Enable Midstream Partners LP signed a 20-year firm transportation agreement with Oklahoma Gas and Electric Co. to support the utility's planned conversion of two 500-MW coal-fired generating units to natural gas.

The 228,000-Dth/d agreement, set to begin in late 2018, would be underpinned by the construction of 77 miles of 20-inch pipeline and associated metering facilities on the 2,200-mile Enable Oklahoma Intrastate Transmission LLC system, according to a Dec. 13 news release.

The midstream partnership also extended two service agreements with other power generators: a four-year extension of an agreement on Enable Gas Transmission LLC for about 126,000 Dth/d of enhanced firm service and a one-year extension on Enable Oklahoma Intrastate Transmission for about 305,000 Dth/d of firm service.

The Enable Oklahoma Intrastate Transmission pipeline system is connected to 14 other natural gas-fired generation facilities in the state.

Oklahoma Gas and Electric is a subsidiary of OGE Energy Corp.