Patent Abstract:
A downhole pipe or casing repair method and apparatus includes a corrosion monitoring tool adapted for examining an interior of a pipe or tubing or casing to create a record of the condition of said interior of said pipe, a surface treatment apparatus for cleaning said interior of said pipe, a plating apparatus for plating a new surface over the interior of said pipe after the surface treatment apparatus cleans the interior of said pipe, a packer sealing apparatus for sealing the surface treatment apparatus from the corrosion monitoring tool, and another packer sealing apparatus for sealing the plating apparatus from the surface treatment apparatus. The corrosion monitoring tool will examine the interior of the pipe, the surface treatment apparatus will clean the interior of the pipe, the plating apparatus will plate a new surface over the newly cleaned interior of the pipe, and the corrosion monitoring tool will re-examine the interior of the pipe after the plating step is completed. This abstract is provided for the sole purpose of aiding a patent searcher; it is provided with the understanding that this abstract shall not be used to interpret or limit the scope or meaning of the claims.

Full Description:
BACKGROUND OF THE INVENTION  
       [0001]     The subject matter of the present invention relates to a method and apparatus for downhole pipe or casing repair including a corrosion monitoring tool for evaluating the extent of corrosion on an internal surface of a pipe, a surface treatment apparatus, such as a sand blaster, for cleaning the internal surface of the pipe and removing the corrosion, and a plating apparatus for plating a new metallic layer on the internal surface of the pipe.  
         [0002]     Corrosion in an oil or gas well is a problem. Tubing disposed downhole in a wellbore can become corroded with rust and, as a result, it is often necessary to determine the extent of that corrosion on an internal surface of the tubing disposed downhole. Corrosion monitoring tools can determine the extent of that corrosion, however, when the corrosion monitoring tool is disposed downhole, there exists no additional apparatus disposed downhole with the corrosion monitoring tool for concurrently repairing the internal surface of the corroded tubing. Therefore, although it would be desirable to determine the extent of the corrosion on the internal surface of the pipe, there exists no additional apparatus for concurrently repairing the corroded pipe downhole without pulling the pipe out of the wellbore, replacing the pipe, and increasing the rig-time and the resultant costs to a customer.  
         [0003]     Therefore, a need exists to provide a downhole pipe or casing repair apparatus adapted to be disposed in a wellbore which would include a surface treatment apparatus and a plating apparatus in addition to the corrosion monitoring tool, the downhole pipe or casing repair apparatus using the corrosion monitoring tool to monitor the extent of the corrosion on an internal surface of a pipe disposed downhole and, when the corrosion is detected, repairing the internal surface of the pipe by using the surface treatment apparatus to remove the corrosion from the internal surface of the pipe and using the plating apparatus to plate a new metallic layer on the internal surface of the pipe disposed downhole.  
       SUMMARY OF THE INVENTION  
       [0004]     Accordingly, one aspect of the present invention includes a downhole pipe repair apparatus, comprising: a surface treatment apparatus adapted for cleaning an interior surface of the pipe; and a plating apparatus adapted for plating a new surface on the interior surface of the pipe after the surface treatment apparatus cleans the interior surface of the pipe.  
         [0005]     Another aspect of the present invention includes a downhole pipe repair apparatus, comprising: a surface treatment apparatus adapted for cleaning an interior surface of the pipe; a plating apparatus adapted for plating a new surface on the interior surface of the pipe after the surface treatment apparatus cleans the interior surface of the pipe; and a corrosion monitoring tool adapted for examining the interior surface of the pipe after the plating apparatus plates the new surface on the interior surface of the pipe.  
         [0006]     Another aspect of the present invention includes a method for downhole pipe repair, the method comprising: cleaning an interior of the pipe, and plating a new surface on the interior of the pipe after the cleaning step.  
         [0007]     Another aspect of the present invention includes a method for downhole pipe repair, the method comprising: examining the interior of the pipe, cleaning the interior of the pipe after the examining step, and plating a new surface on the interior of the pipe after the cleaning step.  
         [0008]     Another aspect of the present invention includes a method for downhole pipe repair, the method comprising: examining the interior of the pipe, cleaning the interior of the pipe after the examining step, plating a new surface on the interior of the pipe after the cleaning step, and re-examining the interior of the pipe after the plating step.  
