In well construction, cementing is one of the most critical operations—responsible for both structural integrity and zonal isolation throughout a well’s productive life. While great effort is placed on designing a successful job, real-world conditions are rarely predictable. Even the best-planned cementing operation can be influenced by factors such as lost circulation, formation influx, inconsistent hole sizes, or fluid contamination. These events can create deviation between the plan and what actually occurs downhole.
That’s where post-operative analysis becomes indispensable. More than just a review of how the job went, it’s an investigative process—one that can uncover the root causes of poor bonding, channeling, or TOC (top of cement) discrepancies, and more importantly, guide improvements for future jobs.
Why Post-Job Evaluation Matters
Once a cement job is executed, evaluating its true effectiveness is often complex. Key questions arise:
- Did the slurry reach the planned height?
- Was displacement as efficient as expected?
- Could unexpected losses have occurred?
- Are the logs confirming or contradicting what was expected?
To answer these, engineers typically turn to a combination of surface measurements (pump pressures, flow rates, densities) and downhole tools (cement bond logs, ultrasonic logs, temperature sensors). But interpreting this data in isolation often leads to ambiguity. What’s needed is a way to stitch together all available inputs—planned and actual—into a coherent picture.
Case Study: Post-Operative Cement Analysis in Action
In a real-world case from Mexico, a well with a total depth of 2,390 meters underwent cementing operations under standard procedural controls. However, as is often the case, questions lingered post-job. Concerns arose about the possibility of losses and whether the cement had properly reached the intended TOC.
To investigate, engineers conducted a detailed post-operative analysis using surface data collected during the job, including pump pressure and flow rates. These were cross-referenced with acoustic logs obtained after the job, revealing some key observations:
- The calculated pressure profile showed a close match to recorded surface pressures, helping confirm that fluid placement had occurred as expected and losses were minimal.
- Displacement efficiency insights pointed to probable channeling between the lead and tail slurries.
- Simulated cement concentration curves indicated that the actual TOC was higher than expected—1300m vs. a planned 1284m (for 50% tail), and extending to 2000m for full tail coverage.
- These simulation findings were validated by log-based acoustic impedance readings, which aligned with the predicted cement heights.
By aligning these multiple data sources through simulation, the team was able to close the gap between the job design and actual field behavior—resulting in stronger confidence and insight for future designs.
Want to dive deeper into the methodology and field results? View the full case study here.
Integrating Simulation into Post-Job Evaluation
Simulation tools—when calibrated with field measurements—can provide meaningful validation of cement placement, pressure behavior, and potential downhole anomalies. In this case, the use of such a model enabled engineers to correlate pressure profiles and cement concentration distributions with log data, offering a clearer understanding of the job’s effectiveness.
Software like CEMPRO supports this level of post-job reconstruction, giving engineers the ability to evaluate outcomes beyond surface indicators. By integrating simulation into the post-operative workflow, teams can refine future cementing designs and enhance long-term well integrity.
Interested in how CEMPRO can support your post-job evaluations or improve future cementing designs? Contact our team today.