EX-10.4

In accordance with your request, we have audited the estimates prepared by Pemex Exploración y Producción (PEP), as of January 1, 2020, of the gross (100 percent) proved reserves and the net gas reserves in 18 fields located in Activo Integral de Producción Bloques (AIPB) AS01-01 (Cantarell) and AS01-02 (Ku-Maloob-Zaap), in Subdirección AS01 (Región Marina Noreste), located in the Bay of Campeche, offshore west of the Yucatan Peninsula of Mexico. PEP is a subsidiary entity of Petróleos Mexicanos. The scope of our work did not include auditing the future net revenue associated with these reserves. The Political Constitution of the United Mexican States provides that the Mexican nation owns all petroleum and other hydrocarbon reserves for these fields; however, these fields have been assigned to and are currently operated by PEP. In accordance with the Energy Reform of 2014, the estimates in this report represent the gross (100 percent) proved reserves to be produced within the economic life of the properties. We have examined the estimates with respect to reserves quantities, reserves categorization, future producing rates, and economic producibility, using the definitions set forth in U.S. Securities and Exchange Commission (SEC) Regulation S-X Rule 4-10(a). Economic analysis was performed by PEP only to confirm economic producibility and determine economic limits for the properties. The estimates of reserves have been prepared in accordance with the definitions and regulations of the SEC and conform to the FASB Accounting Standards Codification Topic 932, Extractive Activities—Oil and Gas. We completed our audit on February 14, 2020. PEP has represented that these properties account for 54.2 percent on a net oil equivalent barrel basis of PEP’s net proved reserves as of January 1, 2020. This report has been prepared for PEP’s and Petróleos Mexicanos’ use internally and in filings with the appropriate regulatory agencies. In our opinion the assumptions, data, methods, and procedures used in the preparation of this report are appropriate for such purpose; there is no guarantee or warranty, implied or expressed, by Netherland, Sewell International, S. de R.L. de C.V. (NSI) for any other use of this report.

2100 Ross AVENUE, SUITE 2200 • DALLAS, TEXAS 75201-2737 • PH: 214-969-5401 • FAX: 214-969-5411

The following table sets forth PEP’s estimates of the gross (100 percent) reserves and the net gas reserves to the combined interest of PEP, the Mexican State, and Pemex Transformación Industrial (PTRI), as of January 1, 2020, for the audited properties:

Oil, condensate, plant liquids, and barrels of oil equivalent (BOE) volumes are expressed in millions of barrels (MMBBL); a barrel is equivalent to 42 United States gallons. Dry gas volumes are expressed in millions of barrels of oil equivalent (MMBOE), determined using dry gas conversion factors provided by PEP. Gas volumes are expressed in billions of cubic feet (BCF) at standard temperature and pressure bases.

When compared on a field-by-field basis, some of the estimates of PEP are greater and some are less than the estimates of NSI. However, in our opinion the estimates of reserves prepared by PEP shown herein are reasonable when aggregated at the total proved level and have been prepared in accordance with the Standards Pertaining to the Estimating and Auditing of Oil and Gas Reserves Information promulgated by the Society of Petroleum Engineers (SPE Standards). Additionally, these estimates are within the recommended 10 percent tolerance threshold set forth in the SPE Standards. We are satisfied with the methods and procedures used by PEP in preparing the January 1, 2020, estimates of reserves, and we saw nothing of an unusual nature that would cause us to take exception with the estimates, in the aggregate, as prepared by PEP.

Reserves categorization conveys the relative degree of certainty; reserves subcategorization is based on development and production status. The estimates of reserves included herein have not been adjusted for risk. PEP’s estimates do not include probable or possible reserves that exist for these properties.

Oil and gas prices were used only to confirm economic producibility and determine economic limits for the properties. It is our understanding that prices used by PEP are representative of the 12-month average for the period January through December 2019. NSI accepted the prices provided without independent review or verification. All prices are held constant throughout the lives of the properties.

Costs were used only to confirm economic producibility and determine economic limits for the properties. It is our understanding that operating costs used by PEP are representative of the 12-month average for the period January through December 2019. These costs include district and regional overhead expenses along with costs to be incurred at the field level. Operating costs for certain non-producing or undeveloped fields are based on PEP’s analogy to a similar type of producing field. Operating costs have been divided into field-level costs, per-well costs, and per-unit-of-production costs. No headquarters general and administrative overhead expenses are included. Capital costs used by PEP are based on authorizations for expenditure and actual costs from recent activity. Capital costs are included as required for workovers, new development wells, pipelines, and production equipment. Abandonment costs used are PEP’s estimates of the costs to abandon the wells, platforms, and production facilities, net of any salvage value. NSI accepted the operating cost parameters and the capital and abandonment costs provided without independent review or verification. Operating, capital, and abandonment costs are not escalated for inflation.

