Quantitative Analysis of Anisotropy Effect on Hydrofracturing Efficiency and Process in Shale Using X-Ray Computed Tomography and Acoustic Emission
Tóm tắt
Hydrofracturing technology has become successful in enhancing the permeability of shale gas reservoirs. However, given the geological complexity in the subsurface, considerable challenges remain in quantitatively analyzing the hydrofracture geometry and understanding the anisotropic fracture process. To investigate, we conducted hydrofracturing tests through a horizontal borehole in shale core samples to simulate a horizontal fracturing stimulation. Based on the X-ray computed tomography scanning and fracture geometry reconstruction results, a new quantification method was established to evaluate the effect of bedding inclination and stress contrast on hydrofracturing efficiency. We concluded that the complex fracture network with higher stimulation index could be created at bedding inclinations of 0°–30° and stress contrast of 10 MPa. In this scenario, the fracturing process presented distinctive stages of fracture initiation, propagation, thoroughgoing failure, and stable seepage. The main fracture propagation in arrester mode would require higher fluid pressure, generate a complex fracture pathway, and a larger amount of acoustic emission amplitude, energy, and events. Also, the time from fracture initiation to physical breakdown was relatively long due to the branching of the main fracture into the weak beddings. With the increase in bedding inclination, the fracturing mode gradually changed from arrester to short transverse. The fracturing process was becoming instant, which was accompanied by a lower breakdown pressure, short acoustic emission response, and simple fracture geometry. The understanding of anisotropic fracture process and evaluation method are of interest in shale reservoir fracturing engineering and academic applications.
Tài liệu tham khảo
Bao X, Eaton DW (2016) Fault activation by hydraulic fracturing in western Canada. Science 354(6318):1406–1409
Borja RI, Yin Q, Zhao Y (2020) Cam-Clay plasticity. Part IX: on the anisotropy, heterogenity, and viscoplasticity of shale. Comput Methods Appl Mech Energ 360:112695
Chandler MR, Meredith PG, Brantut N, Crawford BR (2016) Fracture toughness anisotropy in shale. J Geophys Res Solid Earth 121:1706–1729
Chen H, Meng X, Niu F, Tang Y, Yin C, Wu F (2018) Microseismic monitoring of stimulating shale gas reservoir in SW China: 2. Spatial clustering controlled by the preexisting faults and fractures. J Geophys Res Solid Earth 123:1659–1672
DeReuil AA, Birgenheier LP, McLennan J (2019) Effects of anisotropy and saturation on geomechanical behavior of mudstone. J Geophys Res Solid Earth 124:8101–8126
Duan Y, Li X, Zheng B, He J, Hao J (2018) Crack evaluation and failure characteristics of Longmaxi shale under uniaxial compression using real-time computed tomography scanning. Rock Mech Rock Eng 52:3003–3015
Fisher MK, Heinze JR, Harris CD, Davidson BM, Wright CA, Dunn KP (2004) Optimizing horizontal completion techniques in the Barnett shale using microseismic fracture mapping. In: SPE 90051 presented at the SPE annual technical conference and exhibition, Houston, 26–29
Gehne S, Benson PM, Koor N, Dobson KJ, Enfield M, Barber A (2019) Seisom-mechanical response of anisotropic rocks under hydraulic fracture conditions: new experimental insights. J Geophys Res Solid Earth 124:9562–9579
Gehne S, Inskip NDF, Benson PM, Meredith PG, Koor N (2020) Fluid-driven tensile fracture and fracture toughness in Nash Point shale at elevated pressure. J Geophys Res Solid Earth 125:1–11
He J, Lin C, Li X, Zhang Y, Chen Y (2017) Initiation, propagation, closure and morphology of hydraulic fractures in sandstones cores. Fuel 208:65–70
He J, Li X, Yin C, Zhang Y, Lin C (2020) Propagation and characterization of the micro cracks induced by hydraulic fracturing in shale. Energy 191:116449
Heng S, Liu X, Li X, Zhang X, Yang C (2019) Experimental and numerical study on the non-planar propagation of hydraulic fractures in shale. J Petrol Sci Eng 179:410–426
Heng S, Li X, Liu X, Chen Y (2020) Experimental study on the mechanical properties of bedding planes in shale. J Nat Gas Sci Eng 76:103161
Ishibashi T, Fang Y, Eleworth D, Watanabe N, Asanuma H (2020) Hydromechanical properties of 3D printed fractures with controlled surface roughness: insight into shear-permeability coupling process. Int J Rock Mech Min 128:104271
Jeffrey RG, Chen ZR, Zhang X, Bunger AP, Mills KW (2015) Measurement and analysis of full-scale hydraulic fracture initiation and reorientation. Rock Mech Rock Eng 48:2497–2512
