Reservoir Formation Damage, Myths, Facts, and Lessons Learned From the Damage of a Deep Well in the Western Desert of Egypt

Abstract Formation damage causes a significant loss of both short and long-term profits in the Petroleum Industry. It is the probable cause for the loss of millions of barrels of recoverable oil and billions of cubic feet of gas. Drilling and completion fluids are the first non-indigenous fluids to contact the formation; thus, it is the first opportunity for causing permeability damage. Accordingly, this paper will deal mainly with formation damage that occurs at that earliest stages. In the Western Desert of Egypt, one of the deep wells that was drilled to 13800 ft, was initially producing from formation at 13000 ft, and due to reservoir depletion and high water cut, it was decided to abandon this interval and to produce from another potential interval which was the 1st time to be produced in Agiba. The well was perforated underbalanced and tested using test string. In order to run with the well completion string, the well was killed using NaCl–KCl filtrated and inhibited completion fluid. After the release of the workover rig, the well production decreased by almost 45%, which indicates that the reservoir was severely damaged. Attempted to stimulate the well using several stimulation techniques to recover well production, but unfortunately, the problem worsened and well production drastically decreased. Finally, based on the results of the investigation of damage mechanism, the lower interval of the reservoir was hydraulically fractured in order to bypass the damage, as possible, to recover well production. This paper will discuss the lessons learned from the case of deep well formation damage and will discuss the investigated damage mechanism by which the reservoir was plugged. Also, this paper will present the challenges encountered during the well recovery process, and the novel technique used to avoid introducing the damage again into the reservoir.