| 摘要: |
| 目的 油田钻井现场重大事故事后的分析极其复杂,通过数值模拟的手段研究事故发生的关键参数及其影响规律。方法 通过边界条件假设和试算的方式解决边界条件模糊的问题,利用井漏计算模型和现场数据反演井漏过程,确定井涌模拟所需的前置参数,对不同情况下的漏失影响开展研究。结果 该井落井钻柱长4 500 m,产生20 MPa以上的激动压力,7～8 min累计漏失量可达20 m3以上,对现场作业影响较大,响应时间较短；短钻杆的落井产生的激动压力较小,风险较低；在大裂缝(10 mm以上)情况下,大激动压力可在瞬间产生几十立方米以上的漏失量,无法控制；在窄裂缝(1 mm)情况下,6 min累计漏失量达20 m3；在微裂缝(0.25 mm)情况下,10 h累计漏失量仅为20 m3。结论 长钻具掉落产生较大的激动压力,是产生漏失的主要敏感参数,是诱发井喷的主要原因,应第一时间采取关井措施。 |
| 关键词: 钻具落井 激动压力 漏失速率 缝宽 |
| DOI：10.3969/j.issn.1007-3426.2023.03.016 |
| 分类号: |
| 基金项目:塔里木油田油田分公司项目“博孜区块大斜度井目的层溢流机理研究及应用” |
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| Analysis on influence factors of leakage caused by surge pressure |
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Zhang Xuliang1, Zhou Bo1, Liang Shuang2, Zhang Yaoming1, Luo Fangwei2, Wang Pengcheng1, Ren Haifan2
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1. PetroChina Tarim Oilfield Company, Kuerle, Xinjiang, China;2. CNPC Research Institute of Safety & Environment Technology, Beijing, China
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| Abstract: |
| Objective The post-accident analysis of major hazards is a very complicated research work in oil field drilling site. The key parameters of the accident and its influence rule are studied by numerical simulation. Methods The fuzzy boundary condition is solved by the boundary condition hypothesis and trial calculation method on the premise that the specific parameters cannot be obtained. This paper mainly uses the well loss calculation model and field data to invert the well loss process to determine the leading parameters required for kick simulation, and studies the change law of bottom hole pressure when the string is falling. Results The downhole drilling string of a certain well is 4 500 meters long, generating more than 20 MPa surge pressure, and the cumulative loss for 7-8 minutes can reach more than 20 m3, which has a great impact on field operations and a short response time. The falling of short drill pipe produces less surge pressure and lower risk. The results show that under the condition of large fracture (more than 10 mm), the large surge pressure can instantly produce more than tens of cubic meters of leakage, which can not be controlled. In the case of narrow fracture (1 mm), the accumulated leakage amount reaches 20 m3 in about 6 minutes. In the case of micro-fracture (0.25 mm), the accumulated loss in 10 hours is only 20 m3. Conclusion sThe long drill string drop produces a larger surge pressure, which is the main sensitive parameter of loss and the main reason of blowout. The well shut-in measures should be taken as soon as possible. |
| Key words: drilling tool falling surge pressure loss rate fracture width |
