Abstract: Cot-based cloning and sequencing (CBCS) is a method that permits the cloning and sequencing of an organism's sequence complexity at unprecedented efficiency. DNA renaturation kinetics (i.e., Cot) methods are used to fractionate genomic DNA into single-copy and repeat sequence components, each isolated kinetic component is used to construct a corresponding DNA library, and clones from each library are sequenced in numbers proportional to the complexity of the component from which they were derived. For some species, the number of clones that need to be sequenced in order to attain a specific level of coverage via CBCS is less than one-tenth the number required to achieve the same level of coverage using shotgun sequencing (the current means by which genomes are sequenced).

Abstract: A surface power unit for use on a subterranean well generates a series of pulses of pressurized fluid to a downhole pump. A sequencing mechanism connects and disconnects the surface power unit to each of a plurality of downhole pumps in a predetermined order such that a pulse of pressurized fluid is being applied to one or more of the plurality of downhole pumps during a power cycle while each of the other ones of the plurality of downhole pumps is completing its pumping cycle. The number of downhole pumps which can be operated from a single surface power unit is limited by the ratio of the length of the power cycle to the length of the pumping cycle of the downhole pumps. The sequencing means can include a clocking device such as a shift register which generates a sequence of enabling signals to corresponding signal amplifiers for each well.

Abstract: A surface power unit for use on a subterranean well generates a series of pulses of pressurized fluid to a downhole pump. A pump means generates a flow of fluid from a reservoir through a charging line to a charging side of a cylinder. A piston is slidably disposed within the cylinder, dividing the cylinder into the charging side and a power side. Position or pressure transducer means responsive to the movement of the piston generates control signals representing the position of the piston in the cylinder. The charging line can include a first valve means responsive to one of the control signals for regulating the flow of fluid through the charging line. A return line is provided for returning fluid from the charging side of the cylinder to the pump means. The return line includes a second valve means responsive to another one of the control signals for regulating the flow of fluid through the return line.

Abstract: A downhole pump for a well is disclosed which includes a piston slidably disposed within a housing for pumping fluid from the well. The longitudinal axes of the piston and the housing extend in a generally vertical direction with respect to the surface of the well. A surface unit supplies a pulsating flow of fluid to the piston. A velocity actuated valve is formed in the piston and includes a ball which is spaced from an orifice by a bias. The bias holds the ball away from the orifice such that the valve is normally open. The flow of fluid through the velocity actuated valve during each fluid pulse creates a pressure differential which is resisted by the bias. When the pressure differential exceeds the force generated by the bias, the ball will seat in the orifice and close the valve to further fluid flow. The balance of the fluid pulse will be applied to the lower side of the piston and the piston moves upwardly within the housing, thereby pumping fluid from the well.

Abstract: A combined surface power unit and velocity actuated valve for a downhole pump is disclosed. The surface power unit generates a series of pulses of pressurized fluid. A power line supplies the fluid pulses to a downhole pump. Within the downhole pump, a piston means is slidably disposed for pumping fluid therefrom. The piston means includes an orifice for permitting fluid flow therethrough. The velocity of the fluid passing through the orifice causes a pressure differential across the orifice and valve means closes for the duration of each pulse. When the valve means is closed, pressure builds up in the downhole pump causing the piston means to move in a power stroke, pumping the production fluid. Between pulses, the pressure of the fluid in the downhole pump drops and a velocity valve opens. When the velocity valve is opened, fluid can flow freely therethrough, and the piston means retracts under the influence of gravity in a re-charging stroke.