From Paper to Predictive: A Catalyst for Thailand's Oilfield Maintenance with a Low-Cost Digital Calibration Solution

Abstract This paper presents the development of PTTEP's Digital Job Card system, transitioning from paper-based processes to a digital-first approach. Instrument calibration and function testing, mandatory for ensuring operational accuracy and integrity, were key focus areas. The solution is tailored to in-house field experience design with low-cost CAPEX and OPEX, generating high-quality data that supports analysis, predictive maintenance, and future Al integration. That's extended from the existing data platform which developed by PTT Digital. The implementation began by standardizing design aligned with in-house maintenance standards and embedded within a Continuous Learning Digital Ecosystem. This ecosystem follows a five-phase cycle: Upstream (standardization of calibration sheets), Midstream (integration with SAP PM), Downstream (execution), Vaporize (data analysis), and Rain Back (refinement of master data and maintenance strategy). The calibration sheets are covering transmitters, valves, detectors, and switches. Master data was established for calibration range and function test details. Calibration tools were integrated to ensure recertification. Data was stored in a central database and made accessible for company digital tools. The implementation of the digital instrument calibration system has transformed the management of preventive and corrective calibration work orders, seamlessly integrating them with SAP PM and daily activity reports. This initiative, delivered at a low total cost of approximately USD 60,000, has significantly improved both accuracy and operational efficiency. For example, at the offshore operation site (Aug 2023 – Jul 2025). 2,485 transmitters passed as-found tests, with only 1 requiring recalibration, and 58 failed for proceeding the corrective maintenance. This allowed the calibration and function test intervals (excluding safety-critical equipment) to be safely extended from one year to three years, saving up to 3,000 technician hours annually; Moreover, this can reduce the need for travel to remote wellhead sites. At the onshore operation site. 169 transmitters as-found tests without any recalibrations but required 29 corrective maintenances. Refers to global digital calibration, it can reduce the need of recalibration by 20-30% from interval optimization and human error. The system's digital data also enables real-time trending and alerts, empowering predictive maintenance practices. These results demonstrate that a low-cost system can deliver substantial benefits— improving asset integrity, lowering maintenance costs, reducing costs through fewer field trips, and fostering operational excellence and sustainability.