Abstract: Design and control of well systems with multiple tubing strings is described. An example system models multiple tubing strings in wellbores as segments, with multiple control points selectively located among the segments. Each segment is modeled as one or more equations that describe characteristics of a fluid resource associated with the segment. The system can predict flow of fluids and energy in a wellbore by solving physical conservation equations subject to specified conditions. The system models multiple control points, and solves the equations to convergence to satisfy injection and production targets and specified constraints. Results may be used to improve production of the resource. The system can apply a variety of strategies to model wells via multiple control points, including conservation of mass and energy models, a global phase-component partitioning model, a conductive heat transfer model, a pseudo-pressure model, a non-Darcy flow model, a phase separation model, and so forth.

Abstract: Design and control of well systems with multiple tubing strings is described. An example system models multiple tubing strings in wellbores as segments, with multiple control points selectively located among the segments. Each segment is modeled as one or more equations that describe characteristics of a fluid resource associated with the segment. The system can predict flow of fluids and energy in a wellbore by solving physical conservation equations subject to specified conditions. The system models multiple control points, and solves the equations to convergence to satisfy injection and production targets and specified constraints. Results may be used to improve production of the resource. The system can apply a variety of strategies to model wells via multiple control points, including conservation of mass and energy models, a global phase-component partitioning model, a conductive heat transfer model, a pseudo-pressure model, a non-Darcy flow model, a phase separation model, and so forth.

Abstract: There is disclosed a refuse bin grabbing apparatus for grabbing a bin for movement to an elevated unloading position for emptying into a refuse truck including a power-driven linkage 5 for moving a bin-grasping clamp 2,3 towards inter-engagement with a refuse bin, the grasping clamp including articulated clamping arms 3 for embracing a refuse bin, the arms being fitted with a flexible belt 6 located between the clamping arms and a bin to be clamped so that the belt is tensioned in the bin engaging position; the articulated clamping arms are retractable to an out-of-the-way position (FIG. 1) to ensure that the clamping arms 3 do not protrude from the outer confines of the vehicle in the rest position.