Optimization Of Low-rank CBM Development Technology In Jiergalongtu Depression

Significant achievements have been made in the exploration and development of medium and high rank coalbed methane in China.Industrialization bases have been built in the eastern margin of Qinshui Basin and Ordos Basin and large-scale commercial development has been realized.However,the resources of low rank CBM account for more than 40% of the total resources in China,and it has the characteristics of large coal reservoir thickness,good permeability and high resource abundance,but it has a poor effect in the exploration and development process.The main reasons for this situation are the lack of understanding of the formation law of low rank CBM and the lack of pertinence of key technologies.In view of this,this paper takes the Jiergalongtu depression of Erlian Basin Group as an example,and relies on the major national science and technology projects to deepen the geological understanding of coal reservoirs in this area,and carries out research on the problems such as large loss during drilling and completion,poor cementing quality,and weak pertinence of coal reservoir reconstruction technology.Through optimization analysis,a low-density and high-strength cementing mud system was adopted to improve cementing quality.The application of guanidine gum fracturing combined with the rapid flowback technology after pressure has been successful.A CBM well drainage and production control system with the purpose of "area reduction" has been established,and remarkable results has achieved in the field application.Through the research,a series of drilling and completion-reservoir reformation-drainage and production control technology suitable for low-rank coal reservoir has been formed,which supports the construction of the first low-rank CBM development demonstration area in China,and plays a technical demonstration role for the development of low-rank CBM in China.The paper has 58 illustrations,21 tables,and 153 references.