Abstract:
A method of improving the operation of a gas pipeline having at least some water therein including the steps of introducing into the interior of the pipeline a soluble soap pig that is dimensioned to move through the pipeline by gas flow, the composition of the soap pig being selected such that at least some soap is applied as a film to the interior wall as the soap pig moves through the pipeline and in which the soap pig slowly dissolves within the pipeline. The soap film preferably has anti-corrosive and/or antibacterial properties.

Description:
REFERENCE TO PENDING APPLICATIONS 
     This application is not based upon any pending domestic or international patent applications. 
     REFERENCE TO MICROFICHE APPENDIX 
     This application is not referenced in any microfiche appendix. 
     BACKGROUND OF THE INVENTION 
     Many thousands of miles of pipeline operated in the United States and other countries of the world transport gas and particularly natural gas for use as fuel for heating homes, offices, factory buildings and other applications. Further, gas is a common fuel employed for industrial applications including for use in generating electrical energy and in the chemical manufacturing industry. A natural gas pipeline typically carries with it some water. Water can occur as a result of condensation. Further, natural gas when produced from a well borehole typically has some water entrained therein. Separators are used to extract most of the water, but inevitably some remains. 
     Water is deleterious to a gas pipeline. Water accumulation in a portion of a pipeline, can reduce the effective cross-sectional area of the pipeline and therefore impede flow rates through the pipeline. Further, water in a pipeline can result in corrosion. 
     In addition, water promotes biological growths on the interior walls of pipelines. 
     For these and other reasons, good pipeline maintenance requires that water accumulation be kept to a minimum. Further, for long, trouble-free life of a pipeline it is beneficial to periodically treat the wall of the pipeline to inhibit corrosion as well as reducing the potential for bacteria growth. For these reasons, the invention herein provides a method of improving the operation of a pipeline having gas flow therein that has some water component in which the method includes the use of soluble soap pigs that are dimensioned and configured to move through a pipeline by the force of gas flow. For background information relating to methods for improving the maintenance and operation of pipelines reference may be had to the following previously issued United States Patents: 
     
       
         
               
               
               
               
             
           
               
                   
               
               
                   
                 U.S. patent 
                   
                   
               
               
                 U.S. Pat. 
                 application 
                   
                   
               
               
                 No. 
                 Pub. No. 
                 INVENTOR 
                 TITLE 
               
               
                   
               
             
             
               
                   
                 2001/0049345 
                 Mumoli 
                 Single-Dose Soap Unit and 
               
               
                   
                 A1 
                   
                 Method 
               
               
                 3,063,079 
                   
                 Bergman et al. 
                 Combination Valve and 
               
               
                   
                   
                   
                 Cleaning Ball Launcher For 
               
               
                   
                   
                   
                 Use In 
               
               
                   
                   
                   
                 Pressure Flow Lines 
               
               
                 3,972,823 
                   
                 Howarth 
                 Soap Compositions for 
               
               
                   
                   
                   
                 Non-Gelling Soap Solution 
               
               
                 4,079,015 
                   
                 Paucot et al. 
                 Liquid Detergent 
               
               
                   
                   
                   
                 Compositions 
               
               
                 4,373,225 
                   
                 Eckardstein et 
                 Piping Valve With A 
               
               
                   
                   
                 al. 
                 Housing For The Transfer 
               
               
                   
                   
                   
                 Of A Wiper Insertable In 
               
               
                   
                   
                   
                 Conduits That Supply 
               
               
                   
                   
                   
                 Pressurized Viscous 
               
               
                   
                   
                   
                 Material, Preferably 
               
               
                   
                   
                   
                 Concrete 
               
               
                 4,607,410 
                   
                 Bersch 
                 Apparatus For Cleaning 
               
               
                   
                   
                   
                 Pipelines 
               
               
                   
                   
                   
                 For Beverages And The 
               
               
                   
                   
                   
                 Like 
               
               
                 4,793,016 
                   
                 Valentine et al. 
                 Conduit Cleaning 
               
               
                   
                   
                   
                 Apparatus 
               
               
                 5,072,476 
                   
                 Bersch 
                 Apparatus For Cleaning 
               
               
                   
                   
                   
                 Pipelines 
               
               
                   
                   
                   
                 For Beverages And The 
               
               
                   
                   
                   
                 Like 
               
               
                 5,088,517 
                   
                 Bersch 
                 Apparatus For Admitting 
               
               
                   
                   
                   
                 Flowable 
               
               
                   
                   
                   
