Method for determination of limits of functionality of threaded connections

FIELD: machine building.

SUBSTANCE: according to present method components of analysed group of threaded connections are determined by analysis of model. Further, the first group of threaded connections in an analysed group is subjected to physical tests. There is performed modelling analysis of the first and second groups of threaded connections. Physical tests are not carried out for the second group. After modelling results of a physical test and modelling analysis are compared to obtain a factor of working characteristic for the first group. Further, the factor of the working characteristic is applied for the second group and limits of functionality are determined on base of this factor of the working characteristic.

EFFECT: increased reliability of threaded connections.

18 cl, 5 dwg

 

The technical FIELD

The present invention relates in General to method of analysis within the health group threaded connections with comparable characteristics. More precisely, the present invention relates to a method for such analysis group threaded connections associated with the factor of the working characteristics with limited physical testing of threaded connections.

PRIOR art

The extraction of hydrocarbons such as oil and gas, is carried out for many years. For production of these hydrocarbons in the production system can be used in various devices such as tubular elements, in the well. Typically, the tubular elements are placed inside the wellbore to provide structural support, zonal isolation and to provide communication between underground formations and ground facilities. That is, the tubular elements may provide a flow path for reservoir fluid, such as hydrocarbons, inside the wellbore and to the structures located on the surface. Since these tubular elements are separate sections of pipe, two or more tubular elements can be connected to each other by means of a threaded connection or welding to implement a functional purpose within squag the us.

For threaded connections use two different classifications, namely the connection of the American Petroleum Institute (API) and improved connections. Join ANI, as a rule, are based on the capture of the threaded part of the screw threaded groove to achieve air-tightness (see U.S. patent No. 5411301 and 5212885). Alternatively, improved connections,as a rule, are based on the condensation of the metal-metal formed by threaded connections to ensure a tight seal (see U.S. patent No. 6041487). Such seals are metal-to-metal are a part of the connector tubular elements.

Regardless of the classification of the threaded connection in the wellbore, as a rule, are designed to maintain structural integrity and leak-proof operation during the life of the well, taking into account environmental requirements and safety. For example, integrity is one of the operating characteristics of the threaded connection, which describes the ability of the tubular elements to contain the reservoir under pressure or injection. The tightness of threaded connections affect, among others, the transported fluid, temperature, pressure, tensile and compressive efforts, bending, surface treatment, threaded lubrication, properties of the base material, the geometry of the connection, time stressing about what their factors. Also threaded connections exposed to different conditions during screwing, the space in the wellbore and/or during manufacture and cyclic pressure loads. Essentially, integrity is one of the indicators of efficiency, which can be computed during the analysis of threaded connections formed various tubular elements.

For health analysis of threaded connections there are various ways. One way analysis of operating characteristics of the threaded connection is a physical test of threaded connections when possible conditions expected during its service life. For this method, you must consider the possible work on site to ensure operational indicators that accurately reflect the environment in which most likely will be used for threaded connections. Because of its complexity the physical tests are costly and time-consuming, often taking several months at a cost of several hundred thousand dollars.

The second way of understanding the health of the threaded connection may include an analysis of the method of finite elements. Using the analysis method of finite elements you can get the contact characteristics of the elements of the connection (i.e. the upl is Tania "metal-metal", thread etc), as well as the reaction of threaded connections in tension and compression under different loading conditions. Despite the fact that the analysis by the method of finite elements is not expensive and does not take a lot of time getting the performance of a threaded connection on the basis of the calculation criteria may be misleading. For example, analysis by the method of finite elements does not cover the micromechanisms, such as surface interactions during tightening. In some evaluations false positive result indicating that the calculated value of the criterion corresponds to a load, but subsequent physical tests show that the threaded connection has not calculated performance. Other estimates of physical tests can identify suitable working qualities, while the estimated criterion analysis by the method of finite elements may be unsatisfactory. Ultimately, although the analysis by the method of finite elements can be used to obtain a response to tension and compression, it cannot be used to accurately obtain the influence of certain parameters, such as a thread lubricant or surface treatment on the performance. Essentially, although the use of only analysis by the method of finite elements for the analysis of the servant of the capacity of threaded connections, reduces the time and cost to determine the most appropriate threaded connections for this application, each threaded connection, as a rule, separately subjected to physical testing to ensure proper functionality.

The third way of understanding the health of the threaded connections is to use the analysis method of finite elements in combination with limited physical testing (see document No. 23904 (1992) Society of mechanical engineers, petroleum American Institute of mining engineers "Evaluation of improved threaded connections using the analysis method of finite elements and full-scale tests", Gilbert etc). This method used a standard test to assess the integrity of the threaded connection. The result of this type of assessment, as a rule, is valid for any application (i.e. it is not specific for a single well or loading conditions). However, the dissemination of the results of one test program one joint geometry (i.e. diameter and wall thickness) other geometry is complex and problematic. Additionally, the cost associated with the assessment of the health geometrically similar threads, large.

An example of such a method includes the industrial application criterion analysis by the method of finite elements for the assessment of integrity in the United States in 2004. In this case, the criterion of tightness was obtained and the comparison of the behavior on the subject of leaks in the seal during physical testing behavior, calculated by analyzing the method of finite elements. The criteria for analysis by the method of finite elements was applied to the results of the analysis by the method of finite elements from subsequent evaluations of compounds to obtain combinations of load and pressure at which it is expected proper sealing. These results were entered into a database and used for making business decisions about the cost of the equipment.

Moreover, although the approach described above, as a rule, were used for analysis of individual threads, in 2004 he was also applied to assess groups of compounds in the United States. In this application of physical tests were carried out over the threaded connections on the geometric boundaries of the group. The results of the analysis by the method of finite elements were used for commercial purposes to facilitate interpolation of tightness between these boundaries for other threaded connections. These results were entered into a database and used to make commercial decisions about the cost of the equipment.

The disadvantages of the known methods of analysis are the lack of adequate scalability for single threaded connections and expenses or expenditures of time, caused by the above methods. Also threaded connections contained in the analyzed group, not least is selected on the basis of any criterion to ensure that what limits their performance individually should be the same for other threaded connections in the group. Essentially, the required method of analysis group threaded connections with the accuracy of the physical tests, the simplicity of the analysis by the method of finite elements and definition of the limits of efficiency in the calculation for the various factors affecting the efficiency of the connection.

