A Novel Model for Evaluating Temporary Plugging Effectiveness Between Clusters in Shale Gas Horizontal Wells

In order to evaluate the temporary plugging effectiveness between clusters, this study proposes a novel model to calculate perforation opening ratio before and after the introduction of temporary plugging materials. The model is based on the fracturing operation curve and takes into account the perforations erosive effects. Taking Well A and Well B in the Weiyuan area as examples. The research results indicate the following: before the introduction of temporary plugging materials, the perforation opening ratio ranges from 35.1% to 42.5%, after the introduction of temporary plugging materials, the perforation plugging ratio ranges from 30.5% to 46.2%, following the dissolution of temporary plugging materials, the perforation opening ratio ranges from 76.9% to 83.5%. At a displacement of 14 m3/min with a single plugging operation and 12 m3/min with two consecutive plugging operations, the perforation opening ratios are 79.7% and 82.9%, respectively. The perforation opening ratios are comparable under both conditions, therefore, increasing the displacement and reducing the frequency of temporary plugging operations can effectively increase the perforation opening ratio. The model has been successfully applied in more than ten times in the Weiyuan area, providing robust support for the evaluation of temporary plugging effectiveness between clusters. 1. INTRODUCTION The multi-section and multi-cluster hydraulic fracturing technique in horizontal wells is a crucial technology for shale gas extraction (Zargari et al., 2010; Xu et al 2018) However, factors such as reservoir heterogeneity and stress-shadowing lead to the partial opening of perforation clusters, resulting in incomplete stimulation of the horizontal section (Cramer et al., 2019). The key technology to address these issues is the temporary plugging and diversion (TPDF) fracturing technique. This technique involves introducing temporary plugging materials to plug the already-opened perforations, forcing subsequent fluids to redirect into unopened perforations, creating new fractures, and achieving thorough stimulation of the horizontal section. (Ataur et al., 2017; Leonid et al., 2018; Cyrille et al., 2020).