Thermal heavy oil operators in the Northern Alberta oil sands in Canada have successfully been utilizing Well Tractors for their SAGD operations for over 10 years. Welltec’s reputation in the industry as a reliable and proven service provider continues to encourage operators to capitalize on Welltec’s packaged solution for ranging conveyance services.

Drilling 19 SAGD well pairs using Welltec’s 4½” Well Tractor® in combination with a customer supplied, magnetic ranging tool, Welltec® assisted with drilling 19 SAGD well pairs off a single pad from March to September 2011. The campaign was carried out over 185 continuous days during which Welltec operated for a total of 2.109 hours with zero non-productive time.

Welltec’s efficiency and reliability allowed the operator to maximize their drilling rig efficiency without being subject to downtime or equipment supply issues. Using Welltec’s complete SAGD service package, Well Tractors plus Welltec electric line, versus more traditional approaches also results in an inherently safer operation due to less equipment and people on location.

One of the methods by which heavy oil can be produced is from a technique called Steam Assisted Gravity Drainage (SAGD). A standard approach is to drill two parallel wells, approximately five meters apart, with an injector well positioned over a production well.

The upper well is used for steam injection into the formation which reduces the viscosity of the heavy oil, allowing it to flow. The heated oil then drains via gravity to the lower well from which it is produced.

The production well is typically drilled first and then the injector well is drilled using magnetic ranging technology to ensure the accurate placement relative to the producer.

Welltec provides the electric line and conveyance services for wellbore placement including gyro and magnetic ranging, cement evaluation, casing integrity and thermal distribution logs.