Reservoir Surviellance Planning

A: Acting on the wrong cause sends you chasing phantom reservoir behavior and burns a full day of shut-in with no usable data. Thermal cycling damage fits all symptoms: smooth but accelerating drift that decouples from flow events once the well is static. Skin or model parameter errors distort interpretation but don't create monotonic gauge drift. Sampling resolution issues add noise, not a creeping bias.

A: Picking too short a shut‑in leaves you with near‑wellbore storage effects and a wasted PTA window. Using the diffusivity relation r ≈ √(4αt), where α scales with k/(φμct), plugging the numbers lands you in tens of hours, not single digits. Days are excessive, but hours are optimistic. The 48–72 hr window clears the 800 ft target without crippling production.

A: Ignoring the dominant mechanism risks sudden gauge failure and loss of the surveillance string. At elevated temperature with H₂S, sulfide stress cracking governs material selection and is exactly what ISO 15156 addresses. CO₂ and oxygen effects are secondary here, and galvanic issues don't explain abrupt downhole failures seen in sour service.

A: Skipping the sequence leads to commissioning a gauge that looks alive but is numerically wrong, poisoning every future PTA. Scaling and units must be right before stimulus; otherwise, a good response masks a bad transfer function. Time alignment matters, but only after magnitude is trusted.