API 6A and API 17D cover the same basic function — wellhead and tree equipment — but for two environments different enough that neither standard alone is sufficient for both. Here’s how they divide the work, and why a subsea well needs more than just “API 6A equipment installed underwater.” API 6A: the surface baseline
API 6A vs. API 17D: Surface Wellhead vs. Subsea Wellhead Standards Read More »
A choke’s job sounds simple — restrict flow — but the way it does that, and which type gets used where, has real engineering reasoning behind it. Here’s how choke valves actually work, and why a well might use a fixed choke instead of an adjustable one, or vice versa. The basic principle A choke
How Does a Choke Valve Work? Adjustable vs. Fixed Chokes Explained 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 »
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 »
“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 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 »
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 »
A wellhead stack is a set of stacked pressure-containing spools and hangers, and the names of the main components — casing head, tubing head, hanger — get used constantly without always being explained. Here’s what each one actually does, and how they fit together. The basic idea: a wellhead is stacked, not built as one
Wellhead Equipment 101: Casing Heads, Tubing Heads, and Hangers Explained Read More »
API 6A and API 6D both cover valves used in oil and gas service, and it’s a common point of confusion which one applies to a given piece of equipment. The short version: it comes down to where the valve sits. API 6A governs wellhead and tree equipment; API 6D governs pipeline valves. Same broad
API 6A vs. API 6D: What’s the Difference Between Wellhead and Pipeline Valve Standards? Read More »