This report is the twenty-first report on the progress of the Rock Creek carbon dioxide project in Roane County, West Virginia. Designed, developed, and operated by Pennzoil Company, this project will demonstrate the feasibility of miscible carbon dioxide oil recovery in the Rock Creek Big Injun Field. A successful demonstration of this process will lead to a field wide commercial development. Also, the technical success of this project would be utilized in the development of other miscible carbon dioxide oil recovery projects in numerous fields within the Appalachian area. No significant delays in the project were incurred during the third quarter of 1977. A delay in the delivery of materials needed to complete construction of the carbon dioxide handling system necessitated the completion date of this phase of the project to be extended to the end of the fourth quarter of 1977. During the past quarter, it was discovered that communication between E. Lewis WIW No. 17 and L.W. Shaffer No. 1 exists via a permeable streak in the Big Lime. Attempts will be made to eliminate this problem. With the exception of this water problem in Shaffer No. 1, no major change in fluid production occurred in the producing wells. The water supply and water handling system performed trouble-free throughout the quarter. T. Henderson WSW No. 1 has proven to be a formidable water source by experiencing little drawdown at an average producing rate of approximately 2,900 barrels per day. Water injection continued on schedule into all of the injection wells with the exception of three wells experiencing some problem. Slight casing leaks appeared in two injection wells while a packer failure occurred in the third well. The packer failure has been rectified and the casing leaks will be dealt with in the near future.