裸眼多分支水平井开发特征及主控因素

沁水盆地南部樊庄–郑庄区块裸眼多分支水平井总体开发效果不理想，低产井比例高、单井产量差异大，亟需查明主因，提高开发成效。基于研究区内十余年的开发实践，利用统计分析、回归分析等手段将产气特征归纳为持续高产、先高后低、持续低产3种类型。研究表明，含气量、渗透率、微幅构造、煤体结构是裸眼多分支水平井能否高产且持续稳产的关键地质因素，在同等富集条件下，渗透率大小是裸眼多分支水平井能否高产的关键；微幅构造与煤体结构决定了高产后能否持续稳产。低含气量、低渗透率、钻进过程分支垮塌、钻井液污染储层是持续低产井低产的主因。研究结果指导了裸眼多分支水平井工艺技术优化，大幅提高了单井产气量。 

The development characteristics and main control factors of the open-hole multi-branch CBM horizontal wells

The overall development performance of open-hole multi-branch horizontal wells in Fanzhuang-Zhengzhuang block is not satisfactory because of the high proportion of low-production wells and significant difference in the production among different wells. So the main controlling factors should be researched in order to improve the development performance of open-hole multi-branch horizontal wells. Based on the development practice over 10 years in this area, this paper divides the wells into three types according to different production characteristics by statistics and regression, such as continuous high production type, high production at beginning and low production later type and continuous low production type. Studies show that gas contents, permeability, slight geo-structure and coal body structure are key geological factors determining the production and the stable production period of open-hole multi-branch horizontal wells. Permeability determines whether these wells can reach high production or not and slight geo-structure and coal body structure determine the last time for high production under the same gas content condition. The low gas contents, low permeability, collapse of the multi-branch during drilling and the pollution of drilling fluids are main causes for the continuous low production of these open-hole multi-branch horizontal wells. The results of this paper improve the technology and boost the production of open-hole multi- branch horizontal wells in Fanzhuang-Zhengzhuang block.