Use a Virtual Dig Up to See the Damage You Really Have

3D shape by means of Deep Field Analysis

Our Virtual Dig Up (VDU) service incorporates a disruptive technology: Deep Field Analysis (DFA). DFA is an iterative process where an initial estimation of the shape of the metal loss is used to simulate the MFL-A and MFL-C magnetic responses. The simulation results are compared to the actual magnetic responses and the metal loss shape is refined, until the simulated and as-measured results are in close agreement. This process results in a laser scan like 3D profile of the metal loss that can be used to support a range of integrity assessments, including accurate estimation of failure pressure, anomaly interaction and corrosion growth rate estimation.

The process requires extensive computer processing effort and support from a range of ILI and data analysis specialists to ensure the reliability of the result. Currently, it is therefore targeted at individual anomalies that are challenging to access for verification and repair purposes.

The 3D shape obtained from the DFA process can be used to provide an accurate estimation of failure pressure, using either an effective area approach (such as RSTRENG or the Plausible Profiles - Psqr method) or a finite element analysis (FEA) based assessment. The results of the anomaly assessment are then combined with a range of other activities / assessments, to address the integrity concerns that are particular to the anomaly being assessed. Most notably, it must be determined - with confidence - whether the anomaly is actively growing and if so, at what growth rate. This information can be combined to provide the most accurate estimation of the safe remaining life on a corrosion anomaly.