An anticipated drop in exploration spending has prompted Schlumberger to restructure its WesternGeco marine seismic fleet to lower the company’s operating costs.

In a Dec. 2 filing with the U.S. Securities and Exchange Commission, the company said it plans to reduce its fleet size to nine survey and six source vessels by year-end 2014, from a total of 15 survey and eight source boats at year-end 2013.

“As a result of this restructuring, Schlumberger expects to record a pretax impairment charge of approximately $800 million in the fourth quarter of 2014, primarily relating to the six Explorer-class vessels acquired at a premium in the 2007 purchase of Eastern Echo Holdings Plc. as well as to certain other seismic assets,” the document stated. “Schlumberger will not incur any significant cash expenditures as a result of this impairment charge.”