RU2668582C1 - Method of visual control of spinning of oilfield tubes - Google Patents

Abstract

FIELD: oil industry.SUBSTANCE: invention relates to the oil industry. Method of visual check of the spinning of oilfield and gas tubes extracted from a well, one of which is made with a field end with an external thread, and the other with a collar end with an internal thread, by applying a contrast mark. In this case, a base grease mixed with a paint pigment is used as the mark, contrasting with a color of an application surface. Marks are applied uniformly as a continuous layer, distributing along the external thread of the joint until the color of the application surface disappears throughout the threaded part of the pipe and the visual check of the spinning-up until the contrast mark of the field end disappears under the collar end is provided.EFFECT: technical result is the provision of reliable sealing of threaded joints during multiple spinning-unscrewing.1 cl, 4 dwg, 1 tbl

Description

Method for visual inspection of screwing of oilfield pipes extracted from a well.

A method for visually inspecting the make-up of oilfield pipes extracted from a well relates to the oil industry and can be used in oil fields in conditions of insufficient illumination of oilfield equipment.

Known GOST 632, GOST 633, GOST 53366, API 5 CT which indicate the assembly criteria for threaded joints of casing and tubing. The main assembly criterion is the position of the coupling relative to the signs, marks, end of the thread run, located on the nipple end of the pipe body. Another criterion is the make-up torque, which is calculated for threaded joints with a nominal tightness of the joint with a friction coefficient of 0.06 for threaded joints according to APISpec5B in accordance with the recommendations of ISO10405.

However, the values of the make-up moment should be considered only as indicative, in view of the very large differences in the requirements for the make-up moment, which may exist for a particular connection of different pipe sizes. For this reason, it is important to correlate these values of the make-up torque with the position of the coupling relative to the signs, marks, end of the thread run located on the nipple end of the pipe body.

In the factory, during the assembly process, both axial movement and the make-up moment are controlled.

In this case, a “tolerance field” is formed, limited to:

- horizontally with minimum minimum and maximum maximum permissible values for the make-up moment;

- vertical values of permissible axial displacement.

Since the most important criteria are: position (relative position of the coupling and the nipple relative to each other) and the moment of make-up, which directly depends on the quality of the thread lubricant, its quantity and the uniformity of its distribution over the thread surface, the criteria established in the normative documentation are developed taking into account that thread grease evenly covers the entire surface of the thread.

Fulfillment of the requirements for the assembly of a threaded joint is the key to maintaining the operational properties of the joint, such as the absence of damage to the thread and preservation of tightness, with repeated screwing-unscrewing.

Known GOST 632, which regulates the moments for threaded joints for a nominal interference fit with a friction coefficient of 0.06 for threaded joints noAPISpec5B in accordance with the recommendations of ISO10405.

However, these values should only be regarded as indicative, in view of the very large differences in torque requirements that may exist for a particular joint. For this reason, it is important to correlate these values of the torques with the obtained average value when assembling pipes by linear dimensions.

To clarify the moment of screwing up the threaded pipe joints necessary to ensure the optimum screwing of each factory batch, it is recommended that a sufficient number of screwing be made to fix the speed of force screwing, after screwing the connection to hand.

For pipes with “Buttress” threads, torque values should be determined by carefully measuring the torque required to make each of several joints to the base of the triangular mark (assembly by position).

The torque values obtained in this way are used when making up the remaining pipes of a specific weight and assortment designed for this column.

But, as in the case of using the recommended torques, as well as in the case of specified torques, the minimum torque should be at least 75% of the selected value, and the maximum, no more than 125%.

To prevent seizing when performing make-up of compounds in field conditions, the speed should be no more than 25 rpm.

When making up, it is necessary to observe the torque indicator and the position of the end face of the coupling, with respect to the point of the latter, the risks on the pipe for pipes with triangular thread and OTM, as well as to the base of the triangular sign for pipes with buttress thread (position assembly). with pipes extracted from the well coated with the produced fluid.

When screwing up casing pipes with a threaded connection OTTG, the distance from the internal thrust to the outer end of the coupling is measured using a caliper. Then, at the counterpart of the pipe, risk is applied at a distance from the pipe end equal to the measured distance from the thrust end to the outer end of the coupling. After force make-up, the end face of the coupling should coincide with the risk applied to the nipple part of the pipe. Upon reaching the end of the pipe, the persistent end of the clutch during power make-up, a sharp increase in torque occurs. The torque recorded in this case will be optimal for these conditions of assembly (lubricant used, pipe size, and so on). Further pipe make-up is carried out according to the arithmetic mean value of the torque obtained when making 10 pipes. The speed of force make-up of threaded joints of OTTG should not exceed 10 rpm.

