**U.S. Department of the Interior U.S. Geological Survey**  **Fact Sheet 2014–3047 August** **2014** 

# National and Global Petroleum Assessment 

# Assessment of Unconventional Oil and Gas Resources in **Northeast Mexico, 2014**

**Introduction** The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of State, quantitatively assessed the poten

tial for unconventional oil and gas resources within the Sabinas Basin, Burgos Basin, and Tampico-Misantla Basin provinces of northeast Mexico (fig. 1). Resources of the Veracruz Basin were not quantitatively assessed due to a lack of reservoir informa

tion. Unconventional resources include shale gas, shale oil, tight gas, tight oil, and coalbed gas. Undiscovered conventional oil and gas resources were assessed in Mexico in 2012 (Schenk and others, 2012). The USGS assessment methodology consists of a wellperformance approach (Charpentier and Cook, 2011) that recognizes the geologic variability within assessed reservoirs. For assessments outside of the United States, the USGS assesses shale-gas or shale-oil reservoirs that (1) have greater than 2 weight percent total organic carbon; (2) are within the proper thermal maturity window for oil or gas generation; (3) have greater than 15 meters (m) of organic-rich shale; and (4) contain Type I or II organic matter (Charpentier and Cook, 2011). Areas that do not meet these criteria are unlikely to have significant resource potential without major technological improvements orprice increases. When applied to any given shale-oil or shalegas reservoir, these specific USGS criteria might significantly reduce the potential resource area compared to maps made with greater than 1 percent total organic carbon (TOC). For example, the area of potential reservoir of the Pimienta Shale in the Tampico-Misantla Basin with greater than 2 weight percent TOC is only about 21 percent of the total area of thermally mature Pimienta Shale. An important part of the geologic phase of this study was a formal USGS–PEMEX (Petroleos Mexicanos) Workshop on Unconventional Resources convened in Mexico City in June 2012, during which the geology and current exploration results from within the various shale-oil and shale-gas assessment units of northeast Mexico were discussed in detail. Several maps with geologic data (as outlined above) that were critical to the USGS assessment were supplied by PEMEX. These maps were combined to produce areas within the Sabinas, Burgos, and Tampico-Misantla Basins that were then considered for quanti

tative USGS assessment using the criteria outlined above. The input data for each unconventional assessment unit is shown in table 1. 

# Resource Summary The USGS quantitatively assessed unconventional oil and gas resources in 11 assessment units within 3 geologic prov

inces (table 2). For unconventional oil resources, the mean total is 776 million barrels of oil (MMBO), with a range of 353– 1,365 MMBO; for unconventional gas, the mean total is 23,474 billion cubic feet (BCFG), with a range of 7,431–44,630 BCFG; and a mean total of 883 million barrels of natural gas liquids (MMBNGL), with a range of 278–1,690 MMBNGL. Using a geology-based assessment methodology, the U.S. Geological Survey estimated means of 0.78 billion barrels of unconventional oil, 23.5 trillion cubic feet of unconventional gas, and 0.88 billion barrels of natural gas liquids in the Sabinas Basin, Burgos Basin, and Tampico-Misantla Basin provinces of northeast Mexico.

92° 94° 96° 98° 100° 102° 32°

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16° GULF OF MEXICO

PACIFICOCEAN 

### UNITED STATES

MEXICO

**Tampico-Misantla Basin Province** 

**Veracruz Basin Province**  **Burgos Basin**

**Province Sabinas Basin** 

**Province**

UNITED STATES Area of figure

PACIFIC OCEAN GULF OF MEXICO ATLANTIC OCEAN MEXICO

Assessed provinces Unassessed province **EXPLANATION**

0 10050 150 200 MILES 0 100 15050 200 KILOMETERS 

## Figure 1.Map showing locations of the Sabinas Basin, Burgos Basin, and Tampico-Misantla Basin provinces assessed in this study.

## Of the mean unconventional oil total of 776 MMBO, about 82 percent is in the Tampico-Misantla Basin. Within the basin, 55 percent (426 MMBO) is estimated to be in the Agua Nueva Shale Oil Assessment Unit (AU), and 27 percent (212 MMBO) is in the Pimienta Shale Oil AU. The Agua Nueva Shale Oil AU in the Burgos Basin contains the remaining 18 percent (138 MMBO). For the mean unconventional gas total of 23,474 BCFG, about 66 percent (15,591 BCFG) is estimated to be in the Burgos Basin; 25 percent (5,822 BCFG) is in the Sabinas Basin; and 9 percent (2,061 BCFG) is in the Tampico-Misantla Basin. 

