浮力作用对大斜度井套管居中度的影响

发布时间：2018-12-13 19:41

【摘要】：准确了解套管内外密度差所产生的浮力对套管居中度的影响对于大斜度井合理安放扶正器,降低套管下入风险具有重要的意义。通过对扶正器受力分析模型进行修正,建立了套管内外密度差对套管居中度的影响图版,同时考虑顶替过程中套管内外密度差随时间变化情况,形成埕海油田大斜度井套管扶正器安放方法。计算结果表明,埕海地区扶正器安放间距分别为30 m、20 m、15 m时,通过浮力作用使套管居中度最大可增加36.4%、19.6%、12.2%,井斜角越大、套管内外密度差越大,居中度变化值越大。扶正器安放间距为10 m时,浮力作用减弱,居中度变化值最大仅为6.2%。研究结果表明,扶正器安放间距、井斜角的正弦值、套管内外密度差与浮力作用下的居中度变化量呈三次多项式的非线性正相关。ZH29-30井实践表明,考虑浮力作用的套管居中度设计方法,可以有效提高固井顶替效率,保证套管安全下入。
[Abstract]:It is of great significance to accurately understand the effect of buoyancy caused by the density difference inside and outside the casing on the casing centrality for a well with a high inclination to reasonably place centralizer and reduce the risk of casing entry. By modifying the stress analysis model of centralizer, a chart of the influence of the density difference inside and outside the casing on the casing centrality is established, and the variation of the density difference inside and outside the casing with time during displacement is considered. The setting method of casing centralizer in Chenghai oilfield is formed. The calculation results show that when the spacing of centralizer in Chenghai area is 30 m / 20 m / 15 m, the maximum centrality of casing can be increased by 36.4% and 19.6% / 12.2m by buoyancy, and the inclined angle of well is increased. The greater the density difference inside and outside the casing, the greater the variation value of centrality. When the spacing of centralizer is 10 m, the buoyancy is weakened, and the maximum variation of centrality is only 6.2. The results show that the spacing of centralizer, the sinusoidal value of inclined angle, the density difference inside and outside the casing and the variation of centrality under buoyancy are positively correlated with the cubic polynomial. The practice of ZH29-30 well shows that, The design method of casing centrality considering buoyancy can effectively improve cementing displacement efficiency and ensure safe casing entry.
【作者单位】：中国石油集团渤海钻探第二固井公司;中国石油大港油田石油工程研究院;中国石油大港油田井下作业公司;
【基金】：中油股份公司重大科技专项“大港油区大油田勘探开发关键技术研究”的子课题“高效钻完井及油气层保护配套技术研究”(编号:2012E-10)
【分类号】：TE931.2

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