Crude plant rationalisation

The situation

Designed 50 years earlier, our client’s crude stabilisation plant had been designed for a specific crude oil. The duty for the plant was changing – crude oil production flowrates were declining and the blend in the feed stream to the plant was shifting. Operating costs were driven by a high equipment count in the plant and reliability was becoming a challenge due to the age of the assets.

To address these issues, our client wanted to provide simple, reliable crude stabilisation service combined with a low operating cost by:

• Reducing the equipment count

• Improving the reliability of remaining equipment

• Ensuring reliable operation at lower flowrates

• Reducing the footprint of the plant

With a plant of this scale, complexity and age there were many competing issues that needed to be assessed, selected and defined. The complexity of the competing objectives had inhibited progress on addressing the many issues affecting the plant today and into the future.

Approach

To define and assess competing issues, we applied our decades of knowledge on the plant’s operation. We worked with our client’s projects, operations, maintenance and integrity teams to define the problems at hand and determine the desired outcomes.

The overall project was broken into specific objectives and elements, including:

• Single crude stabilisation train operation

• Reliable liquids export

• Reliable gas and propane refrigerant compression

• Energy efficiency and operational gains

• Shutdown and demolition of redundant crude trains and parts of the remaining crude train

We combined detailed technical analysis of each of the technical elements to identify the range of options available. By breaking down the complex into simpler elements, the solutions were easier to understand and evaluate.

Extensive analysis of past operating problems and predictions of future operating problems was conducted to inform the decision analysis process. Practical upgrade options, maximising the use of existing facilities were identified which allowed the capital cost to be constrained to the target budget range.

In many cases the individual problems could be addressed on a stand-alone basis while in other cases, the solution for one element was linked to other elements of work. These inter-relations between elements were mapped accordingly.

The outcome from the review was a set of 30 sub-projects, addressing specific elements of the overall objectives, which when combined, would meet the overall project objectives. The individual projects addressed life extension issues, turn-down issues, reliability issues and operating cost reduction issues.

Results

Advisian turned an intractable problem into a series of clearly understood projects. Completion of the individual sub-projects would allow the overall objectives of the overarching project to be met. Providing clear justification for each individual sub-project meant they could be reviewed and endorsed by management.

Approval for the projects was received from management allowing prompt initiation of the work.

A highly complex and inter-related problem set with the Crude Stabilisation Plant was translated into a set of sub-projects with clear objectives and scopes of work

Managed obsolescence issues within the plant to allow a substantial extension in the practical life