如何破解我国煤层气开发的技术难题——以沁水盆地南部煤层气藏为例

平均单井产量低已成为制约我国煤层气产业发展的主要瓶颈,直接导致了煤层气开发经济效益低。为此,以山西省东南部沁水盆地南部煤层气藏为例,总结了中国石油华北油田公司在该区煤层气产业的发展及技术现状,梳理了煤层气开发所存在的关键问题:①煤层气开发工程技术不适应特有的地质特征变化;②煤层气田成熟区块仍存在大量的低效区;③单纯增大压裂规模并未能有效提高单井产量;④多分支水平井单井产量高,但总体产能到位率仍偏低;⑤现场管控总体缺乏科学依据。进而对我国煤层气的后续开发提出了以下建议:①改变产能建设模式、提高产能建设效率;②改进地质研究方法,科学设计井位和井型;③用辩证思维的方式,构建主体技术;④优化水平井的设计,提高技术的适用性;⑤改变压裂改造方式,提高单井产量;⑥改变排采工艺,提高投资效益。通过采取以上措施,将有可能破解我国煤层气开发的技术难题。

How to solve the technical problems in the CBM development: A case study of a CMB gas reservoir in the southern Qinshui Basin

The average low single-well production resulting in low economic benefit has become the main bottleneck of the CBM development in China. Therefore, in a case study of a CBM gas reservoir in the south of the Qinshui Basin, we summarized the present status of CBM technology and development here and also pointed out some major common problems in the CBM development. (1) The engineering and technology for the CBM development needs to adapt to the particular geological characteristics; (2) a large number of inefficient zones still exist in the developed blocks in the southern Qinshui Basin; (3) single-well production is not likely to be effectively enhanced only by an increase of the fracturing scale; (4) the production of a multi-branch horizontal well can reach high, but the fulfillment rate of production capacity construction is low for horizontal wells; and (5) on-site management lacks scientific evidence. On this basis, we presented the following feasible countermeasures: (1) the construction mode should be changed, and the fulfillment rate of production capacity construction should be highly improved; (2) CBM geological research should be innovated and well type and locations should be designed reasonably and scientifically; (3) main technologies should be determined in the dialectical thinking mode; (4) a horizontal well should be optimally designed to improve the applicability of the relevant technologies; (5) fracturing techniques should be altered to improve the single-well production; and (6) the drainage technology should be changed to improve economic efficiency.