New Developments in Petroleum System Simulation to Address Ancient Petroleum Systems

Marie-Christine Cacas, Isabelle Faille, Pascal Have, Françoise Willien, Sylvie Wolf, Mathieu Ducros, Maria-Fernanda Romero-Sarmiento, Sylvie Pegaz-Fiornet, Bernard Carpentier, and Muriel Thibaut
IFPEN, Rueil Malmaison cedex, France

Numerical simulation of petroleum systems is now becoming common practice in petroleum industry. However, it has to evolve in order to take up the challenges of exploration of more and more geologically complex basins and non-conventional resources.

Old petroleum systems are challenging for petroleum system modeling as they have a long geological history, with high probability of showing intense tectonic deformation leading to complex faulted architecture, high temperature and high pressure due to deep burial, and very mature organic matter.

We are involved in the development of a new-generation of petroleum system simulator which meets these challenges. Our new simulator Arctem is specially designed in order to handle properly the role of faults, either as major elements of the complex architecture, but also as a controlling factor of fluid flow in deeply buried low-porosity reservoirs. Arctem is based on a non-structured meshing of the basin architecture, which helps to take into account the precise geometry of the faults and the evolution of fault contacts through time. Special numerical schemes and adapted discretization techniques of the fault structure also enable us to account for the complexity of the plumbing system, both across faults and along fault compartments. Examples, even in moderately complex faulted architecture, show how far the plumbing system model can be refined and improved with such a new modeling approach.

Another challenge of ancient petroleum systems is kerogen maturity. We now have kinetic schemes which take late gas generation into account. In parallel, we have developed new functionalities in order to estimate the organic porosity creation, at the basin scale, as a function of the thermal maturity, as well as the adsorption of gas on residual organic matter. These improvements help to better predict the quantity of hydrocarbons retained into source rock, but also the amount of expelled hydrocarbons. Retention has become a function of burial history, namely evolution of temperature and pressure, whereas it was only controlled by porosity in former modeling approaches.

Modeling of complex architecture basins in conjunction with advanced modeling of kerogen structure transformation are still R&D challenges. Although simulation solutions are emerging, acquisition of parameters like fault permeability versus burial and fault slip, or characterization of kerogen pore system as a function of depth burial and thermal maturity, is urgently needed.

AAPG Search and Discovery Article #90175©2013 AAPG Hedberg Conference, Beijing, China, April 21-24, 2013