US3787226A

US3787226A - Method of treating tubular goods while simultaneously testing the interior thereof

Info

Publication number: US3787226A
Application number: US00201448A
Authority: US
Inventors: J Iglehart; H Iglehart
Original assignee: Spinning Pipe Service Inc
Current assignee: Spinning Pipe Service Inc
Priority date: 1971-11-23
Filing date: 1971-11-23
Publication date: 1974-01-22
Anticipated expiration: 1991-01-22

Abstract

A method of treating tubular goods with an inhibitor which comprises forcing the inhibitor into intimate contact with the surface area of the metal goods to be treated by utilizing high pressure techniques. The inhibitor is forced into the multitude of cracks and minute voids located in the irregular surface of the metal, so that after the pressure is removed and the inhibitor drained from the surface, a coating of the inhibitor is left within the outer boundary of the metallic surface, thereby forming a protective film on the surface of the metal. Advantage is taken of this expedient to provide a method of simultaneously treating pipe surfaces with an inhibiting agent, while at the same time the pipe joints are hydrostatically tested.

Description

ite ttes lglehart et a1. I

[ METHOD OF TREATING TUBULAR GOODS WHILE SIMULTANEOUSLY TESTING THE INTERIOR THEREOF [75] Inventors: Jesse ll. lglehart; Hilary H. Iglehart,

both of Odessa, Tex.

[73] Assignee: Spinning Pipe Service, Inc., Odessa,

Tex.

[22] Filed:- Nov. 23, 1971 [21] Appl. No.: 201,448

[ Jan. 22, 1974 10/1969 Ginsburgh et al. 138/97 10/1918 Stern 138/97 X Primary ExaminerEdward G. Whitby Attorney, Agent, or Firm-Marcus L. Bates [5 7] ABSTRACT A method of treating tubular goods with an inhibitor which comprises forcing the inhibitor into intimate contact with the surface area of the metal goods to be treated by utilizing high pressure techniques. The inhibitor is forced into the multitude of cracks and minute voids located in the irregular surface of the metal, so that after the pressure is removed and the inhibitor drained from the surface, a coating of the inhibitor is left within the outer boundary of the metallic surface, thereby forming a protective film on the surface of the metal.

Advantage is taken of this expedient to provide a method of simultaneously treating pipe surfaces with an inhibiting agent, while at the same time the pipe joints are hydrostatically tested.

7 Claims, 5 Drawing Figures PMETH] JAN22 I974 FIG.

BACKGROUND OF THE INVENTION Metallic goods used in conjunction with oil field exploration and production are subjected to the deleterious effects of corrosion, which includes all sorts of known detrimental actions which occurs to metal when it is placed in such an environment. The corrosion engineer, when faced with a specific type of corrosion problem, can usually select an inhibiting agent which will at least mitigate the corrosive attack upon the metallic goods. However, corrosion problems in the oil field is usually restricted to problems associated with production; specifically, sweet, sour, and condensate corrosion problems.

The problem of corrosion commences when tubular goods are stacked in a yard, and rapidly accelerates when the goods are placed in use, as for example, during the drilling process, the. use of corrosive muds contact the drill pipe during earth boring processes. After the well is completed and production tubing installed, the problem of corrosion becomes more pronounced.

In the oil production and drilling art, it is desirable to test joints of pipe whenever possible in order to detect the presence of flaws therein. It is especially desirable to test threaded connections where'one joint of pipe is threadedly secured to another joint to form a string of pipe, which is disposed within a bore hole.

The term corrosion is intended to mean any type attack upon the surface of the metal which reduces its structural integrity and includes oxidation, electrolitic, acid, and hydrogen sulfide corrosion. There are a number of chemicals available to industry which are suitable for use as an inhibiting agent. The term inhibitor or inhibitor agent includes any chemical additive which reduces the corrosion of the metallic goods, and

specifically the organic inhibitors such as hexametaphosphate and other polyphosphates of soda, for example. The protective deposits from two or more different inhibitors used together often is more effective than either one by itself, and it is this type inhibitor which is marketed by oil well service companies.

The preferred inhibitors used herein are identified as follows: KP9, K147, and KPlO, all trade names, and marketed by Treat-O-Lite company of Midland, Tex.

Reference is also made to my co-pending Pat. application Ser. No. 195,658 filed Nov. 4, 1971, for a more comprehensive understanding of the action of a film of corrosion inhibitor upon the mechanical goods.

