Talos Energy has wrapped up appraisal drilling on its Zama discovery offshore Mexico and now believes its gross recoverable resource lies in the upper half of its pre-appraisal estimate of 400–800 million BOE. The Zama consortium is working toward a 2020 final investment decision (FID) on the project.
The Zama-3 appraisal well, which is on Block 7 in the Sureste Basin in the Gulf of Mexico, was drilled downdip of the Zama-1 discovery well, allowing the well to penetrate the oil/water contact in the southern portion of the field, consistent with the geophysical flat spot seen throughout the downdip edge of the reservoir.
The well logged 1,000 ft of gross total vertical depth (TVD) sand and 748 ft of gross TVD pay-bearing section, which is in line with expectations for the southern extension of the Zama reservoir, Houston-based Talos said. The net-to-gross ratio across the entire pay section is similar to prior penetrations, with Zone 3 significantly exceeding expectations with a net-to-gross ratio of 85–90%. Zones 3 and 4 comprise the majority of the Zama resource potential.
Talos captured 717 ft of whole core with 99% recovery. The operator said the additional core samples will provide critical information to assist in evaluating expected recovery factors, completion techniques, and other details to aid in optimizing recovery from the Zama field.
The Zama-2 and Zama-2 ST1 appraisal penetrations, both drilled in this year’s first half, also generated results that met or exceeded the consortium’s expectations, Talos said. Partners in the project are Premier Oil and Wintershall DEA-owned Sierra Oil & Gas.
"Based on the preliminary results of our appraisal program, we have confirmed the combination of outstanding subsurface properties, significant recoverable volumes, and attractive economic potential that have already made Zama a globally-recognized asset,” Timothy S. Duncan, Talos president and chief executive officer, said in a news release.
The group continues to evaluate the full universe of data and samples collected from its four penetrations of the Zama reservoir, including 1,450 ft of whole core, fluid samples from 30 separate points in the reservoir, 180 pressure points, 25 logging runs, and two extended flow tests. It intends to integrate the data with internal models and share them with external auditors to produce an updated contingent recoverable resource report by year end.
Front-end engineering and design work and unitization discussions with Pemex are advancing as the consortium moves toward FID.