Abstract:
An apparatus for increasing oil and gas recovery includes a delivery mechanism for automatically introducing a flow enhancing substance into a plunger of an oil or gas well and method.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to a method and apparatus for increasing oil and gas recovery, and more particularly, but not by way of limitation, to a use of an oil and gas flow enhancing substance and plunger used to deliver the substance into the bottom of the well.  
         [0003]     2. Related Art  
         [0004]     In the recovery of oil from oil-bearing reservoirs, it is often possible to recover only a portion of the oil contained in the underground formation by the so-called primary recovery methods which utilize the natural forces present in the reservoir. Thus, a variety of enhanced recovery techniques, so-called secondary or tertiary recovery have been employed in order to increase the recovery of oil from subterranean reservoirs.  
         [0005]     Chemical activated oil and gas flow enhancing liquids and sticks, such as soaps, are commonly known to reduce scale, paraffin and the viscosity of the fluids in the well and thus increase production of oil and gas recovery. Enhanced recovery techniques presently use a pump truck to pump a slurry mix either “in liquid form” of soap into the oil well either at the well head or through a special inner tubing which extends to the bottom of the hole or “in solid form” by dropping a soap stick into the well tubing.  
         [0006]     These techniques have proved somewhat effective in enhancing oil recovery, but each has drawbacks. The liquid soaps require the use of additional equipment such as pump trucks to effectuate delivery of the soaps as well as building inner tubing to deliver the soap where the soap is most needed, i.e., at the bottom of the well. Delivery using such methods is not economical or practical due to continuous manual intervention, additional equipment and costs associated therewith.  
         [0007]     Soap sticks are commonly used, but lack effectiveness as the soap sticks dissolve either too slowly upon reaching the well bottom or too quickly prior to reaching the well bottom. The length of time it takes for the stick to reach the bottom of the well depends upon well depth, viscosity of fluid, and the reactivity of the chemical stick to fluid environments as well as internal chemical release and aerodynamics of the stick shape. Due to the chemical nature of these chemical activated oil and gas flow enhancing sticks, they have a relatively limited mass or density advantage in the mass and density compared to the fluids in which they are placed and thus are limited in the rate in which they fall to the bottom of the well. In other words, by adding compositions to the sticks to increase their mass and density to decrease their time of decent, the reactivity of the stick is negatively impacted. One attempt to solve the problem employs the use of a plunger having a soap stick attached thereto. While this has provided an improvement, there remains a need for a more economical and effective method of enhancing oil recovery.  
       SUMMARY OF THE INVENTION  
       [0008]     An object is to improve secondary oil and gas recovery using a novel method and apparatus.  
         [0009]     Another object is to increase oil and gas production in an automated manner.  
         [0010]     Accordingly, the present invention is directed to an apparatus for increasing oil and gas recovery in a well by enhancing oil and gas flow therein. The apparatus includes a delivery mechanism which has chamber and valve mechanism for automatically delivering a flow enhancing substance to a head of the well and further has a plunger which includes a storage compartment with a valve for automatically receiving the flow enhancing substance from the delivery mechanism at the well head and releasing the flow enhancing substance upon reaching a lower portion of the well.  
         [0011]     The method of the present invention includes deploying a plunger in a well capable of automatically releasing an amount of flow enhancing substance in a lower portion of a well and automatically delivering an amount of flow enhancing substance to the plunger within the well.  
         [0012]     By so providing, the present invention enables oil and gas flow enhancing material delivery in an improved automated manner with minimal cost and modification to existing equipment. In doing so, improved oil and gas recovery is obtained.  
         [0013]     Other objects and advantages will be readily apparent to those skilled in the art upon viewing the drawings and reading the detailed description hereafter. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]      FIG. 1A  is a longitudinal schematic of well having an automated delivery mechanism and plunger of the present invention therein in one mode.  
         [0015]      FIG. 1B  is a longitudinal schematic of well having an automated delivery mechanism and plunger of the present invention therein in another mode.  
         [0016]      FIG. 2A  is a cross section of an embodiment of a plunger which can be employed in  FIG. 1 .  
         [0017]      FIG. 2B  is a cross section of another embodiment of a plunger which can be employed in  FIG. 1  showing a valve therein closed.  
         [0018]      FIG. 2C  is a cross section of the plunger in  FIG. 2B  showing the valve therein open.  
