Every well control procedure, every BOP, every piece of choke-and-kill equipment on a rig exists because of one event: the kick. Understanding what a kick actually is, and how it gets caught early, is the foundation everything else in well control is built on. What a kick is A kick is an unplanned influx of
What Is a Kick in Well Control, and How Is It Detected? Read More »
“Wellhead” and “Christmas tree” get used interchangeably in casual conversation often enough that it’s worth clearing up — they’re two distinct pieces of equipment, built to somewhat different (though related) standards, doing two different jobs, and understanding the split matters if you’re specifying, reviewing drawings, or troubleshooting equipment. The wellhead: structure and pressure containment The
Wellhead vs. Christmas Tree: What’s the Difference? Read More »
MAWP shows up on every pressure vessel nameplate, every wellhead spec sheet, and nearly every FEA report scope — and it’s frequently confused with related-but-different terms like design pressure or operating pressure. Getting the distinction right matters, because MAWP is the number that actually defines the equipment’s legal and engineering limit. The definition Maximum Allowable
What Does MAWP Mean? Maximum Allowable Working Pressure Explained Read More »
H40, J55, N80, L80, P110, Q125 — API 5CT casing and tubing grades read like a code because, functionally, they are one: a compact way of specifying a pipe’s strength, and in some cases its metallurgy, without writing out a full material spec every time. Here’s what the letters and numbers actually mean, and where
API 5CT Casing and Tubing Grades Explained: H40 to Q125 Read More »
A wellhead or tree component stamped “10M” or “15,000 psi” isn’t giving you a suggestion — it’s stating, per API 6A, the exact maximum pressure that component is qualified to hold, at a specified temperature, tested to a defined procedure. Understanding what those numbers actually mean (and don’t mean) matters for anyone specifying or reviewing
API 6A Pressure Classes Explained: What Do 2,000–20,000 PSI Ratings Mean? Read More »
“Is this sour service?” is one of the first questions that should get asked on any wellhead or valve job — because the answer changes what materials are allowed, and getting it wrong isn’t a cosmetic mistake. It’s the difference between equipment that lasts its design life and equipment that cracks in service. What makes
What Is NACE MR0175 and When Do You Need Sour Service Materials? Read More »
A blowout preventer that hasn’t been tested recently is, for well-control purposes, a blowout preventer you can’t fully trust. API RP 53 sets out how often BOP components actually need to be function- and pressure-tested — and the honest answer is “more often than most people outside drilling operations would guess.” The two kinds of
How Often Should a BOP Be Tested? API 53 Testing Intervals Explained Read More »
“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 »