         [0009]     Further scope of applicability of the present invention will become apparent from the detailed description presented hereinafter. It should be understood, however, that the detailed description and the specific examples, while representing a preferred embodiment of the present invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become obvious to one skilled in the art from a reading of the following detailed description. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]     A full understanding of the present invention will be obtained from the detailed description of the preferred embodiment presented hereinbelow, and the accompanying drawings, which are given by way of illustration only and are not intended to be limitative of the present invention, and wherein:  
         [0011]      FIG. 1  illustrates a preferred embodiment of the downhole pipe or casing repair apparatus of the present invention;  
         [0012]      FIG. 2  illustrates a more detailed construction of the downhole pipe or casing repair apparatus of  FIG. 1  of the present invention;  
         [0013]      FIG. 3  illustrates a detailed construction of the surface treatment apparatus portion of the downhole pipe or casing repair apparatus of  FIG. 2 ,  
         [0014]      FIG. 4  illustrates an alternate embodiment of the corrosion monitoring tool of  FIG. 1 ,  FIG. 2  illustrating one embodiment of the corrosion monitoring tool of  FIG. 1 , and  FIG. 4  illustrating another embodiment of the corrosion monitoring tool of  FIG. 1 , and  
         [0015]      FIGS. 5A and 5B  illustrate the principle behind the operation of the alternate embodiment of the corrosion monitoring tool of  FIG. 4 . 
     
    
     DESCRIPTION OF THE INVENTION  
       [0016]     Referring to  FIG. 1 , a downhole pipe or casing repair apparatus  10 , adapted to be disposed inside a tubing or pipe or casing  16  in a wellbore  12 , is illustrated. In  FIG. 1 , the downhole pipe or casing repair apparatus  10  includes a corrosion monitoring tool  14  adapted for examining the internal wall of the tubing  16  to determine the extent of any corrosion or rust which may exist on the inside of the tubing  16 , a surface treatment apparatus  18  adapted for cleaning the inside of the tubing  16  when corrosion or rust is determined to exist on the inside of the tubing  16 , a plating apparatus  20  adapted for plating a new metallic layer on the inside of the tubing  16  when the surface treatment apparatus  18  cleans the inside of the tubing  16 , a packer sealing apparatus  22  adapted for sealing off the surface treatment apparatus  18  from the corrosion monitoring tool  14  when the surface treatment apparatus  18  is cleaning the inside of the tubing  16 , and a packer sealing apparatus  23  adapted for sealing off the plating apparatus  20  from the surface treatment apparatus  18  when the plating apparatus  20  is plating the new metallic layer on the inside of the tubing  16 .  
         [0017]     Referring to  FIG. 2 , a detailed construction of the downhole pipe or casing repair apparatus  10  of  FIG. 1  is illustrated. In  FIG. 2 , the downhole pipe or casing repair apparatus  10  includes the corrosion monitoring tool  14  which is owned and operated by Schlumberger Technology Corporation of Houston, Tex. Examples of such corrosion monitoring tools  14 , which are owned and operated by Schlumberger Technology Corporation, include the CPET tool, the METT tool, and the CET tool. The corrosion monitoring tool  14  includes a plurality of fingers  14   a  extending from a central conductor  14   b , the fingers  14   a  being adapted for contacting the inside  16   a  of the tubing  16  and flexing when the corrosion monitoring tool  14  is pushed downwardly or pulled upwardly inside the tubing  16 . During the flexing of the fingers  14   a , an electrical signal is generated in each finger  14   a  which is proportional to and representative of the extent of the corrosion which exists on the inside  16   a  of the pipe or tubing or casing  16 . The electrical signal from each finger  14   a  propagates uphole and is recorded on a log which displays the extent of the corrosion existing on the inside  16   a  of the tubing  16 . The downhole pipe or casing repair apparatus  10  further includes a surface treatment apparatus  18  which further includes a cleaning apparatus  18   a  adapted for cleaning the inside  16   a  of the pipe or tubing or casing  16  and a container  18   b  adapted for collecting any corrosive elements which are removed from the inside  16   a  of the pipe or tubing or casing  16  when the cleaning apparatus  18   a  cleans the inside  16   a  of the tubing or casing  16 . A packer sealing apparatus  22  is disposed between the corrosion monitoring tool  14  and the surface treatment apparatus  18 , the packer sealing apparatus  22  sealing off the surface treatment apparatus  18  from the corrosion monitoring tool  14  inside the pipe or tubing or casing  16  when the surface treatment apparatus  18  is cleaning the inside  16   a  of the pipe or tubing or casing  16 . The downhole pipe or casing repair apparatus  10  further includes a plating apparatus  20 , the plating apparatus  20  further including an anode  20   a , a cathode  20   b  which is the pipe or tubing or casing  16 , and an electrolyte  20   c  disposed between the anode  20   a  and the cathode  20   b . Note