A known method of controlling screwing from the description to the author's certificate SU No. 1625974 "Method for assembling non-threaded conical threaded joints of casing and elevator columns" dated 02.01.1985, published: 07.02.1991. IPC E21B 17/08, in which the screwing is carried out until the coupling end is aligned with the mark on the pipe, the distance to which from the pipe end is determined by the formula LI - (F - At) + K + Sm - Am, where L is the distance from the pipe end to the mark; I is the distance from the end of the pipe to the main plane of the thread; F is the actual tightness of the pipe thread; At - a regulated interference thread pipe. K is the optimal conditional interference; See - the regulated distance from the measuring surface of the threaded gauge - plug to the main plane of the coupling thread: Am - the actual tightness of the coupling.

But this method of make-up control does not allow making make-up control already after the first lifting of the pipe from the well, since the pipe body and marks will be “dirty” with the contents of the well. Control is difficult in conditions of insufficient lighting, the presence of grease, its quantity and the “freshness” of a portion cannot be determined by video monitoring.

There is a method of visualizing the relative position of the pipe and the coupling when reaching the minimum, optimal and maximum moments of makeup according to the utility model patent "Consolidation of pipes with tapered thread and mechanical seal" metal-metal "RU 101484 from 07.28.2010 published on 01.20. 2011, IPC Е21В 17/00, while on the pipe (nipple) there are 3 marks, one of which is applied along the generatrix, the second transverse, applied around the circumference of the pipe, the third indicates the place of application of the triangular to the first mark is applied with a special device that imitates the full-sized thread element of the sleeve end of the pipe and is an indicator of the position of the sealing end of the nipple relative to the counter element in the sleeve, the second mark with its width equal to the step of the threaded thread determines the last step of screwing the joint (the base performs a similar function triangle mark), and applied along the generatrix of the lower fixed pipe on the coupling with a special device that imitates a full-sized element Threaded connection pipe, the label is a visual indicator of the mutual arrangement of pipe and coupling when the set consumer or regulatory documentation minimum, optimum and maximum screwing moments.

But this method does not allow the make-up control to be carried out already after the first lifting of the pipe from the well, since the pipe body and marks will be “dirty” with the contents of the well. Make-up control is difficult in low light conditions.

The well-known "Method of assembly of sleeve casing pipes in a string" according to AC SU 1594259 dated 03/04/1988, published: 09/23/1990 MPK5 Е21В 17/08, В23Р 19/06, in which the coupling is screwed up with the pipe in the factory until the torque increases to minimum acceptable level; then apply a longitudinal mark in the form of a strip crossing the sleeve and pipe; bandwidth corresponds to the range of permissible increase in torque; when lowering the casing, the field threaded joint of the coupling is screwed to the pipe until the parts of the marking strip located on the surface of the pipe and coupling from the factory end begin to shift relative to each other; A connection is considered normal if the offset value does not exceed the label strip width.

But this method is applicable only for assembling a factory threaded pair, since after lifting from the well for the next repeated unscrewing and subsequent make-up, such marks are difficult to detect.

The closest is a method for visual inspection of pipe make-up with marking with paint according to patent RU 2297511 dated February 24, 2005, published: 04/20/2007, IPC Е21В 17/00 (2006.01) Е21В 19/16 (2006.01), “Labeling method for visualizing make-up of oil and gas production pipes (options), a method for screwing these pipes and a method for visually inspecting the screwing of these pipes ”, in which first a strip is randomly applied along the longitudinal axis on the second device, and on the first device the strip is applied in stop surfaces with the second fixture opposite the strip applied on the last, then the first fixture is screwed onto the sleeve end of the pipe, on which a mark is applied in the form of a strip, which is a continuation of the strip on the first fixture, and the second fixture is screwed onto the nipple end of the pipe on which a strip mark that is a continuation of the strip on the second fixture; they carry out the fitting of the nipple end of one pipe into the sleeve end of the other pipe, which is secured against rotation, followed by screwing the nipple end of the pipe with an increasing torque; when the contact surfaces of the said pipes contact, the rotation of the pipe end of the pipe combines the mark on this pipe with the mark applied to the fixed end of the pipe from rotation of the pipe, and then tightening the nipple end of the pipe; screwing the nipple end of the pipe is first carried out manually for 4-5 turns, then screwing the indicated pipes to the end of the coupling end of the pipe at the level of the transverse mark on the nipple end of the pipe or below this level, and screwing due to the elastic deformation of the thread elements to achieve the specified tightness in the threaded connection, the sealing belts and the sealing in the thrust ends are carried out smoothly with a jump-free increase in torque at the temperature of the pipe end of the pipe not higher than 80 ° C until combined I marks on the nipple end of the pipe with an additional mark applied on the sleeve end secured from rotation of the pipe at a distance from the first mark on this pipe in the direction of screwing these pipes with the end of the sleeve end of the pipe at the level of the transverse mark on the pipe nipple end or below this level more than 0.5 mm

