Optimization of multi-layer commingled coalbed methane production in Zhijin area, Guizhou province
-
摘要: 贵州省织金地区龙潭组煤层具有多、薄特点。与单一厚层状煤层相比，多煤层合采存在合采兼容性问题，易发生层间干扰，影响合采效果及资源动用程度。为了发挥煤层气井生产潜力，提高开发效益，亟需开展合采层位优选，建立多煤层开发序列。在研究织金区块地质特征的基础上，开展了多煤层地质条件差异研究，结合排采实践及解吸理论，探讨了织金地区多煤层合采影响因素，优选了合采层位。多煤层合采主要受解吸液面高度、纵向跨度、压力梯度、供液能力、渗透率差异影响。织金区块上二叠统龙潭组主力煤层地层供液能力、压力梯度、渗透率差异较小，对合采效果影响较小。层间跨度和解吸液面高度差异是影响区块合层开采的关键因素，16，17，20，23，27，30号煤层90 m跨度可作为一个开发组合，大井组优选此6层煤合采获得2 000 m3/d稳定产量，证实合采层位优选方法正确。Abstract: Coal seams of the Longtan Formation in the Zhijin area of Guizhou province present the characteristics of multiple layers and small individual thickness. Compared with single thick-layered coal seam, multiple coal seams have differences in reservoir pressure gradient, formation liquid supply capacity, permeability and desorption pressure, which affect the efficiency of combined mining and the degree of resource utilization. In order to enahance the production potential of coalbed methane and improve the economics, it is valuable to optimize commingled production and establish a multi-seam development sequence. In view of these problems, this paper carried out a study on the differences of geological conditions of multiple coal seams. Combined with drainage practice and desorption theory, the influencing factors of multi-layer commingled production in the Zhijin area were discussed, and the production strategy was optimized. The results showed that desorption liquid level height, longitudinal span, pressure gradient, liquid supply capacity and permeability difference are the key factors affecting multi-layer commingled production. The main coal seams in the Upper Permian Longtan Formation in the study area have small differences in liquid supply capacity, pressure gradient and permeability, hence these have less impact on commingled production. The differences in longitudinal span and desorption liquid level height are the key factors affecting commingled production in the study area. A 90 m span can be used as a development combination for coal seams no. 16/17/20/23/27/30. A practice in large well group obtained a stable production of 2 000 m3/d, proving that commingled production is viable.
-
图 1 贵州省织金区块岩脚向斜构造
据参考文献[10]，有修改。
Figure 1. Tectonic setting of Yanjiao syncline, Zhijin area, Guizhou province
图 2 贵州省织金区块岩脚向斜上二叠统含煤地层综合柱状图
据参考文献[10]，有修改。
Figure 2. Stratigraphic column of upper Permian coal bearing strata in Yanjiao syncline, Zhijin area, Guizhou province
图 3 贵州省织金区块解吸液面高度、合采跨度对多煤层合采影响模式
Figure 3. Influences of desorption liquid level height and longitudinal span on commingled production, Zhijin area, Guizhou province
图 4 贵州省织金区块煤层中深及解吸液面高度柱状图[10]
Figure 4. Histograms of medium depth and desorption liquid level in Zhijin area, Guizhou province
图 5 贵州省织金区块大井组归一化生产曲线
Figure 5. Normalized production curves of Dajing Formation in Zhijin area, Guizhou province
表 1 贵州省织金区块主力煤层厚度统计
Table 1. Thickness statistics of main coal seams in Zhijin area, Guizhou province
