Citadel recently qualified our new 762 ULTRA MAG valve to 18,000 psi at 400°F with nitrogen gas, using V0 zero bubble acceptance criterion. This testing was performed by Stress Engineering Services in Houston. The gas test was performed after a 20 bpm for 24 hour flow endurance test using 12.9 ppg water based mud at Citadel’s API flow loop at our facility in North Houston.

This groundbreaking performance validation combined with industry leading flow area (7.62 square inches) make the 762 ULTRA MAG the highest performing float valve in the industry by a significant margin.

Contact us or check out the products page to learn more about Citadel float equipment and our other innovative casing equipment/cementing tools.

Another industry first from Citadel: V0 float equipment. If you’re wondering what “V0” is or means, here’s a quick explanation: “V0” is the most stringent product validation grade that comes originally from API 11D1/ISO 14310 (packers and bridge plugs). There are validation grades from V6 (the easiest) down to V0 (the most challenging).

  • V6: supplier/manufacturer defined test criteria
  • V5: liquid test (pressure/temperature only)
  • V4: liquid test plus axial loads
  • V3: liquid test plus axial loads plus temperature cycling
  • V2: gas test plus axial loads
  • V1: gas test plus axial loads plus temperature cycling
  • V0: gas test plus axial loads plus temperature cycling plus zero bubble acceptance criterion

If you’re familiar with API 11D1/ISO 14310 and you’re saying to yourself or to your colleague right now, “those specifications aren’t for float equipment, they’re for packers and bridge plugs”, you’re correct. They are irrelevant to float equipment. However, the term “V0” has evolved in recent years to take on relevance outside of these specifications and the products they govern. The term is now colloquially used to refer specifically to the “zero bubble acceptance criterion” that separates V1 from V0. The V1 validation grade is the same severity of a test as V0, but allows for 20 mL of bypass over each 15 minute hold period, whereas V0 has a zero bubble allowance over the same 15 minute hold period. As such, a leak detection system must be in place in a closed system where any gas bypass through the tested product will be captured and measured. It should be noted that the gas bypasses at high pressure, yet is measured at ambient pressure. In the case of our 18,000 psi pressure test (1225 atm), a gas bubble the size of a water droplet would fill a shot glass when measured at atmospheric pressure.

Typical for float equipment is the API 10F qualification which includes a flow endurance test and an HPHT test each with three levels:

  • I: 10 bpm for 8 hours and maximum pressure of 1,500 psi at ambient temperature
  • II: 10 bpm for 12 hours and maximum pressure of 3,000 psi at ambient temperature
  • III: 10 bpm for 24 hours and maximum pressure of 5,000 psi at ambient temperature
  • A: 1,500 psi at 200°F
  • B: 3,000 psi at 300°F
  • C: 5,000 psi at 400°F

The validation grade for a float valve is designated by the combination of the flow endurance test and the HPHT test (IA, IIA, IIIB, IIIC, etc). There are some issues/limitations to this document which is why it has been updated and re-released as a specification. Specification 10F will be discussed in a future blog post.

So why V0 float equipment? Is that not complete overkill? In most circumstances, yes, absolutely. However, there are circumstances where the float equipment is required to act as a true barrier, preventing fluid flow or pressure from entering the casing when cement is not present or unreliable (intentionally or unintentionally). In a wet shoe system, a barrier style float valve like the ULTRA MAG will prevent formation fluid/gas from entering the casing and making it to surface. Even when a barrier style valve is not required in circumstances such as these, there are benefits to running a bulletproof valve to mitigate NPT and remedial work associated with float failure. A marginal additional expense as insurance to know your floats will hold at the conclusion of the cement job.

Quality is the status quo. Innovation is conventional. Excellence is expected. ORDINARY IS OUR ENEMY.