         [0019]      FIG. 2D  is a cross section of yet another embodiment of a plunger which can be employed in  FIG. 1 .  
         [0020]      FIG. 3  is a schematic showing one mode of operation of the present invention showing a chamber on a modified well cap being filled with chemical.  
         [0021]      FIG. 4  is a schematic showing another mode of operation of the present invention showing the delivery of chemical from the chamber to the plunger.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0022]     Referring to the drawings, a well  10  having a well bore surface  12  drilled into the earth  14 . Typical well string casing  16  exists within the well bore surface  12  and extends into the earth  14  to a gas and/or oil zone  18 . A tubing string  20  is operably installed within the string casing  16  through which the gas and oil flow. Lubricator piping  22  is connected to the top of the tubing string  20 .  
         [0023]     A controller  23  is operably connected to the lubricator piping  20  and sales flow line  25 . The controller  23  senses the pressure in the well  10  and can shut in the well  10  through an operable connection to a flow control valve  27 .  
         [0024]     An oil and gas flow enhancing substance  24  resides in a supply tank or other suitable container which can preferably be located adjacent the well  10 . On top of the lubricator piping  22  is a modified cap  26 . The modified cap  26  has a chamber  28  formed thereon with an open surface  30  therethrough for communicating between the lubricator piping  22  and chamber  28 . An adjustable pressure bellows  29  is operably disposed in the chamber  28 .  
         [0025]     A hollow sliding valve member  32  is operably disposed through the open surface  30  in the cap  26  and includes a side port  34  in end  36  which has a stop head  38  thereon. Valve member  32  has its other end  39  open. An O-ring  40  is disposed in a channel  42  of the open surface  30  to provide a seal between the valve member  32  and the open surface  30 . A controlled valve  50  connects the chamber  28  and the supply tank of flow enhancing substance  24  and is controlled by controller  23  to enable a controlled amount of the substance  24  to enter the chamber  28  when the port  34  is closed thus not enabling communication with the lubricator piping  22 .  
         [0026]     The end  39  extends through a bumper  46 , which can be a polymer or spring element within the lubricator piping  22 , to absorb the impact of a plunger  48 . The plunger  48  can employ a similar type to that known in the art, such as an interlocking expandable, wobble washer, brush plunger, etc, with the modification provided by the present invention, i.e., the plunger  48  include an inlet  52  through which an amount of the substance  24  is received into an inner open surface  54 , and an outlet valve  56  to release the amount of the substance  24  in a lower portion of the well  10 . More particularly, the plunger  48  can include hollow sliding valve member  58  which operably extends through the inner open surface  54  and includes a side port  60  on end  62 . Valve member  58  has a stop head  64  thereon and has its other end  65  open. The valve outlet  56  and side port  60  slide in and out of communication as follows.  
         [0027]     When the well is shut in by the controller  23 , pressure builds in the well  10  which causes the plunger  48  to rise and contact the bumper  46  and causes the sliding valve member  58  to move in a manner which places the outlet  56  and port  60  out of communication. The impact of the plunger  48  also impacts the end  39  of the sliding valve member  32  which opens the side port  34  and permits the substance  24  within the chamber  28  to flow into the plunger  48  via sliding valve member  58 .  
         [0028]     The oil and gas flow enhancing substance  24  can be for example microorganisms, inhibitors, corrosion preventatives, paraffin solvents, foaming agents and/or gas expansion agents. The form of the substance  24  should be such to enable practice of the invention, which can preferably be liquid, or other gels or solids.  
         [0029]     The well  10  is equipped with the controller  23  to open and shut the well fluid flow. The plunger  48  drops to the bottom of the well  10  or to a point where the plunger  48  impacts a fluid level. At such point, the impact moves the stop head  64  into contact with the plunger  48  thereby causing alignment of the port  60  with outlet  56  and the release of the substance  24  at the lower portion of the well to begin chemically reacting releasing the oil and/or gas flow enhancing agent at the most desired point, the oil and/or gas zone.  
         [0030]     Once flow in the well diminishes below a predetermined flow rate as determined by the controller  23 , the controller  23  shuts then the valve  27  and the cycle is repeated. While the preferred embodiment of the present invention is illustrated and described, it is to be understood that this is capable of variations and modifications and therefore, the applicant does not wish to be limited to the precise details set forth, but desires to avail himself of such changes and alterations as fall within the purview of the following claims.