Other information on this issue can be found in the patent application U.S. No. 2003/017847 and U.S. patents№6607220, 6363598, 6176524, 6123368, 6041487, 5895079, 5689871, 5661888, 5411301, 5212885, 4962570, 4707001.

SHORT DESCRIPTION

According to the invention results from the assessment method within the health threaded connections, contains the following stages:

determining by analysis of the model components of the analyzed group of threaded connections, containing a first set of threaded connections and a second set of threaded connections;

the physical testing of the first set of threaded connections in the analyzed group;

conduct a modeling analysis of the first set of threaded connections and a second set of threaded connections, while the second set of threaded connection does not pass the physical tests;

the comparison of the results of physical testing and simulation analysis to obtain the factor of the working characteristics diaperbag many threaded connections;

the use factor of the working characteristics of the second set of threaded connections;

the definition of the limits of health on the basis of this factor operating characteristics.

The analyzed group may contain a threaded connection with comparable features, which can be seal design, thread design, the location of the shoulder and combinations thereof within the specified range.

The analyzed group may contain a threaded connection having comparable performance characteristics, which can be mechanical response to applied load, the reaction pressure contact to changes in mechanical loading and reaction pressure of contact on various conditions of the Assembly.

The method may include the formation of the first set of threaded connections and a second set of threaded connections, at least one range based on the geometric forms of the compounds for the formation of the analyzed group.

The method may include the formation of the first set of threaded connections and a second set of threaded connections, at least one range, with a part of the second set of threaded connections is beyond the geometric limits the first set of threaded connections.

The analyzed group threaded with the joining may include a threaded connection between the tubular elements, used in the extraction of hydrocarbons.

Physical test may contain at least one of the following tests: tests for screwing and unscrewing, testing tensile or compression to failure tests, fracture or rupture tests, water resistance and gas impermeability tests, fatigue tests, bending tests, the impact of cyclical changes in temperature and quenching.

Factor operating characteristics may include at least one of the following factors: factor tightness factor structural integrity, the factor of resistance to wear, factor fatigue strength, the factor of resistance to the environment, and combinations thereof.

Factor operating characteristics may be based at least partly on the conditions of production, containing at least one of the following conditions: properties of the base material, surface finish, dimensions, elements and landing between elements.

Factor operating characteristics may be based at least partly on the conditions during Assembly and install the screw compounds containing at least one of the following conditions: the time of screwing, the speed of screwing and dope.

Factor operating characteristics may be based, at measures which, partly on the conditions threaded connection, containing at least one of the following conditions: temperature, pressure, tensile load, compressive load, bending load and torsional load.

The tightness factor may be based at least partially on the fluids transported through the tubular elements.

Factor structural integrity can be defined as the ability of the distribution of the applied loads on the elements of the threaded connection.

The factor of resistance to wear can be defined as the ability of elements threaded connections to withstand damage to the surface due to frictional sliding.

Factor fatigue strength can be defined as the ability of elements threaded connections to withstand cyclic loading.

The factor of resistance to environment can be defined as the ability of elements threaded connection to withstand the applied load and the resulting tension and compression in the presence of an aggressive environment.

BRIEF DESCRIPTION of DRAWINGS

The above and other advantages of the present invention will become more specific from the following detailed description with reference to the drawings, which depict the following:

figure 1 depicts a variant of the system of production is relevant to the AI with the present invention;

figa and 2B depict variants of tubular elements used in the production system shown in figure 1, connected by means of sealing metal to metal";

figure 3 depicts a block diagram of the selection and use of tubular elements for a system of production figure 1;

figure 4 depicts the block diagram of the analysis process used in the block diagram from figure 3;

figure 5 shows different threaded connections and the range formed by the process in figure 4.

DETAILED DESCRIPTION

In the following detailed description of certain embodiments of the present invention are described according to its preferred embodiments. Though the following description is made specifically for a particular embodiment or separate use of the present invention, it should be considered only as illustrative and provide a brief description of the illustrative embodiments. Accordingly, the invention is not limited to specific embodiments described below, on the contrary, the invention includes all alternatives, modifications and equivalents within the attached claims.

The present invention describes a method of using factor operating characteristics, such as factor tightness, to facilitate analysis of threaded connections. With this method the simulation, in particular anal the C method of finite elements, can be made for threaded joints for determination of the components of the analyzed group. Then additional analysis by the method of finite elements is used for each of the threaded connection in the analyzed group, while only a limited number of threaded connections within the group subjected to physical testing. Results or data physical testing and analysis by the method of finite elements is used to confirm the response of the model and to regulate the value of factor operating characteristics for the analyzed group. Thus, a single factor operating characteristics can be determined for threaded connections with similar features and similar performance, based on a combination of modeling and limited physical testing. Thus, the present invention provides an efficient mechanism for analysis of threaded connections.

Figure 1 shows an illustrative system 100 extraction in accordance with the present invention. In the system 100 ground structure 102 is connected to wellhead 104 located on the surface 106 of the earth. Through wellhead equipment 104 ground structure 102 accesses one or more subterranean formations, such as the subterranean formation 108, which may include many products the active intervals or zones, containing hydrocarbons, such as oil and gas. Preferably the tubular elements, such as conductora casing 124, intermediate or production casing 126 and/or tubing column 128 may be used inside the barrel 114 wells to increase the production of hydrocarbons from the subterranean formation 108. However, it should be noted that the system 100 extraction is depicted for purposes of illustration, and the present methods can be used for extraction or pumping fluid from any of the underwater platform or ground space.

Ground structure 102 has the same configuration, to observe and to extract hydrocarbons from the subterranean formation 108. Ground structure 102 may include storage tanks and/or vessels for processing used for the production of reservoir fluids, such as hydrocarbons. To access productive interval of the subterranean formation 108 ground structure 102 communicates with the wellhead 104 through the pipeline 110. The pipeline 110 may include sections of the tubular elements connected to each other by means of welding or threaded connections.

