Abstract
The electro-hydraulic firing head features a novel combination of electronic control over a hydraulic firing mechanism. An electronics module senses wellbore pressure and, upon seeing a distinct signal, opens a valve that allows downhole pressure to operate a hydraulic firing mechanism. The hydraulic firing mechanism is extremely reliable, does not have sufficient energy to fire until safely downhole, and is immune to electromagnetic interference. The electronic control system prevents inadvertent pressure applications from prematurely activating the firing head. This combination of electronic control and hydraulic firing in a firing head offers unique and distinct benefits in safety, operational flexibility, and risk reduction.
On a recent job, a TCP assembly with dual electro-hydraulic firing heads (stacked vertically for redundancy) was run below a permanent packer and isolation valve. The electro-hydraulic firing head enabled this deployment to be conducted safely, with reduced risk of NPT, and in a single trip. A hydraulic firing head could not be used in this application due to the risk of pressure communication through the isolation valve during packer setting and testing. The TCP assembly was hung off the packer with a ballistically actuated automatic release. The electro-hydraulic firing head has a detonating cord bypass, allowing it to detonate guns below at the same time as actuating the release above. The availability of this firing head allowed this job to be performed more safely, more efficiently, and with reduced risk of NPT than was previously possible.
This paper will present an overview of the design and features of the electro-hydraulic firing head, discuss the recent successes in utilizing its unique abilities to enable more efficient job plans, and discuss other unique applications for this technology.
