完整的论文重点介绍了马来西亚海上废弃油井案例研究，涉及气体迁移以及应用新兴技术来诊断有害气体的根本原因和来源。采用一种结合光纤、声学和超声波测量原理的新技术来同时评估单层和双层套管中的水泥粘结质量和区域隔离。
弃井期间的数据分析和解释在评估井完整性和层位隔离方面发挥着关键作用，特别是如果候选井历史上一直存在气体迁移和持续环空压力问题。测井工具组件的选择、测量原则、数据质量控制、所需的处理和验证运行以及特定的数据交付都至关重要，尤其是如果需要实时评估补救固井作业的必要性时。
井道附近浅层气藏的存在也是一个挑战，当这种浅层气藏附近的井段上没有屏障或水泥隔离时，就会成为一种风险。由于井已投入生产，将发生流压衰竭，并且横向连续的浅层气的存在（仍处于原始储层压力下）将根据压力下降的概念诱导气体向井中迁移。
The complete paper highlights well-abandonment case studies offshore Malaysia involving gas migration and the application of emerging technology to diagnose the root cause and source of the unwanted gas. A novel technology combining fiber-optic, acoustic, and ultrasonic measurement principles was deployed to evaluate cement-bond quality and zonal isolation simultaneously in both single- and dual-casing layers.
Data analysis and interpretation during well abandonment play a key role in the assessment of well integrity and zonal isolation, particularly if the candidate well has been charged historically with gas migration and sustained annulus-pressure issues. The choice of logging-tool components, the principles of measurement, data-quality control, the processing and validation runs required, and specific data deliverables are critical, especially if the necessity of remedial cementing jobs needs to be evaluated in real time.
The presence of shallow gas accumulation near the well path also is a challenge and becomes a risk when no barrier or cement isolation exists across the well interval near such a shallow gas pool. Because the well has been put into production, stream-pressure depletion will occur and the presence of laterally continuous shallow gas, still at the virgin reservoir pressure, will induce gas migration toward the well based on the concept of pressure sink.
