Horizontal wells, extendedreach wells, and multibranch wells were often used to exploit subsea oil and gas efficiently. However, during the sand control screen completion of those wells, the sand control screen pipe was easily deformed. Failure occurred when passing through the bending section due to the large bending section in the wellbore trajectory. A parametric analysis model of the screen pipe was established based on ABAQUS and Python software under pure bending load first. Then, deformation patterns and mechanisms were identified and discussed. The effects of parameters on the screen pipe bending deformation patterns and the ultimate moment were analyzed. Finally, an empirical formula for calculating the ultimate moment of the screen pipe was established. The results showed that the deformation of the screen pipe was complex, and three deformation patterns were related to the hole parameters. Due to an increase in the diameter and number of circumferential and axial holes, the ultimate moment of the screen pipe gradually decreased, and the circumferential holes had a more significant effect on the ultimate moment than the axial holes. The established empirical formula could accurately calculate the ultimate moment of the screen pipe, and the average difference between the formula and numerical simulation results was 3.25%.
Considering onshore oil and gas resource depletion, attention had been gradually focused on offshore oil exploration and development. However, sand production problems were often encountered during offshore and onshore unconsolidated sandstone reservoir development [
With the increase in oil and gas production and consequent economic benefits, horizontal wells, extended reach wells, and multibranch wells were often used onsite. Those well types could expand the exploitation scope of oil and gas wells without offshore platform restrictions. However, the well trajectories of those well types had a large, curved section [
The research activities on the ultimate bending moment of intact and corroded pipes under bending loads were relatively mature. The main research approaches include the finite element method, experimental tests, and analytical treatment. Compared with the previous research object, the structure of the screen pipe was more complex. The bending deformation mechanism of the screen pipe under bending load needed to be clarified, and the lack of a corresponding formula for calculating the ultimate bending moment of the screen pipe caused difficulties in evaluating the ultimate strength.
Chen et al. [
In the present work, a FEM of the bending deformation of a screen pipe under pure bending was established based on ABAQUS and Python script. The sand control screen pipe’s bending deformation patterns and mechanism were discussed in detail, and the influence of the screen pipe and hole arrangement parameters on the bending deformation and ultimate moment of the screen pipe were analyzed. Furthermore, an empirical formula for calculating the ultimate moment of the screen pipe under a bending load was established.
This study adopted the parallel hole arrangement in a perforated screen pipe. Because a screen pipe with a parallel hole arrangement was symmetrical, a 1/2 symmetrical model was used to simplify the calculation, as shown in
ABAQUS provided a secondary development interface [
The screen pipe’s bending deformation patterns and mechanism under bending load were currently unclear. Therefore, the bending deformation of the screen pipes with different screen parameters, as listed in
Numerous results of screen pipe deformation indicated that the deformation could be divided into three patterns: In pattern1, the screen pipe buckled from the middle position, and the hole area did not fracture. In pattern2, the screen pipe first buckled from the middle position, and plastic deformation occurred around the hole area, which eventually fractured as the bending load increased. In pattern3, plastic deformation occurred around the fractured hole area. However, the deformation around the middle of the screen pipe was small.
The three bending deformation patterns of screen pipes were discussed in detail as follows from different aspects, such as the relationship between the rotation angle and moment, ovality change laws at the middle section of the screen pipe and fracture section around the holes, and stress and strain laws at the middle position of the screen pipes and fracture position around the holes.
As the bending load increased, the screen pipe buckled from the middle position. However, the hole area did not fracture.
The deformation was most significant at the middle position of the screen pipe, which is the central area of concern. Therefore, the ovality, stress, and strain in the middle of the screen tube are discussed in detail here.
As the bending load increased, the screen pipe first exhibited overall bending deformation, and buckling deformation occurred at the middle position. In contrast, plastic deformation and fracture occurred around the hole area. The moment–rotation angle curve was divided into five stages, as shown in
Meanwhile, the deformations at the middle position and hole area were significant, the main areas of concern. Therefore, the ovality, stress, and strain at the middle position and the area around the hole are discussed in detail here.
The node stress and element strain at the middle position and the hole areas on the compression and tensile sides of the screen were discussed in detail here.
Comparing the stress and strain variations at the middle and hole positions of the tension and compression sides of the screen pipe, when
In this pattern, as the bending load increased, the screen pipe deformed and fractured at the hole position, whereas the middle position of the screen pipe did not buckle.
Meanwhile, the deformation at the middle position and the area around the hole was significant, which were the main areas of concern. Therefore, the ovality, stress, and strain at the middle position and area around the hole are discussed in detail.
The node stress and element strain at the middle position and the area around the hole on the compression and tension sides of the screen are discussed in detail here.
Comparing the element strain results at the middle position of the screen pipe and hole position, when
The deformation patterns of screen pipes were different under different hole distribution parameters. However, when the moment was less than the ultimate moment, the change law of the rotation anglemoment is similar under different deformation patterns according to the above analysis. The screen tube’s ultimate moment was the field’s main parameter of interest. Therefore, the influence of different hole and screen pipe parameters on the ultimate moment of the screen pipe was analyzed. The selection of the parameters is shown in
The parameters
The parament
The parament
The number of circumferential holes and
The number of axial holes and
A simplified calculation formula was established to simplify the calculation of the ultimate bending moment of the screen pipe under pure bending and facilitate its field application. It was assumed that the ultimate moment of the screen pipe was related to the ultimate moment of the complete casing before perforation and the hole arrangement parameters (
Through fitting with the numerical simulation data, the relationship between
Assuming that the F function in Equation (4) could be expanded into a power series, Equation (4) could be expressed as:
Considering that the ultimate moment of the screen pipe was less than that of the casing before perforation,
The numerical simulation results were used to fit Equation (6) and determine the parameter values in the formula. It was given by:
Due to the lack of literature results on the bending test of screen pipe, the eight groups of screen pipe finite element results shown in
The finite element model of a screen pipe with a parallel hole arrangement under pure bending was defined based on ABAQUS and Python script. The deformation patterns and ultimate moment of screen pipes with different parameters were analyzed. Three deformation patterns were identified and discussed in detail. An empirical formula of the ultimate moment of screen pipes was proposed. The main conclusions are summarized as follows:
(1) The deformation patterns of screen pipes could be divided into three categories under a bending load: In Pattern1, the screen pipes buckled from the middle position, and the area around the holes did not fracture. In Pattern2, the screen pipes first buckled from the middle position. As the bending load increased, plastic deformation appeared around the holes, and fracture occurred. In Pattern3, plastic deformation appeared around the hole area, and fracture occurred. However, the deformation around the middle of the screen pipes was small.
(2) The proposed empirical formula could accurately calculate the ultimate moment of screen pipe under bending load, and the average difference between the empirical formula and numerical simulation results was 3.25%.
(3) With an increase in the diameter and number of circumferential and axial holes, the ultimate moment of the screen pipe gradually decreased, and the circumferential holes had a more significant effect on the ultimate moment than the axial holes.
Numerical simulation model, Y.P. and G.F.; Python Script, Y.P.; Formal analysis, B.S. and S.F.E.; investigation, X.S.; data curation, J.C.; writing, Y.P.; review and editing, G.F.; supervision, B.S. and S.F.E.; funding acquisition, B.S. and S.F.E. All authors have read and agreed to the published version of the manuscript.
Not applicable.
Not applicable.
Not applicable.
The authors declare no conflict of interest.
Loads acting on the curved section of the screen pipe.
The FEM of screen pipe and boundary condition.
Mesh sensitivity analysis.
Material property of the sand control screen.
Secondary development process of FEM.
Moment versus rotation angle and stress contour of screen pipes.
(
The selected elements and nodes of screen pipe.
(
Moment versus rotation angle, and stress contour of screen pipes.
(
Selected elements and nodes.
(
(
Moment versus rotation angle and stress contour of screen pipes.
Ovality versus rotation angle at middle position and hole position of screen pipes.
(
(
The relationship between
Comparison of numerical simulation and formula calculation results.
Screen pipes parameter commonly used in the field.




