Abstract: Methods and systems for providing robust solutions for sub-problems arising from numerical simulations of reservoirs and the like are disclosed. In at least one embodiment, a method of solving a system of non-linear equations in accordance with the present disclosure includes: attempting to iteratively achieve a solution of a portion of the system using one or more iterative solution techniques; determining that the attempting has failed to iteratively achieve the solution of the portion of the system using one or more iterative solution techniques; and responsive to the determination that the attempting has failed, attempting to achieve an interval-based solution of the portion of the system using an interval-based solution technique.

Abstract: A method is disclosed, which is practiced by a reservoir simulator, for simulating a reservoir and generating a set of simulation results, the simulation results including a framework, the framework further including a plurality of grid cells, comprising: generating one or more static and dynamic regions within the grid cells of the framework of the simulation results, the static and dynamic regions each having region values, wherein the region values of the static regions cannot be allowed to change dynamically, and wherein the region values of the dynamic regions can be allowed to change dynamically.

Abstract: A method is disclosed, which is practiced by a reservoir simulator, for simulating a reservoir and generating a set of simulation results, the simulation results including a framework, the framework further including a plurality of grid cells, comprising: generating one or more static and dynamic regions within the grid cells of the framework of the simulation results, the static and dynamic regions each having region values, wherein the region values of the static regions cannot be allowed to change dynamically, and wherein the region values of the dynamic regions can be allowed to change dynamically.

Abstract: A golf swing training aid (10), to be fitted between a player's knees, has an elongate, telescopic body (11), with foam pads (16, 18) on respetive cross-heads (17, 19) at each end of the body (11). A flexible strap (20) releasably secures one cross-head (17) to one of the player's knees and the other cross-head (17) rests against the other knee. The knees are held stable on the backswing and first half of the downswing of the club, but the aid (10) releases the knees as the swing is completed.