Pipe testing is sometime conducted with the pipe being vertically disposed within a borehole by the use of various prior art apparatus or tools made specifically for this purpose, as exemplified by the patent to Dumond Pat. No. 3,503,249 (and the art cited therein) to which reference is made for further background of this invention.

It would be advantageous to be able to treat metallic goods with a corrosion inhibitor so that the metallic goods are protected from the deleterious effects of corrosion from the time that the goods are placed in storage and continuing for a long time after the goods are placed in use. Furthermore, it would be desirable to inhibit the goods'against corrosion after they are placed into production by an improved method which would preclude occurrence of corrosion until a proper corrosion program has been undertaken in the field. Moreover, it would be advantageous to be able to treat the goods in conjunction with some process to which the goods already are subjected.

SUMMARY OF THE INVENTION The present invention comprehends the treatment of tubular goods with an inhibitor wherein the inhibiting agent is forced into intimate contact with the entire exposed surface area of the metallic goods which is to be subjected to corrosion attacks, so as to form a surface film which precludes or reduces corrosion attacks. The invention is carried out by isolating the surface-of the goods to be treated and flow connecting the inhibiting agent to the isolated area, whereupon the pressure of the inhibiting agent is increased to a value which forces the agent to be dispersed'into the natural cavities and crevasses present in the surface of the goods. Several different embodiments of the invention teach the application of pressure to the agent. One form of the invention includes the treatment of the metal goods in conjunction with internal testing of drill pipe and production tubing.

A primary object of this invention is to treat the exposed surface area of the goods so as to mitigate the effects of corrosion.

Another object of the invention is to expose the external or internal surface area of metallic goods to an inhibiting agent under a tremendous pressure so as to force the agent into intimate contact with the surface to be treated.

A further object of this invention is to simultaneously test and treat metallic goods in a new and unobvious manner.

A still further object of this invention is to hydrostatically test the structural integrity of tubular goods while simultaneously treating a peripheral surface thereof with a corrosion inhibitor.

Another and still further object is to utilize commercially available corrosion inhibitors in an improved manner.

An additional object of this invention is to mitigate the deleterious effects of corrosion by subjecting the metallic goods to a corrosion inhibiting agent with the inhibitor being forced into the metal by utilizing tremendous pressure differentials.

These and various other objects and advantages of the invention will become readily apparent to those skilled in the art upon reading the following detailed description and claims and by referring to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a broken view of adiagrammatical representation of a borehole which sets forth one form of the FIG. 5 is a schematical representation which diagrammatically sets forth an important teaching of the present invention.

DETAILED DESCRIPTION OF THE VARIOUS EMBODIMENTS Throughout the various figures of the drawings, like or similar numerals, wherever possible, refer to like or similar elements.

As seen illustrated in FIG. 1, a tubing string is made up of individual joints of tubing 11, 11' joined together by a coupling member 12, and includes the usual peripheral wall surface 13. A testing tool 14, the details of which are known to those skilled in the art, has an outer perpheral wall surface 14; and, between the tubing and the mandrel 15 there is formed an annular area 16. Fluid conduit 17 is flow connected to and supports the mandrel, with the mandrel having spaced apart packing elements 18 and 19 disposed thereon. The distance between the spaced apart packers defines the length of the annulus.

Removable fluid conduit 20 is connected to a source of a liquid chemical inhibiting agent by means of a high pressure pump 21. Valve 22 controls the flow of fluid from the pump into the mandrel while valve 23 releives the pressure within the mandrel. Those skilled in the art will understand that packers l8 and 19 are set when pressure is applied at 17, with the pressure output of pump 21 also being effected upon annular area 16. Hence the surface 13 of the tubing is isolated from the remainder of the tubing by the packers.

In FIG. 2 the elongated tubular member 11, which can be production tubing, drill pipe, or any other tubular goods, is provided with

removable closure members

25 and 26, with flow conduit 27 being connected thereto so as to fill the interior 13 of the pipe with a liquid chemical inhibiting agent. Conduit 27 can be connected to conduit 20 of FIG. 1 if desired.

Looking now to the details of FIGS. 3-5, there is seen apparatus 28 which includes a vertically upstanding high pressure chamber 29 which is bottom supported by structure 30. An upwardly opening flange 31 is disposed at the upper extremity of the chamber. Cantilever arm 32 is attached to and extends above the opening, and is reinforced by web 33 which also aids in supporting the illustrated platform.

