ECMOR VIII - 8th European Conference on the Mathematics of Oil Recovery

Currently the principal problems in the construction of 3D models for reservoir applications are: • The complexity of the model building proces and the difficulty of iterating the process. • The time required defining the model and the computational time to build it. • The accuracy of the geometry and correctness of the topology of the model constructed. This paper describes the details of a new gridding method that is an extension of the POSC-Rescue multiblock approach. The details of the method and lts advantages will be described and discussed.

A mathematical technique is suggested to calculate the 3-D spatial correlation functions for elasticity tensor components. The technique is based on the expansions of elasticity modulus fluctuations into the Fourier series. This method is applied for field data obtained at the seismic frequency. The results of calculations show the existence of maximum amplitudes and minimum of correlation radius of the correlation functions associated with enhanced inhomogeneities at some depth. It is observed that these depths well correlate with oil and gas location indicated by other independent methods. It is shown that the experimental correlation functions cannot be fitted with accepted accuracy by spherical Gaussian functions.

The challenge of the object-based simulation approach presented in this paper is not only to account for well descriptions and proportion data but also to include channel parts inferred from seismic data analysis into the simulations. Indeed, recent progresses in exploration techniques (sonar images, high resolution seismic data and processing algorithms) enable the study of the detailed morphology of deep marine fans. In turbiditic systems, sinuous channel parts have been observed on high-resolution seismic data. Integrating such data then become essential for building realistic 3D reservoir models upon which field development strategies are based.

Two geostatistical methods for history matching are presented. Both rely on the sequential simulation principle for generating geologically sound realizations. The first method relies on perturbing the sequential simulation through the perturbation of the conditional distribution models; the second method relies on the perturbation of random numbers. We show that both approaches are general in the sense that a large variety of geological scenarios can be generated while history matching. However, the conditional probability method is more efficient due to the ability to change the random path during the history matching procedure. We demonstrate these methods on two synthetic examples: a first example demonstrates how history matching can be performed under a training image based geological model constraint using multiplepoint geostatistics; a second example shows how a combinations with an existing streamline-based history matching algorithm can provide efficient history matching yet maintaining geological consistency.

Constant and continuons oil infiltration was considered from a point source into a low permeable horizontal layer of relatively small grain sizes and small pores with an underlying high permeable layer of relatively large grain sizes and large pores. Both porous media have a similar structure, i.e. similar pore structure but different mean pore sizes.

In pore-scale modelling of three-phase flow it is commonly assumed that three-phase displacements can always be described as combinations of two-phase displacements.

Severe fall of injectivity in porous rock occurs from the practice in offshore fields of injecting sea water containing organic and urineral inclusions. In general, injection of a poor quality water in a well curtails its injectivity. The injectivity loss is assumed to be due to particle retention in the porous rock .

In the last years the MPFA control-volume method has been developed for reservoir simulation on general grids.

Flow modelling in heterogeneous media is a great challenge, especially in the presence of wells or hydraulic fractures.