Abstract:
Disclosed is a method and apparatus comprising a side drive system with a drive shaft (24, 24a) driven from the platform level (10) and powering a drilling unit (16) for rotating drill pipe (14). Except for the tethering of the drive shaft at the top of the derrick (60-64) and its coupling to a power source (70) at the platform level, there is preferably no stabilizing means for the system. The drive shaft (24, 24a) is stationary, preferably hollow, and extends the height of the derrick located to one side of the main drilling axis. The power source (70) at the platform level comprises a power takeoff from a conventional rotary table (84). The upper drive assembly (18) of the drilling unit (16) is coupled to the drive shaft (24, 24a) and capable of vertical movement along the drive shaft and providing torque to the drill string. As an option, a stabilizing system for the drilling unit in the form of tension members (182) may be used, or the drive shaft itself may be stabilized at various elevations along its length by stabilizing arms (190) to provide lateral bending restraint yet permitting rotational freedom. The preferred embodiment is such that the side drive system may operate without stabilizing mechanisms for the drilling unit or drive shaft.
Abstract:
An easy break-out tool joint (10) (two embodiments) comprising a drive spindle (stem), or sub (12, 12a) having a shoulder ring (32, 32a) whose shoulder (34) is axially movable but rotatable with the sub (12, 12a) to form a conventionally shouldered (34, 58) drill pipe joint so that, upon rotation in one direction, torque is applied in the conventional manner for drilling or back reaming. The shoulder (34) is initially axially moved relative to the drive sub to disconnect the shoulder (34, 58) when the drive stem is rotated in the opposite, or break-out direction, thereby reducing the torque required for break-out to only that torque necessary to unthread the joint. In the practice of the method of triple back reaming utilizing this easy break-out tool joint, a drilling unit (140, 160) is lowered to the platform and the drive spindle or sub (12, 12a) is connected to the top drill pipe of the string, while the string is held by a spider (156) at the platform level. The string is then rotated as the drill pipe string is withdrawn from the well bore. When the last of the joints in the stand (three lengths of drill pipe) is above the spider (156), the raising and rotation of the drill pipe string is stopped and the drill pipe string is then held by spiders (156). At this, the drive stem (12, 12a) is powered to break-out the joint at the top of the stand. Thereafter, the stand is still held by the rig elevators and appropriate tongs (162, 164) are applied to break the joint at the platform level, thus freeing the stand for movement out of the rig drive axis. The above procedure is repeated until the drill pipe string has been withdrawn.
Abstract:
An emergency evacuation system for a high-rise building includes a cable carried on a spool positioned on the top of the building, such cable having at its end remote from the spool a weighted coupler dimensioned to be received by a powered spool carried within an escape cabin, such escape cabin having an entry-exit side and crawler means supported on that entry-exit side for engaging the building to permit smooth raising and lowering of the cabin.
Abstract:
A compressed natural gas (CNG) vehicle refueling system is designed for refueling fleets of vehicles with identical fuel tanks. The amount of CNG dispensed into the tanks may be closely approximated without the use of a flow meter. An initial standardized volume is calculated based upon the ambient temperature, the initial pressure level and an approximate compressibility of the gas. Gas is dispensed into the fuel tank to a desired pressure which is confirmed with a pressure gage. A final standardized volume of gas contained within the fuel tank is calculated based upon the final pressure level and assuming no change in the compressibility of the gas. The initial standardized volume of gas is subtracted from the final standardized volume of gas to yield an actual volume of gas dispensed from the storage vessel. Empirically derived temperature correction factors may be used to generate an even more accurate approximation of CNG dispensed. The temperature correction factors compensate for the difference in temperature between operating temperatures and the standardized temperature of zero degrees celsius.
Abstract:
A pipe handling apparatus for a drilling rig is mounted on the rig floor. The drilling rig has a top drive with a power drive stem. Elevators are suspended below the drive stem. The lifting member has a supporting arm to receive the bottom of a stand of drill pipe lifted by the elevators. A stabilizing arm is mounted to the lifting member above the supporting arm to stabilize the stand. The lifting member telescopes upward to slide the stand of drill pipe upward through the elevators and into engagement with the drive stem.
