The long tail of a mature basin

This page demonstrates the SubScout story format. Every number in the text is computed from the data when the page is built: hover one to see its exact value, and find all of them in Basis of analysis. The basin, its 7 fields and its operators are invented.

and

Most fields peak early, then fade

Grey is context. One field is in colour because it behaves differently: it held its plateau for 14 years, against a typical 3.

and

A tie-back extended the pattern

A second story colour joins, and a highlight marks the moment that matters. The lines keep their identity; only their emphasis changes. Field C still provides 37% of the basin's output in 2025.

but

But the finds got smaller

The busiest decade brought 52 discoveries, yet the average find has shrunk roughly 27-fold since the first decade.

therefore

Therefore: small, near infrastructure, and price-sensitive

The average 2020s discovery holds about 15 million Sm³ o.e.. Finds that size only pay as tie-backs, and drilling falls hard when prices do: quarterly wells fell 48% after 2015.

Field C held its plateau for 14 years

Production, thousand Sm³ o.e. per day (switch units in the top bar)

Source: SubScout synthetic basin
Units: k Sm³ o.e./d; 1 Sm³ o.e. = 6.29 boe
Confidence: Observed

The average find is a fraction of what it was

Average discovery size by decade, million Sm³ o.e.

Source: SubScout synthetic basin
Confidence: Derived
Note: Sizes are illustrative and rounded.

The detail

The drilling record shows the price cycle as pale bands: the 2015–16 and 2020 troughs.

Drilling follows the oil price

Exploration wells per quarter

Source: SubScout synthetic basin
Confidence: Observed

The fields, ranked by how long they held their plateau:

Two fields held their plateau far longer than the rest

Two fields held their plateau far longer than the rest
Field	Operator	First oil	Peak k Sm³ o.e./d	Plateau years	2025 k Sm³ o.e./d
Field C	Operator A	2004	44	14	27.2
Field F	Operator D	2013	22	9	22.0
Field B	Operator B	2001	38	3	2.1
Field E	Operator B	2011	31	3	9.3
Field A	Operator A	2000	52	2	3.0
Field D	Operator C	2006	27	2	2.2
Field G	Operator E	2016	18	2	8.1

Source: SubScout synthetic basin
Confidence: Observed
Exception: no-pie: Not used; listed here only to demonstrate how a declared exception appears

Appendix

Basis of analysis

Sources

SubScout synthetic basin. Generated by examples/demo/make_data.py. Not real fields, operators or volumes.
Header band, synthetic section, 1000 to 1436 ms; the reservoir top in the highlight colour. Synthetic section generated by examples/demo/make_data.py; no real survey. Source file: make_data.py. The seismic texture is Observed (relative amplitude, TWT [ms], polarity normal); the surfaces are Interpreted picks drawn where they exist, nothing smoothed.

Conventions

Confidence. Observed measured or published by the source; Derived our calculation from observed data, method stated; Interpreted depends on a model, assumption or judgement.
Units. Volumes in Sm³ oil equivalent, with boe via the toggle (1 Sm³ o.e. = 6.29 boe). P90 means a 90% chance of exceeding: the low case.
Narrative arc. abt (and → but → therefore).

Numbers in this story

Every number quoted in the text, with its exact value, method, source and confidence
Number	Exact value	Shown as	Method	Confidence
`longest_plateau`	14 years	14	Plateau length of Field C, years (SubScout synthetic basin)	Derived
`n_fields`	7	7	Count of fields in the dataset (SubScout synthetic basin)	Observed
`typical_plateau`	3 years	3	Median plateau length across fields, years (SubScout synthetic basin)	Derived
`share_2025_c`	0.368272	37%	Field C's share of 2025 production (SubScout synthetic basin)	Derived
`peak_decade_finds`	52	52	Discoveries in the 1990s (SubScout synthetic basin)	Observed
`size_drop`	27.3333	27	Average find size, 1960s ÷ 2020s (SubScout synthetic basin)	Derived
`avg_2020s`	15,000,000 Sm³ o.e.	15 million	Average discovery size in the 2020s, Sm³ o.e. (SubScout synthetic basin)	Interpreted
`wells_drop`	0.483444	48%	Fall in quarterly wells, 2011–13 average to 2015–16 average (SubScout synthetic basin)	Derived

Figures

Every figure with its source, confidence and any declared exception
Figure	Form	Source	Confidence	Notes and exceptions
Field C held its plateau for 14 years	line	SubScout synthetic basin	Observed
The average find is a fraction of what it was	bars	SubScout synthetic basin	Derived	Sizes are illustrative and rounded.
Drilling follows the oil price	heat	SubScout synthetic basin	Observed
Two fields held their plateau far longer than the rest	league	SubScout synthetic basin	Observed	Exception (no-pie): Not used; listed here only to demonstrate how a declared exception appears

About this demo. The data is generated by examples/demo/make_data.py. It shows the format, the house style and the checks; it makes no claim about any real basin.