胡秋嘉，贾慧敏，张聪，等. 高阶煤煤层气井稳产时间预测方法及应用−以沁水盆地南部樊庄−郑庄为例[J]. 煤田地质与勘探，2022，50(9)：137−144. DOI: 10.12363/issn.1001-1986.22.04.0249
引用本文: 胡秋嘉，贾慧敏，张聪，等. 高阶煤煤层气井稳产时间预测方法及应用−以沁水盆地南部樊庄−郑庄为例[J]. 煤田地质与勘探，2022，50(9)：137−144. DOI: 10.12363/issn.1001-1986.22.04.0249
shu
HU Qiujia，JIA Huimin，ZHANG Cong，et al. Stable-production period prediction method and application in high-rank coalbed methane wells：A case study of Fanzhuang-Zhengzhuang Block in southern Qinshui Basin[J]. Coal Geology & Exploration，2022，50(9)：137−144. DOI: 10.12363/issn.1001-1986.22.04.0249
Citation: HU Qiujia，JIA Huimin，ZHANG Cong，et al. Stable-production period prediction method and application in high-rank coalbed methane wells：A case study of Fanzhuang-Zhengzhuang Block in southern Qinshui Basin[J]. Coal Geology & Exploration，2022，50(9)：137−144. DOI: 10.12363/issn.1001-1986.22.04.0249
shu

高阶煤煤层气井稳产时间预测方法及应用以沁水盆地南部樊庄−郑庄为例

Stable-production period prediction method and application in high-rank coalbed methane wells：A case study of Fanzhuang-Zhengzhuang Block in southern Qinshui Basin

    摘要
  • 摘要: 煤层气井稳产时间预测对煤层气井合理稳产气量预测与排采制度优化具有重要意义。基于沁水盆地南部樊庄−郑庄区块不同井型的大量生产数据，明确煤层气井稳产阶段及稳产时间的基本概念，提出稳产时间预测经验公式并分析其影响因素。结果表明，煤层气井依靠持续降低井底流压保持稳产，稳产时间为开始稳产时刻的井底流压降至集气管线压力所用的时间。提出能够有效表征直井、L型筛管水平井、L型套管压裂水平井稳产阶段累积稳产时间与井底流压关系的经验公式，基于经验公式得到的最终稳产时间计算公式能够准确预测各井型的稳产时间，误差仅为−8.30%~8.03%。稳产时间的影响因素较多，第一，稳产流压损耗系数越大稳产时间越短，稳产流压损耗系数与解吸压力成反比，与提产流压损耗系数成正比，提产流压损耗系数控制在0.006 5 d−1以下利于长期稳产；第二，开始稳产时刻，井底流压越高、稳产时间越长，应该高压提产、高压稳产；第三，对不同的煤层气井，稳产气量高，稳产时间不一定短，需确定合理的稳产气量。提出的稳产时间计算方法可实现不同稳产气量下稳产段累积产气量的预测，进而可确定合理的稳产气量。

     

    Abstract: The prediction of stable-production period of Coalbed Methane (CBM) wells is of great significance to the prediction of reasonable stable gas rate and optimization of drainage strategy. Based on mass production data of different well types in Fanzhuang-Zhengzhuang Block, southern Qinshui Basin, the basic concepts of stable-production stage and period of CBM wells are clarified, and the empirical formula for the prediction of stable-production period is proposed and its influencing factors are analyzed. The results show that the CBM well keeps stable production by continuously reducing the bottom-hole-flowing pressure JHH, and the stable-production period is the time required for the bottom-hole-flowing pressure at the beginning of the stable-production stage decreases to the pressure of gas collection pipeline. The empirical formula proposed in this paper can effectively characterize the relationship between cumulative stable-production period and BHFP in the stable-production stage of vertical wells, L-shaped screen horizontal wells and L-shaped casing fractured horizontal wells. The final stable-production period calculation formula based on the empirical formula can accurately predict the stable-production period of each well type, with the error margin of −8.30%-8.03%. Moreover, the stable-production period is affected by many factors. First, the greater the stable-production BHFP loss coefficient, the shorter the stable-production period, and the BHFP loss coefficient in the stable-production stage is inversely proportional to the desorption pressure, while directly proportional to the BHFP loss coefficient in the production-increasing stage. Therefore, keeping the BHFP loss coefficient in the production-increasing stage below 0.006 5 d−1 is conducive to long-term stable production. Second, the higher the BHFP at the beginning of stable-production stage, the longer the stable-production period, and thus a high BHFP should be maintained to stabilize even stimulate production. Third, for different wells, increasing the stable gas rate may not shorten the stable-production period, which needs to be supplemented by a reasonable stable gas rate. The calculation method for stable-production period can also be applied in the prediction of cumulative gas production under different stable gas rates, so as to provide a basis for determining the optimal stable gas rate.

     

    • HTML全文
    • 参考文献(20)
    • 相关文章
    • 施引文献
  • 资源附件(0)

/

返回文章
返回