To access the subterranean formation 108 the wellbore 114 is held in the surface 106 to a depth bordering the productive interval of the subterranean formation 108. Wellhead equipped with the E104, located on top of the wellbore 114 on the surface 106, provides a boundary surface between devices inside the barrel 114 wells and surface structure 102. Accordingly wellhead equipment 104 may communicate with conductoras casing 124, the production casing string 126 and/or the booster casing 128 to ensure the flow path of fluids. Devices mounted in the barrel 114 wells may include subsurface safety valve 132, the packer 134 and one or more tools 136. Subsurface safety valve 132 can be used to block fluid flow from the tubing of the column 128 in case of rupture or fracture above the subsurface safety valve 132. Moreover, the packer 134 can be used to isolate individual zones within the ring of the wellbore from each other. Tools 136 may include a device to combat the flow of sand or other flow control, used to provide flow paths for hydrocarbons in the subterranean formation 108.

To ensure stability and prevent leakage inside the barrel 114 of the well system 100 extraction may also include various tubular elements or pipes, such as conductora casing 124, the production casing 126 and/or us the SNO-tubing column 128. Conductora casing 124 may be installed from the surface 106 to the position at a certain depth under the surface 106. In conductoras casing 124 is located intermediate or production casing 126, which may extend down to a depth of about subterranean formation 108 and may be used to provide support for walls of the barrel 114 wells. Conductora and production casing 124 and 126 can be cemented in a fixed position inside the barrel 114 wells for additional stabilization of the barrel 114 wells. Inside conductoras and production casing 124 and 126 can be used tubing column 128 to create flow paths through the barrel 114 wells for hydrocarbons and other fluids. The area of each of conductoras casing 124, the production casing string 126 and/or tubing of the column 128 may be connected or fastened by means of a threaded connection, as described above.

As an example, threaded connections on figa and 2B depicts an illustrative views of the two tubular elements in the production system shown in figure 1, connected to each other. Accordingly figa and 2B may become clearer when considering in conjunction with figure 1. On figa and 2B are two tubular element 200A and 200b image is the awives in a divided and sealed configurations. However, it should be understood that the tubular elements 200A and 200b may be any two or more lots conductoras casing 124, the production casing string 126 and/or tubing 128 columns.

On figa as the first tubular element 200A and the second tubular element 200b has a patch a and 201b of the main body, plot a and 203b neckline and notched area a and 208b. Tubular elements 200A and 200b may be made of steel or steel alloys, with lots a and 201b of the main body have a certain length 212, for example, from 30 to 40 feet, with defined inner and outer diameters. Plot neck a and 203b may have an external thread a and 204b, and the notched section a and 208b has an internal thread a and 206b. Also plot a and 203b neck has sections 205A and 205b of the sealing metal to metal, and the notched section a and 208b may have sections 207a and 207b seal metal to metal. These sections 205A, 205b, 207a, 207b seal metal to metal can form a seal to at least plot 210 sealing length. Outer thread a and 204b may have a configuration to connect to the internal thread a and 206b for formation of a tight seal between the tubular elements 200A and 200b, as shown in figv.

On FIGU plot a neck of the first tubular is lementa 200A is connected to the notched section 208b of the second tubular element 200b. Tubular elements 200A and 200b are connected to each other by engagement of the outer thread a with internal thread 206b for forming a threaded connection. The seal formed by the sections 205A, 205b, 207a and 207b seal metal to metal and thread a, 204b, a and 206b may prevent leakage. Accordingly, by means of a threaded tubular connection elements 200A and 200b can be connected to each other for the formation of a continuous flow path in the wellbore 114 wells and can also be used to stabilize the shaft 114 of the well.

Allowable leakage through the threaded connection may vary depending on the application, as described above. For example, a threaded connection in harsh operating conditions, such as the inside of the barrel 114 wells may experience excessive temperature and pressure as the penetration of wells to a greater depth, as they are exposed to other environments. Also on the performance of threaded connections can influence the transported fluids, temperature, pressure, tensile and compressive loads, bending, surface treatment, threaded lubrication, properties of the base material, the geometry of the connection, the time of screwing, conditions during screwing, the conditions during the operation, production and/or cyclic pressure loads, or other is ricini. Because of the high cost of repairs tubular within the wellbore 114 wells conductora casing 124, the production casing 126 and tubing column 128, as a rule, are designed to maintain structural integrity and tightness throughout the life of the well to prevent environmental problems, for continuous production and safety. Essentially, a threaded connection can work for the entire life of the well.

To obtain health threaded connections may be used various factors of performance, such as tightness factor, the factor of structural integrity, the factor of resistance to wear, the factor of resistance to the environmental exposure, the factor of fatigue strength or any combination of them. It should be noted that it may be preferable to use only one of the factors of performance for the analyzed group. As an example of the factors performance factor of air-tightness is characteristic of a threaded connection, which describes how well the tank is under pressure or injection fluids are contained within the tubular element. The factor of tightness of the threaded connection is affected, among others, the transported fluid environment temperature, pressure, tensile and compressive loads, bending, surface treatment, threaded lubrication, properties of the base material, the geometry of the connection, the time of screwing, and other factors. Also on the tightness factor is influenced by a variety of conditions experienced during screwing, the space in the wellbore and/or during manufacture and cyclic loads discharge. For these conditions the production conditions include at least one of the following conditions: properties of the base material, surface finish, dimensions, elements and landing between the elements; conditions during Assembly and installation of the threaded connection includes at least one of the following conditions: the time of screwing, speed and screwing the threaded grease, and working conditions threaded connection includes at least one of the following conditions: temperature, pressure, tensile, compression, bending and torsion loads. Essentially, the tightness factor is one measure of health that can be obtained during the analysis of threaded connections formed various tubular elements.

Factor structural integrity is a characteristic of a threaded connection, describing how well the applied load is distributed between the elements of the threaded connection. the and factor structural integrity, impact, among others, temperature, pressure, tensile and compressive loads, bending, surface treatment, threaded lubrication, properties of the base material, the geometry of the connection, the time of screwing, and other factors. Like the above-described production conditions include at least one of the following conditions: properties of the base material, surface finish, dimensions, elements and landing between the elements; conditions during Assembly and installation of threaded connections include at least one of the following conditions: the time of screwing, speed and screwing the screw. grease; and working conditions threaded connection includes at least one of the following: temperature, pressure, tensile, compression, bending and torsion loads. Also factor in the structural integrity is affected by various conditions experienced during screwing, the space in the wellbore and/or during manufacture and cyclic loads discharge.

