固井水泥浆防气窜性能评价方法研究.doc

PAGE 39 摘 要 固井后水泥浆环空发生气窜是当前固井工艺技术存在的三大技术问题之一。至今仍是国内外固井界未能很好解决的问题。据估计，大约25%的完井过程中存在着气窜。固井后环空发生气窜将损坏储层，影响油井自然产能，对油气田开发后续作业造成不利影响，即使采用挤水泥等补救工艺也很难奏效，严重时将导致油气井报废，浪费资源。自上世纪60年代以来，国内外对固井后环空气窜机理、预测方法及防气窜技术方法进行了大量的系统研究，设想客观、准确评价水泥浆的防气窜能力，但还未能从根本上解决固井后环空气窜技术问题，因此气窜的有关成因及防窜措施值得进一步研究和探索。 本文试图分析油井水泥浆发生气窜的原因，进一步主要了解国内外固井水泥浆防气窜性能评价方法以及它的计算式，深入了解美国千德乐公司开发的5265型静胶凝强度分析仪的工作原理，通过此仪器的一个常规水泥浆试验案例来了解一般水泥浆体系的静胶凝强度发展规律，结果表明，温度、压力、稠化时间在水泥浆静胶凝强度的发展过程中的影响比较明显，而水泥浆的失水量和密度对于水泥浆静胶凝强度的发展的影响作用并不是非常的明显。之后在实例数据的基础之上，利用数理统计的方法，建立了水泥浆静胶凝强度的计算模型，为了方便计算水泥浆静胶凝强度，并将其应用于气窜的预测，最后本文结合了水泥浆有效液柱压力计算方法和水泥浆气侵阻力计算方法，从决定气窜发生与否的压力平衡关系出发，设计了水泥浆静胶凝强度预测以及防气窜评价程序，为以后油气井防气窜工作提供科学的依据，从而提高油气田开发的经济效益。 关键词：气窜，静胶凝强度，水泥浆失重，评价方法，固井质量 Abstract After cementing cement annulus gas channeling is one of the three major technical problems of current cementing technology,and this problem is still not well resolved at home and abroad .According to estimates, there are gas channeling in the completion process of about 25%. The annular gas channeling after cementing will damage the reservoir, influence natural productivity of oil wells; and adverse impact on oil and gas field development and subsequent operations; even if the use of cement squeeze, remedial process is also very difficult, which will lead to waste of resources ,even if abandon of oil well.Since 60s n last century, domestic and foreign do a lot of system study to the annular channeling of cementing mechanism, forecasting and preventing gas channeling techniques , How to evaluate the gas-channeling prevention performance of cement slurry objectively and accurately,it is still a question can not resolved perfectly for the cement industry at home and abroad , therefore the causes and channeling prevention measures is worthy of further study and exploration. This paper tries to analyze the reason of oil well cement slurry gas channeling, To further understand the cement slurry anti-gas channeling performance evaluation methods and its calculation method.Mainly