This method does not allow the make-up control to be carried out already after the first lifting of the pipe from the well, since the pipe body and marks will be “dirty” with the contents of the well. The control is difficult in conditions of insufficient lighting, the presence of lubricant, its distribution and “fresh” portion cannot be determined by video monitoring.

The objective of the proposed technical solution is to maintain the operational properties of the threaded connection, such as the absence of damage to the thread and the preservation of tightness, after repeated screwing-unscrewing of threaded oil-grade tubes.

The problem is solved by the method of visually inspecting the make-up of oil and gas production pipes extracted from the well, one of which is made with a nipple end with an external thread, and the other with a female end with an internal thread, by applying a contrast mark, while the base grease is used as the mark, mixed with a coloring pigment contrasting with respect to the color of the application surface, and the marks are applied uniformly in a continuous layer, distributing it along the external thread of the compound until the color of the surface disappears aneseniya across the threaded portion of the tube, and provide a visual control of screwing, until the disappearance of contrast marks pin-end at box-end.

The choice of dye pigment marks, contrasting with respect to the color of the application surface, added to the threaded base grease, which is applied in a continuous layer before each make-up, evenly distributing along the external thread of the joint until the color of the application surface disappears, provides visual control of make-up without exceeding the make-up moment, until the contrast mark of the nipple end disappears under the sleeve end, and at the same time provides visualization of the presence of “freshness” of the portion, continuity of application and distribution of threaded grease to the end of thread run-off before each screwing of oilfield pipes, which together allows you to maintain the operational properties of the threaded joint, such as the absence of damage to the thread and preservation of tightness, after repeated screwing-unscrewing of threaded oil grade pipes.

The conclusions about the materiality of the claimed features are confirmed by the results of the tests shown in the photographs, where in FIG. 1 shows lubricants mixed with different pigments, FIG. 2 photographs of a thread coated with pigmented thread grease; FIG. 3 photographs of a threaded joint after unscrewing, in FIG. 4 - photo screwed threaded connection.

In the photographs of FIG. 2, the quality of applying grease to the thread is clearly visualized, the golden grease is applied carelessly, and the condition “until the color of the coating surface over the entire threaded part of the pipe disappears” is not met. In FIG. 3 in the photo of the threaded connection after unscrewing, the absence of lubrication is also clearly visualized.

In FIG. 4, in photo 10 - the disappearance of the contrast mark under the sleeve end of the pipe at the screwed threaded joint is clearly visualized.

The method of visual control of screwing oilfield pipes is as follows.

A coloring pigment is selected, contrasting with respect to the color of the coating surface, as a component of a thread lubricant, guided by the properties in accordance with GOST 19487-74, for example:

Inorganic pigment (LDP. Mineral pigment): Painted dispersed inorganic substance, insoluble in dispersion media and capable of forming a protective, decorative or decorative-protective coating with a film-forming

Natural inorganic pigment (NDP. Earth pigment): Inorganic pigment obtained by grinding, enriching the heat treatment of rocks and minerals (in Fig. 1 - white)

Synthetic inorganic pigment: Inorganic pigment obtained by chemical reactions.

Metallic pigment: Inorganic pigment, which is a powder of a metal or an alloy of metals (in Fig. 1 - the colors are gray and golden). Anticorrosive Inorganic Pigment: An inorganic pigment that helps reduce or prevent corrosion.

Antifouling inorganic pigment: An inorganic pigment that prevents fouling of a painted surface in water by marine organisms.

