Osama el Ibiary, Ahmed Shimi, Mohamed el Zayat, Hisham Ramadan Wepco Alexandria, Egypt
John E. Hostettler Drilling Specialties Co. Bartlesville, Okla.
David H. Beardmore Phillips Petroleum Co. Bartlesville, Okla.
A redesigned mud system reduced borehole enlargement in shale to an average 2 in. from 8 in. in an Egyptian Western Desert well.
At least one of the three main changes that were made in the mud system was responsible for the improvement.
The three modifications were:
Change the mud from brackish to 15% NaCl
Increase the concentration of shale-stabilizing sulfonated asphalt to 6 lb/b...