Chandrajit Bajaj

Computational Geophysics & Petroleum Engineering



hydro A

Using the two-phase flow model in the IPARS simulator and 64 nodes of the IBM SP2 at Pacific Northwest National Laboratory, Center for Subsurface Modeling researchers examined the behavior of a million-grid-block reservoir with four injection and twelve production wells. The displacement front advancing from the injection wells is clearly seen in the upper contour plot, with the variation in water saturation at the bottom of the reservoir projected onto the plane below. This plane also shows the computational mesh, which is refined in both horizontal directions around each well, and the irregular boundary of the reservoir.

hydro B1, hydro B2, hydro B3

The movement of water through an oil reservoir is critical to determining the economics of the field. The blue contour shows the advance of water from two injection wells, one in each lobe of a tilted oxbow reservoir (so called after the type of meandering river channel that created the original reservoir sand). The orthogonal slices in the planes of the injection wells are colored according to the local rate of change of water saturation, highlighting the width of the water/oil displacement front. The limits of the reservoir are indicated by the red 'curtain'. The circular white contours of pressure in the horizontal plane show the locations of seven production wells. The timing of water arrival at these wells is an important issue in planning oil recovery strategies.

This detailed simulation (125000 grid blocks) was run with the IPARS software on a cluster of 16 PCs at the Center for Subsurface Modeling.

hydro C

Aquifers and oil reservoirs are often highly irregular at large scales (km) due to tectonics and at small scales (m to cm) due to depositional environment, burial history, and diagenesis. An intriguing mathematical framework for capturing these multiscale irregularities is the multiblock concept. Center for Subsurface Modeling researchers have implemented this concept into the IPARS parallel reservoir simulation framework. This animation shows the advance of water from an injection well in one corner of one block toward a production well located in a third block. Several large heterogeneities in rock permeability exist within the blocks, in addition to the dislocation at the block faces. The two isosurfaces (contours of different water saturations) show the complex flow pattern around and through these heterogeneities.

Interactive Visualization of 3D Seismic Data
(Northern Barbados Ridge: Structural Evolution)


Barbados Movie

A volume of three-dimensional seismic reflection data, acquired in 1992, imaged the decollement beneath the northern Barbados Rodge accretionary prism revealing reflection amplitude and waveform variations attributed to fluid accumulations along the plate boundary fault. We visualized the data interactively. The interactivity obtained from parallel rendering using multiple graphics pipes and hardware 3D textures. The above image and movie show wells and hot spots between two layers. The hot spots are created due to subsurface tectonic processes. Water temperature increases highly at such hot spots. Additionally hot water and other hot materials are coming up from beneath the earths mantle.