A coloring pigment is selected, contrasting with respect to the color of the application surface, as a component of a thread lubricant, guided by the properties in accordance with GOST 19487-74, for example:

Inorganic pigment (LDP. Mineral pigment): Painted dispersed inorganic substance, insoluble in dispersion media and capable of forming a protective, decorative or decorative-protective coating with a film-forming

Natural inorganic pigment (NDP. Earth pigment): Inorganic pigment obtained by grinding, enriching the heat treatment of rocks and minerals.

Synthetic inorganic pigment: Inorganic pigment obtained by chemical reactions.

Metallic pigment: Inorganic pigment, which is a powder of a metal or an alloy of metals.

Anticorrosive Inorganic Pigment: An inorganic pigment that helps reduce or prevent corrosion.

Antifouling inorganic pigment: An inorganic pigment that prevents fouling of a painted surface in water by marine organisms.

The selected coloring pigment mixed with anti-seize filler is added to the threaded base grease.

Since pigments are solid fillers (components), the introduction of pigments in a thread lubricant, for example instead of graphite, allows you to adjust the color (visualize), due to the contrast between the color of the place of application of the grease (pipe body) and grease.

In addition, due to the use of pigments, the hiding power (continuity of application) of the lubricant increases. The shape of the pigment particles can be any, for example, a lamellar shape, needle-shaped or spherical.

The introduction of pigments increases the operational properties of threaded lubricants due to: hiding power, structuring ability, and weather resistance. At the same time, new properties of thread lubricant are added: the coloring ability, with the ability to change color and intensity.

Labels in the form of a basic grease mixed with a coloring pigment contrasting with respect to the color of the application surface and with anti-seize filler are applied in a continuous layer, uniformly distributing, along the external and internal threads of the joint, until the color of the application surface disappears over the entire threaded part of the pipe.

At the same time, the sealing and lubricating properties of the lubricant do not deteriorate. Pigment as a component of a thread lubricant imparts color, anticorrosion and other properties inherent in a particular component.

This method can be used in the manufacture of labels from lubricants of any composition. For example, take the lubricant of the reference composition according to the APIPR 5 A3 standard.

To obtain the desired label, replace graphite with a pigment and / or a mixture of pigment with an inert filler. For example: 18% of graphite was replaced with an equivalent amount of a mixture of white pigment (titanium dioxide) and an inert filler - talc. Inert filler pigment is mixed in proportions that provide the desired intensity of staining of the lubricant.

As a result, we obtained a mark from a threaded grease that has the required operational properties (ISO 13678) and with additionally acquired properties that allow us to visualize the screwing process and control the continuity of application and the amount of lubricant applied with repeated screwing-unscrewing.

An evenly prepared grease mixed with a coloring pigment contrasting with the color of the application surface is applied to the pipe extracted from the well, uniformly applied in a continuous layer, distributed over the external thread of the joint until the color of the applied surface disappears over the entire threaded part of the pipe, and the uniformity and coverage of the coating is controlled .

The nipple end coated with base grease mixed with the coloring pigment is planted in one pipe into the sleeve end of the other pipe, which is secured against rotation, followed by screwing the pipe end with a speed of no more than 25 rpm with increasing torque. When make-up, visual check of make-up is carried out, until the contrast mark of the nipple end under the sleeve end disappears.

The disappearance of the pigmented nipple part during make-up signals that the criterion for assembling the threaded connection by position has been met (Fig. 4 photo 10)

Fulfillment of the requirements for the assembly of the threaded connection by the proposed method is the key to preserving the operational properties of the connection, such as the absence of damage to the thread and preservation of tightness, with repeated screwing-unscrewing of threaded joints during the operation of oil and gas fields.

The technical effect of the proposed technical solution is to ensure reliable sealing of threaded joints during repeated screwing-unscrewing, due to the method of visual inspection of screwing of oil and gas production pipes extracted from the well, by marking with a threaded base grease mixed with a coloring pigment contrasting with respect to the color of the applied surface. in a continuous layer, until the color of the application surface disappears along the external thread of the joint, and I provide visual inspection of screwing, until the disappearance of the contrast pin end mark a box-end.

Claims (1)

A method for visually checking the screwing of oil and gas production pipes extracted from a well, one of which is made with a male end with an external thread and the other with a female end with an internal thread, by applying a contrast mark, characterized in that the base grease mixed with a coloring pigment contrasting with respect to the color of the surface of application, with the marks being applied uniformly in a continuous layer, distributing along the external thread of the compound until the color of the surface of the nan Oran across the threaded portion of the tube and provide a visual control screwing until the disappearance of contrast marks pin-end at box-end.

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