Abstract: A sub-surface safety valve having a positional flapper, a valve seat, and a remotely actionable opening prong. The opening prong comprising at least one of a debris wiper, filter, and at least one flow hole. The wiper, filter, and at least one flow hole function according to either position or movement of the flapper and opening prong and prevent debris buildup around the valve seat. The wiper is an extendible material in communication with the valve seat and a surface of the opening prong and it extends radially in response to closing the valve. The extension of the wiper in response to closing the flapper cause the wiper to scrape the surface of the valve seat. The filter can comprise a screen integrated with or attached to the opening prong. The flow holes can be in the form of angled flow holes or elongated slots.

Abstract: An elongated plunger arrangement for moving up and down in a tubing string and a plunger lift system for an oil well and a gas well, the plunger having an upper portion, an intermediate portion and a lower portion, all of the portions having an elongated longitudinally directed bore or cavity therewithin, the plunger also having a direction accelerating arrangement therewithin, the direction accelerating arrangement comprising an elongated acceleration inducing valve containing shift rod extending through the elongated bore, wherein the shift rod is longer than the elongated plunger.

Abstract: A method for reverse cementing may include providing a valve having a sliding sleeve, an outer sleeve situated about at least a portion of the sliding sleeve and connected to a casing string, and a spring configured to position the valve in an open position. The method may also include: running the casing string and valve into a well bore while the valve is in an open position; reverse cementing, while the valve is in an open position; and closing the valve after reverse cementing by allowing the valve to contact the well bore.

Abstract: A gravity valve for a downhole tool for use in a subterranean well and a method of use thereof. The gravity valve is adapted to control the flow of a dowuhole fluid through the downhole tool. The gravity valve typically includes a plunger and a seat. The plunger may embody a substantially non-spherical end that is adapted to mate with a complementary receiving end on the seat. The increase surface area of contact between the plunger and the seat acts to improve the seal therebetween, reduce the stresses thereon, and improve the performance of the gravity valve in general. The components of the gravity valve may be constructed of materials, which are selected based on the specific gravity of the materials in comparison with the specific gravity of the downhole fluid for a given application. A method of constructing and utilizing a gravity valve for a downhole tool.

Abstract: A plunger for well casings and other tubulars comprising: An elongate body having a flow passage with a lower inlet port and an upper outlet port; an internal valve positioned between the ports; at least one first flexible sealing member positioned around the body below the outlet port; an actuator which urges the first sealing member against the interior wall of the casing when the valve is closed; at least one second flexible sealing member positioned around the body and providing an outwardly expandable sealing chamber; and at least one flow port positioned below the valve and providing fluid communication between the flow passage and the sealed chamber. The second flexible sealing member(s) being outwardly expandable by increasing pressure in the sealed chamber.

Abstract: A bypass valve for a plunger in a plunger lift system in an oil and gas well is disclosed. The valve has a valve body, a piston and a spring. The pressure differential across the piston keeps the valve closed during the upstroke of the plunger. The spring opens the valve when the pressure differential decreases to below a selected value.