Abstract: A method for determining an oil-gas-water interface based on the formation pressure equivalent density. The method comprising: determining working parameters of the wireline modular formation tester based on the acquired conventional logging data of a block to be studied; acquiring a series of formation pressure and corresponding depth data based on the working parameter; computing formation pressure equivalent densities at different depths based on the formation pressure and the corresponding depth data; drawing a crossplot of the formation pressure equivalent density and the depth according to the formation pressure equivalent density and the corresponding depth data at the different depths; and determining the oil-gas-water interface according to the position of breaking point of the formation pressure equivalent density on the crossplot of the formation pressure equivalent density and the depth.

Abstract: The present invention provides a method and an apparatus for determining an oil-gas-water interface based on the formation pressure equivalent density. The method comprises determining working parameters of the wireline modular formation tester based on the acquired conventional logging data of a block to be studied; acquiring a series of formation pressure and corresponding depth data based on the working parameter; computing formation pressure equivalent densities at different depths based on the formation pressure and the corresponding depth data; drawing a crossplot of the formation pressure equivalent density and the depth according to the formation pressure equivalent density and the corresponding depth data at the different depths; and determining the oil-gas-water interface according to the position of breaking point of the formation pressure equivalent density on the crossplot of the formation pressure equivalent density and the depth.

Abstract: A truckle includes a swiveling shaft, a rack, a driving unit received in the swivel shaft, and an arresting unit assembled with the driving unit. The swiveling shaft defines a through hole near an end thereof, and has a bearing on another end thereof. The rack has an end connecting with the bearing. The driving unit includes a rotating member corresponding to the through hole, a push member corresponding to a peripheral of the rotating member. The arresting unit includes an axis pole extending into the sleeve for assembling with the push member, a gear disc mounted on the axis pole for corresponding to the latch portion, and an arresting block mounted below the gear disc and corresponding to the wheel. The truckle either limits direction solely or limits direction and rotation simultaneously. The truckle has firm structure and can be arrested reliably.

Abstract: A wheel assembly has a housing, a wheel, a rotating device and a controlling device. The housing has a sleeve, an extending portion extending laterally from the sleeve, and brackets extending from opposite sides of the housing. The wheel is rotatablely mounted between the brackets of the housing via a shaft. A rotating device includes a lower pole for engaging with the sleeve of the housing, and a fixing element at bottom of the lower pole for fixing the lower pole on the sleeve in assembly. The controlling device includes a limiting element and a pressing element cooperating with each other to limit direction of the housing and rotation of the wheel simultaneously. The limiting element is mounted in the extending portion and adjacent to the wheel in assembly. The pressing element is mounted on an end of the extending portion for driving the limiting element.

Abstract: A truckle assembly has a housing, a rotating unit movably mounted on the housing, a limiting unit and a wheel assembly. The housing includes a body and a sleeve. A slope portion is formed inside the body and neighboring the sleeve. The rotating unit includes a central shaft, and a gear ring mounted on the central shaft for corresponding to a first side of the slope portion. The limiting unit includes a pedal, an interferential portion linking an end of the pedal, and an arresting portion linking an end of the interferential portion. The pedal has a first portion extending into the housing, and a second portion extending out of the housing. The interferential portion corresponds to a second side of the slope portion. The wheel assembly includes at least a wheel assembled on sides of the housing, and a shaft pole extending through the wheels and the pedal.

Abstract: A truckle assembly has a housing, a rotating unit movably mounted on the housing, a limiting unit and a wheel assembly. The housing includes a body and a sleeve. A slope portion is formed inside the body and neighboring the sleeve. The rotating unit includes a central shaft, and a gear ring mounted on the central shaft for corresponding to a first side of the slope portion. The limiting unit includes a pedal, an interferential portion linking an end of the pedal, and an arresting portion linking an end of the interferential portion. The pedal has a first portion extending into the housing, and a second portion extending out of the housing. The interferential portion corresponds to a second side of the slope portion. The wheel assembly includes at least a wheel assembled on sides of the housing, and a shaft pole extending through the wheels and the pedal.

Abstract: A wheel assembly has a support unit, a rotating unit and an arresting unit. The support unit includes a sleeve, a stop hole and a recess. Brackets respectively extend from opposing sides of the sleeve. A rotating shaft pivots the wheel between the brackets. The rotating unit includes a base. An axis portion extends from a surface of the base for movably engaging with the sleeve. A tooth-like surface is formed on a side of the axis portion. The arresting unit includes a limiting portion movably pivoted between the brackets and in the vicinity of the wheel. A pressing plate pivots to an end of the limiting portion movably. A link portion movably links the limiting portion and the pressing plate and forms an abutting portion. The limiting portion forms a stop portion thereon. The arresting unit limits movement and rotation directions of the support unit and the wheel simultaneously.