The factor of resistance to wear is characteristic of a threaded connection, describing how well the elements threaded connections withstand surface damage due to frictional sliding. The factor of resistance to wear is influenced, among others, temperature, pressure, tensile and compressive efforts, bending, machining surface is t, screw lubrication, properties of the base material, the geometry of the connection, the time of screwing, and other factors. For these conditions the production conditions include at least one of the following conditions: properties of the base material, surface finish, dimensions, elements and landing between the elements; conditions during Assembly and installation of the threaded connection includes at least one of the following: the time of screwing, the speed of screwing and dope; and working conditions threaded connection includes at least one of the following: temperature, pressure, tensile, compression, bending and twisting forces. Additionally, the factor of resistance to wear is influenced by a variety of conditions experienced during screwing, the space in the wellbore and/or during manufacture and cyclic loads discharge.

The factor of resistance to the environment is characteristic of a threaded connection, describing how well the elements threaded connections withstand the applied load and the resulting tension and compression in the presence of an aggressive environment. Aggressive environment, for example, is the formation, in which there are fluids with a high content of hydrogen sulfide (H2S). The factor of resistance to environments the overall environment impact, among others, the composition of the extracted fluid, temperature, pressure, tensile and compressive loads, bending, surface treatment, threaded lubrication, properties of the base material, the geometry of the connection, the time of screwing, and other factors. Again, under these conditions, production conditions include at least one of the following conditions: properties of the base material, surface finish, dimensions, elements and landing between the elements; conditions during Assembly and installation of the threaded connection includes at least one of the following conditions: the time of screwing, the speed of screwing and dope; and working conditions threaded connection includes at least one of the following conditions: temperature, pressure, tensile, compression, bending and torsion loads. Also on the factor of resistance to the environment is influenced by a variety of conditions experienced during the Assembly, placed in the wellbore, and/or during manufacture and cyclic loads discharge.

Factor fatigue strength is a characteristic of a threaded connection, describing how well the parts of the threaded connection tolerate cyclic load. The factor of fatigue strength is influenced, among others, temperature, pressure, tensile and compressive loads, bending,surface treatment, screw lubrication, properties of the base material, the geometry of the connection, the time of screwing, and other factors. Also on the factor of fatigue strength is influenced by a variety of conditions experienced during screwing, the space in the wellbore and/or during manufacture and cyclic loads discharge. For these conditions the production conditions include at least one of the following conditions: properties of the base material, surface finish, dimensions, elements and landing between the elements; conditions during Assembly and installation of the threaded connection includes at least one of the following: the time of screwing, the speed of screwing and dope; and working conditions threaded connection includes at least one of the following: temperature, pressure, tension, compression, bending and torsion loads. The service life of the tubular elements in the production system is described next with reference to figure 3.

Figure 3 depicts an illustrative block diagram of the selection process and the use of tubular elements for the production system shown in figure 1, in accordance with the present invention. This flowchart 300 may become clearer when dealing with figures 1 and 2. In this flowchart 300 threaded connections can be analyzed before a particular purpose. That is threaded with the organisations between the tubular elements can be analyzed to determine certain performance group threaded connections, such as integrity, structural integrity, resistance to wear, resistance to environmental impact and fatigue strength.

The process includes an initial stage 302. At stage 304 threaded connections in the analyzed group analyzed. The analysis process is described in more detail with reference to figure 4, may include simulation of various threaded connections and define the components of the analyzed groups on the basis of simulation results. Then threaded connections in the analyzed group can be subjected to physical testing and analysis by the method of finite elements. Physical tests can be performed on a subset of threaded connections, which form a band, many bands or band with other threaded connections beyond its limits. According to the results of physical testing and analysis by the method of finite elements defined characteristics can be assigned to other threaded connections within the analyzed group without necessary physical tests of these threaded connections. At stage 306 can be designed tubular elements for a well. Design of tubular elements may be based on the location of wells, geophysical analysis or other processes, opican the x above. Tubular elements for a well can be designed on the basis of conditions at the location of the wells and the expected operational requirements. At stage 308 tubular elements for a well can be obtained on the basis of the design and preliminary analysis of threaded connections. It should be noted that the analyzed group can be formed either before or after the particular destination or oil fields.

At stage 310, after receiving the tubular tubular elements can be installed in the well. The tubular elements may be part of the drilling operations for drilling the borehole 114. At stage 312 of the tubular elements may be used for the production of reservoir fluids, such as hydrocarbons, through the tubular elements. Hydrocarbon production may include the connection of the tubular elements to each other, the connection tubular wellhead 104 and tools 136 for forming the flow paths of fluid through the barrel 114 wells. These flow path of the fluid to allow the hydrocarbons to the surface installations 102. Accordingly, the process ends at stage 314.

Due to the risk and cost associated with the extraction of hydrocarbons, special factors operating characteristics, such as integrity,structural integrity, resistance to wear, resistance to environmental exposure or fatigue strength, threaded connections may be evaluated for various tubular elements to reduce the risk of breakage of the threaded joints in the well. However, the methods of analysis described above, are either expensive and time-consuming, or not should provide versatility for certain applications, as described above. There is therefore a need in the way of analysis group threaded connections with the accuracy of the physical tests and the simplicity of the test by analyzing the method of finite elements, allowing to determine the limits of performance, calculated for different factors affecting the efficiency connections, which are described with reference to figure 4.

Figure 4 depicts an illustrative block diagram 400 of the analysis process used for the production system from figure 1 in accordance with the objects of the present technology. Block 400 may become clearer when considering simultaneously with 1-3. This flowchart 400 illustrates a process for determining the physical by health connection, which was not carried out physical tests. This process uses a pre-made physical testing of threaded connections as the basis for analysis. The results of these the physical test and simulation analysis can also be combined to form a group of threaded connections. For example, the results of physical tests for threaded connections can be associated with an indicator of the tightness of using certain by calculation of the calibration coefficient integrity "k". Using this method some threaded connections can be physically tested and used to determine the characterizing factor for other threaded connections. Threaded connections inside the range or a specific group can be used without cost or for a long time usually required for physical testing of each of the threaded connection.

