CN203925331U - The segment protect structure of contacting to earth of oil transportation standpipe - Google Patents

Abstract

The utility model discloses a kind of segment protect structure of contacting to earth of oil transportation standpipe; described oil transportation standpipe comprises the horizontal segment standpipe being connected with the oil-out of sub-sea drilled wells, the section of the dangling standpipe being connected with offshore boring island and the section of the contacting to earth standpipe between horizontal segment standpipe and the section of dangling standpipe, described in contact to earth segment protect structure comprise be located at the section of contacting to earth standpipe outside sleeve pipe, be located at the ringwise cavity of cross section between sleeve pipe and the section of contacting to earth standpipe and be positioned at the axial support spring that the section of contacting to earth standpipe is outside and contact with internal surface of casing.The utlity model has the application life of having improved the section of contacting to earth standpipe and whole oil transportation standpipe; Effectively suppress the sleeve pipe formation of vortex around, reduced ocean current to the washing away of the pipe end, and reduced the feature of the adverse effect of the groove that washes away formation to touchdown point.

Description

The protection structure of the ground contact section of the oil delivery riser

technical field

The utility model relates to the technical field of offshore oil and gas development, in particular to a standpipe used for isolating the ground-touching section riser and the seabed, reducing the wear rate of the ground-touching section standpipe, and effectively improving the service life of the ground-touching section standpipe and the entire oil delivery riser The ground protection structure of the oil riser.

Background technique

As the development of offshore oil and gas resources develops into the deep sea, as an important device connecting the drilling platform and the subsea wellhead, the riser system plays a more important role in deep sea development. The touchdown point of the oil delivery riser is the part where the riser first touches the seabed. With the movement of the riser, the contact position between the riser and the seabed soil will change continuously, forming a new touchdown point. The distance between the riser and the seabed soil The contact changes from a point to an area with a certain length, called a "touchdown riser".

Fatigue damage of riser is the main form of riser damage. The touch point of riser is affected by platform movement and environmental load at the same time. It is the most vulnerable part of riser to fatigue damage, which directly affects the service life of oil delivery riser .

At present, the oil delivery riser is usually in direct contact with the seabed soil and lacks sufficient protection, especially for the seabed with high rigidity, the fatigue damage at the contact point is very serious.

Chinese Patent Authorized Publication No.: CN00219373.6, authorized public date February 3, 2000, discloses a protective outer ring of an outer steel inner plastic oil pipe, which is composed of a plastic threaded inner liner and a steel plate outer layer, and the plastic threaded inner liner There are fixed inserts on the outer wall of the layer, and fixed sockets are arranged at corresponding positions on the steel plate outer layer, and the plastic thread liner and the steel plate outer layer are fixed by the inserts and the sockets. The disadvantage of this utility model is that it has a single function and cannot be used to protect the ground contact riser of the oil delivery riser.

Contents of the invention

The purpose of the invention of the utility model is to overcome the serious wear and tear of the ground-touching section riser of the oil delivery riser in the prior art, and provide a method for isolating the ground-touching section riser and the seabed, reducing the wear rate of the ground-touching section riser , the ground protection structure of the oil delivery riser that effectively improves the service life of the touchdown section riser and the entire oil delivery riser.

In order to achieve the above object, the utility model adopts the following technical solutions:

A protection structure for the touchdown section of an oil delivery riser, the oil delivery riser includes a horizontal section riser connected to the oil outlet of a subsea oil well, a suspension section riser connected with a drilling platform, and a horizontal section riser and the grounding section riser between the suspension section riser; the grounding section protection structure includes a casing arranged outside the grounding section riser, and a cavity with an annular cross section between the casing and the grounding section riser and an axial support spring located outside the standpipe of the ground contact section and in contact with the inner surface of the sleeve; there are several radial spring groups distributed along the axial direction of the standpipe of the ground contact section between the casing and the standpipe of the ground contact section, each The radial spring group includes several radial springs distributed radially, and the two ends of the radial springs are respectively connected with the standpipe and the bushing of the ground-contacting section.

The bushing of the utility model is used to protect the standpipe of the ground contact section, avoid direct contact between the standpipe of the contact section and the seabed soil, provide space for the support spring and the radial spring group, and connect the standpipe of the contact section with the external water body and the seabed soil Separated to form a space to protect the riser of the touchdown section.

The support spring provides a certain pre-tension for the ground contact riser, which increases the stiffness of the ground contact riser to reduce fatigue damage; at the same time, the movement of the drilling platform structure will form a vertical tension on the contact point, making the contact point bend When the stress reaches the peak value, the tension can be evenly transmitted to the standpipe of the ground contact section through the axially extending support spring, so as to reduce the damage to the standpipe of the ground contact section caused by instantaneous excessive stress.

The radial spring group arranged along the length direction of the standpipe, on the one hand, reduces the movement range of the standpipe in the radial direction, prevents the collision and damage of the standpipe and casing in the ground contact section, and on the other hand forms a "three-dimensional seabed" with a certain rigidity , the riser of the touchdown section is no longer in direct contact with the seabed soil, and the radial spring forms a "flexible seabed", and the fatigue damage of the seabed to the "touchdown point" of the touchdown section riser will be greatly reduced.

