Abstract: An example method includes pumping fluid into a wellbore to fill, at least partly, a region in a lost circulation zone, with the fluid having a first density; and after pumping the fluid, pumping cement slurry into the wellbore. The cement slurry has a second density. The first density is greater than, or equal to, the second density, which causes the fluid to prevent, at least partly, the cement slurry from mixing with other fluid in the lost circulation zone for at least a period of time.

Abstract: A reservoir simulator forms by parallel processing in a multimode computer system estimates of behavior of a subsurface reservoir organized into a matrix grid of three-dimensional cells. The simulator is provided with a module which acts on input data regarding actual reservoir performance and parameters of interest. A grammar is provided which has a sequence of tokens and actions to be taken by the computer system on the input data. Based on the grammar, the input data are arranged into data structures for processing. The module translates the data structures into a set of arithmetic and logical actions to be applied to the original input data provided to the simulator.