煤层气压裂水平井产能影响因素

产能评价对于煤层气的高效开发具有十分重要的意义。依据寿阳区块七元煤矿的地层压力、渗透率、初始含气量、兰格缪尔压力等数据,采用COMET3软件开展煤层气压裂水平井的产能评价,对影响煤层气压裂水平井产能的水平段长度、水平井方位、裂缝条数、裂缝半长、裂缝导流能力、水平井井距等因素进行评价。结果表明:水平段长度、水平井井距、裂缝条数、裂缝半长和裂缝导流能力对水平井产能影响较大。当水平段长度小于600m时,煤层气井的产气量变化较为敏感;煤层非均质性对煤层气高产具有不可忽视的作用;裂缝条数为控制累计产气量的主要因素,其次为裂缝导流能力和裂缝半长;随着水平井井距的减小,累计产气量增大,但水平井井距过小对累计产气量的贡献并不明显。

Factors Influencing Productivity in CBM Fractured Horizontal Wells

Coalbed methane is an important unconventional resource and its productivity evaluation is very significant for the efficient development of coalbed methane.Based on the data of formation pressure,permeability,initial gas content and Langmuir pressure,etc.in Qiyuan Coal Mine of Shouyang block,the software COMET3 is used to evaluate the production capacity of CBM fractured horizontal wells, and the factors influencing well productivity such as horizontal section length,horizontal well spacing and fracture parameters are studied in this paper.The results show that the horizontal section length,horizontal well spacing,fracture amount,fracture half-length and fracture conductivity can significantly affect the productivity of horizontal well.When the horizontal section length is less than 600 m,the variation of gas production of CBM well is sensitive;the heterogeneity of coal bed is very important for the high yield of CBM well;the fracture amount is the main factor controlling cumulative gas production,followed by fracture conductivity and fracture half-length;with the decrease of horizontal well spacing,the cumulative gas production will increase,but too small well spacing does not work well.