Master of Science in Petroleum Engineering (MSPE)


Petroleum Engineering

Document Type



This thesis will analyze the techniques used during the 1989 and 1990 workover programs as well as subsequent operations in 1991/1992. It will also present the techniques and results of the most recent 1999 workover program undertaken to alleviate the most persistent sustained casing pressure (SCP) in a mature Gulf of Mexico field. An extensive literature review is included to better illustrate the complexity of the issues involved and possible SCP mechanisms. The field was drilled during the 1980’s and SCP has been prevalent in some cases previous to initial completion operations. Previous remedial programs resulted in limited success in reducing SCP previous to the most recent workover program beginning in 1999. Critical analysis will be based on a review of the methods used and the results obtained. Knowledge gained from the most recent 1999 workover program will be applied to evaluate the effectiveness of the methods employed. Programs previous to the most recent 1999 workover program were not successful in eliminating SCP since pressure returned almost immediately to the affected casing in most instances. During the programs, perforating or cutting casing to squeeze cement into affected annuli was not successful at any depth. A review of the workover attempts will rely on internal correspondence and drilling reports. These will be compared to the knowledge and results gained from the 1999 rig operations program. The objective of the 1999 workover program was to address SCP in the field with a consistent and effective method. Techniques were developed by analyzing the successes and failures of past operations and applying aggressive remediation programs tailored to individual wellbores. Discussion will include improved design guidelines in hole preparation before milling and cementing operations, improved milling procedures, and application of a latex cement slurry. Even though some remedial rig work was required while operations were still ongoing, all indications are that the 1999 workover program was successful.



Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

Andrew K. Wojtanowicz