A production packer failed to set via the primary method of pressuring the tubing as this did not activate the sleeve actuator. The preferred contingency was to slide open a setting module and then pressure up the tubing to set the packer, which required a plug to be set inside the tubing below the setting module prior to pressuring up.

As the well was highly deviated (85°), the work needed to be performed either on drill pipe, coiled tubing, or conveyed by the Well Tractor®. Initially, Sonangol had considered coiled tubing, but chose Welltec® due to lower cost and reduced time compared to coiled tubing or drill pipe.

For the production packer operation, the Well Tractor conveyed the Well Stroker® to the desired depth to set the plug in the tubing. Welltec then opened the setting module using the Well Stroker, again conveyed by the Well Tractor. The rig pressured up on the tubing and set the upper completion packer.

Finally, the Well Stroker pulled the plug. In all runs, a Welltec Release Device® was placed below the Well Stroker to provide a robust contingency of command release in case the plug or sleeve was stuck.

The benefits of providing the Well Stroker is that it can provide high pushing and pulling forces downhole where and when required in order to easily set and pull plugs, shifts sleeves and valves. When combined with the Well Tractor, this force can be delivered at any location within the well, regardless of the deviation.

Welltec’s wireline equipment provided a number of benefits over CT and drill pipe:
• Faster runs required

• Four days of floater rig-time saved

• Avoided rig-up of CT lifting frame

• Avoided heavy lifts of CT lifting frame

• More cost-effective

Welltec is now the provider of choice for Sonangol as a primary mechanical intervention option.