Multi-Dimensional Digital Validation of Well Integrity With SureTec

Well barriers consist of one or more well barrier elements (WBEs), and the failure of a single WBE can cause the well barrier to fail. If well integrity is compromised by the failure of a well barrier, it can result in loss of production and harm people, the environment, assets, and the operator’s reputation. The lack of validation criteria and the subjective interpretation of test results for critical WBEs are root causes of well integrity issues in the industry. IPT’s software, SureTec, uses proprietary algorithms and stringent criteria to significantly reduce pressurized time for testing WBEs and remove validation subjectivity, saving rig time and reducing risks.

Does Your Organization Use Circular Charts to Verify Well Barrier Integrity?

If your organization uses circular chart recorders (CCRs) to verify the integrity of WBEs, a BSEE report cited the following problems associated with using CCRs.

• Handwritten notes placed on the circular chart can lead to a lot of data manipulation and mistakes during the recording of the tests
• It’s hard to keep track and document the tests on all the different valves
• Most leaks happened in low pressure tests and the clarity of the pressures on the chart recorder is not clear in the low ranges
• The testing procedure is not consistent between different rigs as offshore personnel have their own way of documenting and determining the criteria of pass and failure of the tests
• Any testing plan changes are hard to manage and track
• There are no standards for component or pressure path representation
• Pressure path analysis is done manually

Advantages of Going Digital with SureTec

There are several important advantages in going from using CCRs to SureTec for verifying well barrier integrity.

Increased Accuracy and Objectivity

Digital validation with SureTec is more accurate than CCRs and uses transparent and objective criteria for validating pressure tests. SureTec uses proprietary algorithms to provide enhanced analysis for the most rigorous and effective testing in the industry. Our algorithms use transparent criteria that has been validated against a database of over 10,000 successful tests. The subjective interpretation of CCR tests is prone to human error.

Greater Efficiency & Safety

SureTec provides a 30% reduction in test time versus CCRs by eliminating subjectivity and unnecessary pressurized time. Due to the accuracy of the testing with SureTec, the need to retest is eliminated. This improves safety by removing unnecessary pressurized time, which puts people, the environment, assets and reputation at risk.

Better Documentation and Data Utilization

SureTec provides comprehensive test reports to assure reliable handover with complete documentation. SureTec consists of tools that allow users to create custom schematics, visualize pressure paths and compare tests. Tests can be overlayed to show rate of change differences, pressure paths, and barriers throughout each step of a well’s lifecycle.

Reduced Costs

SureTec reduces costs by decreasing test time and increasing accuracy. This lowers risks, workforce hours, transportation, expenses from incidents, and reputation devaluation.

SureTec Surpasses Its Digital Competitors

Our competitors primarily offer a testing method known as “Percent Decline” analysis, which is the minimum requirement by industry regulators. Percent Decline is a simple math calculation that divides the system pressure drop by a fixed time interval (e.g., 30 minutes). The validation criteria are based on a percentage of required test pressure. This means that the validation criteria fluctuate with the test pressure, making this analysis method incapable of consistently detecting a leak or differentiating between a leak and thermal influences on the test fluid.

SureTec Goes Beyond Percent Decline Analysis to Provide the Highest Level of Assurance

In general, digital testing solutions are more accurate, safe, and efficient than CCRs; however, the level of integrity assurance they provide depends on their analysis method and validation criteria.  Percent Decline offers the lowest level of integrity assurance, so it should not be used alone to validate WBE integrity. SureTec surpasses Percent Decline with “multi-dimensional verification” of WBE integrity using advanced validation algorithms—Rate of Change analysis, Thermally Compensated Leak Detection, and Trend Analysis.

Standard Decline Analysis Is Insufficient

Decline Analysis Passes Leaks

Rate of Change Analysis

IPT’s pressure Rate of Change (ROC) analysis improves assurance by quantifying pressure stabilization over time. In other words, it determines the instantaneous rate of pressure change and will only pass a test if the pressure ROC is less than strict validation criteria, such as 3 psi/min over 5 minutes. In contrast, CCRs validate pressure tests at approximately 8-12 psi/min over 5 min.

Thermally Compensated Lead Detection (TCLD) Analysis

Thermally Compensated Leak Detection (TCLD) uses ROC analysis to create a benchmark profile for each system tested. Then for subsequent test steps with a similar component grouping, test pressure, and type and volume of test fluid pumped, TCLD compares the pressure ROC to the benchmark profile. This allows TCLD to detect the smallest of deviations from the benchmark, similar to facial recognition, and thereby reduce test time with accurate leak detection and component verification.

Trend Analysis

Trend Analysis increases integrity assurance to the highest level by ensuring that the pressure ROC is improving over the validation interval. It can detect subtle leaks based on a non-improving or constant rate of change in pressure. This level of assurance is particularly applicable for stump testing where it is critically important to detect small leaks before splashing the BOP stack.

ROC, TCLD and Trend Analysis are available in the Advanced and Premier tiers of SureTec. For more information, request our white paper  “Advanced Well Integrity Management with SureTec®”.