In the mineral space, a release is a document or legal instrument filed in the public records of a county or parish whereby a mineral lessee releases a mineral lessor from the terms of an O&G lease previously filed in the public record.  The mineral rights owner is the lessor, the party acquiring the mineral rights by way of an O&G lease is the lessee.  The term release does not mean to lease a mineral right again.  Since there is no accepted industry term for that action, we can write it as "re-lease" when discussing a mineral rights owner executing a new O&G lease.

Why those in the industry mention a release.  A release of lease is filed by the lessee as their choice or after a demand for the release by the lessor.  The benefit for the lessor is that the release, once filed in the public record, makes a landman's job easier when they are looking to lease a mineral owner's mineral rights.  Without the release filed of record, a landman would have to take additional time and steps to figure out whether the old lease would still be in force.  When production stops for an extended period of time, an O&G lease expires based on the language in the lease.  In some cases "operations" may serve to hold the lease in force without any production or royalty payments but that is for a set and limited amount of time.  A few months may not be enough depending on the lease language.  When many consecutive months have gone by with no production or payments, it is up to the lessor to seek a release.  It is not the lessee's responsibility to file one.  Upon proper demand notice, a lessee is required by law to file a release.

When the Haynesville Shale land rush took off, operators and the land companies seeking leases on their behalf cut many corners.  One was not performing the due diligence to research whether an old lease was still in force or not for small mineral tracts.  It was quicker to just force pool those small tracts then it was to try and figure out whether the lease filed in the public record was still in effect.  The land rush was a frenzy and competition was fierce.

The failure of mineral rights owners to seek a release also made for a situation where the operator of an old well could attempt to restart production and create a legal question as to the lease that technically terminated for lack of production.  This would either not be questioned by the lessor or the lessor might face the prospect of filing suit to enforce the fact that their lease had indeed expired.  Operators stood to make big bucks off those old leases that covered all depths when they assigned their deep rights to companies looking to drill the Haynesville and Bossier shales.  An old lease with an old royalty fraction was a quick way to get rich by assigning those deep rights for the royalty fractions being offered at the time, 25% - 30%.  That difference between a 12.5% royalty that the operator owed to the lessor and the assignment fraction was equal to many hundreds of millions of dollars.  Dollars that should have gone to the mineral owner instead of to the operator of the old well.