CHEN Jun-bin, WEI Bo, XIE Qing, WANG Han-qing, LI Tao-tao, WANG Hao. Simulation of Multi-Hydrofracture Horizontal Wells in Shale Based on the Extended Finite Element Method[J]. Applied Mathematics and Mechanics, 2016, 37(1): 73-83. doi: 10.3879/j.issn.1000-0887.2016.01.006
 Citation: CHEN Jun-bin, WEI Bo, XIE Qing, WANG Han-qing, LI Tao-tao, WANG Hao. Simulation of Multi-Hydrofracture Horizontal Wells in Shale Based on the Extended Finite Element Method[J]. Applied Mathematics and Mechanics, 2016, 37(1): 73-83.

# Simulation of Multi-Hydrofracture Horizontal Wells in Shale Based on the Extended Finite Element Method

##### doi: 10.3879/j.issn.1000-0887.2016.01.006
Funds:  The National Natural Science Foundation of China(（51374170)
• Rev Recd Date: 2015-10-09
• Publish Date: 2016-01-16
• The cluster spacing optimization of segmented multi-cluster hydrofracture of horizontal wells makes a key point for the hydrofracturing technology in shale reservoir. The fluid-solid coupling mathematical model for the horizontal well hydrofracture was established. Based on the extended finite element method, the propagation process of multiple cracks was simulated. The turning law of simultaneously propagating multiple cracks, as well as the relationships between the stress interference, horizontal principal stress difference, fracture spacing and the crack turning angle, were studied. The results show that the stress interference has restrictive effects on the crack width, and the opening width of 1 single crack is 1.3 times that of 2 concomitant cracks. The crack turning angle increases with the decrease of the stress difference and the lengthening of the fracturing time. The smaller the cluster spacing is, the stronger the stress interference is and the greater the crack turning angle is. For the sake of uniform propagation of the primary fracture, easy packing of the proppant and effective formation of the complex crack network, the optimal cluster spacing is determined as 30 m to 40 m. In the case of the multiple simultaneously propagating cracks, the middle cracks are restricted by those on both sides. The smaller the cluster spacing is, the stronger the restriction is, which results in a longer time of crack development and a lower propagation rate.
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