Geometry nature of hydraulic fracture propagation from oriented perforations and implications for directional hydraulic fracturing

Published on Sep 1, 2020in Computers and Geotechnics3.818
· DOI :10.1016/J.COMPGEO.2020.103682
Qingsheng Bai14
Estimated H-index: 14
(CUMT: China University of Mining and Technology),
Zhenghe Liu1
Estimated H-index: 1
(TUT: Taiyuan University of Technology)
+ 1 AuthorsFangtian Wang12
Estimated H-index: 12
(CUMT: China University of Mining and Technology)
Abstract In this study, hydromechanical hybrid finite-discrete element method (FDEM) models were employed to investigate hydraulic fracturing from oriented perforations at the microscale. Numerical calibrations were first used to obtain the microproperties that can represent the realistic behavior of sandstone. The fracture morphology and breakdown pressure obtained from the numerical hydraulic fracturing show reasonable agreements with the experimental results, indicating that the numerical results are convincing. Then, this method was applied to investigate the effects of the differential stress, perforation angle, perforation length, and injection rate on both the geometry nature of the hydraulic fractures (HFs) and the breakdown pressure. The perforation orientation, differential stress, and injection rate are found to strongly affect the breakdown pressure and HF geometry. However, the perforation length shows a weaker effect, especially when the perforation length is larger than the wellbore diameter. Furthermore, small-scale simulations were performed to investigate the formation of connected fractures developed from multiple perforated wellbores under the concept of directional hydraulic fracturing (DHF). The different fracture propagations and geometries in the DHF model indicate that conclusions from studying hydraulic fracturing from a single perforated wellbore may provide a limited reference for hydraulic fracturing from multiple perforated wellbores. The stress shadow effects during HF interactions were identified as the primary factor that contributed to these differences. Numerical results also provide new information on the roles of several factors (differential stress, injection rate, perforation orientation, and injection sequence) in DHF. DHF could take advantage of stress shadow effects by optimizing related factors. Based on the numerical results, some implications on the design of DHF, from small-scale simulations to field-scale applications, are discussed.
📖 Papers frequently viewed together
5 Authors (Liyuan Liu, ..., Yongjun Yu)
12 Citations
20 Citations
4 Citations
#1Liu Zhenghe (TUT: Taiyuan University of Technology)H-Index: 1
#1Zhenghe Liu (TUT: Taiyuan University of Technology)H-Index: 1
Last. Jianfeng Yang (TUT: Taiyuan University of Technology)H-Index: 6
view all 6 authors...
6 CitationsSource
#1Peng Kong (SDUST: Shandong University of Science and Technology)H-Index: 8
#2Lishuai Jiang (CUMT: China University of Mining and Technology)H-Index: 19
Last. Qingbiao Wang (SDUST: Shandong University of Science and Technology)H-Index: 4
view all 5 authors...
Rocks are a natural material with strong heterogeneity, and the heterogeneity affects the behavior and failure patterns of rocks and rock masses. Therefore, the factor of rock heterogeneity should not be neglected in cases of highly heterogeneous rock masses. In this study, the effect of heterogeneity on the rock mass stability in an underground coal mine roadway is investigated by introducing a stability analysis method that considers rock heterogeneity. The stability analysis method is combine...
23 CitationsSource
#1Shaofeng Wang (CSU: Central South University)H-Index: 22
#2Xibing Li (CSU: Central South University)H-Index: 44
Last. Shaolun DuH-Index: 1
view all 9 authors...
Abstract Stress conditions around deep underground mine openings can significantly influence rock fragmentation and stability, and thus the cuttability of the targeted rock. In this study, rock breakage experiments and associated regression analyses indicate nonlinear rock cuttabilities (decreasing followed by increasing) with increases in the differences between biaxial confining stresses and the values of uniaxial confining stresses. Rock breakages were found to be efficient and safe under low...
59 CitationsSource
#1Qingsheng Bai (CUMT: China University of Mining and Technology)H-Index: 14
#1Qingsheng Bai (CUMT: China University of Mining and Technology)H-Index: 1
Last. R. Paul Young (U of T: University of Toronto)H-Index: 2
view all 4 authors...
Underground excavation causes rock damage, affecting its stability and fluid transport properties. Traditional experiments usually use loading regime (compressive tests) to damage the sample. However, they cannot mimic realistic in situ conditions where excavation unloading also plays a significant role. In the study, we conducted a true-triaxial acoustic emission (AE) experiment to simulate excavation-induced damage by applying in situ 3D stress path to a sample. The path originating 1.0 cm fro...
8 CitationsSource
#1Zhuo Dong (DUT: Dalian University of Technology)H-Index: 1
#2Shibin Tang (DUT: Dalian University of Technology)H-Index: 1
Abstract Hydraulic fracturing is a major technique used to stimulate shale gas development. In this paper, the fracture propagation path, critical water pressure and deflection angle during the hydraulic fracturing process are analyzed using the maximum tangential strain and incremental crack growth method. After verifying the present numerical method by using published experimental results, this method applied to study the effects of the stress anisotropy coefficient, the perforation length and...
