Development and application of experimental apparatus of hydraulic sand fracturing
XU Feng1, YANG Chun-he1,2, GUO Yin-tong1, WANG Lei1, WEI Yuan-long2, HOU Zheng-kun3, BIAN Xiao-bing3
1. State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan 430071, China; 2. State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044, China; 3. Sinopec Research Institute of Petroleum Engineering, Beijing 100101, China
Abstract:In order to study the transport rules of propping agent in unconventional gas exploration, an apparatus of hydraulic sand fracturing is developed. It is mainly composed of rock triaxial testing machines, servo control system of hydraulic fracturing pump and acoustic emission text system. The advantages of the apparatus are illustrated as follows: (1) Hydraulic sand fracturing tests are able to be implemented under different formation stresses and pump rates. (2) Fracturing fluid injection is controlled by means of the pump rate or pump pressure. (3) AE sensor is improved for pressure-resistance, which can be used in triaxial cell. A series of hydraulic fracturing tests are performed under a combination of different formation stresses, different pump rates and fracturing fluid with sand conditions by this apparatus. The results show that the larger the formation pressure and the higher the pump rate, the larger the initiation pressure in red sandstone. The further distance the hydraulic sand fracturing surface off the open hole, the lower the concentrations of agent. But the local part has no propping agent. AE cumulative hits linearly relate with the time at the initial stage and increase rapidly while the sandstone approaches failure.
[1] 童晓光, 郭建宇, 王兆明. 非常规油气地质理论与技术进展[J]. 地学前缘, 2014, 21(1): 9-20. (TONG Xiao-guang, GUO Jian-yu, WANG Zhao-ming. The progress of geological theory and technology for unconventional oil and gas[J]. Earth Science Frontiers, 2014, 21(1): 9-20. (in Chinese)) [2] SONG I, SUH M, WON K S, et al. A laboratory study of hydraulic fracturing breakdown pressure in tablerock sandstone[J]. Geosciences Journal, 2001, 5(3): 263-271. [3] ALSAYED M I. Utilising the Hoek triaxial cell for multiaxial testing of hollow rock cylinders[J]. International Journal of Rock Mechanics and Mining Sciences, 2002, 39(3): 355-366. [4] ISHIDA T. Acoustic emission monitoring of hydraulic fracturing in laboratory and field[J]. Construction and Building Materials, 2001, 15(5): 283-295. [5] ISHIDA T, AOYAGI K, NIWA T, et al. Acoustic emission monitoring of hydraulic fracturing laboratory experiment with supercritical and liquid CO2[J]. Geophysical Research Letters, 2012, 39(16). [6] CHITRALA Y, MORENO C, SONDERGELD C, et al. An experimental investigation into hydraulic fracture propagation under different applied stresses in tight sands using acoustic emissions[J]. Journal of Petroleum Science and Engineering, 2013, 108: 151-161. [7] 郭印同, 杨春和, 贾长贵, 等. 页岩水力压裂物理模拟与裂缝表征方法研究[J]. 岩石力学与工程学报, 2014, 33(1): 52-59. (GUO Yin-tong, YANG Chun-he, JIA Chang-gui, et al. Research on hydraulic fracturing physical simulation of shale and fracture characterization methods[J]. Chinese Journal of Rock Mechanics and Engineering, 2014, 33(1): 52-59. (in Chinese)) [8] 衡 帅, 杨春和, 曾义金, 等. 页岩水力压裂裂缝形态的试验研究[J]. 岩土工程学报, 2014, 36(7): 1243-1251. (HENG Shuai, YANG Chun-he, ZENG Yi-jin, et al. Experimental study on hydraulic fracture geometry of shale[J]. Chinese Journal of Geotechnical Engineering, 2014, 36(7): 1243-1251. (in Chinese)) [9] 陈 勉, 庞 飞, 金 衍. 大尺寸真三轴水力压裂模拟与分析[J]. 岩石力学与工程学报, 2000(增刊1): 868-872. (CHEN Mian, PANG Fei, JIN Yan. Simulation and analysis of real triaxial hydraulic fracturing[J]. Chinese Journal of Rock Mechanics and Engineering, 2000(S1): 868-872. (in Chinese)) [10] 翟 成, 李贤忠, 李全贵. 煤层脉动水力压裂卸压增透技术研究与应用[J]. 煤炭学报, 2012, 36(12): 1996-2001. (ZHAI Cheng, LI Xiao-zhong, LI Quan-gui. Research and application of coal seam pulse hydraulic fracturing technology[J]. Journal of China Coal Society, 2012, 36(12): 1996-2001. (in Chinese)) [11] 温庆志, 翟恒立, 罗明良, 等. 页岩气藏压裂支撑剂沉降及运移规律实验研究[J]. 油气地质与采收率, 2012, 19(6): 104-107. (WEN Qing-zhi, ZHAI Heng-li, LUO Ming-liang, et al. Study on proppant settlement and transport rule in shale gas fracturing[J]. Petroleum Geology and Recovery Efficiency, 2012, 19(6): 104-107. (in Chinese)) [12] 郭建春, 曾凡辉, 余东合, 等. 压裂水平井支撑剂运移及产量研究[J]. 西南石油大学学报(自然科学版), 2009, 31(4): 79-82. (GUO Jian-chun, ZENG Fan-hui, YU Dong-he, et al. Study on fractured horizontal well proppant migration and the productivity[J]. Journal of Southwest Petroleum University (Science & Technology Edition), 2009, 31(4): 79-82. (in Chinese))