煤组 主力煤层 煤层厚度/m 煤层跨度/m 厚度/m Ⅰ煤组 6号 $ \frac{1.5 \sim 5.1}{2.1}$ $\frac{1.5 \sim 6.0}{4.3} $ $ \frac{15.4 \sim 29.8}{18.9}$ 7号 $ \frac{1.3 \sim 6.0}{2.1}$ $ \frac{49.3 \sim 61.2}{56.2}$ Ⅱ煤组 12号 $ \frac{0.8 \sim 1.4}{1.0}$ $ \frac{2.1 \sim 5.0}{4.2}$ $\frac{19.2 \sim 25.6}{20.1} $ 14号 $ \frac{0.8-2.1}{1.2}$ $ \frac{29.2 \sim 36.1}{29.8}$ 16号 $ \frac{0.9 \sim 4.1}{2.0}$ $ \frac{8.2 \sim 11.4}{9.9}$ 17号 $\frac{0.8 \sim 1.4}{1.2} $ $ \frac{17.8 \sim 23.9}{19.7}$ Ⅲ煤组 20号 $ \frac{0.8 \sim 3.2}{1.3}$ $\frac{1.2 \sim 7.9}{4.5} $ $ \frac{20.1 \sim 26.2}{22.3}$ 23号 $\frac{0.9 \sim 2.3}{1.3} $ $ \frac{18.8 \sim 24.1}{20.7}$ 27号 $\frac{0.8 \sim 1.9}{1.3} $ $ \frac{17.6 \sim 24.7}{20.1}$ 30号 $\frac{0.8 \sim 4.0}{1.9} $ 注：表中分式意义为：$ \frac{ { 最小值 \sim 最大值 }}{\text { 平均值 }}$。 
下载: 导出CSV
表 2 贵州省织金区块试气压力梯度、渗透率统计
Table 2. Statistics of gas test pressure gradient and permeability in Zhijin area, Guizhou province
井号 煤号 测点深度/m 储层压力/MPa 压力梯度/(MPa·hm-1) 渗透率/10-3 μm2 X-2 16 374 2.95 0.79 0.017 9 X-2 23 427 3.04 0.71 0.000 2 X-3 16 732 6.86 0.93 0.000 5 X-4 27 510 5.52 1.08 0.074 4
下载: 导出CSV
表 3 贵州省织金区块多煤层合采跨度与降压空间关系
Table 3. Spatial relationship between commingled production span and depressurization of multiple coal seams in Zhijin area, Guizhou province
合采煤层 跨度/m 下部解吸上部可降压空间/MPa 可行性 6-30号 240 0~0.3 不可行 12-30号 130 0.9 基本可行 16-30号 90 1.7 可行 20-30号 60 小井组证实可合采
下载: 导出CSV
-
[1] 姜杉钰, 康永尚, 杨通保, 等. 云南恩洪煤层气区块单井多煤层合采方式探讨[J]. 煤田地质与勘探, 2018, 46(2): 80-89. https://www.cnki.com.cn/Article/CJFDTOTAL-MDKT201802013.htmJIANG Shanyu, KANG Yongshang, YANG Tongbao, et al. Combined CBM drainage of multiple seams by single well in Enhong block, Yunnan Province[J]. Coal Geology & Exploration, 2018, 46(2): 80-89. https://www.cnki.com.cn/Article/CJFDTOTAL-MDKT201802013.htm [2] 李国彪, 李国富. 煤层气井单层与合层排采异同点及主控因素[J]. 煤炭学报, 2012, 37(8): 1354-1358. https://www.cnki.com.cn/Article/CJFDTOTAL-MTXB201208018.htmLI Guobiao, LI Guofu. Study on the differences and main controlling factors of the coalbed methane wells between single layer and multi-layer drainage[J]. Journal of China Coal Society, 2012, 37(8): 1354-1358. https://www.cnki.com.cn/Article/CJFDTOTAL-MTXB201208018.htm [3] 彭龙仕, 乔兰, 龚敏, 等. 煤层气井多层合采产能影响因素[J]. 煤炭学报, 2014, 39(10): 2060-2067. https://www.cnki.com.cn/Article/CJFDTOTAL-MTXB201410020.htmPENG Longshi, QIAO Lan, GONG Min, et al. Factors affecting the production performance of coalbed methane wells with multiple-zone[J]. Journal of China Coal Society, 2014, 39(10): 2060-2067. https://www.cnki.com.cn/Article/CJFDTOTAL-MTXB201410020.htm [4] 党广兴. 滇东老厂矿区多煤层煤层气井产能影响因素及层间干扰分析[D]. 徐州: 中国矿业大学, 2018.DANG Guangxing. Productivity influencing factors of multi-layer CBM well and interlayer interference analysis in Laochang mining area of eastern Yunnan Province[D]. Xuzhou: China University of Mining and Technology, 2018. [5] 吴艳婷. 多煤层区煤层气合层开发产能及经济性研究[D]. 北京: 中国矿业大学(北京), 2018.WU Yanting. Research on well productivity and economic feasibility of commingled coalbed methane production in multi-seam zone[D]. Beijing: China University of Mining and Technology (Beijing), 2018. [6] 孟艳军, 汤达祯, 许浩, 等. 