17 
127.0 
7.52 
6.35 
4 
12 
1600.0 
Effect of
17 
127.0 
7.52 
6.35 
50.36 
125.30 
64.62 
Effect of



17 
127.0 
7.52 
8 
46.44 
121.72 
61.68 
Effect of D/t and circumferential holes on ultimate moment of screen pipes.



17 
127.0 
7.52 
4 
52.04 
127.26 
66.26 
Effect of diameter and axail holes number on ultimate moment of screen pipes.



16 
6.35 
125.86 
125.30 
123.90 
Effect of diameter and circumferential holes number on ultimate moment of screen pipes.



8 
6.35 
66.30 
64.78 
64.78 
Ultimate moment comparison between numerical and formula results.
CASE 


Error  

CASE1  127.0  7.52  12  20  52.63  14.00  36.28  37.17  2.46% 
CASE2  177.8  9.19  8  12  90.91  9.50  124.64  127.50  2.30% 
CASE3  152.6  6.46  12  20  52.63  12.70  54.90  53.40  −2.73% 
CASE4  127.0  7.52  4  12  90.91  9.50  52.04  54.95  5.58% 
CASE5  177.8  9.19  12  20  52.63  16.00  98.76  98.78  0.02% 
CASE6  152.6  6.46  16  16  66.67  6.35  64.78  61.90  −4.45% 
CASE7  152.6  6.46  16  16  66.67  19.00  26.68  28.32  6.16% 
CASE8  127.0  7.52  12  20  52.63  19.00  25.42  26.00  2.28% 