Active Magnetic Ranging While Drilling: Prototype Tool Test

Abstract

A well intercept operation has the scope to drill into an existing well. Similarly, some infill drilling operations are conducted with the scope of avoiding interception with other wells. A prototype of a tool for Active Magnetic Ranging While Drilling (AMR) without the use of a wireline operation has been developed. The main scope of the current article is presenting the results of a prototype test of this new tool in attest well. The ranging tool emits a low frequency alternating current into the formation to reach the target well, and then run through that's casing back to the well being drilled. This electric current set up a variable magnetic field that is measured by the AMR tool determining the direction towards the target well as well as the distance. If drilling a relief well, 10 - 25 wireline runs are needed before the target well is intercepted. The present AMR tool is fully integrated in the drill pipe and, thus, all the tripping operations are avoided. A prototype of an active magnetic ranging tool on the drill pipe has been developed. This tool is outlined in detail in the paper. Most focus will be given to a performance test conducted in a research well in Norway. A drill pipe is placed in a vertical well, being the target well. The AMR tool was run in the research well and the direction and distance to nearby target wells was measured. The set-up and the results of this logging operation conducted on a drill pipe is described in detail. It is shown how the direction and distance between the two wells are measured using the tool. Most intercept operations are not relief well drilling, but cases where a well needs to be intercepted because a well section shall be connected to another well, or during plug and abandonment operation. The tool can also be used for avoiding collision with other wells, which is a relevant scope for drilling infill wells in older fields or radiator wells in geothermal drilling. The tool and its potential are outlined in the paper.