services : pro-kc sucker rod coupling & connection system

Permian Rod Operations introduces a revolutionary innovation in sucker rod connection design.

This connection has undergone extensive laboratory and field-testing and finite element analysis.  The PRO/KC Connection System outperformed standard API connections by 250% in tension and torque tests.  In fatigue testing, the PRO/KC System lasted an average of 6 times more cycles than API connections under the same cyclic load conditions.

Pictured to the right is a cut-out comparison view of a standard API connection and the PRO/KC connection.  Pins and couplings are machined to a precise length and made up to a center torque button with the patented PRO/KC make-up unit.

Pre-load is confirmed by measuring actual pin stretch with a dial indicator; this provides a connection with equal contact pressure on both pin shoulders, equal pre-load stretch of both pin necks and equal contact pressure of both pin noses against the center torque button, creating a pre-load stretch at the coupling center.  This effectively doubles the contact surface and friction area to carry additional loads and resist back-out.

This design provides the strongest, most stable and solid sucker rod connection available in tension, torsion, bending and fatigue.

Couplings are machined to achieve an end-face width as large as possible for maximum pin shoulder contact area.  Pins are machined so that all pin ends have exactly the same dimension from the shoulder to the pin end and the shoulder and pin nose are exactly true relative to each other.  Pin ends also receive wet fluorescent magnetic particle inspection and are shot-peened to improve micro-finish and enhance fatigue resistance.  The torque buttons are locked into place so the connections always break on the same side during work over.

This connection can be applied to all new or inspected used rod strings, API or non-API sizes.  Tension/torsion testing was performed at CFER labs in Edmonton Alberta, Canada using 20,000 lb. tension and torque to failure.  The PRO/KC connection averaged 250% more torque to failure than API samples of the same size and material specs.

Extensive fatigue testing was performed at Southwest Research Institute in San Antonio, Texas on 1.0 inch PRO/KC connections and API 1.0 inch connections using loads of 69,500 lb. tension and 7,800 lb. compression at 10 cycles per second.  The PRO/KC connection averaged 600% more cycles to failure than API connections.

The PRO/KC was field tested by a major oil company on a 3,900 foot well in eastern New Mexico with a progressive cavity pump installed.  Prior to PRO/KC installation, this well had been pulled 15 times in a 38 month period with multiple rod string failures.  Once installed, the PRO/KC string performed flawlessly for 13 ½ months enduring 5 separate failure events, 2 of which resulted in failure of surface components and 3 were down-hole.  The top drive hex shaft failed; the polish rod thread sheared; the top drive belts burned off; the polish rod coupling split.

These failures were related to pump rotor seizure which results in tremendous forces being applied to the rod string during which no PRO/KC connections failed.  The fact that the PRO/KC System was able to withstand this brutal punishment is a testament to its robustness.

Contact Permian Rod Operations for more information and arrange for a trial string for your toughest well.  Preventing work-overs due to premature connection failures will pay substantial dividends with less downtime and lost production.

‹ SUCKER ROD INSPECTION & RECLAMATION SERVICES ›
9009 N. County Rd. West • Odessa, TX 79764 • Tel: (432) 367-4149 • Fax: (432) 367-7015
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