The mature oil field in the Caspian Sea was originally discovered in the 1960’s and more than 100 wells were drilled in the field. When Dragon Oil inherited the field in the 90s, it had a well stock of varying issues and complexities that required a full field well integrity review to cover the entire well lifecycle. Dragon Oil had a field-wide detailed well status report demonstrating that many wells had integrity problems related to sustained annulus pressure (SAP) in a variety of annuli, which, when risk-ranked, clearly identified those wells that needed intervention.
This paper will demonstrate the cases where slickline-conveyed cased-hole memory logging tools were run at three different well lifecycle stages:
Well drilling - to detect the shallow water or gas source and perform a remedial job
Production operations - to identify sustained annulus pressure sources so remedial solutions could be prepared to cure high risk wells
Plug&Abandonment planning - to provide a status report of downhole well conditions so that a cost-effective abandonment programme could be planned and executed.
In each of the above cases, the data collected during logging operations provided a clear identification of the related well issues and was sufficient to allow detailed planning and execution of remedial jobs and abandonment operations.