simulating the behavior of the Production Index affected by downhole restriction in frac plugs considering those are not milled. The proposed evaluation will investigate the real need of milling the flow thru plugs in the well after the frac operations, as the milling operation has a high cost and complexity. The preferred method is to flow the well without milling operation. However, if the effect of the plugs was significant on the productivity of the wells throughout the years, there will be a need to perform milling operation on the wells to ensure full wellbore accessibility. On the other hand, if the effect was not significant on the future production, the flow thru plugs can be left in the well downhole to avoid the milling operation complications. It is worth to note that milling multiple plugs in a well is a very lengthy and extremely expensive operation looking at the CT and Sand Management System (SMS) daily charges as well as the highly nitrogen consumption (Nunez et al. 2021). The analysis in this paper is split in two parts, where initially Well-A is simulated in PROSPER to compare the production performance in a Plug and Perf completed well with plugs installed or milled. Second part of the analysis is to compare 2 offset wells with real-time data: Well-X with flow thru plugs and Well-Y with flow thru plugs being milled. The results of these analysis as well as the operation total cost and complexity will help in identifying most economical way to apply.