Base load mode

To define the Base Load for the refinery use the separate Crudes List under the Base Blend section and enter the Blend Ratio for each crude. You can choose between two modes of operation: Fix base blend ratios and Single balancing crude.

In Fix base blend ratios mode, the crudes in the Base Blend are initially blended in the entered ratio to make a Base Blend. This Base Blend is then blended with the Test Crudes in the percentage entered in the % test crude text box, and a Netback value reported for each separate test crude.

For example, if you have two base blend crudes with a ratio of 50% each, and a test crude with a ratio of 20%, the final blend ratios will be 20% for the test crude and 40% each for the base blend crudes.

In Single balancing crude mode, an extra Balancing Crude column appears, allowing you to select which of the base blend crudes is the balancing crude. The ratios of the non-balancing crudes in the base blend remain the same also in the final blend. The ratio of the balancing crude is reduced in the final blend to make room for the test crude.

For example, if you have two base blend crudes with a ratio of 50% each, and a test crude with a ratio of 20%, the final blend ratios will be 20% for the test crude, 50% each for the non-balancing base blend crude and 30% for the balancing crude.

For the Single balancing crude mode to work, the percentage of Balancing Crude in the Base Blend must be greater than or equal to the largest test crude percentage.

When analysing the result using Fixed % of final blend all Test Crudes are evaluated at the same percentage with the Base Blend. Selecting Variable % of final blend results in an extra column being added to the Crudes List, where the percentage of each Test Crude can be entered, allowing each Test Crude to be evaluated with a different percentage Base Blend.

It is possible to change the basis for reported pricing using the Benchmark menu. Setting the Benchmark menu to Test Crude results in an extra column Benchmark being added to the Crudes List. Set a single crude as the Benchmark. Netback results will be reported relative to the value of the Benchmark crude.

When defining the Blend Ratio it is possible to define it in either Relative or Absolute terms. When defining the Flow rate as Relative the amount of each crude in the Base Blend is defined using a ratio, such as the percentage in the blend. When defining Flow rate as Absolute the amount of crude in the Base Blend is defined in terms of the amount of that crude included per day. If the Blending Mode is weight based this is in tonnes; if the Blending Mode is volume based this is in barrels.

When using Absolute flow rate an extra option Fill to capacity becomes available. In this mode any spare capacity in the CDU (as defined in the refinery configuration), after the Base Blend has been included, is filled with the Test Crude. For example, if the refinery configuration defines the CDU capacity as 100,000 bbl/day, and the sum of the Base Blends amounts is 65,000 bbl/day, then fill to capacity would use 35,000 (100,000 - 65,000) bbl/day of Test Crude to evaluate the Netback margin.