Jiang Y, Qin C, Kang Z, Zhou J, Li Y, Liu H, Song X (2018) Experimental study of supercritical CO2 fracturing on initiation pressure and fracture propagation in shale under different triaxial stress conditions. J Nat Gas Sci Eng 55:382–394
Jiang C, Niu B, Yin G, Zhang D, Yu T, Wang P (2019) CT-based reconstruction of the geometry and propagation of hydraulic fracture in shale. J Petrol Sci Eng 179:899–911
Lee HP, Olson JE, Holder J, Gale JFW, Myers RD (2015) The interaction of propagating opening mode fractures with preexisting discontinuities in shale. J Geophys Res Solid Earth 120(1):169–181
Li L, Tan J, Wood DA, Zhao Z, Becker D, Lyu Q, Shu B, Chen H (2019) A review of the current status of induced seismicity monitoring for hydraulic fracturing in unconventional tight oil and gas reservoirs. Fuel 242:195–210
Lin C, He J, Li X, Wan X, Zheng B (2017) An experimental Investigation into the effects of anisotropy of shale on hydraulic fracture propagation. Rock Mech Rock Eng 50:543–554
Liu K, Sheng J (2019) Experimental study of the effect of stress anisotropy on fracture propagation in Eagle Ford shale under water imbibition. Eng Geol 249:13–22
Mayerhofer MJ, Lolon EP, Warpinski NR, Cipolla CL, Walser D, Rightmire CM (2010) What is stimulated reservoir volume? SPE Prod Oper 25(1):89–98
Meng X, Chen H, Niu F, Tang Y, Yin C, Wu F (2018) Microseismic monitoring of stimulating Shale Gas Reservoir in SW China: 1. An improved matching and locating technique for downhole monitoring. J Geophys Res Solid Earth 123(2):1643–1658
Pandey VJ, Rasouli V (2021) A semi-analytical model for estimation of hydraulic fracture growth calibrated with field data. J Petrol Sci Eng 202:1–23
Patel SM, Sondergeld CH, Rai CS (2018) Hydraulic fracture permeability estimation using stimulation pressure data. Int J Rock Mech Min 101:50–53
Ranjith PG, Wanniarachchi WAM, Perera MSA, Rathnaweera TD (2018) Investigation of the effect of foam flow rate on foam-based hydraulic fracturing of shale reservoir rocks with natural fractures: an experimental study. J Petrol Sci Eng 169:518–531
Roshan H, Masoumi H, Zhang Y, Al-Yaseri AZ, Iglauer S, Lebedev M, Sarmadivaleh M (2018) Microstructural effects on mechanical properties of shaly sandstone. J Geotech Geoenviron Eng 144(2):06017019
Tan P, Jin Y, Han K, Hou B, Chen M, Guo X, Gao J (2017) Analysis of hydraulic fracture initiation and vertical propagation behavior in laminated shale formation. Fuel 206:482–493
Wang F, Li B, Chen Q, Zhang S (2019) Simulation of proppant distribution in hydraulically fractured shale network during shut-in periods. J Petrol Sci Eng 178:467–474
Warpinski NR, Mayerhofer MJ, Vincent MC, Cipolla CL, Lolon EP (2009) Stimulating unconventional reservoirs: maximizing network growth while optimizing fracture conductivity. J Can Petrol Technol 48(10):39–51
Yang S, Yin P, Ranjith PG (2020) Experimental study on mechanical behavior and brittleness characteristics of Longmaxi Formation shale in Changning, Sichuan Basin, China. Rock Mech Rock Eng 53:2461–2483
Zhang F, Damjanac B, Maxwell S (2019a) Investigating hydraulic fracturing complexity in naturally fractured rock masses using fully coupled multiscale numerical modeling. Rock Mech Rock Eng 52:5137–5160
Zhang X, Shi W, Hu Q, Zhai G, Wang R, Xu X, Xu Z, Meng F, Liu Y (2019b) Pressure-dependent fracture permeability of marine shales in the Northeast Yunnan area, Southern China. Int J Coal Geol 214:1–15
Zhang Y, He Z, Jiang S, Lu S, Xiao D, Chen G, Li Y (2019c) Fracture types in the lower Cambrian shale and their effect on shale gas accumulation, Upper Yangtze. Mar Petrol Geol 99:282–291
Zhang Q, Fan X, Chen P, Ma T, Zeng F (2020) Geomechanical behaviors of shale after water absorption considering the combined effect of anisotropy and hydration. Mar Petrol Geol 269:105547
Zhao Y, Zhang F, He P (2019) A composite criterion to predict subsequent intersection behavior between a hydraulic fracture and a natural fracture. Eng Fract Mech 209:61–78
Zheng H, Pu C, Sun C (2020) Study on the interaction between hydraulic fracture and natural fracture based on extended finite element method. Eng Fract Mech 230:106981
Zou Y, Zhang S, Zhou T, Zhou X, Guo T (2016) Experimental investigation into hydraulic fracture network propagation in gas shales using CT scanning technology. Rock Mech Rock Eng 49:33–45
Zuo J, Lu J, Chandriz R, Wang J, Li Y, Zhang X, Li J, Li H (2020) Mesoscale fracture behavior of Longmaxi outcrop shale with different bedding angles: experimental and numerical investigations. J Rock Mech Geotech Eng 12:297–309