The ratings of 17 oil and gas stocks are down this week, according to the Portfolio Grader database. Each of these rates a “D” (“sell”) or “F” overall (“strong sell”).

Crescent Point Energy Corp. (CPG) earns an F (“strong sell”) this week, moving down from last week’s grade of D (“sell”). In Portfolio Grader’s specific subcategories of Earnings Revisions, Earnings Surprise, Cash Flow and Margin Growth, CPG also gets F’s. The stock currently has a trailing PE Ratio of 54.70. For more information, get Portfolio Grader’s complete analysis of CPG stock.

This week, Golar LNG Partners (GMLP) falls to a D (“sell”), worse than last week’s grade of C (“hold”). Golar LNG Partners owns floating storage and regasification units and liquefied natural gas carriers. To get an in-depth look at GMLP, get Portfolio Grader’s complete analysis of GMLP stock.

The rating of Cosan Limited Class A (CZZ) declines this week from a D to an F. Cosan is a fully integrated company in the renewable energy and infrastructure segments in Brazil. The stock gets F’s in Cash Flow and Margin Growth. For more information, get Portfolio Grader’s complete analysis of CZZ stock.

Goodrich Petroleum Corporation (GDP) experiences a ratings drop this week, going from last week’s C to a D. Goodrich Petroleum explores, develops, produces and acquires oil and natural gas properties. The stock receives F’s in Earnings Growth, Earnings Revisions, Equity and Cash Flow. As of Dec. 5, 2014, 38.1% of outstanding Goodrich Petroleum Corporation shares were held short. To get an in-depth look at GDP, get Portfolio Grader’s complete analysis of GDP stock.

EXCO Resources, Inc. (XCO) gets weaker ratings this week as last week’s D drops to an F. EXCO Resources is an oil and natural gas company involved in the exploration, exploitation, development and production of onshore North American oil and natural gas properties. The stock gets F’s in Earnings Surprise, Equity and Cash Flow. As of Dec. 5, 2014, 12.4% of outstanding EXCO Resources, Inc. shares were held short. For more information, get Portfolio Grader’s complete analysis of XCO stock.

Calumet Specialty Products Partners, L.P.’s (CLMT) rating weakens this week, dropping to an F versus last week’s D. Calumet Specialty Products produces hydrocarbon products in North America. The stock gets F’s in Earnings Growth, Earnings Momentum and Earnings Revisions. Cash Flow and Margin Growth also get F’s. To get an in-depth look at CLMT, get Portfolio Grader’s complete analysis of CLMT stock.

Dynagas LNG Partners LP (DLNG) earns a D this week, falling from last week’s grade of C. The stock also gets an F in Cash Flow. Shares of the stock are changing hands at twice the rate they were a week ago. For more information, get Portfolio Grader’s complete analysis of DLNG stock.

Slipping from a C to a D rating, Plains All American Pipeline, L.P. (PAA) takes a hit this week. Plains All American Pipeline is involved in interstate and intrastate crude oil pipeline transportation and crude oil terminalling storage activities. To get an in-depth look at PAA, get Portfolio Grader’s complete analysis of PAA stock.

This week, TransCanada Corporation’s (TRP) rating worsens to an F from the company’s D rating a week ago. TransCanada develops and operates energy infrastructures, including natural gas pipelines. Shares of the stock have been trading at an exceptionally rapid pace, up fourfold from the week prior. For more information, get Portfolio Grader’s complete analysis of TRP stock.

This is a rough week for Enbridge (ENB). The company’s rating falls to F from the previous week’s D. Enbridge is in the business of transportation and distribution of crude oil and natural gas primarily in Canada and the United States. The stock gets F’s in Earnings Growth, Earnings Momentum and Cash Flow. Shares of the stock have been changing hands at an unusually rapid pace, up 895.4% from the week prior. The trailing PE Ratio for the stock is 59.40. To get an in-depth look at ENB, get Portfolio Grader’s complete analysis of ENB stock.

StealthGas (GASS) is having a tough week. The company’s rating falls from a C to a D. StealthGas offers marine transport services for liquefied petroleum gas producers and users. In Earnings Growth, Earnings Revisions, Earnings Surprise and Cash Flow the stock gets F’s. For more information, get Portfolio Grader’s complete analysis of GASS stock.

The rating of Ultrapar Participacoes S.A. Sponsored ADR (UGP) slips from a D to an F. Ultrapar Participacoes is engaged in the fuel distribution and chemical businesses in Brazil. To get an in-depth look at UGP, get Portfolio Grader’s complete analysis of UGP stock.

This week, Gevo (GEVO) drops from a D to an F rating. Gevo operates as a technology development company for biobutanol. The stock gets F’s in Equity, Cash Flow and Sales Growth. For more information, get Portfolio Grader’s complete analysis of GEVO stock.

PDC Energy (PETD) earns a D this week, moving down from last week’s grade of C. PDC Energy is an oil and gas company with drilling and production operations in the Rocky Mountains, the Appalachian Basin and Michigan. The stock gets F’s in Earnings Revisions and Cash Flow. To get an in-depth look at PETD, get Portfolio Grader’s complete analysis of PETD stock.

Chevron Corporation (CVX) experiences a ratings drop this week, going from last week’s D to an F. Chevron is an integrated energy company with operations in countries located around the world. For more information, get Portfolio Grader’s complete analysis of CVX stock.

This week, Kinder Morgan, Inc. Class P’s (KMI) rating worsens to an F from the company’s D rating a week ago. Kinder Morgan is a pipeline transportation and energy storage company. As of Dec. 5, 2014, 14.2% of outstanding Kinder Morgan, Inc. Class P shares were held short. The stock has a trailing PE Ratio of 34.60. To get an in-depth look at KMI, get Portfolio Grader’s complete analysis of KMI stock.

Jones Energy, Inc. Class A’s (JONE) rating weakens this week, dropping to a D versus last week’s C. The stock gets F’s in Earnings Momentum, Earnings Revisions, Earnings Surprise and Cash Flow. For more information, get Portfolio Grader’s complete analysis of JONE 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.