Abstract: A fluid transfer module is provided with multiple flow paths for transferring multiple fluids. The module is particularly useful in downhole pumps for passing oil upwardly through a central passage and for passing gas up or down through concentric passages around the central passage. The module also can be used for water or fuel, particularly for downhole steam generation. The module includes an elongate housing or production tubing with an inner coupling having an attached, elongate inner tube which together form a central passage extending substantially the length of the housing. An outer coupling with an attached, elongate outer tube form an inner concentric passage with the inner coupling and tube and an outer concentric passage with the housing. The concentric flow paths are less restrictive to the flow of fluids therethrough.

Abstract: A pressure-operated valve is provided, particularly for use with a downhole pump of the fluid-driven, successive-stage, bladder type. Such a pump includes a plurality of pump and transfer modules. The pump modules have bladders which are operated by fluid, preferably gas, under pressure supplied through two separate internal passages in the modules to pump liquid upwardly through transfer modules. The pressure-operated valve is located below the bottom of the pump module and normally closes off the two gas passages. When gas under pressure above operating pressure is supplied through one of the passages, to establish a sufficient pressure differential between the passages, the valve opens to connect the passages. Heated gas can then be circulated to increase the temperature of internal oil passages extending through the modules to prevent paraffin formation. The two gas circuits can also be connected to enable removal of condensate.

Abstract: A liquid pump is provided and particularly a downhole pump for use in an oil well bore for pumping oil or in a gas well to remove condensate. The downhole pump includes a plurality of pump and transfer modules, each of which includes an elongate housing with end couplings and with two internal passages extending therethrough. The pump module further has a bladder extending between the end couplings around the internal passages with the couplings having passages connecting one of the internal passages to space on one side of the bladder. When fluid, preferably gas, under pressure is supplied to that passage, the bladder forces liquid therein upwardly into the next module. At the same time, fluid under pressure is exhausted through one of the passages from the space on the opposite side of the bladder of the next pump module, aiding it to receive liquid from the pump module therebelow.

Abstract: A liquid pump is provided and particularly a downhole pump for use in an oil well bore for pumping oil or in a gas well for removing condensate. The downhole pump includes a plurality of pump and transfer modules, each of which has an elongate housing with end couplings and with two internal gas passages and a liquid passage extending therethrough. The pump module further has a bladder extending between the end couplings around the internal passages with the couplings having passages connecting one of the internal passages to space on one side of the bladder. When fluid, preferably gas, under pressure is supplied through the coupling passages, the bladder forces liquid therein upwardly into the next module. At the same time, fluid under pressure is exhausted through the coupling passages of the next pump module, aiding it to receive liquid from the pump module therebelow.

Abstract: A liquid pump is provided and particularly a downhole pump for use in an oil well bore for pumping oil or in a gas well to remove condensate. The downhole pump includes a plurality of pump and transfer modules, each of which includes an elongate housing with end couplings and with two internal passages extending therethrough. The pump module further has a bladder extending between the end couplings around the internal passages with the couplings having passages connecting one of the internal passages to space on one side of the bladder. When fluid, preferably gas, under pressure is supplied to that passage, the bladder forces liquid therein upwardly into the next module. At the same time, fluid under pressure is exhausted through one of the passages from the space on the opposite side of the bladder of the next pump module, aiding it to receive liquid from the pump module therebelow.

Abstract: A liquid pump is provided and particularly a downhole pump for use in an oil well bore for pumping oil or in a gas well to remove condensate. The downhole pump includes a plurality of pump and transfer modules, each of which includes an elongate housing with end couplings and with two internal passages extending therethrough. The pump module further has a bladder extending between the end couplings around the internal passages with the couplings having passages connecting one of the internal passages to space on one side of the bladder. When fluid, preferably gas, under pressure is supplied to that passage, the bladder forces liquid therein upwardly into the next module. At the same time, fluid under pressure is exhausted through one of the passages from the space on the opposite side of the bladder of the next pump module, aiding it to receive liquid from the pump module therebelow.

Abstract: A coal burning grate for furnaces which is reciprocatably mounted to feed coal from a hopper into the furnace and to simultaneously remove ash from the furnace to an external ashpit. The grate may include a heel attached to the grate shoe to move ash in the ash pit to assist in the removal of the ash from the furnace.