Quicksilver Resources Inc. (NYSE: KWK) has closed the previously announced acquisition and exploration agreement with SWEPI LP , a subsidiary of Royal Dutch Shell Plc , on December 28, 2012.

Quicksilver now owns a 50% interest in approximately 320,000 net acres in the Sand Wash Basin in Northwest Colorado, which will be jointly developed with SWEPI. The agreement also established an area of mutual interest covering in excess of 850,000 acres in the basin.

SWEPI paid Quicksilver an equalization payment for 50% of the acreage contributed by Quicksilver in excess of the acreage that SWEPI contributed. Further terms of the transaction were not announced.

The company also provided an update on additional transaction efforts, as well as an update on Horn River volumes and recently-completed wells in the Sand Wash Basin and in the Midland Basin in West Texas.

Fort Worth, Texas-based Quicksilver Resources is an independent oil and gas company engaged in the exploration, development and acquisition of oil and gas, primarily from unconventional reservoirs including gas from shales and coal beds in North America.