The grades of 3 Energy Equipment & Services stocks are better this week, according to the Portfolio Grader database. Every one of these stocks has an “A” (“strong buy”) or “B” overall (“buy”) rating.

Patterson-UTI Energy, Inc. (PTEN) improves from a C to a B rating this week. Patterson-UTI Energy, Inc. provides land-based drilling services to major and independent oil and natural gas companies. For more information, get Portfolio Grader’s complete analysis of PTEN stock.

North American Energy Partners Inc. (NOA) is seeing ratings go up from a C last week to a B this week. North American Energy Partners Inc. is a resource services provider to oil and natural gas, and other natural resource companies, with a primary focus in the Canadian oil sands. The company also gets A’s in free cash flow. For more information, get Portfolio Grader’s complete analysis of NOA stock.

Recon Technology Ltd. (RCON) gets a higher grade this week, advancing from a C last week to a B. Recon Technology Ltd. is a holding company that provides services designed to automate the extraction of petroleum in China. For more information, get Portfolio Grader’s complete analysis of RCON 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.