The reserves shown in this report are estimates only and should not be construed as exact quantities. Proved reserves are those quantities of oil and gas which, by analysis of engineering and geoscience data, can be estimated with reasonable certainty to be economically producible; probable and possible reserves are those additional reserves which are sequentially less certain to be recovered than proved reserves. Estimates of reserves may increase or decrease as a result of market conditions, future operations, changes in regulations, or actual reservoir performance. In addition to the primary economic assumptions discussed herein, estimates of PEP and NSI are based on certain assumptions including, but not limited to, that the properties will be developed consistent with current development plans as provided to us by PEP, that the properties will be operated in a prudent manner, that no governmental regulations or controls will be put in place that would impact the ability of PEP to produce and recover the reserves, and that projections of future production will prove consistent with actual performance. If the reserves are recovered, the revenues therefrom and the costs related thereto could be more or less than the estimated amounts used to confirm economic producibility and determine economic limits for the properties. Because of governmental policies and uncertainties of supply and demand, the sales rates, prices received for the reserves, and costs incurred in recovering such reserves may vary from assumptions made while preparing these estimates.

It should be understood that our audit does not constitute a complete reserves study of the audited oil and gas properties. Our audit consisted primarily of substantive testing, wherein we conducted a detailed review of all properties making up the total proved reserves. In the conduct of our audit, we have not independently verified the accuracy and completeness of information and data furnished by PEP with respect to oil and gas production, well test data, historical costs of operation and development, product prices, or any agreements relating to current and future operations of the properties and sales of production. Our audit did not include a review of PEP’s overall reserves management processes and practices.

We used standard engineering and geoscience methods, or a combination of methods, including performance analysis, volumetric analysis, analogy, and reservoir modeling, that we considered to be appropriate and necessary to establish the conclusions set forth herein. As in all aspects of oil and gas evaluation, there are uncertainties inherent in the interpretation of engineering and geoscience data; therefore, our conclusions necessarily represent only informed professional judgment.

Supporting data documenting this audit, along with data provided by PEP, are on file in our office. The technical persons primarily responsible for conducting this audit meet the requirements regarding qualifications, independence, objectivity, and confidentiality set forth in the SPE Standards. Eric J. Stevens, a Licensed Professional Engineer in the State of Texas, has been practicing consulting petroleum engineering at Netherland, Sewell & Associates, Inc. (NSAI), of which NSI is a subsidiary, since 2007 and has 5 years of prior industry experience. Ruurdjan (Rudi) de Zoeten, a Licensed Professional Geoscientist in the State of Texas, has been practicing consulting petroleum geoscience at NSAI since 2008 and has 18 years of prior industry experience. We are independent petroleum engineers, geologists, geophysicists, and petrophysicists; we do not own an interest in these properties nor are we employed on a contingent basis.


Sincerely,

NETHERLAND, SEWELL INTERNATIONAL, S. DE R.L. DE C.V.

By:
		Robert C. Barg, P.E.
		President

In accordance with your request, we have audited the estimates prepared by Pemex Exploración y Producción (PEP), as of January 1, 2020, of the gross (100 percent) proved reserves and the net gas reserves in 46 fields located in Activo Integral de Producción Bloques (AIPB) S01 (Macuspana-Muspac) and S04 (Cinco Presidentes), in Subdirección de Producción Bloques Sur, located in the states of Chiapas, Tabasco, and Veracruz in southern Mexico. PEP is a subsidiary entity of Petróleos Mexicanos. The scope of our work did not include auditing the future net revenue associated with these reserves. The Political Constitution of the United Mexican States provides that the Mexican nation owns all petroleum and other hydrocarbon reserves for these fields; however, these fields have been assigned to and are currently operated by PEP. In accordance with the Energy Reform of 2014, the estimates in this report represent the gross (100 percent) proved reserves to be produced within the economic life of the properties. We have examined the estimates with respect to reserves quantities, reserves categorization, future producing rates, and economic producibility, using the definitions set forth in U.S. Securities and Exchange Commission (SEC) Regulation S-X Rule 4-10(a). Economic analysis was performed by PEP only to confirm economic producibility and determine economic limits for the properties. The estimates of reserves have been prepared in accordance with the definitions and regulations of the SEC and conform to the FASB Accounting Standards Codification Topic 932, Extractive Activities—Oil and Gas. We completed our audit on February 14, 2020. PEP has represented that these properties account for 3.5 percent on a net oil equivalent barrel basis of PEP’s net proved reserves as of January 1, 2020. This report has been prepared for PEP’s and Petróleos Mexicanos’ use internally and in filings with the appropriate regulatory agencies. In our opinion the assumptions, data, methods, and procedures used in the preparation of this report are appropriate for such purpose; there is no guarantee or warranty, implied or expressed, by Netherland, Sewell International, S. de R.L. de C.V. (NSI) for any other use of this report.

