This week, 6 Energy Equipment & Services stocks are improving their overall rating on Portfolio Grader. Each of these rates an “A” (“strong buy”) or “B” overall (“buy”).

This is a strong week for Core Laboratories NV (CLB). The company’s rating climbs to B from the previous week’s C. Core Laboratories NV serves the oil and gas industry by providing it with proprietary and patented reservoir description, production enhancement, and reservoir management services. For more information, get Portfolio Grader’s complete analysis of CLB stock.

Tenaris S.A. Sponsored ADR (TS) boosts its rating from a C to a B this week. Tenaris S.A. Sponsored ADR manufactures and supplies steel pipe products and related services for the world’s energy industry. For more information, get Portfolio Grader’s complete analysis of TS stock.

Diamond Offshore Drilling, Inc.’s (DO) ratings are looking better this week, moving up to a B from last week’s C. Diamond Offshore Drilling, Inc. is a global offshore oil and gas drilling contractor. The company also gets A’s in earnings revisions, earnings surprise, and earnings momentum. For more information, get Portfolio Grader’s complete analysis of DO stock.

RPC, Inc. (RES) improves from a C to a B rating this week. RPC, Inc. provides specialized oilfield services and equipment to independent and major oilfield companies. The company also gets A’s in earnings surprise. For more information, get Portfolio Grader’s complete analysis of RES stock.

This week, Transocean Partners LLC’s (RIGP) ratings are up from a C last week to a B. The company also gets A’s in earnings momentum and return on equity. For more information, get Portfolio Grader’s complete analysis of RIGP stock.

North Atlantic Drilling Ltd. (NADL) is seeing ratings go up from a C last week to a B this week. The company also gets A’s in earnings revisions, earnings surprise, earnings momentum, and free cash flow. For more information, get Portfolio Grader’s complete analysis of NADL 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.