Abstract: A method for calibrating a direct flow simulation of a rock sample involves providing a 3D image of a rock sample and generating a segmented structural image of the rock sample from the 3D image by selecting voxels to represent either a pore space or a solid material. Fluid flow is simulated on the segmented structural image with a direct flow simulation. A 3D spatially-resolved fluid velocity map is generated for one or more fluid phases at a pore-scale resolution using pulsed field gradient nuclear magnetic resonance imaging. The simulated fluid flow and the 3D spatially-resolved fluid velocity map are compared to calibrate the direct flow simulation across the rock sample.

Abstract: An imager and method for imaging fluid of a subsurface formation is disclosed. The imager includes a housing having a sidewall defining a passage to receive a core sample of the subsurface formation therethrough. The housing is positioned in a downhole tool and has a fluid inlet to receive fluid from the subsurface formation into the passage. The imager also includes a permanent magnet positioned in the sidewall of the housing, a radio frequency coil positioned in the sidewall of the housing between the permanent magnet and the passage, a gradient field in the sidewall of the housing between the permanent magnet and the radio frequency coil, and a chemically-selective imager. The chemically-selective imager is operatively connected to the radio frequency coil to selectively pulse frequencies according to a pulse sequence whereby individual fluid measurements of the sample are generated.

Abstract: An imager and method for imaging fluid of a subsurface formation is disclosed. The imager includes a housing having a sidewall defining a passage to receive a core sample of the subsurface formation therethrough. The housing is positioned in a downhole tool and has a fluid inlet to receive fluid from the subsurface formation into the passage. The imager also includes a permanent magnet positioned in the sidewall of the housing, a radio frequency coil positioned in the sidewall of the housing between the permanent magnet and the passage, a gradient field in the sidewall of the housing between the permanent magnet and the radio frequency coil, and a chemically-selective imager. The chemically-selective imager is operatively connected to the radio frequency coil to selectively pulse frequencies according to a pulse sequence whereby individual fluid measurements of the sample are generated.

Abstract: A reversibly actuatable fluid hydraulic pump is described for use in a hydraulically driven elevator. The pump comprises a cylinder and a piston linearly actuatable within the cylinder by a ball screw race disposed over a spindle and connected to the piston. The shaft of the piston is hollow to receive the spindle as the piston is drawn along by virtue of the motion of the race along the spindle, and seals are provided at the free end of the piston which sealingly engage against the walls of the cylinder, and on the cylinder which sealingly engage with the shaft of the piston. A further feature of the invention is the provision of a compressible gas between the end of the cylinder and the end of the piston so that the expansion thereof reduces the work required to move the piston out of the cylinder, whereas when the system is relaxing, the compressible gas provides extra resistance and thus a smoother motion.