moved its headquarters to Fargo, North Dakota. The acquisition gave Conoco the red bar-and-triangle logo previously used by Marland. Conoco used the logo between 1930 and 1970, when the current red capsule logo was adopted. Conoco was based in Ponca City until 1949, when it moved to Houston, Texas. In 1998, Conoco acquired an interest in 10.5 blocks in the Kashagan Field in the Caspian Sea off Kazakhstan through the North Caspian Sea Production Sharing Agreement (NCSPSA). On November 26, 2012, in its largest acquisition ever, ONGC Videsh agreed to buy ConocoPhillips’ 8.4% stake in the Kashagan oilfield for approximately US$5 billion. On August 30, 2002, Conoco Inc. and Phillips Petroleum Company, whose headquarters were in nearby Bartlesville, Oklahoma merged into ConocoPhillips. By January 2002, the groups organizing the merger had selected Houston as the site of the headquarters. Governor of Oklahoma Frank Keating said that the move to Houston was "regrettable." In September 2004, the company invested $2 billion in Lukoil. In March 2006, ConocoPhillips acquired Wilhelmshavener Raffineriegesellschaft mbH, based in Germany. It also acquired Burlington Resources for $35 billion in cash and stock. On May 10, 2006, Richard Armitage, former deputy-secretary of the U.S. State Department, was elected to the board of directors of the ConocoPhillips oil company. On July 14, 2011, ConocoPhillips announced its intent to separate the company's upstream and downstream businesses into two stand-alone, publicly traded corporations, with the intent of maximizing shareholder value. On May 1, 2012, all midstream, downstream, marketing and chemical operations were separated into a new company named Phillips 66, headquartered in Houston. As a result, ConocoPhillips continued its operations as an upstream (exploration and production) company. In April 2012, ConocoPhillips sold its Trainer Refinery to Monroe Energy LLC, a subsidiary of Delta Air Lines. In May 2012, ConocoPhillips completed the corporate spin-off of its downstream assets as Phillips 66. In 2012, the company began the process of divesting onshore and offshore assets in Nigeria. ConocoPhillips contracted a French bank, BNP Paribas to sell all assets including a 17% stake in Brass Liquefied Natural Gas LNG, Oil Mining Lease OML 131 in which ConocoPhillips had a 47.5℅ stake. ConocoPhillips operated in Nigeria for more than 46 years. In January 2013, Conoco announced that it would sell its Rocky Mountain assets to Denbury Resources for $1.05 billion. In July 2016, the company agreed to sell a 35% stake in three Senegalese deepwater