EXPERIMENTAL STUDY OF EFFECT OF TEMPERATURE ON COAL GAS PERMEABILITY UNDER GAS-SOLID COUPLING
-
摘要: 为得到温度对煤瓦斯渗透率的影响规律, 在实验室通过改装三轴渗透仪, 进行了不同温度条件下煤瓦斯的渗透率测定实验。实验结果表明, 在不同温度下, 渗透率随有效应力的减小均呈二次抛物线趋势, 即渗透率先减小后增大。在卸载初期, 温度较低时煤瓦斯渗透率下降梯度比高温时大, 渗透率值较高; 卸载后期, 较高温度时煤瓦斯渗透率上升梯度比低温时大, 渗透率值大。由实验可知, 煤层气开采过程中, 对于不同温度, 煤瓦斯渗透率的变化关系均具有典型煤层气开采的三阶段主导作用特征。有效应力、气体吸热和煤固体受热是影响煤体渗透率的重要因素。在卸载初期, 煤固体受热膨胀及有效应力对渗透率起主导作用, 卸载中后期, 气体滑脱和气体吸热对渗透率起主导作用。实验分析后认为, 开采煤层气时采用先压裂后注热的方式将有助于提高煤层气的产量。Abstract: To observe the effect of temperature on coal gas permeability, an experiment of coal gas permeability was carried out at different temperatures through a three-axial penetration instrument.The results show that, at different temperatures, the permeability of coals assumes a trend of quadric parabola, that is, the permeability first decreases and then increases as the effective stress decreases. In the early unloading, the degressive gradient of coal gas permeability is greater at lower temperature than at high temperature.In the late unloading, coal gas permeability ascending gradient is greater at high temperature than at low temperature.The results show that, in the process of coal bed gas mining, the change of coal gas permeability demonstrate three master phases of typical coal bed methane mining at different temperatures.The effective stress, gas heating and coal solid heating are the important factors influencing coal body permeability.In the early unloading, coal solid heating, expansion and effective stress play a leading role in permeability; in the later unloading, gas sliding and gas absorbing heat play a leading role in permeability.After experimental analysis, adopting the exploitation way of coal bed methane fracturing after injection will help to improve production of coal bed methane.
-
Key words:
- coal gas /
- permeability /
- effective stress /
- temperature
-
图 1 温控三轴渗透率测定实验系统示意图
Figure 1. The scheme of experimental system of measuring three-axial permeability controlled by temperature
图 2 温控三轴渗透率测定实验装置
Figure 2. The experimental instrument of measuring three-axial permeability controlled by temperature
图 3 不同温度下华兴煤样渗透率随有效应力变化曲线
Figure 3. Changing curve of permeability for Huaxing coal at different temperatures
图 4 不同温度下铁法煤样渗透率随有效应力变化曲线
Figure 4. Changing curve of permeability for Tiefa coal at different temperatures
图 5 不同温度下海州煤样渗透率随有效应力变化曲线
Figure 5. Changing curve of permeability for Haizhou coal at different temperatures
-
[1] Sommerton W.J, Soylemezoglu I M, Dudley R C.Effect of stress on permeability of coal[J].Int.J.Rock Mech.Min. Sci.and Geomech.Abstr.1975, 12 (2):129~145. http://d.old.wanfangdata.com.cn/Periodical/mtxb201403017 [2] Brace W F.A note on permeability change in geologic material due to stress[J].Pageoph, 1978, 116 (4/5):627~632. doi: 10.1007/BF00876529 [3] Enever J R E, Hening A. the relationship between permeability and effective stress for Australian coal and its implications with respect to coalbed methane exploration and reservoir mode[A]. In. Proceedings of the 1997 international Coalbed M ethane Symposium[C]. Tuscalosa, AL, USA : University of Alatama, 1997, 13~22. [4] 周世宁, 林柏泉.煤层瓦斯赋存与流动理论[M].北京:煤炭工业出版社, 1999. [5] 赵阳升, 胡耀青.孔隙瓦斯作用下煤体有效应力规律的试验研究[J].岩土工程学报, 1995. http://cdmd.cnki.com.cn/Article/CDMD-10704-1016901512.htm [6] 吴世跃, 赵文.含吸附煤层气煤的有效应力分析[J].岩石力学与工程学报, 2005, 24 (10):1674~1678. doi: 10.3321/j.issn:1000-6915.2005.10.007 [7] 唐巨鹏, 潘一山, 李成全, 等.有效应力对煤层气解吸渗流影响试验研究[J].岩石力学与工程学报, 2006, 25 (8):1564~1567. http://d.old.wanfangdata.com.cn/Periodical/yslxygcxb200608007 [8] 姜德义, 张广洋, 胡耀华, 等.有效应力对煤层气渗透率影响的研究[J].重庆大学学报, 1997, 20 (5):22 ~25. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=QK199700076171 [9] 谭学术, 鲜学福, 张广洋, 等.煤的渗透性研究[J].西安科技学院学报, 1994, 1:22~25. http://d.old.wanfangdata.com.cn/Periodical/yslxygcxb2013z2097 [10] 孔祥言.高等渗流力学[M].合肥:中国科学技术大学出版社, 1999.45~49. [11] 梁冰, 刘建军, 范厚彬, 等.非等温条件下煤层中瓦斯流动的数学模型及数值解法[J].岩石力学与工程学报, 2000, 19 (1):1~5. doi: 10.3321/j.issn:1000-6915.2000.01.001 [12] 程瑞端, 陈海焱, 鲜学福, 等.温度对煤样渗透系数影响的实验研究[J].矿业安全与环保, 1998, 1:13~16. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=QK199800075204 [13] Harpalanis.Schraufngel R A.Shrinkage of coal matrix with release of gas and its impact on permeability of coal[J].Fuel, 1991, 69 (5):551~556. doi: 10.1016-0016-2361(90)90137-F/ -
下载:
点击查看大图
计量
- 文章访问数: 166
- HTML全文浏览量: 66
- PDF下载量: 5
- 被引次数: 0
