Breitburn Energy Partners LP fka BBEPQ

[floatingt]

Impairments are a significantly subjective evaluation. In Breitburn's case, a heavily biased one even by their own admission:

We consider the inputs for our impairment calculations to be Level 3 inputs. The impairment reviews and calculations are based on assumptions that are consistent with our business plans.

The key phrase there is "consistent with our business plans."

From IFRS 13:

Level 3 inputs

Level 3 inputs inputs are unobservable inputs for the asset or liability. [IFRS 13:86]

Unobservable inputs are used to measure fair value to the extent that relevant observable inputs are not available, thereby allowing for situations in which there is little, if any, market activity for the asset or liability at the measurement date. An entity develops unobservable inputs using the best information available in the circumstances, which might include the entity's own data, taking into account all information about market participant assumptions that is reasonably available. [IFRS 13:87-89]