煤层气井井身结构的地质适应性与优化方法——以黔西地区为例

Geological adaptability and optimization method of well structure for coalbed methane well: with Western Guizhou as an example

结合黔西地区煤层群赋存的地质特点和钻井难点,从工程实际和储层保护出发,分析了现有煤层气参数井、预探井井身结构的地质适应性,划分出4种地层(含煤体)结构条件;提出了不同条件下设计与施工优化的4类8种配套井身结构变化形式,并对其优缺点和适用范围进行了分析评价,以期为复杂地质条件下煤层气探井的井身结构设计提供新的思路。

Large amount of coalbed methane （CBM） resource is distributed in Western Guizhou, and it is under conditions of coal seam groups. But the process of CBM exploration and development is lagging behind for the complex geological conditions. The used well structure is difficult to meet the need of construction in geologicaly complex area. Based on engineering practice and reservoir protection, combined with geological features and drilling difficulties, the geology adaptability of CBM well was analyzed; four stratum structure （including coal structure） conditions were also divided. Finally, four kinds of well structure design and eight working structure were put forward, and their adaptability and applicable scope were also analyzed. So the conclusion can provide a new thinking for CBM structure design in complex geological condition.