Talos Energy, operator of Zama offshore Mexico said its consortium achieved successful test results from the second of three appraisal wells in Mexico’s Sureste Basin.
The Zama-2 ST1 well was drilled 589 feet (180 meters) updip of the Zama-2 well and approximately 1.4 miles (2.1 kilometers) north of Zama-1 exploration well.
The well logged 873 feet (266 meters) of gross true vertical depth pay, within expectations for the northern extension of the Zama discovery and confirming a consistent net-to-gross ratio range of 68 per cent-73 per cent through multiple penetrations. Talos also captured an unprecedented 714 feet of whole core with 98 per cent recovery, the longest whole core acquired in a single well in the history of offshore Mexico, the company said in a statement.
The consortium partners include Sierra Oil & Gas, a company of DEA Deutsche Erdoel AG, and Premier Oil.
Talos President and chief executive officer Timothy S. Duncan said: "The Zama-2 ST1 operation was another success for the consortium. With each stage of the appraisal program, our experience and understanding has continued to strengthen in the region, and this is evident in our operational performance. The coring operation allowed us to gather important rock samples, which indicate excellent rock properties with similarities to world-class reservoirs in the United States Gulf of Mexico.
The well was cased and perforated totaling 248 gross feet of perforated section with varying rock properties. Hydrocarbon flow was established without stimulation in two separate flow tests and achieved a combined rate of 7,900 barrels of oil equivalent per day (Boe/d), of which 94 per cent was oil with API gravity ranging from 26-30 degrees, and 6 per cent was gas. The flow rate was restricted with limited pressure drawdown and each zone was shut-in for an extended period to establish a significant radius of investigation for each test, and neither gave any indication of depletion or significant barriers within the reservoir.
The operation to sidetrack from the Zama-2 location, drill, core and reach total depth (TD) of 11,643 feet (3,549 meters) of measured depth (MD) was completed approximately 9 days ahead of schedule and 16 per cent below budget. The well test operation was completed approximately 5 days ahead of schedule and more than 30 per cent below budget. Operations were safely coordinated and executed with the assistance of several local contractors, including the Mexican-flagged floating storage and production vessel utilised in the flow test.
“The production rate of 7,900 Boe/d from two zones in a very simple rate-restricted test over only a portion of the total pay column confirmed our expectations that the Zama wells will provide exceptional productivity,” Duncan added. “The tests also confirmed our geologic model of well-connected reservoirs, which should allow for a high ultimate oil recovery. Given the water depth of approximately 550 feet (168 meters), we believe that a combination of fixed platforms, dry trees and short-cycle development wells will maximize both capital efficiency and optionality with regard to how many total wells and completions per well will be necessary to maximize recovery. Also, given the deliverability of the perforated intervals demonstrated in the flow test, we believe a peak production rate between 150,000 – 175,000 Boe/d is achievable."
In the next stage of the appraisal program, the Zama-3 appraisal well will be drilled to the south of the original Zama-1 exploration well and will assist in delineating the reservoir continuity and quality in the southern part of the field. The Zama-3 appraisal operation includes collecting an additional core to better understand the reservoir geology.
Duncan added, "We will now move to the southern end of the discovery with the Zama-3 appraisal well to continue to collect data before concluding appraisal operations. Concurrently, we are working with Petróleos Mexicanos (Pemex) on unitisation prior to submitting a development plan to the regulator. Our goal is to reach final investment decision and first production as soon as possible. With the continued focus of the Talos operating team, our partners, and local workforce, Zama will be an impactful asset for the Company and the Mexican economy, and we are proud to play a key role in its development."