This week, the overall grades of three Energy Services stocks are lower, according to the Portfolio Grader database. Each of these rates a “D” (“sell”) or “F” overall (“strong sell”).

This week, Pacific Drilling S.A. (NYSE:PACD) falls to a D (“sell”), worse than last week’s grade of C (“hold”). PACD also rates an F in Portfolio Grader’s specific subcategory of Earnings Revisions. The stock currently has a trailing PE Ratio of 121.50. For a full analysis of PACD stock, visit Portfolio Grader.

This week, ION Geophysical’s (NYSE:IO) rating worsens to a D from the company’s C rating a week ago. ION Geophysical provides geophysical technology, services, and solutions for the global oil and gas industry. The stock gets F’s in Earnings Revisions and Earnings Surprise. To get an in-depth look at IO, get Portfolio Grader’s complete analysis of IO stock.

This is a rough week for Noble Corp. (NYSE:NE). The company’s rating falls to D from the previous week’s C. Noble is an offshore drilling contractor, engineer, and consultant for the oil and gas industry. The stock also gets an F in Cash Flow. For more information, get Portfolio Grader’s complete analysis of NE stock.

Louis Navellier’s proprietary Portfolio Grader stock ranking system assesses roughly 5,000 companies every week based on a number of fundamental and quantitative measures. Stocks are given a letter grade based on their results — with A being “strong buy,” and F being “strong sell.” Explore the tool here.