Detailed Description :

Background

The Kinsale head gas field started production in 1978. The field is produced through two platforms, Alpha and Bravo, with Bravo production routed through the Alpha platform, co-mingled with the Alpha production and exported via a 24 inch pipeline to the onshore distribution system.

The earlier Kinsale Head re-configuration project carried out by ODE on behalf of it’s client equipped the Alpha platform with upgraded compressors during 2000 enabling compression of both Alpha and Bravo gas. Conversion of Bravo to a normally unmanned platform followed with subsequent tie-back of a second subsea well and modifications to the onshore terminal at Inch to allow the terminal to be controlled from Alpha outside of normal office hours

Following this re-configuration project further optimisation of the platforms operation by using the South West Kinsale field for gas storage purposes was initiated. This project was nominated as the Kinsale Head Re-profiling project.

Kinsale Head Re-profiling project.

The South West Kinsale field was brought on stream during 1999 with free-flow to the Bravo platform. As the field declined the profile the reservoir became ideal for use as gas storage to enable injection of surplus Kinsale gas during the summer, then export of the stored gas to shore during peak demand periods in the winter months.

In order to minimise the impact on the Re-configuration project, the re-profiling project was divided into three distinct phases:

• Phase 1 – Installation of a new re-injection compressor casing on Bravo (replacing the existing C-2000 compressor) configured in series operation with the existing C-4000 compressor train, to enable gas injection into South West Kinsale during the summer of 2001. Implementation of the phase 1 design was during spring 2001.
• Phase 2 – Installation of a new high pressure interfield pipeline between Bravo and Alpha for the import/export of HP gas to the SW Kinsale field, plus the installation of two new subsea gas injection wells on the SW Kinsale field.
• Phase 3 - Re-location of the re-injection compressor to the Alpha platform to enable the remote operation of Bravo in the un-manned mode.

When completed the re-profiling project provided the capability of operating the Alpha platform in five different operating modes as detailed below:

• Mode 1 – Platform shutdown
• Mode 2 – Platform exporting and/or S.W. Kinsale draw-down to Inch terminal only
• Mode 3 – Platform injecting to S.W. Kinsale only
• Mode 4 – Exporting to Inch terminal, spare production capacity used for injection to S.W. Kinsale
• Mode 5 – Injection to S.W. Kinsale, spare production capacity exported to Inch