The process begins with the stage 402. At stage 404 is defined components or threaded connections of the analyzed group. The components of the analyzed group may include a threaded connection with comparable characteristics, such as the seal design (spherical or conical), thread design (number of coils per inch, geometric shape, location, shoulders, etc. within a certain range. The components of the analyzed groups can be combined in a range, based on information provided by the manufacturer of the respective tubular elements. Alternatively, the components of the analyzed groups can be determined after TP the subsequent data analysis manufacturer of tubular elements. Modeling analysis may include an analysis of the method of finite elements to identify similarities or differences between the threaded connections of different sizes, with different thread design or different designs of seals.

After defining the components of the analyzed groups on several typical threaded connections may be conducted physical testing stage 406. Some typical threaded connections or components may be a subset or group from the analyzed group, while another subset or group of analyzed groups may not be subjected to physical testing. Physical tests may be conducted on the model components of the analyzed groups to identify the effects of geometric variations, loading conditions (including bending), temperature, screw lubrication, surface treatment, etc. on certain performance characteristics, such as sealing, structural integrity, resistance to wear, resistance to environmental exposure or fatigue strength. These physical tests can be carried out on the basis of testing programs that meet certain standards. See, for example, "Program analysis"connections, vol. 1, ExxonMobil (2001) and "the Oil and gas industry is islenet - procedures for testing casing and tubular connections," international organization for standardization 13679 (2002). Then modeling analysis, such as analysis by the method of finite elements, each of the threaded connection in the analyzed group on stage 408. Using simulation analysis, it is possible to get standard design features threaded connections and identify trends negatively affecting the efficiency of the connection, such as the stiffness, the contact seal and the contact shoulder. For example, modeling by analyzing the method of finite elements can be used to calculate the response in tension-compression elements under these boundary conditions, or to calculate the contact pressure between the elements. This type of analysis can be useful in determining the homogeneity of the threaded connections in the analyzed group for different operating characteristics, which may include integrity, structural integrity, resistance to wear, resistance to environmental exposure or fatigue strength.

Then factor operating characteristics, such as factor tightness or other factors mentioned above, the threaded connections in the analyzed group, can be defined in stages 410-416. At stage 410 can be derived factor servant who whose characteristics. This may include pre-set factor working characteristics. For example, if factor operating characteristics is the factor of integrity, sets the value at which hypothetically the connection will be tight, but at values below which the connection will be hypothetically give leaking. Then the results of physical tests are compared with the simulation results (for example, by analyzing the method of finite elements) for certain standard threaded connections in the analyzed group on stage 412. This comparison may include determining a leak or leaks in threaded joints attached at various loading conditions. Then is the same whether these results with the stage 414. This report may include a review to spread thresholds. If the results are not the same and may fall outside the variation of threshold values, the tightness factor is recomputed at the stage 410. If the results are the same, or lie within the scatter thresholds, factor operating characteristics is applied to each of the threaded connections that do not pass the physical tests at the stage 416. This can be accomplished through the implementation of additional analysis of the way the con is cnyh elements and counting the tightness factor for different load combinations. For load combinations with the tightness factor is above the value defined at stage 410, the screw connection must be sealed. For load combinations with the tightness factor is less than the value defined at stage 410, a threaded connection may leak. Accordingly, the process ends in block 418.

Despite the fact that each of the threaded connection is used the analysis method of finite elements to determine the health, only a limited number of threaded connections with the same design and material properties subjected to physical analysis to obtain health for a larger group or range of threaded connections analyzed in this group. Can also be effected by an additional physical modeling of the tested compounds for details of software analysis and testing, such as behavior depending on the particular path. This information is derived from software testing can be used to confirm the response of the model and regulation previously established trends health. These trends are then used to determine the integrity of each of the threaded connections in the analyzed group. Thus, limited physical testing can be implemented is received for evaluation within the health group threaded connections, includes threaded connection with a similar geometric shape and/or threaded connection with such performance. In particular, the tightness factor, along with analysis by the method of finite elements can be used to obtain bounds tightness for both tested and untested compounds. Preferably use factor operating characteristics simplifies the analysis by providing the possibility of using a single parameter to each of the components of the analyzed group.

Figure 5 depicts a chart of the various threaded connections and analyze the group generated by the process in figure 4, in accordance with certain objects of the present technology. Figure 5 threaded connection of the tubular elements having outer diameter 504 from 2 3/8 inches to 7 inches, pending against 502 thickness to the outer diameter in the form of a chart 500. The chart 500 of the analyzed group of threaded connections includes fifty-two threaded connections, each of which has similar features and is composed of similar carbon steels (for example, from S to s that includes 4 stamps). Each of these separate threaded connections shown various points. These points include the boundary points 508 (presented trapolin the mi marks), point 512, lying outside the range (represented by circular marks), and internal point 510 (represented by diamond-shaped markers). Boundary points 508 form the range 506 limiting threaded connections that meet the threshold values for the respective application.

When using these technologies physical test is carried out for typical components of a family of screw connections for receiving sealing design of threaded connections in a given range of material properties. For this example, the analyzed group is defined, and physical tests are performed on threaded connections, presents boundary points 508. Then, for each threaded connections is analyzed by the method of finite elements for the assessment of trends of the contact seal and shoulder for the analyzed group. After analysis by the method of finite elements eight threads, which are points 512, not included in the range are defined as compounds with a functionality that is not fully described by testing eight threaded connections. Essentially, these threaded connections, represented by 512 points lying outside this range are excluded from the analyzed group, which uses forty-four threaded connections.

After analysis by the method of finite elements of the test in this way eight physically tested threaded connections is determined by a single factor tightness. These threaded connections subjected to further analysis by the method of finite elements to obtain individual results of the test program. The tightness factor is compared with data obtained during physical testing of threaded connections, and can be adjusted on the basis of the actual test conditions, landing point, screwing and other special variables tests. For example, measurement of tension can be used to identify what pre-designed landing shoulders properly combined with models obtained by analysis by the method of finite elements, resulting in a factor of tightness is adjusted.

