Surface commingling is the surface mixing of the production from two or more lease tracts and/or unit participating areas into a common manifold, separator, tank, and/or gathering system.

In Texas, surface commingling generally involves the surface commingling of two or more Texas Railroad Commission (RRC) oil lease numbers and/or RRC Gas ID numbers.

The lessee of a state lease must obtain written permission from the GLO, per 31 TAC §9.35(a)(3), before surface commingling oil or gas production from a state lease or pooled unit with the production from any other private or state lease and/or unit into (i) a common manifold and/or separator, (ii) common storage, (iii) a common gathering system or pipeline, or (iv) to utilize an off-lease gas supply to inject gas for lift purposes into any oil- or gas-producing formation in the leased premises.

These requirements are in addition to, and apart from, the requirements of any other state and/or federal entity.