Since the application of slickline technology for wellbore intervention, the need for a measurement device to determine not only strain on the wire but forces applied to the toolstring at depth has been required.

What stands between a successful intervention and a 'miss-run' is the skill of the slickline operator and the surface weight indicator known as a load cell.

This paper will address the lesson learned from applying 'Impact Sensors' to slickline toolstrings in over 100 applications since it's launch in September 2005. The paper will also cover a case study that utilized the technology to better understand downhole conditions and their effects on toolstrings of various geometries. Completion technology has altered greatly and the results of directional drilling technology and horizontal completion architecture have proven to enhance the delivery of hydrocarbons to surface.

The application of new technology has been implemented by the Electric Line, Coil Tubing, Drilling, Reservoir Analysis and other groups in the industry, however the application of new technology to the slick line intervention business has been greatly lacking and because of this many completion engineers develop completion installation programs with the least amount of wire in the hole as possible.

Much of this reluctance is due to the perceived risk associated with deploying slick line into the well bore where an 'unknown event' may cause irreparable damage to the completion system or at the very least a costly exercise in equipment recovery.

The application of impact sensors to the slick line toolstring eliminates much of associate unknown risk factors by supplying the operator with known parameters being applied at depth.


The focus of this paper is the application of the technology primarily for slick line intervention but not limited to this as the technology is being adopted in the Coil Tubing industry where lack of down hole bottom hole assembly information is similar to that of the slick line operations.

The primary reason for the deployment of Impact Sensors is to offer the end user digital data relayed on charts that displays the actual forces being applied to a given toolstring configuration at depth. Toolstring configurations differ greatly and there can be literally hundreds if not thousands of ways to configure a toolstring assembly for a given installation or retrieval.

Completion geometry also differs from field to field and therefore toolstring dimensions must change to accommodate this. Where the field operates on small tubular then smaller toolstring and therefore smaller impact forces are at play. The same is true for larger tubulars.

Horizontal completion technology greatly accelerates production but greatly reduces functionality of slick line deployed equipment. Well bore deviation causes friction to act on toolstrings thereby reducing functionality of the impact jars which ultimately impedes the operation, sometimes to the point that the operation cannot be completed successfully.

Whilst the application of this technology greatly benefits both the service provider and the operator it cannot remove the need for the surface weight indicator or 'load cell'. To function properly it requires the application of three critical components; the impact sensor, the load cell and the skill of the slick line engineer.

Impact Sensor Overview
Downhole Equipment

The design of the impact sensor must be in line with today's' slick line toolstring geometry and because of this the system comprises a single modular structure that emulates slick line weight bars both dimensionally and in physical properties.

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