Improvement to brine density calculations
For ECLIPSE 300, a new formulation is implemented for well behavior when brine density changes with salinity (using the BDENSITY and PVTWSALT keywords). This uses the well salt concentration to calculate the density of brine for wells etc. instead of the reference salt concentration from the PVTWSALT keyword. Various improvements to the brine model have been implemented.
Workflow and usability
For ECLIPSE 100, a number of coal bed methane (CBM)-related solution section keywords can now be manipulated using ECLIPSE operation keywords (for instance, ADD, EQUALREG, MULTIREG, and OPERATER). The CBM keywords are the initial coal gas and saturated coal gas concentration, initial coal solvent concentration, and the solvent fraction in the gas phase.
New and improved functionality
This release addresses the following issues discovered in previous releases:
• An alternative workflow has been created which recalculates transmissibilities for restart cases incorporating all schedule section multipliers. This avoids the problem with the standard restart workflow where changes to NNC transmissibilities were not preserved, and does not require the base case to be rerun with the latest version of the simulator.
• The Temperature option has been improved for better rock conductivity calculations and improved heat capacity handling of gas.
• There have been several improvements to the parallel mode. For instance, an issue that could have caused serious convergence issues and run failures for some surfactant cases has been fixed and the WBP summary vectors are now calculated correctly regardless of geometry or exact numbers of processors. Also, an issue which meant that only small auto-refinements would work correctly has now been addressed.
• An issue which could cause ECLIPSE to fail in a restart run that also activated pressure flux boundary conditions has been fixed.
• In parallel mode, a number of mnemonics, previously reporting a value of 0, now report the correct values. These include summary vectors for flows such as BFLOWI+ at parallel boundaries, summary vectors associated with instantaneous gradients with respect to well control variables (for wells not on processor 1), and restart information such as oil density when the KVGEN keyword was used for grid blocks not on processor 1. In addition to these improvements, NNC connections are now made correctly in cases where a boundary between dual and single porosity regions coincides with the boundary between processors. • The processing of the EDITNNC keyword has been optimized for speed.
• UDQs and ACTION keywords previously assumed that groups and network groups were ordered identically. This assumption is no longer made and the correct network nodes are used.
• The algorithm used to calculate hydrocarbon pore volume has been improved. The previous algorithm could cause a serious loss of precision in cases with extremely small pore volume values in the chosen unit set, especially for a very large number of grid blocks.
• The cell indices and values in the minimum/maximum table in the print file are now correct.