地下储气库封堵井起压原因分析及处置对策
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摘要
封堵井起压是枯竭油气藏型地下储气库目前存在较为普遍的一个安全问题,如何科学合理处置封堵井起压直接关系到整个储气库的运行安全。以中国石化文96、文23储气库为例,目前多口封堵井已出现起压现象,为了落实封堵井起压原因,综合利用气藏地质、历史生产及动态监测等资料开展了深入分析,查找原因从而研究针对性处置对策。研究结果表明:(1)两座储气库封堵井起压分别由临井采油注水和井内防腐泥浆脱气引起;(2)封堵井堵剂性能直接关系到气井封堵效果,堵剂设计时应充分考虑临井注采活动影响以确保其能够适应所处地层环境;(3)针对防腐泥浆脱气起压一类封堵井,因安全风险低,日常管理以定期巡检观察为主;对于临井采油注水起压一类封堵井,因安全风险高,制定了"定期巡检、特殊时期加密巡检、井口规范放压"的管理制度;(4)鉴于文23储气库目前仍处于建设阶段,应加强对封堵井周边作业的风险评价工作,确保封堵井安全可控。
For one underground gas storage rebuilt from depleted oil and gas reservoirs, pressure increase in plugged wells is a common security issue. Scientifically and reasonably dealing with this pressure increase may ensure operation security and protect people's lives and property. Taking Sinopec Wen 96 and Wen 23 underground gas storages as examples, we found pressure increase all happening in plugged wells. So, an intensive study on its reason was conducted according to reservoir geology, previous production history, and dynamic monitor. And some countermeasures were made. Results show that (1) pressure increase may be caused by either oil production and water injection or anti-corrosion slurry degassing from adjacent wells;(2) since for one plugging agent, its performance may directly influence plugging effect, production and injection activities should be taken into consideration when agent design;(3) in view of one pressure increase caused by degassing, daily management should be based on regular inspection, whereas the management system of regular inspection, inspection increasing in special time, and strict pressure release at wellhead for another increase caused by oil production and water injection; and (4) in the light of Wen 23 storage under construction, risk evaluation on whatever operation around plugged wells should be intensified in order to ensure these wells under safe and controllable situation.
For one underground gas storage rebuilt from depleted oil and gas reservoirs, pressure increase in plugged wells is a common security issue. Scientifically and reasonably dealing with this pressure increase may ensure operation security and protect people's lives and property. Taking Sinopec Wen 96 and Wen 23 underground gas storages as examples, we found pressure increase all happening in plugged wells. So, an intensive study on its reason was conducted according to reservoir geology, previous production history, and dynamic monitor. And some countermeasures were made. Results show that (1) pressure increase may be caused by either oil production and water injection or anti-corrosion slurry degassing from adjacent wells;(2) since for one plugging agent, its performance may directly influence plugging effect, production and injection activities should be taken into consideration when agent design;(3) in view of one pressure increase caused by degassing, daily management should be based on regular inspection, whereas the management system of regular inspection, inspection increasing in special time, and strict pressure release at wellhead for another increase caused by oil production and water injection; and (4) in the light of Wen 23 storage under construction, risk evaluation on whatever operation around plugged wells should be intensified in order to ensure these wells under safe and controllable situation.
引文
[1]张刚雄,李彬,郑得文,等.中国地下储气库业务面临的挑战及对策建议[J].天然气工业,2017,37(1):153-159.
[2]谢丽华,张宏,李鹤林.枯竭油气藏型地下储气库事故分析及风险识别[J].天然气工业,2009,29(11):116-119.
[3]李国韬,金根泰.油气藏型储气库废弃井封堵技术浅析[J].油气井测试,2017,26(6):50-51.
[4]何汉平.油气井环空允许带压值的计算方法探讨[J].钻采工艺,2018,41(4):16-18.
[2]谢丽华,张宏,李鹤林.枯竭油气藏型地下储气库事故分析及风险识别[J].天然气工业,2009,29(11):116-119.
[3]李国韬,金根泰.油气藏型储气库废弃井封堵技术浅析[J].油气井测试,2017,26(6):50-51.
[4]何汉平.油气井环空允许带压值的计算方法探讨[J].钻采工艺,2018,41(4):16-18.