Improved Integrity of Primary Cemented Wells

加拿大是全球十大石油和天然气生产国之一，该行业是加拿大最大的单一私营部门投资者。尽管替代能源不断增长，但约70%的一次和二次能源消费来自石油和天然气。该项目解决了上游石油工业中影响环境和/或生产效率的技术问题，特别是固井。在生产油气之前，每口井都要进行一次固井。该操作密封了油井外部，提高了产量，并防止地下流体渗透到地面。传统的采收率通常为20-40%，即使损失几个百分点的产能也很重要。天然气采收率更高，但天然气泄漏到地面也更常见。世界各地的油井泄漏率和严重程度各不相同。人们普遍认为，10-20%的井筒泄漏会对健康和安全以及环境/生态造成影响。弃井的进一步后果是：在最终弃井之前，初级固井密封不良需要进行修复/补救。该项目主要研究与井初固井相关的4个领域，以改进生产和后期弃井的工艺。研究了流体驱替/除泥、不规则井眼和水泥水化过程。这是基于我们之前的研究。新的结果将通过发表的论文和论文、行业演示以及用于设计目的的工程软件公布。加拿大已经钻了50多万口井，其中约有三分之一的井被废弃，其中许多井由于地面压力而关闭。尽管有强有力的证据表明，在许多情况下，初次固井并不有效，但它仍然是一个相对缺乏研究的过程。尽管最近行业不景气，2015年加拿大仍完成了4800多口井。改进的动机永远存在。

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.