Crossover Connectors That Make Mismatched Strings Work

The oilfield is full of odd couples—strings that don’t quite meet in the middle. That’s where a Tubing Crossover earns its keep. Built by Hengshui Weijia Petroleum Equipment Manufacturing Co., Ltd., the product—simply called Crossover—bridges different thread types and sizes for tubing and casing. In fact, it’s one of those quiet parts that only gets noticed when it’s missing.

What it is and why drillers still care

A Tubing Crossover connects, say, EUE tubing to BTC casing or steps tubing sizes up/down during completions, workovers, geothermal hookups, even CCUS injection strings. Many customers say the real win is field flexibility—“it saved the run” comes up more than you’d think. And, to be honest, in tight schedules, a well-made crossover can be the difference between NPT and a clean handover.

Typical specifications (real-world use may vary)

How it’s made (short version)

• Materials: API-grade alloy steel bar/forging with traceable heats.
• Methods: CNC turning, premium-thread cutting (API 5B gauging), stress relief, phosphating.
• Testing: Thread gauges (L1, taper, lead), drift, hydro test ≥ 1.1× WP, MPI/UT on critical zones, hardness mapping.
• Service life: ≈ 3–10 years depending on cycles, corrosion, and make-up discipline.
• Industries: Upstream O&G, geothermal, well intervention, salt-cavern and CO₂ injection strings.

Field use, advantages, and a bit of reality

Operators use a Tubing Crossover to marry legacy inventory to new programs, reduce urgent procurement, and simplify workover logistics. Advantages? Faster rig-up, fewer thread mismatches, and—surprisingly—better inventory ROI. Caveat: follow torque-turn charts and thread dope specs; most failures come from rushed make-up, not metallurgy.

Vendor snapshot (indicative)

Customization, certification, and test data

Weijia supports special pin-box mixes, material upgrades (e.g., 13Cr), and sour-service controls to NACE MR0175. Sample hydro test: 10,000 psi for 15 min, no visible leakage; torque-turn curves logged and archived. Certification stack typically includes ISO 9001, heat traceability, and API thread gauge records.

Quick case study

Middle East workover: mismatched 2-7/8" EUE tubing to 7" BTC liner top. A custom Tubing Crossover (L80 to P110, copper-plated threads) arrived in 9 days, passed yard hydro at 12,500 psi, and eliminated a planned two-day delay. The superintendent’s note was short: “It just worked.”

What users say

• “Finish is clean, threads gauge first time.”
• “Nice to get 1–2 piece rush orders without drama.”
• “Torque-turn sheets make the auditors happy.”

References

1. API Specification 5CT – Casing and Tubing. American Petroleum Institute. https://www.api.org/products-and-services/standards
2. API Specification 5B – Threading, Gauging and Thread Inspection. American Petroleum Institute. https://www.api.org/products-and-services/standards
3. ISO 15156 / NACE MR0175 – Materials for H2S service. International Organization for Standardization. https://www.iso.org/standard/51819.html
4. ISO 9001:2015 – Quality management systems. International Organization for Standardization. https://www.iso.org/iso-9001-quality-management.html