Abstract: The development of deep coalbed methane using clustered vertical–deviated wells faces several challenges, including unclear productivity-controlling factors and significant variation in single-well production, which constrain the efficient utilization of deep coalbed methane resources in areas with multiple thin coal seams. To enhance single-well production, this study investigated 105 clustered vertical–deviated wells in the Daning–Jixian Block and systematically identified the key factors controlling productivity. Through single-factor analysis,11 geological and engineering parameters influencing productivity were clarified, among which resource abundance and reservoir fracability served as the geological foundation for high productivity. Multiple linear regression and a decision tree model were subsequently applied to identify four engineering-dominant factors: total proppant volume, fracturing pressure, shut-in duration, and post-fracturing assisted fluid flowback volume. Based on this, a high-productivity development pathway was established following the strategy of “deploy optimally–stimulate effectively –mitigate damage – boost efficiency.” An efficient development technology system was developed, centered on integratedgeological–engineering sweet spot identification, large-scale volume fracturing, rapid post-fracturing flowback, and multi-source energy synergy for enhanced drainage and pressure drawdown. This was supported by engineering organization strategies such as early-stage artificial lift deployment, staged surface facility construction, and multi-process coordinated execution, forming a full-lifecycle development model for clustered vertical–deviated wells. Field tests conducted on 9 wells in the Yichuan area demonstrated the effectiveness of this technology system, with average daily gas production per well increasing from 0.8×10⁴ m³ to 1.8×10⁴ m³, and EUR reaching 2000×10⁴ m³. Reservoir pressure drawdown efficiency was improved significantly, and stable production capacity was notably enhanced. The results provide systematic technical support for efficient development of deep CBM in Yichuan and offer a reference path and practical basis for large-scale application of the technology in similar blocks.

Key words: deep coalbed methane, clustered vertical–deviated wells, productivity-controlling factors, high-productivity development pathway, efficient development technology system, engineering organization strategy