Statistical differences for primary energy products

For several years there has been a problem regarding statistical difference between the supply and use of petroleum products in the Norwegian Energy Balance. This should not be unexpected from a country exporting almost 90 per cent of its petroleum products. Just minor discrepancies between production and export on the supply side of the balance may result in significant imbalances with the use side figures. There has, however, been a tendency for a positive bias in the statistical difference for a long time, which has caused uncertainty whether the domestic use of petroleum products might have been underestimated. Therefore a project was launched in 2012 in order to address the bias and make corrections if possible.

In Norway, most of the produced petroleum products are primary , while most of the domestic use relates to secondary petroleum products. Hence, separate energy balances for primary and secondary petroleum products were elaborated in the project. To further increase the transparency, more detailed product categories and one transfer item were elaborated as well. New data on primary petroleum products were identified and collected, in order to establish alternative export figures and new revision controls. No alternative data on secondary petroleum products was found, and hence these products were not prioritized.

The new export data is consistent with the production figures, and most discrepan¬cies can be discussed with the data owner without breaking the confidentiality rules. Hence, the new data provides a solid basis for quality control. A similar crosschecking of the original export data from the external trade statistics (ETS) is tedious, or for some products almost impossible. Moreover, corrections must be made in the energy balance to obtain consistency between the export and produc¬tion data.

All new data is readily available from the Norwegian Petroleum Directorate, one terminal and one pretreatment facility, respectively, and suitable for routine revision control. Compiling them for use in the energy balance is relatively simple. One dataset is not distributed by destination country, and in international reporting of country specific figures this data should instead be used to adjust the current ETS export data.

Based on new and original data, two alternative detailed energy balances for primary petroleum products were established, for revision purposes. Most causes of statistical difference for primary petroleum products were found due to the new data and revision methods, and the statistical differences for these products were significantly reduced.

 The new export data will be used for all primary petroleum products in the energy balance instead of ETS export, due to superior revision possibilities. All correc¬tions developed in this project will be considered implemented as well. Whenever an unacceptably high statistical difference occurs in a product category containing primary petroleum, the revision controls and the detailed energy balance setup developed in this project will be used to diagnose the problem. Routines are established to obtain consistency between the energy balance and ETS, including routines for coordinated revision and publishing.

The new export data on crude oil was used in the published energy balance for 2014, based on findings in this project. Moreover, revised export figures on crude oil from 2013 onwards in the ETS were published in November 2015.

Author: Håkon Frøysa Skullerud