“Christmas tree” is one of those oilfield terms that confuses more people outside the industry than it should — there’s no decoration involved. It’s the stack of valves and fittings sitting on top of a well that controls everything flowing in or out of it, and the name comes simply from how the branching arrangement
What Is a Christmas Tree in Oil and Gas? Surface vs. Subsea Explained Read More »
“I need this pipe to hold 5,000 psi — what wall thickness do I actually need?” is one of the most common early-design questions we get, and it’s really just our Internal Yield (Burst) Pressure formula run backwards. This post walks through solving Barlow’s equation for wall thickness instead of pressure, and where that number
Sizing Pipe Wall Thickness for a Target Design Pressure Read More »
Every calculator on this site so far checks one failure mode at a time: burst, or collapse, in isolation. Real strings don’t fail that way — pressure and axial load act together, and a pipe that comfortably passes a burst check and a collapse check separately can still yield when both loads are on at
Why Burst and Collapse Checks Alone Aren’t Enough: The Triaxial Envelope Read More »
Every string looks lighter once it’s in the hole. That’s not the rig lying to you — it’s buoyancy, and it’s why a driller’s hook-load reading never matches the pipe tally’s air weight once the string is wet. This post covers the shortcut oilfield engineers actually use to get from air weight to buoyed weight,
Why Your String Weighs Less Downhole: The Buoyancy Factor Shortcut Read More »
Ask five reservoir engineers to size a surface choke for the same well and you may get five different answers — not because anyone did the math wrong, but because there is no single, universally accepted formula for two-phase flow through a choke. Our Choke Bean Sizing calculator is built around that reality: it lets
Why Five Engineers Can Size the Same Choke Five Different Ways Read More »
Torque specs on a bolted flange look precise — “450 ft·lbf, three passes, star pattern” — but the number behind that spec is built from a chain of assumptions, and the weakest link in that chain is almost always friction, not the bolt itself. Our Flange Bolt Torque calculator walks through that chain explicitly so
Torque Is a Proxy for Tension: The Logic Behind Our Flange Bolt Torque Calculator Read More »
Two codes get named on almost every pressure-equipment analysis scope in this industry — API 6X and ASME BPVC Section VIII Division 2 — and it’s a fair question why you’d need both, or which one actually governs a given job. The short answer: they’re not competitors. One is a general pressure-vessel design code; the
No one builds a physical wellhead, bolts it up, and pressure-tests it to destruction just to find out where it would fail — and even if you did, that single test wouldn’t tell you what happens at a different temperature, a different load combination, or a slightly different wall thickness. That’s the gap Finite Element
What Is FEA (Finite Element Analysis) and Why Does It Matter for Pressure Equipment? Read More »
“Can you analyze this for us” means two different jobs depending on whether the part exists yet. Design validation checks a new design before it’s built. Re-rating (or re-qualification) checks an existing, already-proven design against a duty it wasn’t originally analyzed for. They use the same FEA tools and the same codes, but the question
Run a linear-elastic FEA on a pressure-containing component and it’s common to get a result that says the design fails — calculated stress above yield at a local hot spot — on a part that, in reality, has years of safe service behind it or would clearly survive a hydrotest. That’s not a wrong answer;
Elastic-Plastic vs. Linear-Elastic FEA: When Do You Actually Need Limit-Load Analysis? Read More »