This study developed the fluid pipe element that can consider fluid distribution, perforation erosion, and temporary plugging effects based on the Finite Element Analysis. This element can be easily coupled with finite element models to achieve multi-fracture propagation simulation. The element test shows the numerical solution is consistent with the analytical solution and experimental results. Subsequently, the limited-entry fracturing case (LEF) and the temporary plugging fracturing (TPF) case are simulated based on the element. The result shows that the LEF case has a good limited-entry ability in the initial stage, but the limited-entry ability is greatly reduced as the fracturing time increases; The cumulative fluid ratio of the side, sub-side, and center fractures are 26.29%, 20.62%, and 7.29%, respectively. The fracture length and the cumulative fluid ratio of each fracture are very uneven. The TPF case has a better limited-entry ability. The cumulative fluid ratios of the side, sub-side, and center fractures are 20.30%, 18.66%, and 21.19%, respectively. The total fracture length of the TPF case is 18.8% higher than that of the LEF case. The TPF case has a relatively uniform fluid injection volume, but the fracture length is still uneven. This paper provides a convenient means for the finite element simulation of multi-cluster fracture propagation.

1. Introduction

Hydraulic fracturing has been proved to be an effective method to stimulate low-permeability or unconventional oil and gas reservoirs. The fracturing fluid will be injected to create multiple hydraulic fractures along the horizontal well, thereby improving the permeability of the reservoir (Chen et al., 2009). However, the reservoir heterogeneity and the stress interference make it difficult to make multiple fractures obtain even fracture length. To promote the initiation and propagation of multiple fractures, field practice often adopts limited-entry fracturing (LEF) and temporary plugging fracturing technology (TPF) (Xing and Zhang, 2009; Zhou et al., 2019). The key operation of the LEF is to reduce the number or diameter of perforations in the wellbore, which will increase the perforation friction and limit the fluid entry of each fracture (Crump and Conway, 1986). Although the Limited-entry fracturing method is widely used in oilfield practice, the advanced monitoring data shows that the fracture propagation is still uneven (Miller et al., 2011). Numerical simulations have shown that the stress interference between fractures or perforation erosion will reduce the perforation limited-entry capacity, which makes it difficult to predict the multi-cluster fracture propagation geometry after fracturing (Li et al., 2020; Cramer et al., 2019; Guo et al., 2009; Zhou et al., 2020)

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