Well Control Rentals

Rental barriers for well control

Well control is the discipline of keeping formation fluids where they belong and being able to shut the well in if they do not. The in-string barriers — the valves that can close off the bore of the drill string itself — are a critical part of that system, complementing the BOP stack at surface. If a kick enters the well while making a connection or tripping, these valves let the crew close the string and regain control. Drillstrings rents these barriers, inspected, pressure-tested and deployment-ready, so a rig always has certified, in-date well-control valves on hand.

The in-string barrier toolkit

• Pressure control equipment covers the core well-control valves: kelly valves and cocks, inside BOPs (IBOPs), full-opening safety valves, and drop-in check and dart valves that provide deployment-ready barriers in the string.
• Kelly equipment includes the upper and lower kelly cocks that isolate the string above and below the kelly on rotary rigs.
• Handling tools let the crew stab and make up a full-opening safety valve quickly when a barrier has to be installed under pressure.
• Downhole tools and BHA components provide the crossovers and subs to place a barrier at the correct point in the string.

Verified, in-date, ready to deploy

A well-control barrier is only a barrier if it is proven to hold, so verification is everything. Every valve we rent is pressure-tested to its rated working pressure and certified, so its rating is not assumed but demonstrated. Full-opening safety valves are supplied with the correct crossovers so a crew can stab and make up a barrier fast when a kick is taken. Our guide to well-control barriers explains how these in-string valves fit the two-barrier philosophy, and rig-floor handling tools covers deploying them safely.

The two-barrier philosophy

Well control rests on always having two tested, independent barriers between formation pressure and the environment. In the drill string, the in-string valves are one leg of that system: an upper and lower kelly cock (or their top-drive equivalents), an inside BOP that can be stabbed and made up under flow, and drop-in check or dart valves that stop backflow up the string. Together with the BOP stack and the drilling fluid’s hydrostatic column, they form the redundant barrier envelope. A valve only counts as a barrier once its rating is verified by test — an assumed rating is no barrier at all. Our well-control barriers guide explains how these legs combine.

Rating the valves to the well

Well-control valves are selected to the well’s maximum anticipated surface pressure with margin, and their connections must match the string they drop into. A valve rated below the pressure it may see is worse than no valve, because the crew relies on it. Confirm working pressure, connection (NC46, NC50, FH or premium) and bore against the string before the job. Where the well is sour, every barrier in the envelope must be NACE MR0175 material to resist sulfide stress cracking under H2S.

Common pitfalls

• Under-rated valve — a barrier that cannot hold the anticipated pressure fails when it is needed.
• Wrong connection — a full-opening safety valve that will not stab into the string cannot be deployed under pressure.
• Expired test certification — an in-date pressure test is what makes the valve a barrier.
• Non-sour material in an H2S well — sulfide stress cracking can fail the valve without warning.

Inspected, sour-service ready, delivered

Every well-control valve we rent is inspected, serialized for traceability, available in NACE MR0175 sour-service material and pressure-tested to its rated working pressure before dispatch. Rigs typically keep a set of certified barriers on hand; whether to rent or own them is worth weighing in our rent vs buy guide. From our network of yards, and backed by our quality program, we keep certified, in-date barriers ready to ship. Tell us your working pressure and connection requirements and we’ll quote deployment-ready barriers.