Despite the need for accurate oil and gas reserves estimates which honor disclosure requirements of the United States Securities and Exchange Commission (SEC), a number of exploration and production companies have allegedly overstated and subsequently written down their reserves during the last 20 years. Reserves write-downs are of great interest to numerous groups involved in the reserves estimation process and outcome, including estimators, managers, investors, creditors, and regulators. Considering the magnitude and nature of some alleged overstatement cases, it appears that some of these parties may benefit from a better understanding of reserves reporting, the relative risk of overstatements, the regulatory environment and enforcement procedures, and identifying questionable reserves data. After discussing the context and importance of reserves and write-downs, there is a detailed examination of the SEC, including the agency's reserves reporting requirements, and their enforcement methods. A number of alleged overstatement and write-down "case studies" are presented, with details on the specific Federal Laws alleged to have been violated by corporations or individuals and then cited by the SEC and shareholder lawsuits. We also conclude that there may be greater write-down potential due to the updated SEC reserves reporting guidelines. A comprehensive series of systematic questions have been compiled and quick-look graphical techniques have been developed that may be used to gain insight into -and potentially raise questions about- an operator's reserves data.

Despite the need for accurate oil and gas reserves estimates which honor disclosure requirements of the United States Securities and Exchange Commission (SEC), a number of exploration and production companies have allegedly overstated and subsequently written down their reserves during the last 20 years. Reserves write-downs are of great interest to numerous groups involved in the reserves estimation process and outcome, including estimators, managers, investors, creditors, and regulators. Considering the magnitude and nature of some alleged overstatement cases, it appears that some of these parties may benefit from a better understanding of reserves reporting, the relative risk of overstatements, the regulatory environment and enforcement procedures, and identifying questionable reserves data. After discussing the context and importance of reserves and write-downs, there is a detailed examination of the SEC, including the agency's reserves reporting requirements, and their enforcement methods. A number of alleged overstatement and write-down "case studies" are presented, with details on the specific Federal Laws alleged to have been violated by corporations or individuals and then cited by the SEC and shareholder lawsuits. We also conclude that there may be greater write-down potential due to the updated SEC reserves reporting guidelines. A comprehensive series of systematic questions have been compiled and quick-look graphical techniques have been developed that may be used to gain insight into -and potentially raise questions about- an operator's reserves data.