-          Description of NUTECH services

-          How NUTECH’s process is used in new unconventional plays like La Pimienta

-          Similarities and differences between the Eagle Ford, Haynesville and La Pimienta formations

-          Tangram and Céfiro examples – Petrophysical analysis, core analysis, geomechanical modeling and completion design considerations

-          Comparison of Results with other unconventional wells in Mexico and Texas (using official Pemex production data)

-          Lessons learned and moving forward (modeling the play)

In 2013, Pemex drilled the well Tangram-1, their fourth well in the La Pimienta Formation in Northern Mexico. Of the previous three, only one (Anhélido-1) had yielded positive results with an initial production of 333 BOPD and 1.9 MMCFPD of associated gas. The two other wells (Nuncio-1 and Kernel-1) had IPs below 2.9 MMCFPD of dry gas (Source: Pemex).

The Tangram-1 well offered a range of challenges given the exploratory nature of the play. Some sources quote La Pimienta Formation as showing similarities with the Haynesville Shale in the US. Both formations are Upper Jurassic source rocks and have TOC of around 3% and like the Haynesville, the Pimienta Formation was expected to be in the gas window with thermal maturities above 1.4% (Source: EIA/ARI World Shale Gas and Shale Oil Resource Assessment). However, the results of the Anhélido well showed potential for oil production to the south of the play as well as other significant differences.

As is the case with any unconventional play, heterogeneity and modeling of the geo-mechanical properties are critical factors in completion design. This is amplified in a new play like La Pimienta. The evaluation and completion optimization of Tangram-1, therefore, required the utilization of the experience and advanced tools to calibrate as many properties as possible and access to the extensive database of unconventional wells available at NUTECH to characterize the formation.

NUTECH Solution:

1. Run core analysis on the available cuttings to calibrate the petrophysical model.
2. Characterize the formation and provide a petrohysical and geomechanical model for the well.
3. Design the completion of the well and optimize it based on the requirements of Pemex and the service company to improve the production in La Pimienta Formation.

The Tangram-1 became the best dry gas producer in La Pimienta with over 10MMCFPD IP.

After the successful completion of the Tangram-1, Pemex requested the evaluation and completion of a new well, the Céfiro-1 but added a number of specific parameters, including different landing points and other variations in order to evaluate the effect on expected production. Following the same process (without the availability of core calibration), the well also had an IP of over 10 MMCFPD of IP. According to Pemex, these two wells remain the two most successful dry gas wells in La Pimienta.

Despite the fact that both wells targeted the same formation, NUTECH had very specific, tailored designs for each well to account for heterogeneity and client requests. Results show the different approaches and completion strategies with successful results.

Moving forward, NUTECH will propose to use existing seismic data and well logs from all the wells in La Pimienta to develop and model optimal fracturing channels and optimize future completions even further.