# For Further Information Supporting studies of the geologic models and the methodology used in the assessment of northeast Mexican unconventional resources are in progress. Assessment results are available at the USGS Energy Resources Program website, http://energy.usgs.gov/oilgas/

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# References Cited Charpentier, R.R., and Cook, T.A., 2011, USGS methodology for assessing continuous petroleum resources: U.S. Geological Survey Open-File Report 2011–1167, 75 p.,http://pubs.usgs. gov/of/2011/1167/

. Schenk, C.J., Charpentier, R.R., Cook, T.A., Klett, T.R., Pitman,

J.K., Pollastro, R.M., and Weaver, J.N., 2012, Assessment of undiscovered conventional oil and gas resources of Mexico, Guatemala, and Belize, 2012: U.S. Geological Survey Fact Sheet 2012–3069, 4 p.,http://pubs.usgs.gov/fs/2012/3069/

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# Northeast Mexico Assessment Team Christopher J. Schenk, Ronald R. Charpentier, Timothy R. Klett, Marilyn E. Tennyson, Stephanie Gaswirth, Michael E. Brownfield, Mark J. Pawlewicz, and Jean N. Weaver.

Austin Chalk

Boquillas/Eagle Ford Formation

Buda Limestone



## Exposure of Boquillas/Eagle Ford Formation on south bank of Langtry Creek in Pump Canyon, Val Verde County Texas. Photograph taken by Michael Lewan, August 19, 2010.**Assessment input data Burgos Basin**  **Rio Escondido Basin Olmos Coalbed Gas AU 53000281 Burgos Basin**  **La Casita Shale Gas AU 53000361 Minimum**  **Mode Maximum**  **Calculated mean Minimum**  **Mode Maximum** **Calculated mean** Potential production area of AU (acres) 10,000 250,000 750,000 336,667 100,000 828,0002,500,000 1,142,667 Average drainage area of wells (acres) 40 80 160 93 80 120 160 120 Percent of AU untested 100 100 100 100 100 100 100 100 Success ratios (%) 50 70 90 70 40 60 80 60 Average EUR (MMBO, oil; BCFG, gas) 0.03 0.2 1 0.24 0.3 0.6 0.9 0.61 **Burgos Basin Agua Nueva Shale Oil AU 53000461**  **Burgos Basin Agua Nueva Shale Gas AU 53000462**  **Minimum Mode**  **Maximum Calculated mean**  **Minimum Mode**  **Maximum Calculated mean**  Potential production area of AU (acres) 100,000 704,000 1,100,000 634,667 100,0002,259,0003,530,000 1,963,000 Average drainage area of wells (acres) 160 280 400 280 80 120 160 120 Percent of AU untested 100 100 100 100 100 100 100 100 Success ratios (%) 50 70 90 70 50 70 90 70 Average EUR (MMBO, oil; BCFG, gas) 0.04 0.08 0.2 0.086 0.4 0.8 1.2 0.813 **Burgos Basin Wilcox-Lobo Tight Gas AU 53000561**  **Sabinas Basin La Casita Shale Gas AU 53230161**  **Minimum Mode**  **Maximum Calculated mean**  **Minimum Mode**  **Maximum Calculated mean**  Potential production area of AU (acres) 10,000 550,000 700,000 420,000 94,000 565,0001,882,000 847,000 Average drainage area of wells (acres) 40 110 180 110 80 120 160 120 Percent of AU untested 100 100 100 100 100 100 100 100 Success ratios (%) 50 70 90 70 10 50 90 50 Average EUR (MMBO, oil; BCFG, gas) 0.25 0.6 1.5 0.645 0.3 0.6 0.9 0.610 **Sabinas Basin Agua Nueva Shale Gas AU 53230261**  **Tampico-Misantla Basin Pimienta Shale Oil AU 53010261**  **Minimum Mode**  **Maximum Calculated mean**  **Minimum Mode**  **Maximum Calculated mean**  Potential production area of AU (acres) 100,000 704,000 2,400,000 1,068,000 100,000 695,0002,100,000 965,000 Average drainage area of wells (acres) 80 120 160 120 140 240 300 227 Percent of AU untested 100 100 100 100 100 100 100 100 Success ratios (%) 10 50 90 50 40 60 80 60 Average EUR (MMBO, oil; BCFG, gas) 0.4 0.8 1.2 0.813 0.03 0.08 0.14 0.082 **Tampico-Misantla Basin Pimienta Shale Gas AU 53010262**  **Tampico-Misantla Basin Agua Nueva Shale Oil AU 53010361**  **Minimum Mode**  **Maximum Calculated mean**  **Minimum Mode**  **Maximum Calculated mean**  Potential production area of AU (acres) 10,000 33,000 100,000 47,667 1,052,0002,104,0002,735,000 1,963,667 Average drainage area of wells (acres) 80 120 160 120 160 280 400 280 Percent of AU untested 100 100 100 100 100 100 100 100 Success ratios (%) 40 60 80 60 50 70 90 70 Average EUR (MMBO, oil; BCFG, gas) 0.3 0.6 0.9 0.610 0.04 0.08 0.2 0.086 **Tampico-Misantla Basin Agua Nueva Shale Gas AU 53010362**  **Minimum Mode**  **Maximum Calculated mean**  Potential production area of AU (acres) 10,000 128,000 368,000 168,667 Average drainage area of wells (acres) 80 120 160 120 Percent of AU untested 100 100 100 100 Success ratios (%) 50 70 90 70 Average EUR (MMBO, oil; BCFG, gas) 0.4 0.8 1.2 0.813 

