Improved Integrity of Primary Cemented Wells

加拿大是全球十大石油和天然气生产国，该行业是加拿大最大的私营部门投资者。尽管能源交替增长，但约70%的一次和二次能源消费来自石油和天然气。该项目涉及上游石油工业影响环境和/或生产效率的技术方面：特别是固井。 在生产碳氢化合物之前，每口井都要进行一次固井。这种操作密封了油井的外部，提高了产量，并防止地下流体渗入地面。常规石油采收率通常为20%-40%，即使是几个百分点的产能损失也是很大的。瓦斯采收率较高，但瓦斯泄漏到地面的情况也比较常见。世界各地的油井渗漏率和严重程度各不相同。一种普遍的看法是，10%-20%的井筒泄漏，这既有健康和安全后果，也有环境/生态影响。废弃油井会带来进一步的后果：一次固井密封不良，需要在最终废弃之前进行修复/补救。该项目的目标是研究与油井一次固井有关的4个领域，以期改进生产和后期废弃的工艺。我们研究了流体驱替/排泥、不规则井眼和水泥水化过程。这是建立在我们之前研究的基础上的。新的成果将通过已发表的论文和论文、行业演示文稿以及可用于设计目的的工程软件公开。 加拿大已钻探了50多万口油井，其中约三分之一被废弃，其中包括许多因地面压力而关闭的油井。尽管有强有力的证据表明，一次固井在许多情况下并不有效，但它仍然是一个相对研究较少的过程。即使在最近行业低迷的情况下，加拿大2015年仍完成了4800多口油井。改进的动力一直存在。

Canada is a top-10 producer of oil and natural gas globally and this industry is the largest single private sector investor in Canada. Despite alternate energy growth, ~70% of primary and secondary energy consumption comes from oil and natural gas. This project addresses technological aspects of the upstream petroleum industry that impact the environment and/or production efficiency: specifically well cementing. Before hydrocarbons are produced every well undergoes primary cementing. This operation seals the outside of the well, increasing production and preventing subsurface fluids from percolating to surface. Conventional oil recovery rates typically are 20-40%, losing even a few % of productivity is significant. Gas recovery rates are higher, but gas leakage to surface is also more common. Well leakage rates and severity vary worldwide. A common perception is that 10-20% of wellbores leak, which has both health & safety consequences and environmental/ecological impact. Further consequences come at well abandonment: where a poor primary cementing seal necessitates repair/remediation before eventual abandonment. This project targets research in 4 areas related to primary cementing of wells, with a view to improving the process for both production and later abandonment. We study the processes of fluid displacement/mud removal, irregular wellbores and cement hydration. This build on our previous research. New results will be made public via published papers & theses, industry presentations and through engineering software available for design purposes. Over 0.5 million wells have been drilled in Canada, with about 1/3 abandoned, which includes many that are shut-in with pressure at surface. Despite strong evidence that primary cementing is not effective in many cases, it remains a process that is relatively under-researched. Even with the recent industry downturn, over 4800 wells were completed in Canada in 2015. The incentive to improve is ever present.