Hydraulically actuated cylinder 34 has the usual flow conduits 35 attached thereto, with the cylinder including a piston having a piston rod 36 journalled at 37 to a closure member 38. The closure member preferably is in the form of a round door which is journaled to the flange and arm at 39, and can be moved from the opened into the closed position, and vise versa.

Web 40 supports a latch member 41 in journaled relationship therewith, with the latch member being adapted to engage the closure member so as to securely and sealingly hold it locked into the closed position.

4 The interior 42 of the chamber contains a plurality of tubular goods 11 which may be inserted and removed therefrom through the opening formed by the flange. A ladder 43 leads to the working platform, with banister 44 being optionally provided for safety.

In FIG. 5, the supply of liquid inhibitor has an outflow connection 27 connected to a high pressure pump 21 which in turn is flow connected to conduit 45. Conduit 45 leads to heat exchanger element 46 located within heater 47, with the outlet of the heating element being connected to conduit 48 which leads to chamber 49. The chamber 49 can be any treatment chamber such as exemplified by tubular members 11 of FIG. 1,

5 11 of FIG. 2, or 29 of FIG. 3. Stack 50 emits flue gases to the atmosphere while a fuel burner is connected to a suitable source of air and fuel by means of conduit 51.

In the operation of the first embodiment as illustrated in FIG. 1, the tool testing apparatus 10 is generally dis- 10 posed within a tubing string 11 so as to hydrostatically test the threaded connections between each joint as well as to subject the entire inside pipe surface to a high pressure in order to practice the present invention. Pump 21 is connected to an inhibiting agent which can 15 be a water dispursed or an oil soluble chemical addi- 20 20, through conduit 17, and into the annular area 16.

Prior to the chemical flowing into the annulus, packers 18 and 19 are set," thereby isolating the surface of the goods to be treated. As the pressure of the inhibiting agent increases it completely fills the annulus, thereby 25 increasing the presure of the inhibiting agent upon the isolated surface to a value below the bursting strength of the pipe so as to cause the agent to displace any remaining compressible fluid from the isolated surface.

The pits, crevasses, and minute cracks normally found 30 in the irregular surface of any tubular goods will be contacted by the chemical as the pressure increases. The increase in pressure precludes capillary action causing adherence of minute air pockets to the surface of the metal. When the pressure reaches several thousand psi it is believed that the gases adjacent to and included within the surface of the metal is driven into solution with the agent, or, on the other hand, the gases will be compressed to an infinitesimally small volume. As the pressure continues to rise within the annulus,

40 the inhibiting agent is forced into intimate contact with 45 gauge, and held for a predetermined length of time in order to determine possible leakage of threaded fastener l2, whereupon the pressure is released by using the valve 23, with excess inhibitor agent preferably returning to the source. With close fitting packers, it is possible to leave the annulus filled with the inhibitor while the tool is moved to the next joint to be tested.

In the embodiment of FIG. 2, tubular member 13 is to be treated with an inhibitor agent, and therefore the interior surface of the goods is isolated by means of

closure members

25 and 26. Conduit 27 is connected to pump 21, for example, which in turn is connected to a suitable source of treatment fluid. The pressure exerted on the interior surface 13 to be treated is increased to a value slightly below the designed breaking strength strength of the pipe. After completion of the treatment, the end caps 25, 26 are removed, with the excess fluid contained therewithin first being retrieved by means of flow conduit 27.

In FIGS. 3 and 4, a workman ascends ladder 43 onto the platform so as to supervise the joints of pipe as they are each placed within chamber 29. After the chamber is filled to capacity with pipe, hydraulic cylinder 34, which is flow connected at 35 to a source of fluid pressure, is actuated thereby causing piston rod 36 to move the closure member 38 into sealing engagement with the flange. Latch 41 retains the closure member sealingly engaged with the flange 31 so as to isolate the surface of the goods to be treated. Conduit 27 enables an inhibiting agent to flow to and from a source into contact with the isolated pipe to be treated. As the liquid flows into the interiorof the chamber, it is subjected to an increasing pressure which is maintained below the breaking strength of the chamber for several minutes in duration so as to enable any compressible gases which were inadvertently or necessarily left on the surface of the metal to enter into solution. After treatment of the tubular goods, the pressure is released at 27, closure member 38 is moved to the open position, and the tubular goods removedfrom the treatment chamber. 7

In FIG. 5, if desired, the source of chemical 29 can be heated by element 46 prior to being introduced into the treatment chamber 49 to thereby accelerate the treatment process. This expedient can be used in carrying out any one of the above described treatment operations.