                 Additive To A Liquid 
               
               
                 5,095,572 
                   
                 Wagner 
                 Automated Cleaning 
               
               
                   
                   
                   
                 Device For Beverage 
               
               
                   
                   
                   
                 Drafting And Dispensing 
               
               
                   
                   
                   
                 Systems 
               
               
                 5,208,937 
                   
                 Cooper 
                 Apparatus For Launching 
               
               
                   
                   
                   
                 Pigs Into Pipelines 
               
               
                 5,957,675 
                   
                 Buehrer et al. 
                 Thick Matter Pump With A 
               
               
                   
                   
                   
                 Cleaning Cartridge And 
               
               
                   
                   
                   
                 Blocking Slide 
               
               
                   
               
             
          
         
       
     
     BRIEF SUMMARY OF THE INVENTION 
     The invention herein is a method of improving the operation of a pipeline having gas flow therethrough and in which some water occurs. In a gas pipeline water is harmful since it augments corrosion and bacteria growth and if accumulated in significant quantities can reduce gas flow through the pipeline. 
     The method of this invention includes introducing into the interior of a pipeline a soluble soap pig that is dimensioned to move through the pipeline by gas flow. The composition of a soap pig is selected so that a soap film is applied to the interior wall of the pipeline as the soap pig moves by the force of gas flow through the pipeline. Further, the dimension and composition of the soap pig is selected such that it slowly dissolves by the water component of the pipeline so that it is not necessary to recover the soap pig from the interior of the pipeline. 
     The soap pig may be formulated so that it is anti-corrosive, anti-bacterial or both. 
     A more complete understanding of the invention will be obtained from the following description and claims taken in conjunction with the attached drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an elevational external view of portions of a pipeline including provisions by which a soap pig may be introduced into the pipeline. The soap pig is moved by gas flow through the pipeline. 
     FIG. 2 is an external view of a spherical soap pig that may be employed in this invention. 
     FIG. 3 is an external view of a cylindrical soap pig of a type that may be employed in the invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1 illustrates a portion of a natural gas gathering pipeline having a meter run therein. Pipeline  10  is shown emerging from the earth&#39;s surface  12 . The direction of gas flow through the pipeline is indicated by an arrow  14 . A meter run  15  that typically includes a gas recorder (not shown) is connected downstream of pipeline  10 . From meter run  15  the gas flows through a valve  18  and ultimately into a continuation  16  of the pipeline. Between valve  18  and the continuation  16  of the pipeline a soap ball launcher system is provided that will now be described. 
     The invention will be described as if it is employed specifically in a natural gas gathering pipeline. In such case, the pipeline extension  16  may extend to a compressor station or other facilities whereby the gas is transmitted over a distance, either long or short, to a place where the gas is used. For instance, the pipeline extension  16  may connect to an electric generating facility wherein natural gas is used as a fuel for generating electricity. Instead, pipeline extension  16  may connect to a distribution system that ultimately carries the gas to homes, businesses, schools, factories and so forth. Or, pipeline extension  16  may connect to a chemical manufacturing facility. In any event, the pipeline system (shown in FIG. 1, including pipeline  10  and pipeline extension  16 ) is representative of a part of a gathering system for natural gas. 
     Between meter run  15  and pipeline extension  16  there is a soap pig launching system that includes three basic portions—that is, the upstream valve  18 ; a downstream valve  20  and a soap pig launcher generally indicated by the numeral  22 . Upstream valve  18  may be any type of valve commonly employed to control gas flow through a pipeline and includes a handle  24  which is representative of a means of opening and closing the valve. Handle  24  is representative of a manually, electrically or hydraulically operated system for selectively opening and closing gas flow through valve  22 . In like manner, downstream valve  20  is representative of valves commonly employed in the pipeline industry for opening and closing gas flow through a pipeline and is illustrated to include a handle  26  which, like upstream valve handle  24 , may be manually, electrically or hydraulically actuated. 
     Positioned between upstream and downstream valves  18  and  20  is a soap pig launcher that has an upwardly extending soap pig receiver  28  connected at its lower end with a horizontal tubular portion  30  of the soap pig launcher  22 . Affixed to the upper end of soap pig receiver  28  is a removable cover  32 . The removable cover  32  is illustrated to be of the type that includes a cover support arm  34  so that when cover  32  is detached from the upper end of soap pig receiver  28 , it can be swung, by use of arm  34 , to clear soap pig receiver  28  and permit a soap pig to be deposited therein. After a soap pig has been deposited within receiver  28 , cover  32  is replaced and sealed against the upper end of the receiver. 
