Williams Cos. and separately, Williams Partners LP, on Tuesday completed acquisitions that build their portfolios in the Marcellus and Bakken shales.

Williams Partners paid $150 million to buy Cabot Oil & Gas Corp.’s midstream assets in Susquehanna County, PA (see Shale Daily, Nov. 22). In the deal the partnership obtained about 75 miles of gathering pipelines and two compressor stations that are currently gathering 230-240 MMcf/d of Cabot’s gas output.

The partnership also agreed to a 25-year dedicated gathering agreement with Cabot for its northeastern Pennsylvania production. The agreement covers an area of mutual interest that includes about 138,000 net acres.

Williams and its entities hold about 100,000 net acres in the Marcellus Shale.

In related news Williams Cos. paid $925 million cash to buy a private leasehold in North Dakota’s Bakken Shale (see Shale Daily, Nov. 16). The transaction gives the company 100% of the interests in Dakota-3 E&P Co. LLC.

Dakota-3 has about 85,800 net acres on the Fort Berthold Indian Reservation in the Williston Basin and produces 3,300 b/d net from 24 existing wells. Williams said it would continue an existing contractual arrangement for services with the contract operator and field services provider after closing. Dakota-3 now has three rigs operating on its acreage, and Williams expects to double it to six rigs by 2012.