Evaluating the potential for gas reserve growth at the Aktas field

Background: This paper examines the opportunity to expand the gas reserves of reservoir unit J-IIA of the Aktas field. A previously overlooked prospect was identified based on production anomalies from Well No. 11, whose output did not align with the earlier geological model of the formation. It is proposed that the unusually high production may be linked to the presence of a previously undetected paleo-channel, not captured in earlier seismic interpretations. Aim: Aim of this study is to refine the geological model of the Aktas field and to identify prospective zones – sandy bodies that may serve as lithological gas traps. Materials and methods: The study was based on production well data, integrated with a time cube of the ExChroma attribute extracted from the seismic volume covering the Aktas Field and adjacent areas Results: Among the technologies evaluated, the eXchroma method proved most effective for identifying ancient channel systems in the seismic wavefield of the study area. Using this technique, a channel feature was identified extending along the western structural nose of the Aktas structure, near Well No. 11. The study also highlights a non-structural geological link between the Aktas and Zhetybai structures, and provides an estimate of the gas resources associated with the interpreted paleo-channel. Conclusion: The integrated analysis of available data revealed promising non-structural traps within the Jurassic deposits of the study area. The results of seismic data processing and interpretation are supported by geological, geophysical, and production data obtained from Well No. 11.