The widening acceptance of intelligent well technology beyond initial applications in traditional areas such as the Gulf of Mexico, the North Sea, etc. is illustrated by the first intelligent well to be installed off the east coast of Canada. The well was installed by Baker Oil Tools last spring in a gas-producing field 180 miles (290 km) off the coast of Nova Scotia, with water and reservoir depths of approximately 80 ft (25 m) and 14,500 ft (4,420 m), respectively. The well was drilled and completed from a jackup-type rig and is being produced from a fixed, unmanned platform.

Despite shallowwater depths, the field's remote location, lack of rig availability and harsh, arctic conditions make operating costs very high. In order to improve project economics, the operator desired a completion solution that would accelerate production by commingling three producing zones while simultaneously providing remote selective zonal isolation to be used in the event of water breakthrough, sand production problems or early depletion of any of the zones. Commingling the zones without selective zonal isolation could lead to water breakthrough and additional back pressure from any of the zones. It could also cause cross-flow between zones due to the loss of pressure or depletion of any of the zones. Any of these occurrences could hamper overall production.

A completion with mechanical sliding sleeves and appropriate sealing technology could meet the flow control and selective zonal isolation requirements for the well. However, it would require intervention, including rig mobilization, in an environment where operating costs compete with those of deepwater. An intelligent well system would meet all well objectives and eliminate the costs and risks associated with well intervention. Baker Oil Tools was named project integrator and was charged with interfacing and coordinating with multiple vendors, including the drilling contractor and providers of wireline services, tubulars, fluids, wellhead and tubing hanger, pressure and temperature gauges, and fiber optic distributed temperature sensing (DTS).

Intelligent completion design

The intelligent completion design for this application included an InForce Hydraulic Intelligent Well System for flow control. A specially designed 95⁄8-in. x 53⁄4-in. Premier packer was used for reliable zone isolation in the high pressure/high temperature gas production environment. The packer provides performance similar to that of a permanent packer graded V0 (zero gas bubbles acceptance criterion) under ISO 14310 standard, with the additional benefit of removable capability. The packer also incorporates seven pressure-testable feed-through ports for by-passing the 1⁄2-in. outside diameter (OD) lines that control and monitor the intelligent well system.

Remote flow control is enabled by three HCM Plus hydraulically operated, non-elastomeric sliding sleeves. Three CM mechanically operated sliding sleeves are also included in the completion string, to be used only as contingency. Electronic pressure/temperature gauges and fiber optic distributed temperature sensing devices monitor downhole conditions. The completion uses 81⁄2-in. OD lines to the surface. Four hydraulic lines operate the three sliding sleeves (common close configuration). Two lines are used for the pump-down fiber optic DTS. One cable is devoted to the four pressure/temperature gauges, and one hydraulic line controls a Baker sub-surface safety valve.

The metallurgy for all completion components uses Super 13 Chrome corrosion-resistant alloy (CRA) material designed for sour environments.

New, inverted hydraulic sliding sleeve

To meet the needs of this well, Baker Oil Tools developed a specially modified, inverted version of its HCM Plus hydraulic sliding sleeve. Typical intelligent wells call for the flow control valves to be placed above the perforations, with the control chamber above the flow ports. This design creates an upward flow path from the perforations through the flow ports to the control chamber.

In this particular case, the operator wanted to place the flow control valves below the perforations because of expected accumulations of sand production at the bottom of the packer. Placing the flow ports immediately below the perforations could combat sand accumulation by enabling the fluid flow to wash the sand out and avoid perforation plugging. However, the conventional configuration of the sliding sleeve, with the control chamber above the flow ports, would have limited flow area. To alleviate this situation, a new, inverted version of the sleeve was developed.

New blast joint design protects IWS lines across perforations

Running the IWS lines in this well across the perforations called for additional protection against potentially damaging blast from high-flow, high-pressure gas. Specially designed blast joints with control line shields provided the needed protection. The new blast joints have since been used in other intelligent well systems throughout the world and are on their way to becoming standard for protecting IWS lines across perforations in high-pressure, high-flow-rate wells.

Managing the project

As project integrator, Baker Oil Tools was charged with interfacing and coordinating with multiple equipment and service providers, meeting a tight delivery schedule, and developing and implementing stringent Quality and Safety plans.

The project's Quality plan included 100% dimensional inspection of each component, third-party inspections, special testing and traceability. Safety issues, including hazards, operating procedures and contingency plans, were addressed through several operator/service provider meetings that culminated in the development of written procedures for each step and for the overall project.

System installation

The first offshore East Canada intelligent well was installed in late May/early June of this year, largely under conditions of high winds, low temperatures and heavy rain. A global team of experts in each aspect of the completion was assembled to oversee the operation.

In order to save rig time and increase reliability, the system sub-assemblies were assembled and pre-plumbed in a local Baker Hughes facility. Barreting of threaded connections allowed for the alignment of eccentric components. Additionally, control lines were subjected to rigorous pressure testing, and the tests were charted in accordance with operator mandate.

System installation was helped significantly by using a tubular services company-supplied hydraulic pusher arm to push the four flatpacks containing the IWS lines against the tubing, making it easier to secure clamps and protectors.

Once the completion was landed, a Baker selective Sur-Set plug was run to isolate the packers in order to enable the tubing to be pressure tested before the packers were set.

Eastern Canada's first offshore intelligent well system was delivered just 4 months after the order was placed and installed a month later. Two months after installation, the field is producing as per operator expectations, with sand production successfully controlled and the individual producing zones having been successfully, remotely isolated for well evaluation. The operator has commended the completion services team for its exceptional performance and, as a result of the successful implementation of this project, scheduled additional intelligent well system installations in other assets.