Abstract:
A well slip assembly including a support structure adapted to be placed on a well drilling rotary table and to turn therewith, a vertically movable slip suspending carrier structure, latch means for releasably retaining the carrier structure and slips in a lower active position relative to the support structure, and yielding means urging the carrier structure upwardly to a retracted position. The support structure is desirably formed separately from a slip bowl structure positionable in the rotary table. The carrier structure may be urged upwardly by fluid pressure type spring means, such as air springs, with an accumulator chamber for the pressure fluid system preferably being contained in or carried by the vertically movable slip carrier structure.
Abstract:
A compressed natural gas (CNG) vehicle refueling system has a hydraulic fluid reservoir, an accumulator, and two banks of cylinders, each of which has an axially moveable piston, a pair of inlets and an outlet. The pistons separate the CNG from hydraulic fluid. The refueling system drains the banks one at a time by refueling CNG vehicles with a plurality of refueling depots. Hydraulic fluid is pumped from reservoir to the cylinders to maintain 3600 psi of pressure in the cylinders while CNG is being dispensed. A pressure limiting valve limits pressure in the vessel tanks to 3000 psi. When the bank is drained of CNG, the pistons stop moving, the pressure at the outlets drops below 3000 psi, and the pressure at the inlets increases. This difference in pressure is sensed, causing the control panel to change banks. The pressure in the accumulator and the lack of pressure in the reservoir causes the hydraulic fluid to return to the reservoir. The second bank simultaneously begins to dispense CNG in the same manner as the first bank.
Abstract:
A torque coupling for connecting between upper and lower tubular members of a drill rig allows make up and break out at lower torques than normally required. The coupling has a body which has an upper end that connects to the upper tubular member and lower end which connects to the lower tubular member. The lower tubular member has an upward facing torque shoulder. A torque shoulder sleeve mounts slideably to the body. The torque shoulder sleeve has a downward facing shoulder that engages the torque shoulder of the lower tubular member. The body and the torque shoulder sleeve have opposed load shoulders, at least one of which is conical. A wedge member locates between these load shoulders. When the wedge member slides outward, it decreases the distance between the load shoulders and reduces the pressure of the lower end of the torque shoulder sleeve against the upper end of the lower tubular member.
Abstract:
A slip unit for releasably supporting a well pipe, including a support structure to be positioned on and turn with a rotary table and preferably taking the form of a slip bowl, and a vertically movable slip carrier structure suspending a number of pipe-gripping slips and adapted to be releasably retained by latch means in a lower active position, with the carrier and slips being yieldingly urged upwardly to inactive positions when the latch means are released. The support structure and carrier structure are both desirably formed of complementary sections hinged for relative swinging movement between closed positions about the pipe and open positions permitting movement of the unit laterally relative to the pipe, and with an additional latch being provided for retaining the structures in their closed positions. The carrier structure and slips are urged upwardly by spring cartridges which are removable as units from the slip assembly in a condition maintaining the actuating springs under compression and preventing injury or damage by release of the spring force during removal. Vertical guides are provided circularly between the slips for centering a well pipe in a manner preventing damage to the slips by engagement with enlargements on the pipe.
Abstract:
A storage vessel is filled with compressed gas by filling a first tank with gas from a low pressure gas source. Hydraulic fluid is drawn from a reservoir and pumped into the first tank in contact with the gas. This causes the gas in the first tank to flow into the storage vessel as it fills with hydraulic fluid. At the same time, gas is supplied from the gas source to a second tank. Hydraulic fluid previously introduced into the second tank flows out to the reservoir as the second tank fills with gas. When the first tank is full of hydraulic fluid, a valve switches the cycle so that the hydraulic pump begins pumping hydraulic fluid back into the second tank while the first tank drains. The cycle is repeated until the storage vessel is filled with gas to a desired pressure.