the corroded areas  24  which exist on the inside  16   a  of the pipe or tubing or casing  16 . A spacer/centralizer  20   d  will centralize the anode  20   a  inside the pipe or tubing or casing  16 . The anode  20   a  is adapted for depositing a metallic layer on the cathode  20   b  via an electrolytic reaction when a voltage “V” is applied across the anode  20   a  and cathode  20   b . Assume that the plus side of voltage V is applied to the anode  20   a  via a central conductor  21  and the negative side of the voltage V is applied to the tubing or casing ‘cathode’  20   b . The metallic layer can be either a Nickel (Ni), Chromium (Cr), Iron (Fe), or Copper (Cu) layer. A packer sealing apparatus  23  is disposed between the plating apparatus  20  and the surface treatment apparatus  18 , the packer sealing apparatus  23  sealing off the plating apparatus  20  from the surface treatment apparatus  18  inside the pipe or tubing or casing  16  when the plating apparatus  20  is plating a new metallic layer on the inside  16   a  of the pipe or tubing or casing  16 .  
         [0018]     Referring to  FIG. 3 , a detailed construction of the cleaning apparatus  18   a  of  FIG. 2  is illustrated. In  FIG. 3 , although the cleaning apparatus  18   a  can be either a mechanical cleaning apparatus or an ultrasonic cleaning apparatus, the cleaning apparatus  18   a  of  FIG. 3  includes a central bore  18   a   1  in which a fluid or sand propagates downwardly in  FIG. 3  along a longitudinal axis of the cleaning apparatus  18   a , and a transverse bore  18   a   2  in which the fluid or sand will propagate from the central bore  18   a   1  in a transverse direction with respect to the longitudinal axis of the cleaning apparatus, as shown in  FIG. 3 . The cleaning apparatus  18   a  of  FIG. 3  can be the “Jet Blaster” tool that is owned and operated by Schlumberger Technology Corporation of Houston, Tex. In operation, the Jet Blaster cleaning apparatus  18   a  of  FIG. 3  will propagate a fluid or sand at a high velocity through the central bore  1  gate and through the transverse bore  18   a   2 , the fluid or sand being blasted against the inside  16   a  of the pipe or tubing or casing  16  at the high velocity thereby removing the corroded areas  24  from the inside  16   a  of the pipe or tubing or casing  16 . The corrosive elements of the corroded areas  24  will fall into the container  18   b  when the corrosive elements are removed from the inside  16   a  of the pipe or tubing or casing  16  by the Jet Blaster cleaning apparatus  18   a  of  FIG. 3 . Referring to  FIGS. 4, 5A  and  5 B, an alternate embodiment of the corrosion monitoring tool  14  of  FIG. 1  is illustrated. In  FIG. 4 , the alternate embodiment of the corrosion monitoring tool  14  of  FIG. 1  is an Ultrasonic Imaging Tool that uses a single rotating transducer  26 , housed in a sub at the bottom of the tool, to give full coverage of the tubing or casing  16 . In  FIG. 4 , the transducer  26  is used to resonate the tubing or casing  16 . The fundamental mode of resonance is analyzed in the received waveform to obtain information regarding the existence of corrosion on the inside  16   a  of the pipe or tubing or casing  16 . The Ultra Sonic Imaging Tool of  FIG. 4  is owned and operated by Schlumberger Technology Corporation of Houston, Tex. The principle of operation of the Ultrasonic Imaging Tool of  FIG. 4  is discussed below with reference to  FIGS. 5A and 5B . In  FIG. 5A , a sonic monopole transmitter  28  produces positive compressional waves in the tubing or casing  16  on both sides of the transmitter via volumetric expansion and constraction of the transmitter  28 . Compressional waves are generated in the pipe or tubing or casing  16 , the compressional waves propagating longitudinally along the axis of the pipe or tubing or casing  16 . One or more corroded areas  24  on the inside of the pipe or tubing or casing  16  will affect the propagation of the compressional waves which are propagating along the pipe or tubing or casing  16 . A receiver  30  will record the compressional waves which are received from the pipe or tubing or casing  16 , that record produced by the receiver  30  reflecting the extent of the corroded areas  24  which exist on the inside of the pipe or tubing or casing  16 . In  FIG. 5B , a sonic dipole transmitter  32  produces a positive shear wave on one side of the pipe or tubing or casing  16  and a negative shear wave on the other side of the pipe or tubing or casing  16 . No net volume change is produced. A positive shear wave propagates longitudinally on one side of the pipe or tubing or casing  16  and a negative shear wave propagates longitudinally on the other side of the pipe or tubing or casing  16 . One or more corroded areas  24  on the inside of the pipe or tubing or casing  16  will affect the propagation of the shear waves which are propagating along the pipe or tubing or casing  16 . A receiver  34  will record the shear waves which are received from the pipe or tubing or casing  16 , that record produced by the receiver  34  reflecting the extent of the corroded areas  24  which exist on the inside of the pipe or tubing or casing  16 . The principle of operation described above with reference to  FIGS. 5A and 5B  is also discussed in U.S. Pat. No. 5,036,945 to Hoyle et al, the disclosure of which is incorporated by reference into this specification.  
