Offshore Mexico Appraisal Well Encouraging

Offshore Mexico Appraisal Well Encouraging
The Zama appraisal program includes three penetrations.

Talos Energy reported late Wednesday that the initial phase of appraisal drilling near its Zama-1 discovery in Block 7 offshore Mexico was concluded.

The company, serving as operator of a Block 7 consortium that includes Premier Oil Plc and Sierra Oil and Gas S. de R.L. de C.V., noted that the Zama-2 appraisal well was successfully completed Jan. 20 – approximately 28 days ahead of schedule and 25 percent below initially projected costs.

As Rigzone reported early last month, the Ensco 8503 spudded the Zama-2 appraisal well in the Sureste Basin of the Gulf of Mexico Nov. 29, 2018. A joint venture of McDermott International, Inc. and Baker Hughes, a GE company (BHGE) is executing the engineering services contract for the Zama field development.

“We are very pleased with the results of the Zama-2 well as we were able to achieve our primary goals of understanding the depositional environment and the presence of thick sand bodies needed for robust aquifer support, both of which help with ultimate recovery,” Timothy S. Duncan, president and CEO of Talos, said in the company’s written statement emailed to Rigzone.

“We also confirmed that this section of the reservoir has similar or better rock properties as compared to the Zama-1 discovery well and that the pressure information indicates connectivity to Zama-1,” continued Duncan. “Perhaps most importantly, the oil-water contact was encountered at the predicted depth, if not slightly deeper.”

The appraisal well, drilled approximately 1.3 miles (2.1 kilometers) north of Zama-1, reached the top of the Zama reservoir at approximately 10,759 feet (3,279 meters) of true vertical depth (TVD), the company added. According to Talos, the well encountered:

  • A contiguous Zama sandstone interval of 1,676 feet (511 meters) of gross TVD sand. Talos pointed out that interval is materially thicker sand than that of the Zama-1 discovery well and slightly thicker than the pre-drill estimates for Zama-2. It also noted that the well encountered several other thick, wet sands of similar age directly beneath the main Zama horizon, translating into approximately 2,350 feet (716 meters) TVD of high-quality Upper Miocene sands.
  • Approximately 581 feet (177 meters) of gross TVD oil pay logged before reaching the oil-water contact, initially estimated at 11,254 feet (3,430 meters) – roughly 100 feet (30 meters) deeper than the anticipated oil-water contact depth. Talos also noted that the preliminary net-to-gross factor in this pay interval ranges from 68 to 73 percent, with rock properties like those at Zama-1.
  • Preliminary pressure data, which helped confirm the oil-water contact depth and complemented the traditional logging results, showed that the reservoir’s northern section is connected to Zama-1. Talos pointed out that the Zama-2 sidetrack and the Zama-3 well will increase understanding of the reservoir connectivity and consistency.

Talos stated that the appraisal program will include two more penetrations. Next will be an up-dip vertical penetration in the Zama reservoir from the main bore hole of Zama-2. The company noted that it will subsequently drill the second appraisal well, Zama-3, to the south of the original discovery well.

“On the operational side, the team has done an exceptional job,” stated Duncan. “By incorporating the lessons learned and experiences from the Zama-1 discovery well, the team was able to successfully and safely execute the well significantly ahead of expectations. We are staying focused on working with urgency to meet the project timely to achieve first oil by the second half of 2022.”


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