织金区块煤层气合采生产特征及开发策略

针对南方煤层层数多、单层薄，煤层气有效开发难度大的问题，以贵州织金区块煤层气井实际生产数据为基础，分析定向井不同煤组合采、薄煤层水平井生产特征及产气影响因素，并提出相应开发建议。分析表明，不同煤组合采产气差异较大，受地层供液能力、解吸液面高度及合采跨度影响，中、下煤组合采效果好于上、中、下煤组合采效果，其中16/17/20/23/27/30号煤层合采是区块最优合采层位；压裂规模显著影响煤层气井产气效果，压裂规模越大产气效果越好，增大压裂规模，提高压裂改造效果是多煤层煤层气有效开发的重要手段之一；水平井产气效果是定向井3~4倍，薄煤层水平井适应性得到证实，根据地质及地表条件采用水平井、定向井组合开发，可提高多煤层煤层气开发效果。综合认为，在地质条件有利的区域优选合采层位，增大压裂规模，优选实施水平井，可提高多薄煤层煤层气开发效果。

Combined CBM production behavior and development strategy of multiple coal seams in Zhijin block

Aiming at the problems that the CBM layers are numerous and thin, it is difficult to develop it effectively in south China, on the basis of the actual production data of CBM wells in Zhijin block, the production characteristics and the influencing factors of gas production of the directional wells for co-extraction of different seams and the horizontal wells for thin seams were analyzed, and corresponding suggestions for CBM development were put forward. The analysis indicated that the gas production of co-extraction of different seams was quite different, was influenced by the liquid-supplying capacity of formation, the height of desorbing liquid surface and the span of co-extraction, the effect of co-extraction of middle and lower seams was better than that of co-extraction of the upper, middle and lower seams, of them the co-extraction of seams 16,17, 20, 23, 27 and 30 was the optimal horizons for co-extraction in the block; The fracturing scale influenced significantly the gas production result of CBM wells, the bigger the fracturing scale, the better the gas production result, increasing the fracturing scale and enhancing the fracturing reformation effect are the important approaches for effec-tive development of multiple seams; The gas production of horizontal wells is 3-4 times higher than that of directional wells, the adaptability of horizontal wells for thin seams was confirmed. According to the geological and surface conditions, using horizontal wells and directional wells for combined development can improve the development effect of multiple seams. It is comprehensively considered that optimization of co-extraction horizons in an area with favorable geological conditions, in-crease of the fracturing scale, optimal use of horizontal wells will improve the development effect of multiple thin coal seams. methane well. The larger the fracturing scale is, the better the gas production effect will be. Increasing the fracturing scale and improving the fracturing transformation effect is one of the important means to effective development of multiple thin coal seams.