         [0019]     A functional description of the operation of the downhole pipe or casing repair apparatus  10  of the present invention will be set forth in the following paragraphs with reference to  FIGS. 1 through 5 B of the drawings.  
         [0020]     Assume that the downhole pipe or casing repair apparatus  10  of  FIGS. 1 and 2 , which includes the corrosion monitoring tool  14 , the packer sealing apparatus  22 , the surface treatment apparatus  18 , the packer sealing apparatus  23 , and the plating apparatus  20 , is lowered downwardly into the pipe or tubing or casing  16 , as indicated by downwardly directed arrow  17  in  FIG. 2 . In  FIG. 2 , in response to the downward movement of the downhole pipe or casing repair apparatus  10 , the fingers  14   a  of the corrosion monitoring tool  14  will flex whenever corroded areas  24  are encountered on the inside  16   a  of the tubing  16  thereby generating an electrical signal which propagates uphole along the central conductor  21  and records the existence of corroded areas  24  on the inside  16   a  of the pipe or tubing or casing  16 . The packer sealing apparatus  22  will seal off the corrosion monitoring tool  14  of  FIG. 1  from the surface treatment apparatus  18  and the packer sealing apparatus  23  will seal off the surface treatment apparatus  18  from the plating apparatus  20 , since an electrolyte solution  20   c  will be disposed above the packer sealing apparatus  23  inside the pipe or tubing or casing  16  of  FIG. 2 . In  FIG. 2 , in response to the downward movement of the downhole pipe or casing repair apparatus  10 , when the corrosion monitoring tool  14  is recording the existence of the corroded areas  24  on the inside of the pipe or tubing or casing  16 , and when the packer sealing apparatus  22  and  23  are both firmly sealed against the inside  16   a  of the tubing or casing  16 , the cleaning apparatus  18   a  of the surface treatment apparatus  18  is busy cleaning the inside  16   a  of the pipe or tubing or casing  16  by removing the corroded areas  24  from the inside  16   a  of the pipe or tubing or casing  16 . When the corroded areas  24  are removed from the inside  16   a  of the tubing or casing  16  by the cleaning apparatus  18   a , the removed corroded areas  24  are deposited into the container  18   b  of the surface treatment apparatus  18 . In  FIG. 3 , the cleaning apparatus  18   a  cleans the inside  16   a  of the pipe or tubing or casing  16  by initially rapidly propagating a fluid or sand down the central bore  18   a   1  of the cleaning apparatus  18   a , in  FIG. 3 , at a high velocity and then rapidly propagating the fluid or sand transversely through the transverse bore  18   a   2  of the cleaning apparatus  18   a  at a high velocity, the rapidly propagating fluid or sand which is transversely propagating in the transverse bore  18   a   2  striking the inside  16   a  of the pipe or tubing or casing  16  while the downhole pipe or casing repair apparatus  10  is still moving downwardly inside the pipe or tubing or casing  16 . As a result, the rapidly propagating fluid or sand, exiting the transverse bore  18   a   2  of  FIG. 3 , will function as a jet blaster since the fluid or sand will blast against the inside  16   a  of the pipe or tubing or casing  16  while the downhole pipe or casing repair apparatus  10  is moving downwardly inside the pipe or tubing or casing  16  of  FIG. 1  or  2 . The corroded areas  24  are removed from the inside  16   a  of the pipe or tubing or casing  16 , the removed corroded areas  24  being deposited into the container  18   b  of the surface treatment apparatus  18 . In addition to or simultaneously with the blasting of the fluid or sand from the transverse bore  18   a   2  of the cleaning apparatus  18   a  of  FIG. 3  against the inside of the tubing or casing  16 , the inside  16   a  of the tubing or casing  16  can be acid washed using an acid solution comprised of approximately 15% of HCL in order to remove any rust from the inside  