Reuters reports that “after years of declining output, major oil companies have ramped up crude production this year, just as they are being battered by a plunge in prices due to already excessive supplies.”  

“Executives have taken pride in seeing billions worth of investments in new technologies and new fields in places such as Brazil, the North Sea and West Africa kick in and boost output.”  

“But most of the investment was made three to five years ago when oil was about $100 a barrel, around double current levels.”  

“Now, the new production is contributing to a glut in supply due mostly to the North American shale boom, a faltering global economy and OPEC’s decision not to cut output.”