After adjusting the tightness factor is applied to the remaining thirty-six compounds in the analyzed group. The factor of tightness physically tested threaded connection is used along with a standardized analysis method of finite elements to obtain the limits of tightness for the remaining untested threaded connections in the analyzed group. The result of this analysis is STO semidecent threaded connections with proper tightness. When determining this result only eight threaded joints were subjected to physical tests, while the operability of the remaining one hundred and sixty eight threaded joints was determined by calculation by a factor of tightness.

In addition to the common range 506 analyzed group may include threaded connections in multiple ranges or with a separate threaded connections. For example, the analyzed group may include the first set (i.e. group) threaded connections and a second set of threaded connections. The first and second groups can form a range, based on the geometric form of connection, to limit the analyzed group. Alternatively, the first and second groups can form a lot of ranges, based on the geometric form of the compounds, to limit the analyzed group. In another embodiment the first and second groups form a band, with a part of the second group of threaded connections falls for the geometric boundaries of the first group of threaded connections. As a final example, the first and second groups form a variety of ranges and part of the second group of threaded connections is beyond the geometric boundaries of the first group of threaded connections.

p> Additionally, as indicated above, can be used various combinations of factors of performance. For example, the tightness factor and the factor of resistance to wear can be used separately for one of the analyzed group. This type of analysis can be carried out just as described above. The results can then be combined to eliminate a great threaded connections that do not satisfy both factors. Accordingly, based on this approach, two, three, four or more factors can be used simultaneously for certain tests.

In addition to the above it should be noted that the tubular elements may have an external shape different from that shown in figa and 2B. These differences may include, without limitation, the location and the geometric shape of the connection details, such as seals, shoulder, thread, etc. Additionally, the connecting mechanism may be made in the form of a coupling or other threaded connections. Essentially, these different features do not violate the limits of these technologies.

Despite the fact that the real technology of the invention may be susceptible to various modifications and take alternative forms, illustrative embodiments described above have been shown only by way of example. However, it should be understood, Thu the present invention described here is not limited to the individual embodiments. On the contrary, the present technology of the invention cover all modifications, equivalents and alternatives that are consistent with the nature and scope of the invention defined in the following the following claims.

1. Assessment method within the health threaded connections, contains the following stages:
determining, using the analysis model, the components of the analyzed group of threaded connections, containing a first set of threaded connections and a second set of threaded connections;
the physical testing of the first set of threaded connections in the analyzed group;
conduct a modeling analysis of the first set of threaded connections and a second set of threaded connections, while the second set of threaded connection does not pass the physical tests;
the comparison of the results of physical testing and simulation analysis to obtain the factor of the working characteristics of the first set of threaded connections;
the use factor of the working characteristics of the second set of threaded connections;
the definition of the limits of health on the basis of this factor operating characteristics.

2. The method according to claim 1, in which the analyzed group contains a threaded connection with comparable features.

3. The method according to claim 2, in which comparable persons whom nosti contain, at least one of the following features:
seal design, thread design, the location of the shoulder and combinations thereof within the specified range.

4. The method according to claim 1, in which the analyzed group contains a threaded connection having comparable performance characteristics.

5. The method according to claim 4, in which comparable performance characteristics include at least one of the following:
mechanical response to applied load, the reaction pressure contact to changes in mechanical loading and reaction pressure of contact on various conditions of the Assembly.

6. The method according to claim 1, containing formation from the first set of threaded connections and a second set of threaded connections, at least one range based on the geometric forms of the compounds for the formation of the analyzed group.

7. The method according to claim 1, containing formation from the first set of threaded connections and a second set of threaded connections, at least one range, with a part of the second set of threaded connections is beyond the geometric limits the first set of threaded connections.

8. The method according to claim 1, in which the analyzed group of threaded connection includes a threaded connection between tubular elements used in the extraction of hydrocarbons.

9. The method according to claim 1, wherein the physical test contains at least one of the following tests:
tests for screwing and unscrewing, testing tensile or compression to failure tests, fracture or rupture tests, water resistance and gas impermeability tests, fatigue tests, bending tests, the impact of cyclical changes in temperature and quenching.

10. The method according to claim 1, in which the factor of the working characteristics includes at least one of the following factors: factor tightness factor structural integrity, the factor of resistance to wear, factor fatigue strength, the factor of resistance to the environment, and combinations thereof.

11. The method according to claim 10, in which the factor of the working characteristics based at least partly on the conditions of production, containing at least one of the following conditions: properties of the base material, surface finish, dimensions, elements and landing between elements.

12. The method according to claim 10, in which the factor of the working characteristics based at least partly on the conditions during Assembly and install the screw compounds containing at least one of the following conditions: the time of screwing, the speed of screwing and dope.

13. The method according to claim 10, in which the fact is R working characteristics are based, at least partially on the operating conditions threaded connection, containing at least one of the following conditions: temperature, pressure, tensile load, compressive load, bending load and torsional load.

14. The method according to claim 10, in which the tightness factor is based at least partially on the fluids transported through the tubular elements.

15. The method according to claim 10, wherein the factor structural integrity is defined as the ability distribution of the applied loads on the elements of the threaded connection.

16. The method according to claim 10, in which the factor of resistance to wear is defined as the ability of elements threaded connections to withstand damage to the surface due to frictional sliding.

17. The method according to item 12, wherein the factor fatigue strength is defined as the ability of elements threaded connections to withstand cyclic loading.

18. The method according to claim 10, in which the factor of resistance to the environmental exposure is defined as the ability of elements threaded connection to withstand the applied load and the resulting tension and compression in the presence of an aggressive environment.



 

Same patents:

FIELD: machine building.

SUBSTANCE: device consists of metal case in form of cylinder with internal cylinder groove restricted with internal circular lug, and also having cylinder lug on external surface. Two stepped cylinder of dielectric material and a sealing padding are set between the pipe and the groove of the case. A metal ring, a C-shaped ring made of material harder, than material of the pipe and a movable bush are arranged between the pipe and the cylinder of dielectric material. Uniform around circumference transfer of the end cover, of the stepped cylinder positioned before it and the pipe, and of the movable bush occurs in axial direction at tightening bolts which enter orifices in the cylinder lug of the case and the end cover. With its internal conic surface the movable bush weighs upon external surface of the C-like ring, compresses it, forces pointed radial lugs of the C-like ring into a body of the pipe and fixes the pipe in the insulating device for pipe assembly. It also compresses the insulating padding.