Abstract: A wheel assembly has a swiveling shaft, a support member movably assembled with the swiveling shaft, an arresting member and wheels. The swiveling shaft includes a swiveling sleeve, a pressing element disposed on the swiveling sleeve, and a first gear bracket and a second gear bracket. The support member includes a rack with an opening, and a third gear bracket snapped in the opening, The arresting member is mounted on the rack. A first resilient element is provided between the arresting member and the rack. A second resilient element is provided between the arresting member and the third gear bracket. The wheels respectively pivot to the rack, and are limited at opposite sides of the arresting member. The pressing element limits rotation of the wheels, preventing deformation of the wheels thereby effectively stopping the wheels and lengthening lives of the wheels.

Abstract: A wheel assembly has a swiveling shaft, a support member movably assembled with the swiveling shaft, an arresting member and wheels. The swiveling shaft includes a swiveling sleeve, a pressing element disposed on the swiveling sleeve, and a first gear bracket and a second gear bracket. The support member includes a rack with an opening, and a third gear bracket snapped in the opening, The arresting member is mounted on the rack. A first resilient element is provided between the arresting member and the rack. A second resilient element is provided between the arresting member and the third gear bracket. The wheels respectively pivot to the rack, and are limited at opposite sides of the arresting member. The pressing element limits rotation of the wheels, preventing deformation of the wheels thereby effectively stopping the wheels and lengthening lives of the wheels.

Abstract: A wheel assembly has a support unit, a rotating unit and an arresting unit. The support unit includes a sleeve, a stop hole and a recess. Brackets respectively extend from opposing sides of the sleeve. A rotating shaft pivots the wheel between the brackets. The rotating unit includes a base. An axis portion extends from a surface of the base for movably engaging with the sleeve. A tooth-like surface is formed on a side of the axis portion. The arresting unit includes a limiting portion movably pivoted between the brackets and in the vicinity of the wheel. A pressing plate pivots to an end of the limiting portion movably. A link portion movably links the limiting portion and the pressing plate and forms an abutting portion. The limiting portion forms a stop portion thereon. The arresting unit limits movement and rotation directions of the support unit and the wheel simultaneously.

Abstract: A base member for swivel caster comprises a fixed base, a rotation base and a hollow staff. The fixed base includes a ring member, and a plurality of first raceways lathed in an inward surface of the ring member. A support cavity is defined through a center of the rotation base. Assembling holes are defined in a connecting portion and communicate with the support cavity and the second raceways. During assembly, a plurality of rolling balls are extended through the assembling holes and loaded into the first raceways and the second raceways. Then a plurality of biasing balls is loaded into the assembling holes. The staff is inserted into the support cavity and blocks the assembling holes. The rolling balls contact the biasing balls instead of fixed components whereby the rolling balls swivel and rotate smoothly.

Abstract: A base member for swivel caster comprises a fixed base, a rotation base and a hollow staff. The fixed base includes a ring member, and a plurality of first raceways lathed in an inward surface of the ring member. A support cavity is defined through a center of the rotation base. Assembling holes are defined in a connecting portion and communicate the support cavity and the second raceways. During assembly, a plurality of rolling balls are extended through the assembling holes and loaded into the first raceways and a second raceways. Then a plurality of biasing balls is loaded into the assembling holes. The staff is inserted into the support cavity and blocks the assembling holes. The rolling balls contact the biasing balls instead of fixed components whereby the rolling balls swivel and rotate smoothly.

Abstract: A wheel assembly has a housing, a wheel, a rotating device and a controlling device. The housing has a sleeve, an extending portion extending laterally from the sleeve, and brackets extending from opposite sides of the housing. The wheel is rotatablely mounted between the brackets of the housing via a shaft. A rotating device includes a lower pole for engaging with the sleeve of the housing, and a fixing element at bottom of the lower pole for fixing the lower pole on the sleeve in assembly. The controlling device includes a limiting element and a pressing element cooperating with each other to limit direction of the housing and rotation of the wheel simultaneously. The limiting element is mounted in the extending portion and adjacent to the wheel in assembly. The pressing element is mounted on an end of the extending portion for driving the limiting element.

Abstract: The present invention relates to the structural improvement of a wheel, and more particularly to an assembled wheel structure that has excellent resilience and no need to fill in air as well as is free of air leakage and easy to be disassembled. The present invention is constructed by a wheel body and a tire, wherein the wheel body is further constructed by a wheel shell and a matching wheel cover, while the tire, made of resilient materials (e.g., plastic, PU, etc.), inside accommodates a resilient inner tire to provide double-layered resiliency. There are several position pads on both sides of the inner circumference of the tire and the position pads 421, 431 on two sides are alternated with each other. A hole 422, 432 is formed on each position pad 421, 431 to allow the position rods to set in place and form a complete wheel structure.

Abstract: A roller skate wheel includes an outer wheel body defining a receiving space and having an inner wall formed with a first annular flange and a second annular flange spaced from each other, an inner tire received in the receiving space, a first wheel cap secured to the first annular flange, a first bearing received in a first opening defined in the first wheel cap, a second wheel cap secured to the second annular flange and securely coupled with the first wheel cap, and a second bearing received in a second opening defined in the second wheel cap.