Abstract: A rheology device comprises an elongated body having a flow path defined therein, first and second pressure lines in communication with the first and second ends of the flow path, respectively, and a differential pressure sensor for measuring a difference in pressure between the first and second pressure lines. In embodiments, the pressure lines are filled with a spacer fluid different from the fluid in the flow path. Based on at least three measurements of difference in pressure and corresponding flow rates, a yield point, a consistency factor, and a power factor can be calculated, and a rheology model of the fluid can be generated. Related methods are described which allow fluid rheology models to be determined and updated frequently. The device and methods herein may be useful in oil and gas operations, for example for rheology and hydraulic modeling in drilling operations.

Abstract: A method for drilling a wellbore comprises using drilling mud having a mud weight less than the formation pore pressure while drilling the horizontal section, to release some formation gas to mix with the drilling mud. As the mixture flows up the wellbore annulus, the resulting pressure in the vertical section is within the mud weight window (MWW) of the weak zones, thereby maintaining wellbore stability without the need for intermediate casings. The wellbore is killed by introducing a volume of heavy mud via a circulation sub in the drill string and periodically introducing additional heavy mud to fill the void left behind by the drill string as it is pulled uphole. The ratio of light mud and heavy mud in the killed well is such that the resulting pressure in the vertical section is within the MWW of the weak zones.

Abstract: An axial flow fan has a hub and plural blades. Each blade extends from hub to a blade support ring and has a pitch which decreases over a first inner part of the radial extent and increases over a second outer part of the radial extent. In a preferred embodiment, the trailing edge of the blade tip and the median point of the blade root are situated on a common radial line. In a further preferred embodiment, a median point on the tip chord of the blade is disposed angularly ahead of a median point of the root chord. The fan provides improved noise performance.

Abstract: A fan assembly comprising a fan, a stationary airflow directing device and a support inner ring. The fan has a hub portion and a plurality of fan blades. Each of the fan blades has a root region and a tip region. The root regions of each fan blade are secured to the hub portion wherein the fan blades extend substantially radially of a fan rotational axis. The airflow directing device has a plurality of stator blades extending radially about the support inner ring. The stator blades receive air flow from the fan and divert the airflow. The surface area of the stator blades is substantially less than the surface area of the fan blades. Each stator blade has a planar surface and a curved surface opposing the planar surface. The planar surface is disposed such that rotational components of air flow from the fan are incident on the planar surface.

Abstract: A stator assembly for a fan has a passage member which defines a passage for air flow due to the fan, a fan mount for the fan and at least one support arm extending between the passage member and the fan mount. A plurality of air flow directing members extend between the passage member and the fan mount. The passage member is preferably ring shaped and the fan mount is concentric with the ring. The air flow directing members may be straight, or skewed with respect to the direction of rotation of the fan. Different forms of the air flow directing members are described.

Abstract: An axial flow fan has a hub with a longitudinal axis of rotation and an outer periphery for the hub. Several blades are secured at their root regions to the hub's outer periphery. Each of the blades has a medial line that is tangential to a respective hub radius at the hub's outer periphery.

Abstract: A fan for an automotive radiator has a hub with a group of blades extending radially outwardly from the hub. A support member joins together the outward extensions of the blades in the first group. A second group of blades extend radially outwardly from the support member and a second support member joins together the ends of the blades in the second group.

Abstract: An axially compact axial flow fan with improved air-moving properties has a first array of fan blades that extend radially from a fan hub to a circumferential blade support member, a second array of fan blades extend from the first support member to a radially outward second circumferential blade support member. The fan blades in the second array each enjoy pitch angles that decrease from the second circumferential blade support radially along only a portion of each blade length. Thereafter, the pitch angles for the blades in the second array remains constant to the second circumferentially extending blade support member.

Abstract: A fan has a hub and a plurality of blades each having a medial line, a root region secured to the hub and extending radially outwardly to a tip region, with a leading edge and a trailing edge of each blade having a respective surface portion which is tangential to a respective radius of the fan, the leading edge and the trailing edge of each blade at the tip region being circumferentially behind, with respect to a first direction of rotation, the leading edge and trailing edge at the root region whereby the fan is rearwardly skewed wherein each blade has a dihedral angle formed between a plane perpendicular to a center axis of the fan and a line tangent to the medial line, each blade having a surface which is curved so that the dihedral angle decreases along the span of the blade moving from the root to the tip over a portion of the span equal to about 50% of the total span and wherein the dihedral angle increases over the remaining portion of the span.

Abstract: An axial flow fan has a hub with a back plane that is perpendicular to the axis of hub rotation. The leading and trailing edges of the fan blades that bound the inner region of the respective blades are in general radial alignment with the hub. The leading portion of the tip region is swept forward relative to the back plane and the trailing portion of the tip region is swept in the opposite direction. The forward swept tip region forms an acute angle with the back plane.

Abstract: The axial flow fan structure has an outer ring and an inner ring that establish an annular air passage. An odd-number of arms join the inner and outer rings together and at least one of the arms is skewed with respect to a radius of the annular air passage in order to reduce noise and vibration and to increase fan efficiency. Labyrinth air passages are provided between the fan and the outer ring to impede air blow-past and to improve further efficiency and noise reduction. Internal vanes are also provided to cool the fan-driving motor in which each of the vane members have at least two edges, the respective edges forming different angles relative to the axis of fan rotation.

Abstract: A fan comprises a hub rotatable about a central axis and a plurality of blades each having a root region secured to the hub and extending radially outwardly to a tip region. Each blade is designed with particular characteristics to reduce noise without affecting the performance of the fan.