With oil prices mired in a lengthy slump and energy producers scrambling to prop up sliding earnings, a common tactic has been to cut production to better cope with the oil and natural gas glut.

About $1.5 trillion of potential global investment, including money that could go into North America’s shale oil boom, is “out of the money” at current oil prices close to $50 per barrel and is unlikely to go ahead, reports Christopher Adams for the Financial Times.

With low oil prices pressuring oil producers’ bottom line, industry experts expect capital spending on new projects to decline by 20% and 30% on average, according to Wood Mackenzie, an energy consultancy. The consultant calculated that about $220 billion in investments have been cut so far, or $20 billion more than previously estimated two months ago, after the recent price declines.

Spending cuts by the companies found in ETFs such as the Energy Select Sector SPDR (NYSEArca: XLE) affect the holdings in funds such as the Market Vectors Oil Service ETF (NYSEArca: OIH), the largest oil services exchange traded fund. [More M&A for Oil Services ETFs]

“The world’s oil companies have canceled or delayed final investment decisions on ~150 projects that could wipe out 19M bbl/day from the world’s hydrocarbons and stay underground for several years longer than expected amid lower crude oil prices, according to a new report from Tudor Pickering Holt,” reports Seeking Alpha.

On the back of some recent strength in the sector, strength in the energy sector, integrated oil companies have adjusted to the low oil environment by reducing costs, divesting businesses and squeezing suppliers for better deals.