页岩气井同心双管排采新工艺研究
New Process of Water Drainage for Shale Gas Recovery
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摘要: 为了克服单一排采举升工艺的不足,实现页岩气井在高液量和低液量时期均能连续排采,研究应用了同心双管组合排采工艺。基于速度管柱排水采气可以降低页岩气井临界携液流量、增大井筒中气体流速、提高气井携液能力的思路,优化了页岩气井速度管柱,速度管柱直径优化为φ48.3 mm;实现了排采前期液量充足时采用高排量电潜泵排液,液量较低时采用气举诱喷。该技术在彭页 HF-1 井开展了现场试验,措施后排采井日产液37 m3,日产气量20 250.65 m3,累计产气量151.32×104 m3。试验结果表明, 页岩气同心双管排采工艺技术可以降低页岩气井临界携液流速,为页岩气井的连续排采提供了新的技术支持。Abstract: In order to ensure continuous production of shale gas wells both in high and low liquid content period,and to overcome the defects of drainage gas recovery lifting process,water drainage and gas recovery with concentric double tubing has been developed for shale gas wells.Because velocity string can reduce the critical flow rate to carry liquid so as to increase gas flow rate in the wellbore and improve liquid carrying capability of gas wells,the velocity string diameter in shale gas wells is optimized at φ48.3 mm;high capacity electric submersible pump is used in early production stage when gas flow rate is high,and gas lift is used to induce production when the gas flow rate is low.The technique has been tested in Well Pengye HF-1,the water drainage and gas recovery well produced 37 m3/d of liquid,20 250.65 m3/d of gas,and cumulative gas 151.32 ×104 m3 after the measures are implemented.The test results show that the water drainage and gas recovery with concentric double tubing can reduce the critical gas flow rate for liquid carrying,providing a new technical means for continuous production of shale gas wells.