     Extending from soap pig receiver  28  is a short-length pipe  36  that has a small valve  38  at the outer end thereof. A gauge  40  extends from pipe  36 . 
     The soap pig launcher  22  is configured to permit an operator to inject into pipeline extension  16  a soap pig. This is achieved by the following sequence: First, the operator closes upstream valve  18  and downstream valve  20 . Next the operator opens a small valve  38  to relieve pressure of gas from within the soap pig launcher. After the pressure has been completely relieved, the operator can then remove cover  32  and swing it out of the way so the upper end of the soap pig receiver is clear. The operator may then insert a soap pig or pigs into the interior of receiver  28 , each pig falling downwardly into horizontal tubular portion  30  of the soap pig launcher. 
     A typical soap pig is shown in FIG.  2  and identified by the numeral  42 . Soap pig  42  is spherical—that is, a round, solid ball of soap. The diameter of the spherical soap pig  42  is preferably substantially equal to the internal diameter of the pipeline  16 . When soap pig  42  is deposited within soap pig receiver  28 , the operator can then rotate arm  34  to move cover  32  back over the top of receiver  28  and the cover is then sealably secured to the top end of the soap pig receiver. This can be accomplished by having an externally threaded upper end of the receiver  28  and internal threads in cover  32  so that the cover may simply be threaded into position and sealed. However, this is by way of example only as there are other means of removably securing a cover to the end of a tubular member that would function to practice the invention. 
     After cover  32  is sealably in position, the operator closes small valve  38  and opens downstream valve  20  and upstream valve  18 . With valves  18  and  20  open, gas can freely flow from pipeline  10  to and through pipeline extension  16 . The spherical soap pig  42  is moved out of horizontal tubular portion  30  and into pipeline extension  16  by gas flow. As the spherical soap pig  42  moves through the pipeline it moves entrapped water in the pipeline forwardly in the direction of the gas flow. The soap ball pig acts like a sponge. By emulsifying with water in the pipeline the accumulation of water is kept to a minimum thereby helping to prevent accumulated water from interfering with the operation of the pipeline. 
     Further, the soap pig  42  is preferably formed of a product that leaves a thin layer of soap—that is, a soap film on the interior wall of the pipeline  16  as the soap pig moves through it. It is not imperative that soap pig  42  coat the full 360° interior surface of the pipeline  16  as it moves through the pipeline—it is only important that it covers at least a portion of the surface. The interior portion of the pipeline that is missed by one soap pig will most likely be contacted by subsequent soap pigs so that ultimately at least a significant part of the interior wall of the pipeline  16  is coated by passage of a soap pig  42  as soap pigs are periodically launched into the pipeline. 
     The soap pig  42  is preferably composed of material that forms a protective, corrosion resistant coating or film on the pipeline interior wall. Further, soap pigs  42  may preferably be of the type that leaves an anti-bacterial coating on the interior of the pipeline. 
     The soap pig  42  is dimensioned and composed such that it ultimately completely dissolves as it passes through pipeline  16 . Thus, it is not necessary to retrieve the soap pig  42  once it is launched into the pipeline. The use of structural pipeline pigs for cleaning, batching and inspection services is well known however these type pigs can be used only in systems that have both a pig launcher and a pig receiver. The system of this invention employs only a soap pig launcher and does not require a receiver. Therefore, the costs of installing facilities to practice the invention are substantially reduced compared to most systems that use pipeline pigs. 
     Soap pig  42  is preferably composed of chemical constituents that arc beneficial even without physically providing a film on the pipeline wall. 
     FIG. 3 is a small isometric view of an alternate geometrical arrangement of a soap pig. Instead of being spherical as in FIG. 2, FIG. 3 illustrates a cylindrical and somewhat elongated soap pig. This illustrates that the invention may be practiced with differently shaped soap pigs. A cylindrical soap pig would require a somewhat different launcher than that disclosed herein in which cylindrical pigs are inserted in a way so that they arc longitudinally aligned with the pipeline when they enter into the horizontal tubular portion  30 . A system of this type is not illustrated herein since launchers for longitudinally shaped pigs are well known in the art. Thus, the invention herein is not limited to the use only of soap pigs having a spherical shape. 
     It is understood that the invention herein is not limited by the illustrated preferred means of practicing the invention since the invention can be practiced by utilizing mechanisms and systems that in physical appearance would be completely different from those illustrated in the drawings and described herein. Instead, it is to be understood that the invention is limited only by the scope of the attached claim or claims, including the full range of equivalency to which each element or step thereof is entitled.