Apache first quarter 2015 earnings: May 7 The Denver-based oil-and-gas producer lost $353.7 million in the fourth quarter and also made the Wolfe Research list of likely takeover candidates-but the company said late last month that it will only pursue non-core asset sales rather than a "significant" transaction. Whiting Petroleum ( WLL ) became the largest producer in North Dakota's Williston Basin when it bought Kodiak Oil & Gas last December, assuming $2.2 billion of Kodiak's debt but gaining enough wells to help boost proved reserves 78 percent last year. It also sold $1 billion of common stock and $2 billion in convertible notes last month, which caused its stock to slump as it coincided with the management decision to not find a buyer.