EFFECT: insulating padding, three cylinders and insertion of dielectric material form reliable electro-insulating circuit.

2 dwg

FIELD: machine building.

SUBSTANCE: connection consists of first and second expanded tubular elements each containing multitude of bent sheets. Each sheet has concave and convex surfaces and a place of connection whereat one of multitude of bent sheets is attached to another from multitude of bent sheets, and multitude of connecting elements each positioned on at least one of multitude of bent sheets. The first and the second expandable elements can be expanded and compressed. Multitude of connecting elements of the first tubular element interacts with multitude of connecting elements of the second tubular element.

EFFECT: increased strength and pressure tightness of connection.

33 cl, 28 dwg

FIELD: machine building.

SUBSTANCE: electro-insulated connection of pipelines consists of metal branches with ring bosses whereon there is formed fastener in form of bush out of composite material, of protective ring out of dielectric material installed between ends of branches and of packing collar out of elastomer material enveloping end sections of branches. Circular recesses are made on the end sections of the branches on their end surfaces; behind the cross section of the recesses to the side of the opposite branch there are made circular projecting sections. The protective ring has a narrow section installed between the circular projecting sections and a convex section put on the circular projecting sections. The packing collar envelopes the protective ring with its internal surface; while with its external surface it contacts surface of a cavity formed with the fastener and ends of the branches. Adjacent surfaces of the projecting sections of the branches ends and the packing collar are glued.

EFFECT: increased reliability of pressure tightness of connection under low and high loads.

2 cl, 2 dwg

FIELD: machine building.

SUBSTANCE: connection of main and lateral pipelines in heat systems consists of T-joint on main pipeline and of L-shaped tubular insertion. The side branch of the T-joint is perpendicular to the lateral pipeline. According to the first version the L-shaped insertion connects the side branch of the T-joint with the lateral pipeline. The distinguished feature of the claimed design of the first version is connection of the L-shaped insertion with the side branch of the T-joint by means of a hinge wherein axis of rotation coincides with axis of the branch. According to another version the lateral pipeline has a L-shaped tubular element wherein one axis is parallel to axis of the side branch of the T-joint, while a "П"-shaped tubular insertion is installed between the branch of the T-joint and the L-shaped element of the lateral pipeline. The tubular insertion is connected to them by means of pivot connections with axes of rotation coinciding with axes of the side branch and L-shaped element.

EFFECT: increased reliability of pipelines connection.

2 cl, 5 dwg

FIELD: machine building.

SUBSTANCE: coupling is made with grooves. In the middle part of the coupling there is located an arrester for centring connected pipes. Grooves are cut on ends of connected pipes on external side; before connection the grooves are preliminary filled with glue composition; ends of the pipes are successively press fitted into the coupling.

EFFECT: raised reliability of pipes connection, preservation of internal coating of pipes.

1 dwg

FIELD: machine building.

SUBSTANCE: dielectric pads are arranged between adjacent ends of two branches made out of pipeline material and between branches and connecting them external coupling. The branches are permanently connected with the coupling by means of joint radial expansion of the branches and coupling thus forming circular lugs on external surface of the branches and coupling with height exceeding thickness of the dielectric pads between the branches and the coupling. Internal surface of the branches is lined with a polymer coating ends of which are fastened and sealed by means of radial deformation of metal binding tips in them. The circular ends on external surface of the coupling and branches are formed at a certain distance from the ends of the coupling, while end sections of the coupling are reduced by means of radial squeezing and forming internal lugs in the branches.

EFFECT: raised reliability of insertion at high pressure in pipeline.

4 cl, 1 dwg

FIELD: machine building.

SUBSTANCE: dielectric pads are arranged between adjacent ends of two branches made out of pipeline material and between branches and external coupling connecting them. The branches are permanently connected by a coupling by means of joint expansion of branches and coupling, thus forming circular lugs on external surfaces of the branches and coupling with height exceeding thickness of the dielectric pads between the branches and the coupling. Internal surface of the branches is lined with polymer coating, ends of which are secured and sealed. Also the dielectric pads between the branches and coupling are compound. In zones of external biases of at least of one of the lugs and within the range of each branch there are positioned dielectric pads out of material of low creep, while on the rest of sections there are used the dielectric pads out of plastic or elastic material.

EFFECT: raised reliability of insertion at high pressure in pipeline.

5 cl, 1 dwg

FIELD: machine building.

SUBSTANCE: between nozzles and external coupling that connects them there are dielectric gaskets installed of hot melt polymer, having adhesion to materials of coupling and nozzles, nondetachable joint of nozzles is arranged with coupling by means of joint radial expansion of nozzles and coupling to form circular ledges on external surfaces of nozzles and coupling with height that exceeds thickness of dielectric gaskets between nozzles and coupling. Radial pressing of end sections of coupling is done to form internal ledges in nozzles, central part of coupling is heated up to temperature of hot melt polymer melting start with maintenance of temperature of end sections of coupling below temperature of polymer melt, and internal surface of nozzles is lined with polymer shell, ends of which are fixed and sealed by means of radial deformation of metal jamming tips in them.

EFFECT: increased reliability of current-isolating insert at high pressure in pipeline.

5 cl, 1 dwg

FIELD: machine building.

SUBSTANCE: specified parts have edges with grooves. Isolation insert is arranged by means of injection and provides for internal flow for liquid passage between specified parts and covers specified parts with grooves, providing for tight connection of isolation insert with specified parts.

EFFECT: invention improves reliability of joint.

18 cl, 3 dwg

FIELD: machine building.

