Magnetic Ranging
Whether the objective is to intersect or avoid a nearby wellbore, conventional surveying techniques may not be adequate. Since the inception of magnetic ranging technology more than 30 years ago, the ability and the need to reference nearby wellbores has increased significantly, as have magnetic ranging capabilities.

Sperry Drilling services is the leader in magnetic ranging with the most extensive portfolio of ranging services. We can provide the right ranging solution, whether for intersection or avoidance, for accurately determining the relative positions of two or more wellbores.

Determining the distance and direction between wellbores is critical in many applications. In addition to being used for relief-well applications, parallel twinning for developments such as steam-assisted gravity drainage (SAGD) and coalbed methane (CBM) horizontal-to-vertical intersections have almost exclusively used magnetic ranging technology. As more fields mature, magnetic ranging technology can be used in other applications such as plug and abandonment wells, frac recovery, and for in-fill applications where anti-collision and relative wellbore positioning between multiple wells is of concern.

Wellbore Intersection
•Relief well
•Plug and abandon
•Multiple intersections
•Intersect verticals and horizontals
•Connect end to end (river crossing)
•Open/cased hole re-entries

Wellbore Avoidance
•Twinning (SAGD, Frac Recovery)
•In-fills and re-drills
•Pad optimization
•Anti-collision

Active and Passive Magnetic Ranging
Magnetic ranging technology can be classified as either "active" systems, which generate the necessary magnetic field, or "passive" systems, which rely on the remnant magnetic field of the steel in the target wellbore.

In addition, both active and passive ranging technologies are further categorized as either access-dependent solutions, which depend upon having access to the existing (target) wellbore to deploy a magnetic source or receiver; or access-independent solutions, which do not require access to the existing (target) wellbore, such as in relief well applications.


Steam-Assisted Gravity Drainage (SAGD) Solutions
With the introduction of the steam-assisted gravity drainage (SAGD) drilling technique, production efficiencies of 60 percent or better are now possible in heavy oil reserves.

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