This week, the overall grades of 7 Oil Gas & Consumable Fuels stocks are lower, according to the Portfolio Grader database. Each of these rates a “D” (“sell”) or “F” overall (“strong sell”).

Energen Corporation (EGN) slips from a C to a D this week. Energen Corporation engages in the development, acquisition, exploration, and production of oil, natural gas, and natural gas liquids in the continental United States. The company also gets F’s in sales growth, operating margin growth, earnings growth, earnings momentum, and free cash flow. For more information, get Portfolio Grader’s complete analysis of EGN stock.

ONEOK, Inc. (OKE) experiences a ratings drop this week, going from last week’s D to a F. ONEOK, Inc. is involved in the natural gas and natural gas liquids business across the United States. The company also gets F’s in sales growth and free cash flow. For more information, get Portfolio Grader’s complete analysis of OKE stock.

Dorchester Minerals, L.P. (DMLP) gets weaker ratings this week as last week’s D drops to a F. Dorchester Minerals, L.P. acquires, owns, and administers producing and nonproducing natural gas and crude oil royalty, net profits, and leasehold interests in the United States. The company also gets F’s in sales growth. For more information, get Portfolio Grader’s complete analysis of DMLP stock.

Slipping from a C to a D rating, USD Partners LP (USDP) takes a hit this week. The company also gets F’s in free cash flow. For more information, get Portfolio Grader’s complete analysis of USDP stock.

This week, VOC Energy Trust’s (VOC) rating worsens to a F from the company’s D rating a week ago. VOC Energy Trust acquires and holds a term net profits interest of the net proceeds from production of the interests in oil and natural gas properties in the states of Kansas and Texas. The company also gets F’s in sales growth. For more information, get Portfolio Grader’s complete analysis of VOC stock.

Vertex Energy, Inc.’s (VTNR) rating weakens this week, dropping to a D versus last week’s C. Vertex Energy, Inc. is a middle market consolidator, refiner and re-refiner of distressed petroleum streams, such as used oil, transmix, fuel oils and off-specification commercial chemical products. The company also gets F’s in sales growth, operating margin growth, earnings revisions, return on equity, and free cash flow. For more information, get Portfolio Grader’s complete analysis of VTNR stock.

This week, Abraxas Petroleum Corporation (AXAS) drops from a D to a F rating. Abraxas Petroleum Corporation is an independent energy company that engages in the acquisition, development, exploration, and production of oil and gas in the United States and Canada. The company also gets F’s in sales growth, operating margin growth, earnings growth, earnings revisions, earnings momentum, return on equity, and free cash flow. For more information, get Portfolio Grader’s complete analysis of AXAS 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.