中国深层煤层气压裂关键技术进展与发展展望OA

China is rich in abundant deep coalbed methane(CBM)resources with considerable development potential.However,their commercial exploitation faces geological and engineering challenges,such as great burial depth,poor reservoir physical properties,strong heterogeneity,and high in-situ stress,which have long impeded effective resource utilization.In response to the exploration and development needs of deep CBM,this paper systematically reviews the key technological advances and engineering practices in fracturing,and then proposes future research directions.The following results are obtained.First,the comprehensive fracable sweet spot prediction method integrating geological and engineering parameters accounts for both favorable resource zones and favorable engineering operation zones,providing a scientific basis for fracturing well and layer selection.Second,the large-scale network fracturing technology with horizontal well guided by the concept of"enlarging stimulated reservoir volume and achieving effective proppant placement"currently serves as the primary base process,while the ultra-large-scale network fracturing technology based on the core concept of"extreme-scale stimulation"is better suitable for low-grade and difficult-to-stimulate reservoirs.Third,differentiated technology combination strategies(volume acid fracturing,multi-cycle temporary plugging and diverting fracturing,and energy-focused fracturing),variable-viscosity slickwater fracturing fluid system,multi-size blended proppants,and novel self-suspending proppants,supported by specialized tools and fracturing monitoring and evaluation methods,effectively enhance the stimulated reservoir volume and utilization efficiency of network fracturing.Fourth,to meet the requirements of sustainable economic development,future efforts should focus on the key technologies such as water-free or water-saving fracturing,dual-temporary plugging fracturing,low-or zero-proppant fracturing,full-scale proppant-support fracturing,and intelligent fracturing.In conclusion,the large-and ultra-large-scale network fracturing technology centered on maximizing fracture network complexity represents the fundamental pathway for unlocking deep CBM resources and driving technological upgrading and industrial transformation,and provides a key support for constructing a fracturing technology system for the efficient development of deep CBM.This technology is of great significance for promoting the large-scale and efficient development and utilization of deep CBM resources in China.