Gaspar Franco Hernández, of CNH, discusses the abundant opportunity to develop Mexico’s over 200 mature fields (First published in the December 2017 OE, access the full issue here).
Map of Mexico’s mature fields. Image from CNH.
There are several definitions of mature fields, which are based on different criteria of the production degree that the oil field presents, all definitions refer to those with additional hydrocarbon recovery potential, through the implementation of geoscience technologies, oil engineering and many other disciplines applicable at reservoir, well and facility level.
Some ways to define a field as mature are the following:
- Np ≥ 0.5 R2P. When the accumulated field production is equal or greater than 50% of the original 2P reserves, it is considered as mature.
- Production ≥ 25 years. When a field has been producing for 25 years or more, it can be considered as mature because, despite not having produced half or more of the 2P reserves, the useful life of the surface and sub-surface facilities may present the need for some new strategy.
- Declining Trend. When observing the production history of the fields, those that have already passed their peak of production and tend to decline, are also considered as mature fields.
- Economic limit after primary and secondary recovery. When revenues from the sale of hydrocarbons equal the costs incurred in extracting them, it is said that the field has reached its economic limit. This definition, although accepted for mature fields, could be understood as marginal fields.
Some suppliers of information associated with the oil activity have their own definitions of a mature field:
- Wood Mackenzie: Mature field is one with a Remaining Reserve <=33%.
- DAKS IQ: The Mature stage is the final period of initial production and is characterized by a relatively low production rate (with respect to peak) and a low rate of decline.
There is no standard or general definition of a mature field for the whole industry, a country or an oil company can classify a field as mature according to the considerations fitting its strategic objectives.
Based on information from the International Energy Agency and the US Energy Information Administration, the average global oil production in 2017 is 97.89 MMb/d (IEA) and 98.3 MMb/d (EIA), respectively; It is estimated that approximately 70% of world oil production comes from mature fields.
In the case of Mexico, by July 2017 oil production was 1.988 MMb/d and it was associated with around 200 fields in production, more than 90% of the producing fields are mature and contribute over 80% of national production. In addition, mature fields account for more than 60% of national 3P equivalent crude oil reserves. Additionally, in the world, the average final oil recovery factor is estimated to be 35%, while in Mexico it is estimated that the average final oil recovery factor is around 24%. To reach the international average of hydrocarbons recovery in the country’s reservoirs would represent an increase of 11%, 7.415 billion bbl and almost double the proven reserves of the nation.
According to the Mexican Reserves to 1 January 2017, there are 39 offshore mature fields located in shallow waters within the Cuencas del Sureste basin:
Of the 39 offshore mature fields, 36 are still in production and to July 2017 they report a production volume of 1.263 MMbo/d.
While the new hydrocarbon discoveries and the findings of greater potential in fields that are being evaluated will contribute to increasing Mexico’s reserves and production, the potential of mature fields represents a great opportunity and is something that should be exploited through business models that involve the application of the optimal technology combination that allows for cost reduction and optimization of hydrocarbon recovery.
Involvement in the extraction of hydrocarbons in mature fields has the disadvantages of dealing with the aging of the facilities and deciding on the allocation of investments to develop the remaining resources, however, they have the advantages of having a large amount of information, existing infrastructure, production is connected to a transport system, registration of the implementation of different methods, technologies and development strategies, greater knowledge of mature field reservoirs and in some cases, with feasibility studies of additional recovery methods or processes to rejuvenate the field.
Oil companies that wish to take advantage of the potential of mature fields in Mexico will have technical information that will allow them to make decisions for the implementation of best practices, as well as create scenarios for the implementation of secondary recovery technologies, enhanced recovery and advanced hydrocarbon recovery, according to the specific characteristics of the country’s reservoirs and fields, to increase production and reduce costs.
Following the Energy Reform of 2013, Mexico offers new forms of participation and investment in the oil industry; the new energy model allows the competition of national and international oil companies, which individually or in consortium can access the opportunities offered by the hydrocarbons exploration and extraction sector.
Likewise, bids have been made for areas containing mature fields with adjacent zones that also allow exploration, increasing the technical-economic feasibility of projects in the short- and long-term, which in addition to producing immediately or almost immediately, will allow the identification and increase of hydrocarbon reserves and production.
It is clear that the volumes of hydrocarbons with less uncertainty are found in mature fields and, as happens worldwide, a great share of Mexico’s production will come from this type of fields in the next few years, so the Mexican State will continue to generate the necessary conditions that make the implementation of projects proposed by the oil operators more efficient.
Gaspar Franco Hernández is Commissioner for the National Hydrocarbons Commission in Mexico. He spent 14 years with Petroleos Mexicanos (Pemex) in many positions such as field engineer, well engineer, programming and evaluation coordinator at Cantrell, and Superintendent of Hydrocarbon Reserves and Production Projects in the Northeast Marine Region of Pemex Exploration and Production (PEP). He joined CNH as Deputy General Director for Production projects and has held several roles within CNH, eventually being elected Commissioner by the Mexican senate in April 2016. He holds a bachelor’s degree in Petroleum Engineering from the National Autonomous University of Mexico (UNAM). In 2004, he earned his master’s degree in Management Skills from the Autonomous University of Carmen (UNACAR).