INTERNATIONAL energy services group Weatherford has developed a rigless integrated well service package at the heart of which is a capillary string deployment system for chemical injection into live gas wells where water is an issue. The primary target initially will be wells in the Southern Gas Basin sector of the UK North Sea.
In essence, this new package, dubbed the Multi Functional Well Maintenance System (WMS), will be capable of evaluating, maintaining and remediating mature wells, effectively giving them a fresh lease of life.
While capillary technology has been in use for a considerable period in North America and around Europe, this is the first time it has been made available in such a compact form and which has been packaged with a suite of complementary service technologies. The Weatherford system is capable of deploying
The overarching objective is to offer a cost-effective, versatile toolbox that may enable a borderline gas well with severe water problems to remain viable, according to Ian Smith, business group manager – intervention services for Weatherford in Aberdeen.
WMS is capable of conducting the following operations:
Continuous chemical injection to assist in optimising well flow.
Safety valve installations/ remediation.
Real-time/memory data acquisition.
Slickline.
Deployment of an array of thru-tubing applications.
Smith suggests that the use of WMS also offers the potential for reducing workovers due to scale, paraffin, corrosion and salting problems. Crucially, the design takes into account the space and crane weight restrictions that are typically found on Southern Gas Basin installations and, for that matter, small gas platforms in other sectors of the North Sea, including offshore Netherlands and Denmark.
It can also be utilised aboard satellite platforms that have typically been inaccessible to larger systems. It is for this reason that the system has been designed in a modular fashion, with the aim of keeping the weight of each component under 1,000kg, thus delivering a smaller footprint.
Besides being relatively easy to deploy from small platforms, this also makes it a convenient size for handling easily and safely aboard offshore support vessels and for road logistics.
According to Smith, WMS also means fewer people are required, despite the systems suite of capabilities. A further knock-on benefit will be reduced operational costs and fewer vendor-client interfaces.
Although the package is compact, this does not mean that its ability to cope with standard-sized equipment is compromised.
For example, in the case of slickline, WMS can handle the full standard range. It can deal with conventional interventions, plus carry out intelligent slickline operations (trigger, slick-pump, and provide an alternative to E-Line interventions), memory logging and surface readout intervention operations.
Turning to thru-tubing services deployment by wireline, capabilities include:
Water shut-off and tubing integrity.
Single trip straddle systems.
Mechanical and inflatable plugs and packers.
Retrofit completion.
Safety-valve installations.
Gas-lift valve installations.
Jet-pump installations.
Sand control.
Sand screen hang off operations.
The safety valve remediation element is based on the Weatherford Renaissance system and is a combination of new safety valve, packer, wellhead and capillary technology which allows the retrofit of a new surface controlled Subsea Safety Valve (SSSV). The first WMS package will be going on display in late July at Weatherford’s Technology and Training Centre in Bridge of Don, Aberdeen, prior to deployment.
The objective is to build a stable of either three or four packages and, while the emphasis will be on the UKCS, deployment in other parts of the North-west Europe Continental Shelf is a possibility, too.