The Analytical Framework
The EHA framework answers the question standard reserve reporting cannot: not how much oil is left, but why this operator will exit this field before the oil runs out.

Event History Analysis and
Organisational Ecology

The Meginráð UKCS EHA Series applies the Hannan-Freeman Organisational Ecology framework to the UKCS field population. Working Paper No. 1, 'The North Sea is not declining. It is being demolished.' July 2026 (V15.6.0, corrected). Click the Cox equation to open the full methodology, or download the working paper (PDF).

Why Standard Industry Analysis Is Insufficient

Standard industry analysis asks: how much oil is left, and what will it cost to produce? This is necessary but not sufficient. It explains what the reservoir contains. Not why an operator exits a field that still has reserves, why a regulator's approval timeline changes without any geological change, or why a fiscal shock propagates differently through a Major IOC versus a PE-backed independent.

Organisational Ecology treats the population of UKCS fields not as individual engineering problems but as a population of organisations subject to evolutionary pressures: founding rates, mortality rates, density dependence, and structural inertia. Three concepts operationalise this framework for the UKCS.

The Cox Proportional Hazards Model. Click to Open Full Methodology h(t) = h₀(t) × exp(β₁X₁ + β₂X₂ + … + βₖXₖ) Formula · Key · Covariate Specification · Stata Commands · Hazard Curve → →
🌊Density Dependence
As population density rises, founding rates first increase then decrease; mortality rates first decrease then increase. The UKCS peaked at 361 active fields in 2016. It has been in net decline ever since. Not because the oil ran out — because the population exceeded the carrying capacity of the infrastructure.
⚙️Liability of Obsolescence
Organisations face elevated mortality when their structures were designed for an environment that no longer exists. Mean active UKCS platform age in 2026: 21.7 years (OSPAR 2023, 84% coverage). 14 platforms over 40 years old. Maintenance costs escalate non-linearly. At 78% effective tax rate, the economics cannot absorb them.
🔏Structural Imprinting
Organisations bear the structural characteristics of the environment in which they were founded. The OGA (2015, $52/bbl) was imprinted on production urgency. The NSTA (2022, $100/bbl) was imprinted on energy transition urgency. These successive regulatory bodies carry fundamentally different institutional imprints.
Cox Proportional Hazards. Full Methodology

The Cox Model. Specification and Application

Core Equation h(t) = h₀(t) × exp(β₁X₁ + β₂X₂ + … + βₖXₖ)
  • h(t). The hazard function: the instantaneous probability that a field ceases production at time t, given it has not already done so.
  • h₀(t). The baseline hazard: the underlying mortality rate shaped by the ecological era (Era I–VII periodisation).
  • exp(β𝑖X𝑖). The covariate contribution: each variable shifts the individual field's hazard above or below the baseline by the factor exp(β).
  • β > 0. Covariate accelerates cessation. exp(β) = 2.0 doubles the CoP rate.
  • β < 0. Covariate protects against cessation. exp(β) = 0.5 halves the CoP rate.
  • EPL covariate. Time-varying: changes value at May 2022, November 2022, October 2024 intervention dates.

Hazard Ratio Illustration

The hazard ratio curve shows how cessation probability changes as water cut increases. Below 0.65: marginal elevation. 0.65–0.85: elevated risk zone. Above 0.85: exponential acceleration. 123 of 253 currently active UKCS fields with water-cut data sit at or above the 0.85 threshold (SFS=0.711).

Right-Censoring Note

271 fields remain active or suspended (219 fully producing, 52 suspended) as of the 2024 observation date. These are right-censored observations: they contribute to the denominator of the partial likelihood but not to the numerator. The Cox model handles this correctly. This is why EHA is more appropriate than logistic regression for this problem.