Schlumberger has just announced another round of layoffs.The oil service company says it plans to cut another 11,000 jobs worldwide. It did not specify how many of those jobs are in the Houston area.in response to plunging oil prices. This second round of layoffs brings the total number of job reduction to about 15 percent.""Looking at the macro environment, the global economy continues its steady recovery, and oil demand is still expected to increase by 1 million bbl/d in 2015. However, the significant reductions in E&P spend are starting to impact supply in both North America and internationally, and supply is expected to tighten further in the second half of the year," the company said in a prepared statement.Schlumberger is not the only company downsizing. BP, Swift Energy and Apache are among the other businesses in the energy business who have slashed their workforce.