Accordingly, in each of the above procedures, it will be noted that the surface of the goods to be treated has first been isolated, whereupon an inhibiting agent is then flow connected from a source to the isolated area. Thereafter, the pressure of the inhibiting agent upon the isolated surface of the goods is increased to thereby cause the agent to displace compressible fluid from the isolated surface by either compressing the fluid so as to reduce it in volume'or to cause the fluid to enter into solution. The increased pressure causes the inhibiting agent to be forced into the metal exposed to the agent, so that the outer boundary of the metal is coated with the inhibitor. The residual inhibitor, that is, the inhibitor which is not required to coat the surface of the pipe or the inhibitor which is not required for carrying out the next batch operation is returned to the source.

I claim:

1. Method of treating tubular goods with an inhibitor comprising:

1. isolating the interior surface of the goods to be treated by placing a plurality of pipe joints into an enclosure means;

2. flow connecting an inhibiting agent from a source upon the interior of said enclosure means so as to cause the agent to coat the interior surface of the 5 goods and to displace any compressible fluid which may be present on the isolated surface thereof; 4. and, removing the residual inhibitor from the isolated surface after carrying out step (3). I 2. The method of claim 1, and further including the following steps:

7. movably affixing a closure means to the enclosure means; and

8. actuating the closure means by hydraulic ram.

3. The method of claim 1, wherein:

the enclosure means is an upright vessel having a closure means at the upper extremity thereof through which the tubular goods may be transported.

4. Method of testing coupling members of a series connected string of pipe joints while simultaneously treating the interior surface thereof with an inhibitor comprising the steps of:

l. placing spaced packer elements within the pipe string with the coupling members being disposed therebetween so as to isolate at least one half of a marginal interior longitudinally extending length of adjacent joints of pipe from the ambient;

2. flow connecting an inhibiting agent from a source to the isolated area located between the packers;

3. increasing the pressure of the inhibiting agent to coat the isolated surface and to displace any compressible fluid which may be present on the isolated surface;

4. carrying out step (3) while at the same time hydrostatically testing the structural integrity of the coupling member of the pipe string by adjusting the pressure to a value which is representative of the working pressure of the pipe joint;

5. removing the residual inhibitor from the isolated surface after carrying out step (3).

5. The method of claim 4 wherein said inhibiting agent includes an oil soluble organic liquid inhibitor.

6. The method of claim 4 wherein said inhibiting agent includes a water dispersed inhibitor.

7. The method of claim 4 wherein the inhibiting agent of step (2) includes a liquid which wets the entire surface undergoing treatment.

upon the isolated surface so as to cause the agent i

Claims

2. flow connecting an inhibiting agent from a source to the isolated area located between the packers;
2. The method of claim 1, and further including the following steps:
2. flow connecting an inhibiting agent from a source of supply to the interior of said enclosure means;
3. increasing the pressure of the inhibiting agent upon the interior of said enclosure means so as to cause the agent to coat the interior surface of the goods and to displace any compressible fluid which may be present on the isolated surface thereof;
3. The method of claim 1, wherein: the enclosure means is an upright vessel having a closure means at the upper extremity thereof through which the tubular goods may be transported.
3. increasing the pressure of the inhibiting agent upon the isolated surface so as to cause the agent to coat the isolated surface and to displace any compressible fluid which may be present on the isolated surface;
4. carrying out step (3) while at the same time hydrostatically testing the structural integrity of the coupling member of the pipe string by adjusting the pressure to a value which is representative of the working pressure of the pipe joint;
4. Method of testing coupling members of a series connected string of pipe joints while simultaneously treating the interior surface thereof with an inhibitor comprising the steps of:
4. and, removing the residual inhibitor from the isolated surface after carrying out step (3).
5. The method of claim 4 wherein said inhibiting agent includes an oil soluble organic liquid inhibitor.
5. removing the residual inhibitor from the isolated surface after carrying out step (3).
6. The method of claim 4 wherein said inhibiting agent includes a water dispersed inhibitor.
7. The method of claim 4 wherein the inhibiting agent of step (2) includes a liquid which wets the entire surface undergoing treatment.
7. movably affixing a closure means to the enclosure means; and
8. actuating the closure means by hydraulic ram.