## Table 1.Key assessment input data for unconventional assessment units in northeast Mexico. [EUR (estimated ultimate recovery per well), well drainage area,and success ratios are from U.S. shale-gas, shale-oil, tight-gas, and coalbed gas analogs. MMBO, million barrels of oil; BCFG, billion cubic feet of gas; AU, assessment unit, %, percent. The average EUR input is the minimum, median, maximum, and calculated mean.]ISSN 2327-6916 (print) ISSN 2327-6932 (online) http://dx.doi.org/10.3133/fs20143047 **Total Petroleum Systems (TPS)**  and Assessment Units (AU) AU Prob

ability Field Type **Total Undiscovered Resources Oil (MMBO)**  **Gas (BCFG) NGL (MMBNGL)**  **F95 F50**  **F5 Mean**  **F95 F50**  **F5 Mean**  **F95 F50**  **F5 Mean**  **BURGOS BASIN Olmos Coalbed Gas TPS**  Rio Escondido Basin Olmos Coalbed Gas AU 53000281 1.0 **Gas** 125 479 1,544 612 0 0 0 0 **Upper Jurassic La Casita TPS**
La Casita Shale Gas AU 53000361 1.0 **Gas** 1,148 3,253 6,730 3,516 69 195 407 211 **Turonian Agua Nueva TPS** Agua Nueva Shale Oil AU 53000461 1.0 **Oil** 52 129 251 138 96 252 533 275 2 5 11 6 Agua Nueva Shale Gas AU 53000462 1.0 **Gas** 3,211 9,320 15,982 9,403 127 368 654 376 **Paleogene TPS** Wilcox-Lobo Tight Gas AU 53000561 1.0 **Gas** 535 1,675 3,431 1,785 5 16 36 18 **SABINAS BASIN Upper Jurassic La Casita TPS** 
La Casita Shale Gas AU 53230161 1.0 **Gas** 577 1,899 4,687 2,172 17 56 144 65 **Turonian Agua Nueva TPS** Agua Nueva Shale Gas AU 53230261 1.0 **Gas** 941 3,189 7,922 3,650 37 127 321 146 **TAMPICO-MISANTLA BASIN Upper Jurassic Pimienta TPS**  Pimienta Shale Oil AU 53010261 1.0 **Oil** 69 194 412 212 82 232 498 254 2 7 15 8
Pimienta Shale Gas AU 53010262 1.0 **Gas** 58 136 272 147 2 4 8 4 **Turonian Agua Nueva TPS** Agua Nueva Shale Oil AU 53010361 1.0 **Oil** 232 402 702 426 406 789 1,502 852 7 16 32 17 Agua Nueva Shale Gas AU 53010362 1.0 **Gas** 252 754 1,529 808 10 30 62 32 **VERACRUZ BASIN Turonian Maltrata TPS**  Maltrata Shale Oil AU 53020261 **Oil** Not quantitatively assessed
Maltrata Shale Gas AU 53020262 **Gas**Not quantitatively assessed **Total unconventional resources**  353 725 1,365 776 7,431 21,978 44,630 23,474 278 824 1,690 883 

## Table 2.Northeast Mexico unconventional oil and gas resource assessment results. [MMBO, million barrels of oil. BCFG, billion cubic feet of gas; MMBNGL, million barrels of natural gas liquids;TPS, total petroleum system; AU, assessment unit. Results shown are fully risked estimates. For gas fields, all liquids are included under the NGL (natural gas liquids) category. F95 represents a 95 percent chance of at least the amount tabulated. Other fractiles are defined similarly. Shading indicates not applicable.]