A finite element simulation-based framework for constructing performance envelope curves of downhole safety valves

Downhole safety valves are critical well-control barriers in completion strings and are exposed to coupled axial loads and internal and external pressures during running-in-hole, packer setting, acid fracturing, production, and shut-in operations. However, a unified approach for defining their load-bearing boundaries under these conditions remains unavailable. This study develops a finite element simulation-based framework for constructing four-quadrant performance envelopes of downhole safety valves. A three-dimensional full-valve model was established for the Realm-16.75 tubing-retrievable downhole safety valve. Critical components, material properties, boundary conditions, and the onset-of-yield criterion were defined, and stepwise loading was applied under single and combined loads. The predicted single-load limits were 3320 kN in tension, 2995 kN in compression, 190 MPa under internal pressure, and 148 MPa under external pressure. Eleven combined-load boundary points were then used to form a closed performance envelope. Load–operation tests on a comparable tubing-retrievable downhole safety valve showed changes of +0.50% and −7.66% in the mean hydraulic control pressures at the fully open and fully closed states, respectively, with no leakage or structural damage. Field-condition assessment showed that all operating points from two representative wells remained within the safe operating domain; the corresponding maximum von Mises stresses were 618.2 and 650.2 MPa, both below the Alloy 718 yield strength. The proposed framework provides a unified basis for structural design, valve selection, and field safety assessment.