16   a  of the tubing or casing  16  prior to a plating operation using the plating apparatus  20  of  FIGS. 1 and 2 . In  FIG. 2 , in response to the downward movement of the downhole pipe or casing repair apparatus  10 , when the corrosion monitoring tool  14  is recording the existence of the corroded areas  24  on the inside of the tubing or casing  16 , and when the packer sealing apparatus  22  and  23  are both firmly sealed against the inside  16   a  of the tubing or casing  16 , and when the cleaning apparatus  18   a  of the surface treatment apparatus  18  is cleaning the inside  16   a  of the pipe or tubing or casing  16 , the plating apparatus  20  is busy plating a new metallic surface on the inside  16   a  of the tubing or casing  16 . In  FIG. 2 , a voltage V is applied across the anode  20   a  and the cathode  20   b  when an electrolyte solution  20   c  is disposed inside the pipe or tubing or casing  16  above the packer sealing apparatus  23 . As a result, due to an electrolytic reaction which is taking place between the anode  20   a  and the cathode  20   b  in  FIG. 2 , a new metallic layer is being deposited on the inside  16   a  of the tubing or casing  16  of  FIG. 2 , the new metallic layer being deposited over the cleaned areas on the inside  16   a  of the tubing or casing  16  where the corroded areas  24  previously existed. The new metallic layer can be either Chromium, Iron, Nickel, or Copper.  
         [0021]     In  FIG. 2 , the downhole pipe or casing repair apparatus  10  of  FIG. 2  is now moved upwardly inside the pipe or tubing or casing  16  for the purpose of confrmning the repaired pipe or tubing or casing, as indicated by the upwardly directed arrow  19  in  FIG. 2 . During the movement upwardly inside the pipe or tubing or casing  16 , the corrosion monitoring tool  14  of  FIGS. 1 and 2  will now create a new record of the existence of any remaining corroded areas  24 , if any, on the inside  16   a  of the tubing or casing  16 . The fingers  14   a  of the corrosion monitoring tool  14  of  FIG. 2  will flex when a corroded area  24  is encountered on the inside  16   a  of the pipe or tubing or casing  16 . However, in view of the above referenced cleaning operation, wherein the inside  16   a  of the pipe or tubing or casing  16  was cleaned by the surface treatment apparatus  18  and the inside  16   a  was plated by the plating apparatus  20 , the new record of the inside  16   a  of the pipe or tubing or casing  16  that was created by the corrosion monitoring tool  14  will now record the absence of any corroded areas  24  on the inside  16   a  of the pipe or tubing or casing  16 .  
         [0022]     Instead of using the electrolytic plating apparatus  20  shown in  FIG. 2 , a chemical plating method and apparatus could be used. Electroless or chemical plating is a chemical deposition process autocatalytically occurring on the metal surface without applying electric current in contrast to the conventional electroplating. The deposited metal ions are reduced on the metal surface by reducing agents instead of current. The reducing agents give up electrons to the deposited ions directly forming a metal layer which is coated on the substrate surface. Due to the chemical reaction, the thickness of the coated metal layer is very uniform and accurate as compared with electroplating, especially in connection with a complicated shape of metal parts. Electroless Ni and its alloy (Ni—P) were proven superior in corrosion resistance, especially in a highly corrosive oil and gas production environment, which may contain H2S, CO2 and brine at high pressure and high temperature.  
         [0023]     In addition, instead of using the corrosion monitoring tool  14  shown in  FIG. 2 , the corrosion monitoring tool shown in  FIGS. 4 and 5  could be used in order to accomplish the function of the downhole pipe or casing repair apparatus  10  of the present invention.  
         [0024]     The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.

Technology Classification (CPC): 2