Abstract
The high structural uncertainty present in a field in Egypt required special logging-while-drilling (LWD) measurement specifications to achieve economically satisfying production results. East Zeit Oil Company (Zeitco) was targeting an oil-bearing sandstone reservoir that is characterized by the presence of subseismic faults and high structural uncertainty. This uncertainty ranges from 6° to 23° in structure dip, which makes drilling successful horizontal wells in this reservoir challenging. A well with a horizontal penetration envelope from a minimum 500 ft measured depth (MD) to an optimum 1,600 ft MD was planned for this reservoir to make the well economic. Steering in such a challenging reservoir required having realtime measurements as close as possible to the bit to make the required real-time decisions. A real-time density image and with other azimuthal data were the primary measurements used in steering this horizontal well. Being used with a rotary steerable tool, the multifunction LWD tool provided density image at only 39 ft behind the bit, which was crucial for the success of the well. The well was successfully drilled with 100% exposure inside the sandstone reservoir with 1,532 ft MD horizontal penetration. In addition, well testing results indicated a natural flow of 2,000 BOPD, which made this well the highest oil producer in the field.