2100 ROSS AVENUE, SUITE 2200 • DALLAS, TEXAS 75201-2737 • PH: 214-969-5401 • FAX: 214-969-5411

Costs were used only to confirm economic producibility and determine economic limits for the properties. It is our understanding that operating costs used by PEP are representative of the 12-month average for the period January through December 2019. These costs include district and regional overhead expenses along with costs to be incurred at the field level. Operating costs for certain non-producing or undeveloped fields are based on PEP’s analogy to a similar type of producing field. Operating costs have been divided into field-level costs, per-well costs, and per-unit-of-production costs. No headquarters general and administrative overhead expenses are included. Capital costs used by PEP are based on authorizations for expenditure and actual costs from recent activity. Capital costs are included as required for workovers, new development wells, pipelines, and production equipment. Abandonment costs used are PEP’s estimates of the costs to abandon the wells and production facilities, net of any salvage value. NSI accepted the operating cost parameters and the capital and abandonment costs provided without independent review or verification. Operating, capital, and abandonment costs are not escalated for inflation.

We used standard engineering and geoscience methods, or a combination of methods, including performance analysis, volumetric analysis, and analogy, that we considered to be appropriate and necessary to establish the conclusions set forth herein. As in all aspects of oil and gas evaluation, there are uncertainties inherent in the interpretation of engineering and geoscience data; therefore, our conclusions necessarily represent only informed professional judgment.

Supporting data documenting this audit, along with data provided by PEP, are on file in our office. The technical persons primarily responsible for conducting this audit meet the requirements regarding qualifications, independence, objectivity, and confidentiality set forth in the SPE Standards. Joseph M. Wolfe, a Licensed Professional Engineer in the State of Texas, has been practicing consulting petroleum engineering at Netherland, Sewell & Associates, Inc. (NSAI), of which NSI is a subsidiary, since 2013 and has 5 years of prior industry experience. Dana D. Coryell, a Licensed Professional Geoscientist in the State of Texas, has been practicing consulting petroleum geoscience at NSAI since 1999 and has 12 years of prior industry experience. We are independent petroleum engineers, geologists, geophysicists, and petrophysicists; we do not own an interest in these properties nor are we employed on a contingent basis.


Sincerely,

NETHERLAND, SEWELL INTERNATIONAL, S. DE R.L. DE C.V.

By:
		Robert C. Barg, P.E.
		President


	Gross (100%) Reserves
			Liquid Components and Dry Gas
Category	Wellhead Oil⁽¹⁾ (MMBBL)		Condensate⁽²⁾ (MMBBL)		Plant Liquids⁽³⁾ (MMBBL)		Dry Gas⁽⁴⁾ (MMBOE)		BOE⁽⁵⁾ (MMBBL)		Wellhead Gas⁽⁶⁾(BCF)		Net Gas⁽⁷⁾ (BCF)
Proved Developed Producing		1,163.7		3.2		40.7		66.5		1,274.2		574.6		455.9
Proved Developed Non-Producing		1,169.3		3.0		63.7		104.1		1,340.2		938.4		713.4
Proved Undeveloped		1,231.3		1.8		18.0		29.5		1,280.6		257.2		202.0

Total Proved		3,564.3		8.0		122.5		200.2		3,895.0		1,770.2		1,371.3


		PRESIDENT - ROBERT C. BARG VICE PRESIDENTS RANDOLPH K. GREEN JOHN G. HATTNER MICHELLE F. HERRERA
		C. H. (SCOTT) REES III
		DANNY D. SIMMONS
		ERIC J. STEVENS
		JOSEPH M. WOLFE


Category	Gross (100%) Reserves												Net Gas⁽⁷⁾ (BCF)
	Wellhead Oil⁽¹⁾ (MMBBL)		Liquid Components and Dry Gas						BOE⁽⁵⁾ (MMBBL)		Wellhead Gas⁽⁶⁾ (BCF)
	Wellhead Oil⁽¹⁾ (MMBBL)		Condensate⁽²⁾ (MMBBL)		Plant Liquids⁽³⁾ (MMBBL)		Dry Gas⁽⁴⁾ (MMBOE)		BOE⁽⁵⁾ (MMBBL)		Wellhead Gas⁽⁶⁾ (BCF)
Proved Developed Producing		60.9		0.8		25.4		56.1		143.2		387.4		292.0
Proved Developed Non-Producing		41.7		0.3		7.4		16.4		65.8		142.8		85.1
Proved Undeveloped		23.3		0.1		5.3		10.9		39.7		82.5		56.9

Total Proved		125.9		1.2		38.2		83.4		248.7		612.7		433.9