煤层气水平井产出剖面光纤监测工艺技术

Optical-fiber Monitoring Technology for Production Profile of Coalbed Methane Horizontal Well

文章从分布式光纤DAS、DTS测量原理出发,结合煤层气水平井的生产实际,分析了产水和产气对井筒环境的影响,论证了分布式光纤DAS、DTS用于煤层气水平井方法的适用性,首次提出了利用DAS量化水平段产气量的评价方法。根据煤层气水平井特殊的生产工艺特点,制定了水平段采用油管内泵送布设、直井段采用油管外绑定的光纤布设方法,解决了油管与套管的环空过小、射孔处有煤粉煤块产出等工程难题,同时采用偏心井口密闭技术为安全施工提供保障,总结出一套适用于煤层气水平井产出剖面光纤监测的工艺技术。通过一口水平井实际案例应用分析,证明该工艺技术在煤层气水平井产出剖面监测中有非常好的适用性。

Based on the distributed optical-fiber DAS and DTS measurement principle,this paper analyzes the influence of water production and gas production on the wellbore environment,combining with the production practice of coalbed methane horizontal wells,the applicability of DAS,DTS and coalbed methane horizontal well method is demonstrated,and the evaluation method of gas production in horizontal section quantized by DAS is put forward for the first time.According to the characteristics of the special production technology of coalbed methane horizontal well,the optical-fiber layout technology of pumping in the horizontal section and binding ode the tubing in the straight section has been worked out,the engineering problems such as too small annulus of tubing and casing,coal powder produced at perforation and so on are solved.At the same time,the eccentric wellhead sealing technology is adopted to provide a guarantee for safe construction,a set of optical fiber monitoring technology suitable for coalbed methane horizontal well production profile is summarized.Through the analysis of a practical case of a horizontal well,it is proved that this technology has very good applicability.