초록 ▼

A subsurface control which can be installed and retrieved from the interior of a borehole by a wireline. The apparatus is preferably located at the bottom of the borehole and controls the flow of well fluids by a pulse flow-type operation which shuts in the well prior to reaching the critical flow r

A subsurface control which can be installed and retrieved from the interior of a borehole by a wireline. The apparatus is preferably located at the bottom of the borehole and controls the flow of well fluids by a pulse flow-type operation which shuts in the well prior to reaching the critical flow rate, and re-establishes flow after sufficient pressure buildup in the borehole and formation. The apparatus more efficiently utilizes well energy in lifting liquid to the surface of the ground, and includes apparatus which cyclically flows the well in response to flow rate and bottomhole pressure. In one embodiment of the invention, the apparatus is used in combination with a free traveling plunger.

대표청구항 ▼

In a borehole having a fluid producing formation located downhole therein, and a production tubing extending downhole into proximity of the formation, with the tubing forming a produced fluid flow path and a borehole annulus, the improvement comprising: a subsurface flow controller for controlling f

In a borehole having a fluid producing formation located downhole therein, and a production tubing extending downhole into proximity of the formation, with the tubing forming a produced fluid flow path and a borehole annulus, the improvement comprising: a subsurface flow controller for controlling flow of fluid from the formation into the tubing string, said controller being in the form of a fluid conducting hollow body and having an upper and lower end portion, said hollow body having means forming a piston chamber, a production inlet chamber, and a production outlet chamber therewithin; said piston chamber having a piston reciprocatingly received therewithin and dividing the last said chamber into an upper and lower piston chamber; a pilot valve, means by which said pilot valve is actuated in response to the pressure differential between the bottomhole pressure and the tubing pressure above the tool to thereby control the flow of produced fluid into and out of said lower piston chamber; a production valve seat separating said production outlet chamber From said production inlet chamber, a production valve element having means by which it is actuated by said piston from an opened to a closed position for controlling fluid flow through said production valve seat; a choke forming a produced fluid inlet into said production inlet chamber; means forming a bleed port which is arranged respective to the piston so that downhole pressure is effected within said upper piston chamber when said production valve is closed and which is effected within said lower piston chamber when said production valve is moved to the open position; and means biasing said production valve element towards the closed position; so that increased bottomhole pressure opens said pilot valve to cause said piston to open said production valve element, and fluid flow can occur through said production valve seat until a reduced flow rate through the last said seat causes the production valve element to assume a closed position. Method of controlling mixed liquid and gaseous fluid flow from a producing formation located downhole in the borehole, wherein the produced fluid flows uphole through a production tubing string, comprising the steps of: 1. locating a flow controller downhole in a borehole in proximity of the production formation; 2. connecting the flow controller to the tubing string so that fluid flow through the tubing string is controlled by the action of the controller; 3. sensing the pressure differential between the formation pressure and tubing pressure, and moving the controller to a fluid flow position in response to the bottomhole pressure increasing to a value which will expel most of the accumulated liquid from the borehole; 4. sensing the flow rate through the tubing string and moving the controller to a position to prevent fluid flow through the tubing string in response to the flow rate decreasing to a value which is in excess of a rate of flow where insufficient velocity through the tubing string is available to carry liquid to the surface by entrainment.