SUBSTANCE: electrically insulating flange connection of plain tubes includes metal housing in the form of cylinder restricted on one side with inner annular projection, and on the other side rigidly connected to one flange. The other flange is equipped with cylindrical projection tightly enclosed in metal housing to which cylinder from dielectric material is inserted without a gap, between which and cylindrical projection of the flange the annular rubber gasket is installed, which protects inner cavities of connection against atmospheric action. Annular sealing gaskets, metal rings, C-shaped rings made from material which is harder than tube material, movable metal bushes and stepped bushes from dielectric material are in series located symmetrically from electrically insulating insert between tubes. When tightening the fasteners the sealing gaskets are pressed in closed volume between side surfaces of electrically insulated insert and metal rings, and inner conical surface of movable metal bushes acts on outer spherical surface of C-shaped rings, presses them, and pointed projections on inner surface of C-shaped rings are pressed to the tube body by fixing electrically insulating flange connection of plain tubes.

EFFECT: invention improves the connection reliability.

1 dwg

FIELD: pipeline engineering.

SUBSTANCE: joint comprises two metallic branch pipes and ring made of dielectric material and interposed between the faces of branch pipes. The branch pipes have bells which are interconnected through insert by permanent dielectric adhesive joint from the inside and through metallic coupling by permanent dielectric locking adhesive joint on the outside.

EFFECT: enhanced reliability and prolonged service life.

4 cl, 1 dwg

FIELD: electrical engineering.

SUBSTANCE: proposed device has case for abutting against body to be brought in contact and at least one contact member set in wiring position between case and body to be brought in contact so as to establish electrical connection with current-conducting part of this body. At least one laminated contact member is made of alloy that has in its composition at least 94.5% of copper (Cu), 2 - 4% of nickel (Ni), 0.5 - 1% of silicon (Si), and 0.05 - 0.25% of magnesium.

EFFECT: reduced pressure on contacted body.

21 cl, 7 dwg

Pipe // 2260736

FIELD: pipeline transport.

SUBSTANCE: pipe comprises fiberglass layer with electroconducting binder. The electroconducting binder is applied only on the outer side of the reinforced fiberglass layer.

EFFECT: enhanced reliability.

1 dwg

FIELD: the invention refers to the field of the pipeline transport and may be used for electric disconnection of pipelines and/or their sections particularly at protecting them from corrosion.

SUBSTANCE: dielectric insertions are placed between adjacent butt-ends of two sockets fulfilled out of the material of the pipeline and between the sockets and the exterior muff connecting them. The interior surface of the sockets in the zone of location of the muff is provided with ring lugs with the height exceeding the thickness of the dielectric insertions between the sockets and the muff and radial distribution of sockets is carried out as a minimum until elimination of gaps between the sockets and the muff along the entire length of their coupling. The ring lug on the interior surface of the sockets are made by way of fixing of packing rings inside the sockets. As dielectric insertions between the sockets and the muff an exterior plastic covering of the sockets may be used. In case of transporting along the pipeline of electrically conducting fluid the inner surface of current insulating insertion is provided with dielectric covering.

EFFECT: reduces labor-intensiveness of manufacturing.

4 cl, 3 dwg

Insulating coupling // 2271494

FIELD: construction.

SUBSTANCE: insulating coupling comprises thickened branch pipes which are cut in the pipeline over their outer diameters. The inner side of the branch pipes is provided with thin-walled sealing members arranged with a spaced relation to each other. The insulating coupling is mounted in the split coupling. The spaces between the split coupling and branch pipes receive the reinforced dielectric material.

EFFECT: enhanced reliability.

2 cl, 2 dwg

FIELD: pipeline engineering.

SUBSTANCE: electrically insulating fitting comprises two metallic branch pipes and dielectric member which are interconnected through the threaded joint whose inter-thread space is filled with the glue composition. The flexible member is interposed between the face of the dielectric member and face surfaces of branch pipes for permitting control of the load in the thread to provide optimal gluing pressure.

EFFECT: enhanced reliability.

1 dwg

FIELD: pipe joints.

SUBSTANCE: joint comprises male member provided with thread turns that define the pitch of the load-bearing side, pitch of the stabilizing side, and nominal pitch. The female member has thread turns that engage the thread turns on the male member. The turns of the thread on the female member define the pitch of the load-bearing side, pitch of stabilizing side, and nominal pitch. At least one of the pitches of the load-bearing side and pitches of the stabilizing side on, at least, the female member or on the male member changes controllably from the specified distance from the end of the thread turns. The pitch of loading and pitch of stabilizing are different at least over a part of the thread length.

EFFECT: enhanced reliability.

44 cl, 26 dwg

Nondetachable joint // 2292490

FIELD: rocket-space engineering.

SUBSTANCE: nondetachable joint comprises end member made of bushing with shank at its one end and face ring groove at its other end and tubular member made of composition material glued in the groove of the end member. The end member is provided with axial slots from the side of the face ring groove to define pairs of tabs each of which has inner and outer tabs. The pairs of inner and outer tabs are tightened to corresponding surfaces of the tubular member by means the radial fastening members. The bend rigidity in the cross-sections of the inner and outer tabs may be the same. The tubular member may be provided with ends strengthened in radial direction.

EFFECT: enhanced reliability.

2 cl, 3 dwg

FIELD: mechanical engineering.

SUBSTANCE: joint comprises joining member made of a material with the shape memory effect. The end of one of the parts is provided with ring provided with a groove. The end of the other part is provided with the second ring having a projection. The projection is coated with a material with the shape memory effect. The thickness of the coating depends on the deformation to be recovered.

EFFECT: enhanced reliability.

1 cl, 1 dwg

FIELD: engines and pumps.

SUBSTANCE: elongated column assemble contains hollow pumping booms and jointing elements with an axle jointed together between the driving head arranged of the petroleum well surface and rotary pump arranged in the hole bottom. Every boom has, at least, one end with inner thread to mate the jointing element outer thread, e.g. a nipple. To optimise the strain distributions across the structural elements, the threads with various profiles are used, e.g. an asymmetric truncated cone and varying taper thread profiles. The collars to transmit torque have maximum possible mean diameter and cross-section to rule out accumulation of reactive torque in the column. A modified nipple has, preferably, a seal on its free end to reduce the risks of corrosion. A modified boom can have a number of orifices on each its end to increase flow of medium to forced out.

EFFECT: higher shear resistance, lower concentration of strains and lower accumulation of reactive torque.

34 cl, 35 dwg, 1 tbl

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