煤层气开发中的层间矛盾问题: 以柳林地区为例[J]. 煤田地质与勘探, 2013, 41(3): 29-33. https://www.cnki.com.cn/Article/CJFDTOTAL-MDKT201303010.htmMENG Yanjun, TANG Dazhen, XU Hao, et al. Interlayer contradiction problem in coalbed methane development: a case study in Liulin area[J]. Coal Geology & Exploration, 2013, 41(3): 29-33. https://www.cnki.com.cn/Article/CJFDTOTAL-MDKT201303010.htm [7] 王镜惠, 梅明华, 梁正中, 等. 沁水盆地南部高煤阶煤层气高产区定量评价[J]. 油气藏评价与开发, 2019, 9(4): 68-72. https://www.cnki.com.cn/Article/CJFDTOTAL-KTDQ201904013.htmWANG Jinghui, MEI Minghua, LIANG Zhengzhong, et al. Quantitative evaluation of high production areas of CBM with high coal rank in southern Qinshui Basin[J]. Reservoir Evaluation and Development, 2019, 9(4): 68-72. https://www.cnki.com.cn/Article/CJFDTOTAL-KTDQ201904013.htm [8] 窦新钊, 姜波, 张文永, 等. 黔西地区构造变形特征及其煤层气地质意义[J]. 中国煤炭地质, 2014, 26(8): 54-59. https://www.cnki.com.cn/Article/CJFDTOTAL-ZGMT201408013.htmDOU Xinzhao, JIANG Bo, ZHANG Wenyong, et al. Structural deformation features and its CBM geological significance in western Guizhou[J]. Coal Geology of China, 2014, 26(8): 54-59. https://www.cnki.com.cn/Article/CJFDTOTAL-ZGMT201408013.htm [9] 周德华, 李倩文, 蔡勋育, 等. 黔西地区红果区块煤层气资源评价与勘探潜力分析[J]. 油气藏评价与开发, 2020, 10(4): 12-16. https://www.cnki.com.cn/Article/CJFDTOTAL-KTDQ202004003.htmZHOU Dehua, LI Qianwen, CAI Xunyu, et al. Resource assessment and exploration potential analysis of CBM in Hongguo Block, western Guizhou[J]. Reservoir Evaluation and Development, 2020, 10(4): 12-16. https://www.cnki.com.cn/Article/CJFDTOTAL-KTDQ202004003.htm [10] 胡海洋, 赵凌云, 陈捷, 等. 基于煤储层可采性的多煤层合采开发层段优选: 以黔西地区发耳矿区为例[J]. 断块油气田, 2019, 26(6): 775-779. https://www.cnki.com.cn/Article/CJFDTOTAL-DKYT201906023.htmHU Haiyang, ZHAO Lingyun, CHEN Jie, et al. Optimum selection of multi-seam development based on coal reservoir mineability: a case study of western Guizhou Fa'er ming area[J]. Fault-Block Oil & Gas Field, 2019, 26(6): 775-779. https://www.cnki.com.cn/Article/CJFDTOTAL-DKYT201906023.htm [11] 周效志, 桑树勋, 易同生, 等. 煤层气合层开发上部产层暴露的伤害机理[J]. 天然气工业, 2016, 36(6): 52-59. https://www.cnki.com.cn/Article/CJFDTOTAL-TRQG201606011.htmZHOU Xiaozhi, SANG Shuxun, YI Tongsheng, et al. Damage mechanism of upper exposed producing layers during CBM multi-coal seam development[J]. Natural Gas Industry, 2016, 36(6): 52-59. https://www.cnki.com.cn/Article/CJFDTOTAL-TRQG201606011.htm [12] 杨兆彪. 多煤层叠置条件下的煤层气成藏作用[D]. 徐州: 中国矿业大学, 2011.YANG Zhaobiao. Coalbed methane reservoiring process under condition of multi-coalbeds overlay[D]. Xuzhou: China University of Mining and Technology, 2011. [13] 康永尚, 孙良忠, 张兵, 等. 中国煤储层渗透率分级方案探讨[J]. 煤炭学报, 2017, 42(S1): 186-194. https://www.cnki.com.cn/Article/CJFDTOTAL-MTXB2017S1025.htmKANG Yongshang, SUN Liangzhong, ZHANG Bing, et al. Discussion on classification of coalbed reservoir permeability in China[J]. Journal of China Coal Society, 2017, 42(S1): 186-194. https://www.cnki.com.cn/Article/CJFDTOTAL-MTXB2017S1025.htm -
点击查看大图
计量
- 文章访问数: 271
- HTML全文浏览量: 82
- PDF下载量: 102
- 被引次数: 0
苏公网安备32021102000780号