Mukhaizna Steam Flood Project: Thermal Surveillance Practices and Log Response

Mukhaizna is a heavy oil field located in southern Oman. The heavy oil (700 to 3900 cP at reservoir conditions) was found at a true vertical depth of 2000 to 2460 ft, which is considered rather deep for a steam flood. Initial reservoir pressure was 1,300 psi, and the initial temperature was 122°F. The field has been developed with horizontal producers, vertical steam injectors, and vertical infill producers in patterns of about 67 acres in size. To date, 3000+ wells have been drilled in Mukhaizna field, and a huge amount of Petrophysical data has been acquired. Petrophysical surveillance work provides monitoring of time lapse thermal efficiency sweeping, perforation picking strategies of hot, swept and cold zones, as well understanding open hole log response in thermal hot wells. Using this information, we were able to target the correct zones to improve the thermal sweep and increase oil production. The first part of this paper will describe the open-hole log response in thermal wells and how perforation intervals are picked based on this log response. These perf picks were later corroborated with well production data to ensure alignment with well production performance. The second part of this paper will present a field-specific correlation of steam quality measured at the separator with spinner surveys at wellhead injectors, aiming to estimate steam quality directly from a spinner survey without having to run a steam quality separator, which is time-consuming and involves extensive effort.