Commissioning and start-up of large gas projects is a project in its own right, running in parallel to the main project. It requires years of advance planning. The management and detailed planning of this phase is crucial to the smooth transition from construction to operation.

This paper discusses the commissioning and start-up aspects of large projects in the oil and gas industry. These aspects are addressed in the context of a major "grass root" project which has been recently commissioned in Abu Dhabi.


In order to exploit the prolific gas condensate reservoirs in Abu Dhabi, a major "grass root" has been recently implemented. The project is located in a remote desert location 200 km south the city of Abu Dhabi. The project aims at producing gas and recovering the condensate for export. The residue gas is re-injected into the reservoir. Detailed description of the field development plan and project facilities are described elsewhere [1], [2]. This paper deals primarily with the commissioning and start up of the facilities.

The project facilities include:

  1. Producing wells, gas gathering pipelines, and remote gas stations.

  2. A central gas processing plant for condensate recovery and export, as well as high injection compressors.

  3. Injection gas network.

The project was implemented using two separate EPC (Engineering, Procurement and Construction) contracts:

  1. Upstream contractor; for the gas gathering system and remote stations together with the gas injection network.

  2. Downstream contract; for the central gas plant and condensate export pipeline.

This is shown schematically in Figure 1.

Planning for commissioning begins right from the start of a project. Before discussing commissioning activities, a typical project life cycle is first reviewed.

Project Life cycle

In recent years, the most popular contracting strategy for implementing large projects in the oil &gas sector has been the EPC approach. A single contract is awarded for the Engineering, Procurement and Construction (EPC) of the project.

In such a case, typical project phases are:

  1. Conceptual Design (pre-FEED)

  2. Front End Engineering Design (FEED)

  3. EPC Tender

  4. EPC

The duration to implement a project from concept to operations will vary depending on the particular project, but can be 4 to 5 years. It took 41/2 years to implement the "grass root" project referenced in this paper [2].

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