Background and Parties

Cimarex Energy Co. held a mineral lease covering a portion of a Ward County property, while Anadarko Petroleum Corp. held a larger mineral interest in the same property as co-tenant. The parties had previously entered into a settlement agreement requiring Anadarko to provide Cimarex with an accounting of and share of the value of production from two wells on the property. Cimarex brought a breach of contract action alleging Anadarko failed to comply with this settlement agreement. Anadarko moved for summary judgment, asserting that Cimarex's lease and interest in the property had terminated. The district court granted summary judgment in favor of Anadarko and awarded attorney's fees.

The Lease Termination Dispute

The central issue was whether Cimarex's mineral lease extended into the secondary term based on production from wells operated by its co-tenant Anadarko. Cimarex argued that its payment of royalties on its share of Anadarko's production extended the lease beyond the primary term, and that Anadarko was estopped from asserting the lease had terminated because the lessors had accepted these royalty payments. Cimarex also contended that the settlement agreement between the parties constituted a joint operating agreement that should be interpreted to extend the lease term. Anadarko countered that the habendum clause in Cimarex's lease required production attributable to Cimarex's own leasehold operations, not merely co-tenant production.

The Court's Analysis

The Court of Appeals affirmed the summary judgment in favor of Anadarko on multiple grounds. First, the court held that the habendum clause in Cimarex's mineral lease did not permit Cimarex to rely on Anadarko's production to extend the lease into the secondary term. The court found that the lease's language required production from Cimarex's own operations, not production by a co-tenant on separate leasehold interests.

Second, the court rejected Cimarex's estoppel argument, holding that the lessors' acceptance of royalty payments by Cimarex on its share of Anadarko's production did not estop Anadarko from arguing the lease had terminated. Third, the court determined that the settlement agreement between Cimarex and Anadarko was not a joint operating agreement that would alter the lease's termination provisions.

Because Cimarex's lease had terminated, Anadarko's top lease covering the same mineral interests became effective. The court noted that a top lease is a subsequent oil and gas lease which covers one or more mineral interests that are subject to a valid, subsisting prior lease (the bottom lease), and that a top lease becomes effective as to those mineral interests upon termination of the bottom lease.

Significance

This decision addresses the critical distinction between a lessee's own production and co-tenant production for purposes of extending a mineral lease into its secondary term. The case also clarifies that payment of royalties on co-tenant production does not create an estoppel preventing assertion of lease termination, and that settlement agreements regarding production allocation are not automatically treated as joint operating agreements affecting lease duration.