This excerpt taken from the CHK 10-K filed Mar 14, 2006.
Our hedging activities may reduce the realized prices received for our oil and gas sales and require us to provide collateral for hedging liabilities.
In order to manage our exposure to price volatility in marketing our oil and gas, we enter into oil and gas price risk management arrangements for a portion of our expected production. Commodity price hedging may limit the prices we actually realize and therefore reduce oil and gas revenues in the future. The fair value of our oil and gas derivative instruments outstanding as of December 31, 2005 was a liability of approximately $945.8 million. In addition, our commodity price risk management transactions may expose us to the risk of financial loss in certain circumstances, including instances in which:
Some of our commodity price and interest rate risk management arrangements require us to deliver cash collateral or other assurances of performance to the counterparties in the event that our payment obligations exceed certain levels. As of December 31, 2005, we were required to post a total of $50 million of collateral with our counterparties through letters of credit issued under our bank credit facility with respect to commodity price and financial risk management transactions. As of March 10, 2006, we were required to post $50 million of collateral with our counterparties through letters of credit. Future collateral requirements are uncertain and will depend on arrangements with our counterparties and highly volatile natural gas and oil prices.