4 CitationsSource
#1Jianxiong LiH-Index: 5
#2Shiming DongH-Index: 9
Last. Xiaolong LiH-Index: 3
view all 5 authors...
Refracturing is a key technology in enhancing the conductivity of fractures from hydraulically-fractured wells. However, the deflecting mechanism of the diverting fracture is still unclear. In this paper, a fully coupled seepage-stress model based on the extended finite element method (XFEM) was developed to realize the deflection mechanism of the refracturing fractures. The modified construction of refracturing was then verified by laboratory experiments. Furthermore, two new deflection angles ...
2 CitationsSource
#1Qingsheng Bai (CUMT: China University of Mining and Technology)H-Index: 14
#2Shihao Tu (CUMT: China University of Mining and Technology)H-Index: 19
It is believed that underground longwall mining usually produces fractures in the surrounding rocks. On the one hand, mining-induced fractures not only degrade the strength of the rock mass but also serve as main channels for fluids (e.g., water and methane). Fractures facilitate the failure of the rock mass and fluid inrush into working spaces. Therefore, mining-induced fractures are significant for the safety evaluation of underground structures and finding feasible solutions. On the other han...
29 CitationsSource
#1Li ZhuangH-Index: 8
#2Kwang Yeom KimH-Index: 15
Last. Ki-Bok Min (SNU: Seoul National University)H-Index: 23
view all 5 authors...
Hydraulic fracturing tests on Pocheon granite cylinders at seven different injection rates varying from 1 to 100 mm3/s were conducted. They were compared with sleeve fracturing tests in which borehole was sleeved, and therefore, water infiltration influence was excluded. Hydraulic fracturing behavior of granite is significantly influenced by water infiltration, which is closely related to the preexisting microcracks in granite as well as the cleavage anisotropy. There was a threshold injection r...
34 CitationsSource
#1Qingyuan He (UNSW: University of New South Wales)H-Index: 7
#2F. T. Suorineni (UNSW: University of New South Wales)H-Index: 12
Last. Joung Oh (UNSW: University of New South Wales)H-Index: 13
view all 4 authors...
Abstract Cave mining has become a popular underground mass mining method and extends its applications to more component orebodies at depths. To ensure continuous cave propagation, effective pre-conditioning of the orebody to improve its caveability and fragmentation sizes is essential. Hydraulic fracturing has been used as a pre-conditioning method in cave mining by creating artificial fractures in the orebody. In a previous study, the requirement for creating orientation-controllable hydraulic ...
12 CitationsSource
#1Bo Wang (China University of Petroleum)H-Index: 5
#2Fujian Zhou (China University of Petroleum)H-Index: 17
Last. Jia Hu (China University of Petroleum)H-Index: 3
view all 6 authors...
Abstract Refracturing can effectively enhance hydrocarbon production from hydraulically fractured wells. Using self-degradable diverting agents, people can temporarily plug previously generated fractures, and generate a new pair of fractures perpendicular to the direction of the original maximum principle stress (i.e., near-wellbore temporary plugging and diverting technique). To simulate the plugging and diverting process, a numerical model is established using the cohesive zone model (CZM) bas...
25 CitationsSource
Cited By2
#1Qingshan Ren (CUMT: China University of Mining and Technology)
#2Yaodong Jiang (CUMT: China University of Mining and Technology)H-Index: 17
Last. Nima Noraei Danesh (CUMT: China University of Mining and Technology)H-Index: 4
view all 0 authors...
The extraction of low-permeability coalbed methane (CBM) has the dual significance of energy utilization and safe mining. Understanding hydraulic fracturing mechanism is vital to successful development of CBM. Therefore, it is important to improve the law of hydraulic fracture propagation in coal and rigorously study the influencing factors. In this paper, laboratory experiments and numerical simulation methods were used to investigate the hydraulic fracture propagation law of coal in coalbed me...
#1Liu Zhenghe (TUT: Taiyuan University of Technology)H-Index: 1
#2Jun Yang (TUT: Taiyuan University of Technology)
Last. Haojie Lian (TUT: Taiyuan University of Technology)H-Index: 13
view all 6 authors...
Abstract In this technical paper, large-scale true triaxial tests were conducted with sandstone specimens to investigate several factors that determine whether hydraulic fractures can propagate from the tips of axial prefabricated cracks (pre-cracks). Specifically, we investigated the influence of pre-crack inclination angles on hydraulic fracture initiation locations and how the critical pre-crack angle varies with different confining stresses, fluid viscosities, and leak-off effects. The exper...
#1I. A. Garagash (Skolkovo Institute of Science and Technology)H-Index: 8
#2Andrei A. Osiptsov (Skolkovo Institute of Science and Technology)H-Index: 11
Abstract We study the propagation of a fracture in an initially stressed anisotropic reservoir under shear. The focus is made on the deviation of the fracture from the principal direction due to the shearing conditions. An asymptotic model is developed, which yields the solution in terms of the effective K 2 c and the deviation angle. Then, we analyse formation of the fluid lag during propagation of a hydraulic fracture in the cases of plane and radial fracture. It is shown that there is lag bet...
1 CitationsSource