Product Overview

The Double Stage Cementing Collar, also known as a Stage Cementer or DV (Differential Valve) Tool, is a critical component for multi-stage cementing operations in oil and gas wells. Manufactured by Junchi (SANMON), this tool enables cement slurry placement in two or more stages, effectively managing hydrostatic pressure and reducing circulation loss risks in wells with weak formations. Available in both hydraulic-actuated and mechanical-actuated (free-fall plug) configurations, the stage collar features precisely machined ports, high-strength shear pins, and a robust closing sleeve that ensures reliable stage isolation.

Constructed from premium-grade alloy steel and engineered to API Standards, our stage collar provides consistent and predictable operation at depths exceeding 15,000 feet. Each unit is assembled and tested in our Tianjin facility using advanced CNC machining, hot press forming, and ultrasonic inspection equipment to guarantee field performance under the most demanding conditions.

Technical Specifications

Applications

• Long Casing Strings: Enables cementing of extended casing intervals (>3,000m) in a single trip by dividing the cement column into stages.

• Lost Circulation Zones: Reduces effective hydrostatic pressure on weak formations during cementing, preventing lost circulation and formation damage.

• Gas Migration Control: Provides an additional cement barrier to prevent gas migration behind casing in shallow gas zones.

• Salt Dome Cementing: Effective in salt formation cementing where cement contamination and washout are concerns.

• Dual-Stage Cementing: Allows selective cement placement across production and non-production zones, optimizing slurry design and cost.

Advantages

• Reduced Circulating Pressure: By cementing in stages, ECD (Equivalent Circulating Density) is significantly reduced, minimizing formation breakdown risk.

• Cost-Effective: Eliminates the need for multiple cementing trips, reducing rig time and operational costs.

• Reliable Operation: Precision-calibrated shear pins and smooth port geometry ensure consistent opening and closing at target pressures.

• Full-Bore After Drill-Out: Internal components are fully drillable, leaving a full-bore casing ID for subsequent operations.

• Customizable Opening Pressure: Shear pins can be configured to customer-specified opening pressure to match well conditions and cementing program.

• Verified Quality: Each unit undergoes functional testing, dimensional inspection, and ultrasonic C-scan verification before shipment.

Why Choose SANMON

Sanmon brings decades of oilfield equipment manufacturing expertise to every stage collar we produce. Our Tianjin factory houses advanced CNC machining centers, hot presses, and autoclaves, enabling complete in-house production from raw material to finished product. We utilize computerized tensile testing machines and ultrasonic C-scan systems for comprehensive quality assurance. Our technical team has extensive field experience in cementing operations and can provide application-specific recommendations, installation procedures, and post-job analysis support. With a proven track record of supplying stage collars to projects in the Middle East, Central Asia, and Southeast Asia, Junchi/SANMON delivers reliable, cost-effective cementing solutions. We prioritize fast response times, competitive pricing, and flexible order quantities to meet the needs of both large operators and smaller service companies.

FAQ

Q: What is the difference between hydraulic and mechanical actuation?
A: Hydraulic stage collars are opened by applying pump pressure against a closed end (baffle plate below), while mechanical types use a free-fall plug that lands on the opening seat to shift the sleeve.

Q: Can the opening pressure be customized?
A: Yes, we can install shear pins calibrated to open at your specified pressure, typically ranging from 1,500 to 2,500 psi.

Q: Is the stage collar drillable?
A: Yes, all internal components including the closing sleeve, seats, and plugs are manufactured from drillable materials compatible with PDC and roller-cone bits.

Q: What documentation is provided with each order?
A: Each shipment includes a material certificate, dimensional inspection report, pressure test chart, and certificate of conformance. Full MTR (Material Test Report) packages are available upon request.

Q: Do you provide after-sales support?
A: Yes, our engineering team provides technical support including installation guidance, troubleshooting, and field service coordination as needed.