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Concentration Risk: How Much of the Book Rides on the Top 10 Wells?

A producing book with 60% of its output coming from a handful of wells behaves very differently than one spread evenly. Here's how to measure top-well concentration from the record before you underwrite it.

Two operators pump the same 4,000 bbl/d. One does it across 300 wells averaging a little over 13 bbl/d each. The other does it with 40 wells, and 8 of them carry more than half the volume. Same headline number, completely different risk profile.

Concentration is one of the first things a careful buyer or lender should quantify, because it drives everything downstream: how exposed the cash flow is to a single downhole failure, how steep the aggregate decline will run, and how much of your valuation is really a bet on a few flush-production wells that are already past their peak. It's also one of the easiest things to overlook when you're staring at a monthly total.

The question you'd actually ask

You don't need a spreadsheet full of lease codes to start. Connect an AI client to the Wellsite data lake and ask it plainly:

"For [operator] in [county], rank their producing wells by the last three months of oil, and tell me what share of total production comes from the top 10."

Behind that question, the platform pulls the operator's producing wellbores, sums recent production per well, orders them, and returns the cumulative share. The number that comes back — say, the top 10 wells account for 58% of oil volume across a 120-well book — is your concentration ratio. That single figure reframes the whole package.

Why the ratio matters more than the total

A high concentration ratio isn't automatically bad, but it changes what you're underwriting:

Layering in age and decline

The ratio alone is a snapshot. The next question sharpens it:

"For those top 10 wells, show me first production dates and the recent decline rate on each."

Now you can see whether your concentration sits in flush new completions or in seasoned wells that have already flattened onto a shallow tail. Ten wells producing half the book at a 45% annualized decline is a very different asset than ten wells at a 12% decline. The record carries the production history to compute both, so you can benchmark each of those anchor wells against its county average and its offsets — is this well genuinely outperforming, or was it just brought on last quarter and hasn't declined yet?

That distinction separates durable cash flow from a cliff you're buying at the top of.

Comparing books apples to apples

Concentration also makes operator-to-operator comparison honest. Run the same top-10 share across a few candidate packages and you can rank them not just by volume but by how the volume is distributed. A package with a 35% top-10 share and shallow declines on its anchor wells is a steadier revenue stream than one at 65% riding on three-month-old wells, even if the second one shows a bigger current rate. The record lets you compute the same ratio the same way across every operator, so you're not comparing one broker's cherry-picked highlight reel to another's.

Watching it after you close

Concentration isn't only a diligence metric — it's an operating one. If you own the book, the same top-10 wells are exactly the ones worth putting alerts on. A production-change or decline flag on a well that carries 8% of your total revenue deserves a same-day look; the same flag on a 4 bbl/d stripper can wait for the monthly review. Setting alerts against your concentration list means your attention tracks your dollars, not your well count.

The takeaway

Before you value a producing package — or manage one — ask the record who's actually carrying it. The top-10 share, the age and decline of those anchor wells, and how they benchmark against the surrounding area tell you whether you're buying a diversified stream or a bet on a few wells that may already be past their best month. It's a five-minute question with a real bearing on the price you should pay.