Well type
Producer, cased hole
Max. temperature
43.84°
Fishing depth
9,100 ft (2,774m)
Deviation
35°
Pressure
3,626 psi (250 bar)
Temperature
~230°F (~ 110°C)
The worst had happened. During a routine e-line operation on a Norwegian platform, the setting tool had malfunctioned resulting in a partially set plug and a stuck tool. After parting the weakpoint, the fishing neck had been subjected to four runs with heavy duty fishing equipment on braided wire, including 207 jar attempts. Not surprisingly, the fishing neck was showing signs of wear.
Welltec® suggested using the new Well Stroker XXS as a contingency to avoid the possibility of a workover rig. The challenge was twofold: to complete the setting sequence and retrieve the setting tool at 9,100 ft (2,774m). The plug had been partially set but the setting tool had failed before it could break the stud connecting to the plug. The operator anticipated that the force needed to shear the stud and free the setting tool could be up to 40,000 lbs.
Planning was complicated by the worn out fishing neck. It was uncertain how many latches and to what force the fishing neck could sustain. Applying the new Well Stroker XXS would ensure that the most force available from an e-line tool would be put to work from the onset. As well, two Welltec Release Devices® (WRDs) were combined in the toolstring, one below the Well Stroker and one below the cable head. These addressable devices would allow further contingencies to mitigate risk and increase safety.
As expected, there were some difficulties to latch the worn fishing neck. The first attempts were unsuccessful as the fish unlatched from the overshot. However, on the fourth attempt a good latch was observed with 900 lbs overpull applied. The tool was then activated and with 31,500 lbs force seen at surface, the shear stud parted completing the setting sequence and freeing the stuck setting tool.
Despite the worn fishing neck, the fishing operation was completed in just four grapple attempts. The operator was very pleased to get the well work back on track while avoiding the costs of a workover rig. The application of this new technology and the crew’s performance saved an estimated five days of rig time.
The well is now ready for the next phase of operations and the Well Stroker XXS has proved its worth to the operator. In fact, the operator now uses Welltec for any fishing job where a slickline company has failed or where differential pressure makes other operations too risky.
Despite the worn fishing neck, the fishing operation was completed in just four grapple attempts.