Shifting of Isolation Valve

April 2006

In a deviated producer with stand alone screens in Africa an operator experienced failure in an isolation valve that refused to open despite several attempts with pressure cycles. It became clear that the operator needed to shift the valve mechanically and opted for the Well Key run in combination with the Well Stroker and Well Tractor due to the small size of the Well Key.

Because the Well Key is shorter than a coiled tubing shifter, the Well Key has a better chance of locating in the profile with the estimated amount of junk above the ball. Welltec’s casing collar locator gave a precise indication of where the tool string was in the completion and the operation was carried out quickly and to the operator’s satisfaction.

Savings

The entire Well Stroker/Well Key intervention was performed in less than 12 hours and only required 2 people, which far surpasses other approaches. As the Well Stroker is far more precise than coiled tubing with depth control and forces applied, time and therefore money were saved. Subsequently, the operator concluded that the Well Stroker/Well Key would be the prime contingency because depth control and forces applied are more precise than when using coiled tubing.

HSE Benefits

• Precise intervention
• Reduced required personnel on rig
• Eliminated heavy lift requirements
• Safer operation as the Well Stroker eliminates the use of explosives

Well Data

Equipment used:       Well Tractor, Well Stroker and Well Key
Maximum deviation:  54.53º
Operation time:         11 hrs and 45 mins