Antrim Shale Mineral Rights

The Antrim is a shallow, low-pressure biogenic gas play, and most of the Michigan Basin acreage under it has been held on the same leases since the late 1980s boom.

The Antrim Shale sits shallow across the northern Michigan Basin, centered on Otsego, Antrim, Montmorency and surrounding counties, and it was developed almost entirely with vertical wells drilled between the mid-1980s and mid-1990s. There has been very little new drilling in this play for two decades, which changes how we approach every interest we look at here compared to an active shale basin. The wells are old, the decline curves are long and shallow because the gas is biogenic rather than thermogenic, and many leases have been held by production on marginal volumes for thirty-plus years.

We buy royalty interests tied to these legacy Antrim wells, and occasionally small overriding royalty interests assigned out of the original operator packages. Because this is a mature, low-activity play, our review focuses less on new spacing orders and more on confirming the lease is still validly held and the well is still economically producing rather than sitting in a marginal-well exemption status.

Why Antrim decimals look different from a shale-boom state

Antrim wells were mostly drilled on 40- or 80-acre vertical spacing rather than the large horizontal units common in newer plays, so your royalty decimal is usually tied to a small, fixed tract rather than a pooled section that could change. That is a title-friendly feature, since it means we can usually confirm the decimal against the original lease and a single well record without chasing amended pooling orders. What takes more work is confirming continuous production, because Michigan's marginal well program allows some Antrim wells to report low but qualifying volumes for years, and a check that has shrunk to a few dollars a month does not always mean the lease has lapsed.

We pull the well's production history from the state regulator before quoting, and we ask sellers for a recent statement even if the dollar amount is small, because a live statement is the clearest proof the lease is still held.

Old leases, flat royalty language, and gas measurement

Many original Antrim leases were written with royalty language that predates modern post-production cost disclosure standards, and deductions for gathering, compression and dehydration on this shallow gas can take a visible bite out of a small check. We read the lease's royalty clause against the current statement to see whether deductions are being taken consistent with what was actually negotiated, because a below-market decimal on paper sometimes reflects deductions that were never clearly authorized. This does not change what we can pay for the interest, but it is part of the documentation review we do before extending an offer.

Heirship on interests that have not moved in decades

Because so much of the Antrim play has been quiet since the 1990s, it is common for the recorded owner of an interest to be a person who has been deceased for years, with heirs receiving checks under an informal arrangement rather than a recorded transfer. Michigan probate and the county register of deeds records are where we start, and we can often work from a will or affidavit of descent rather than requiring a full new probate, provided the chain from the original lessor to the current heir is documented well enough to record a deed.

If there are multiple siblings or cousins each holding a fraction of the same original tract, we can buy just your share without requiring the rest of the family to sell.

What a marginal, mature well is worth to us

We are upfront that a value on a mature Antrim interest is set against a shallow decline that is already most of the way down its curve, not against the kind of new-well upside you would see in an active horizontal play. Any number we quote is tied to trailing production and current gas pricing rather than a promise, and it will vary with how the well has been performing over the last several statements. For sellers who simply want the small, irregular checks off their hands and the paperwork resolved, that trade is usually still worth making even on a modest volume interest.