Arrow-type check valves are high-pressure-drop single-directional valves designed for internal blowout prevention (IBOP) in drill strings. Featuring a dart-shaped sealing mechanism, they instantly close under reverse circulation pressure or spring force to seal the drill pipe conduit, preventing uncontrolled hydrocarbon flow up the string.
Technical Specifications & Operation
Parameter&Specification
Sealing Mechanism:Tungsten-carbide-tipped dart with HNBR seals
Activation Time :<0.5 seconds upon flow reversal
Pressure Rating:5,000-15,000 psi (345-1035 bar)
Temperature Range:-20°C to 175°C (HPHT models: 230°C)
Installation:Between drill bit and drill pipe
Locking System:Spring-assisted hydraulic closure
Core Functions
1. Reverse Flow Blocking
- Automatically shuts when backflow pressure exceeds 50-200 psi (3.5-14 bar)
- Prevents "u-tubing" during tripping or well control events
2. Continuous Circulation
- Locking sleeve tool holds valve open during normal drilling (allowing downward flow)
- Removable via wireline/slickline when emergency sealing required
3. Rapid Deployment
- Pre-assembled with quick-connect subs (API REG/NC connections)
- Installs in <3 minutes when kick indicators detected (e.g., pit gain, flow increase)
Deployment Workflow
1. Pre-installation
- Valve locked open with retrievable sleeve tool stored on rig floor
- Installed directly above bit during BHA makeup
2. Kick Response Protocol
- Step 1: Observe flow/pressure anomalies during tripping
- Step 2: Stab valve into stand (using elevators) → torque to 15-20 kft-lb
- Step 3: Pump down to eject locking sleeve (1-2 bbl fluid volume)
- Step 4: Valve armed – seals if backflow occurs
3. Post-Event Retrieval
- Reinsert sleeve tool via wireline to reopen valve
- Continue drilling or pull out of hole
Maintenance & Certification
- Pressure Testing: 1.5x working pressure every 14 days (API 53 Standard)
- Critical Components:
- Dart stem: Replace after 1,000 drilling hours
- Seals: Change every 6 months (NORSOK M-710 compliant)
- Certifications: API 6A/16A, ISO 28781, DNV GL-OS-E101
Arrow-type check valves provide fail-safe drill string isolation through rapid dart-sealing technology. Their instant closure capability, compatibility with continuous circulation systems, and rig-floor deployability make them essential for modern well control, reducing blowout risks by 92% compared to manual IBOPs (IADC Well Control Data).
