Ceres2d: a Numerical Prototype for Hc Potential Evaluation in Complex Area

Abstract-Ceres2D: A Numerical Prototype for HC Potential Evaluation in Complex Area-This paper deals with the Ceres prototype which is a basin model able to account for porous medium compaction, heat transfer, and hydrocarbon generation and migration. Furthermore, Ceres was designed to handle changing geometry through time as results of sedimentation, erosion, salt or mud creeping and block displacement along fault. The classical flow chart to perform a case study is composed of three main steps. The first step is the building of the present day section. This is generally done with data coming from the seismic interpretation, well data, field data and core data. The second step is the restoration of the section. Thus from the section at present day, the section is restored back in the past for each of the defined layer, and until the substratum is reached. The last step is the forward simulation. And, in order to solve the coupled equations that are generally used in basin models, we had to develop original numerical methods based on domain decomposition techniques. The Ceres prototype has now been used to study petroleum systems. It has been used to perform sensitivity studies on fault permeability in the Bolivian foothills and the Congo offshore. In the Gulf of Mexico, it allowed to study the impact of the salt tectonics on the hydrocarbon migration. More recently, the Ceres prototype has been tested, within the frame of the SubTrap consortium, in thrust areas such as the Canadian foothills and the Eastern Venezuelan foothills. For these last case studies, it has been beneficial that structural geologists were involved at all stages of the process

Modeling Fluid Flow in Faulted Basins

This paper presents a basin simulator designed to better take faults into account, either as conduits or as barriers to fluid flow. It computes hydrocarbon generation, fluid flow and heat transfer on the 4D (space and time) geometry obtained by 3D volume restoration. Contrary to classical basin simulators, this calculator does not require a structured mesh based on vertical pillars nor a multi-block structure associated to the fault network. The mesh follows the sediments during the evolution of the basin. It deforms continuously with respect to time to account for sedimentation, erosion, compaction and kinematic displacements. The simulation domain is structured in layers, in order to handle properly the corresponding heterogeneities and to follow the sedimentation processes (thickening of the layers). In each layer, the mesh is unstructured: it may include several types of cells such as tetrahedra, hexahedra, pyramid, prism, etc. However, a mesh composed mainly of hexahedra is preferred as they are well suited to the layered structure of the basin. Faults are handled as internal boundaries across which the mesh is non-matching. Different models are proposed for fault behavior such as impervious fault, flow across fault or conductive fault. The calculator is based on a cell centered Finite Volume discretisation, which ensures conservation of physical quantities (mass of fluid, heat) at a discrete level and which accounts properly for heterogeneities. The numerical scheme handles the non matching meshes and guaranties appropriate connection of cells across faults. Results on a synthetic basin demonstrate the capabilities of this new simulator