Installation of WFV using high expansion Well Key® for new well stimulation and production

Downhole hardware
JCO151502 First installation of WFV using High Expansion Well Key® for new well stimulation and production
  • Well type Oil / gas producer
  • Reservoir type Sand
  • Short term delivery 6 weeks from order to delivery


An operator in West Africa expanded the objectives of their first well in a new field from producing first gas to producing first gas and first oil. This change in goals shortly before spudding challenged the drilling team to find and deliver the best solution for an optimum completion.

Welltec® proposed incorporating the 4-1/2” Welltec® Flow Valves (WFV) with multiple flow area (choking) configurations. These would enable the client to retain maximum control of the dual zone completion without having to make major alterations to their previous, single zone well design.

In addition to multiple choke settings, the WFV is ISO14998 V3 qualified to 8,000 psi burst at 135°C and can be manufactured with varying specifications to meet operators’ needs. It is operated via a reliable, e-line conveyed toolstring consisting of the Well Tractor®, Well Stroker® and Well Key.

Within six weeks of initial discussion, five WFVs with three different, customer specified flow areas (chokes) were delivered for the operation. Additionally, the Well Stroker and Well Key HEX (high expansion) implemented within this same time period to function within the 4-1/2” WFV after passing through a 2.75” restriction in the previously planned upper completion.


Four, 4-1/2” WFV were run as part of the lower completion inside the previously run, cemented, and perforated 7” liner. One WFV was positioned in the planned oil zone at 9,285 ft (2,830m) MD along with a third party fracking sleeve and three additional WFVs were positioned in the planned gas zone between 8,907 – 9,005 ft MD (2,715m MD and 2,745m MD) with 50 ft (15m) spacing.

The two zones were separated by hydraulically set packers. The lower completion was run on a 4-1/2” frac string with the planned purpose of facilitating the fracking operation before being pulled and replaced by the upper completion.

The lower completion and frac string were run to TD without incident. But prior to the frac operation the 3rd party frac sleeve failed to open despite multiple attempts using coil-tubing. Welltec used Computation Fluid Dynamics (CFD) modeling to evaluate the option of fracking through the WFV and determined the valves function would not be affected by this operation.

Deciding to proceed with this option, the Well Tractor, Well Stroker and Well Key HEX were used to quickly open the WFV within the oil zone. The operator then continued with the planned frac without having to pull the completion or resort to other, alternative deconstructive solutions.

A proppant frac was initiated through the WFV using x-linked fluids and proppants. A total of 723 bbls was pumped up to maximum surface pressure of 7,100 psi (490 bar).

After completion and clean-up of the oil zone, Welltec opened all three WFVs in the shallower gas zone on a single descent. This allowed the operator to evaluate the full flowing gas production prior to determining their desired choke settings. The three, different flow configurations on each of the WFVs across the gas zone gave the operator multiple options to choke the flow as desired for optimum production.


Incorporating this new product, the operator was quickly able to overcome the challenges presented both by the new objective of producing oil as well as that from the malfunctioning, 3rd party frac sleeve.

This was the world’s first installation of Welltec’s Flow Valves and demonstrated the flexibility and ease by which it can be ordered, delivered, deployed and operated.

Within six weeks the WFV’s were manufactured and delivered along with the modified Well Stroker and Well Key HEX. Shortly thereafter they were run in this new well completion and performed flawlessly, despite being subject to unplanned contingency operations.

• First WFV installation
• First prop frac through a WFV
• Three WFVs opened in one run

First job using newly modified, high expansion Well Key HEX.