Therefore, the utility model avoids the direct contact between the oil delivery riser and the seabed soil, improves the service life of the ground contact riser and the entire oil delivery riser; the utility model has the characteristics of simple structure, easy modification and installation, and low cost.

As a preference, the tube wall of the sleeve is provided with several staggered accommodation chambers, the accommodation chambers are perpendicular to the outer peripheral surface of the sleeve; the housing chamber is provided with tube wall springs and balls, and the outer ends of the tube wall springs are in contact with the balls ; One end of the ball is exposed outside the outer peripheral surface of the casing.

The arrangement of the accommodation chamber, the pipe wall spring and the ball makes the frictional movement of the casing on the seabed into a rolling movement, further reducing the stress applied to the riser of the ground contact section.

Preferably, several spiral strakes arranged at intervals are provided on the outer peripheral surface of the casing.

The spiral strake has the effect of disturbing the water flow acting on the casing, making it difficult to form a vortex around the casing, reducing the vortex-induced vibration of the casing, and at the same time inhibiting the formation of the vortex, reducing the scouring of the bottoming area, and reducing the formation of the scouring groove The adverse effect of the groove on the contact point of the riser increases the service life of the standpipe at the contact point and the entire oil delivery riser.

Preferably, the number of radial springs in the radial spring group is 4 to 8, and the radial springs are evenly distributed along the circumferential direction of the cross section of the riser of the ground contact section.

Preferably, the bushing includes trumpet-shaped pipes arranged at both ends of the bushing, and the trumpet-shaped pipe is connected with the standpipe of the contact section through a flange.

Preferably, each radial spring group is connected to the standpipe of the ground contact section through a standpipe ring arranged on the outer peripheral surface of the standpipe of the ground contact section, and connected to the casing through a sleeve collar arranged on the inner peripheral surface of the casing .

Therefore, the utility model has the following beneficial effects: the direct contact between the oil delivery riser and the seabed soil is avoided, the service life of the ground contact riser and the entire oil delivery riser is improved; the vortex around the casing is effectively suppressed The formation reduces the erosion of the bottom of the pipe by the sea current, and reduces the adverse effect of the groove formed by the erosion on the contact point; the structure is simple, easy to transform, and the cost is low.

Description of drawings

Fig. 1 is a kind of structural representation of the oil delivery riser of the present utility model in use state;

Fig. 2 is a kind of structural representation of the protection structure of the ground contact section of the utility model;

Fig. 3 is another structural schematic diagram of the protection structure of the ground contact section of the present utility model;

Fig. 4 is a structural schematic view of the tube wall, accommodating cavity, tube wall spring and ball of the sleeve of the present invention.

In the figure: horizontal section riser 1, suspension section riser 2, ground contact section riser 3, casing 4, cavity 5, support spring 6, radial spring group 7, radial spring 8, accommodation chamber 9, pipe wall Spring 10, ball 11, trumpet 12, riser collar 13, sea surface 14, seabed 15, drilling platform 16, flange 17, casing collar 18.

Detailed ways

Below in conjunction with accompanying drawing and specific embodiment, the utility model is further described.

The embodiment shown in Figure 1 is a protection structure for the touchdown section of an oil delivery riser, which includes a horizontal section riser 1 connected to the oil outlet of a subsea oil well, connected to a drilling platform 16 The suspension section riser 2 and the ground contact section riser 3 between the horizontal section riser and the suspension section riser; the drilling platform is located on the sea surface 14, and the horizontal section riser is located on the seabed 15;

As shown in Figure 2, the ground protection structure includes a sleeve 4 arranged outside the ground riser, a cavity 5 with an annular cross section between the sleeve and the ground riser, and a cavity 5 located outside the ground riser. And the axial support spring 6 that is in contact with the inner surface of the casing; the radial spring group 7 distributed along the axial direction of the ground-contacting section riser is arranged between the casing and the ground-contacting section standpipe, and each radial spring group includes 4 The radial springs 8 are radially distributed, and the two ends of the radial springs are respectively connected with the standpipe and the bushing of the ground-contacting section. Three spaced spiral strakes are arranged on the outer peripheral surface of the casing.

As shown in Figure 4, the tube wall of the sleeve is provided with staggered accommodation chambers 9, the accommodation chambers are perpendicular to the outer peripheral surface of the sleeve; the housing chamber is provided with tube wall springs 10 and balls 11, and the outer ends of the tube wall springs are in contact with the balls. Contact; one end of the ball is exposed outside the outer peripheral surface of the casing.

As shown in FIG. 3 , the number of radial springs in the radial spring group is four, and the radial springs are evenly distributed along the circumferential direction of the cross section of the riser of the ground contact section. The bushing includes trumpet-shaped pipes 12 arranged at both ends of the bushing, and the trumpet-shaped pipe is connected with the standpipe of the contacting section through a flange 17 .

As shown in Figure 2 and Figure 3, the radial spring group is connected with the standpipe of the ground contact section through the standpipe collar 13 arranged on the outer peripheral surface of the standpipe of the ground contact section, and through the casing collar arranged on the inner peripheral surface of the casing 18 is connected with sleeve pipe.

The setting of the bushing avoids the direct contact between the riser of the ground contact section and the seabed soil, and provides space for the supporting spring and radial spring group, and separates the stand pipe of the contact section from the external water body and the seabed soil, forming a protective contact section Riser space.

The support spring provides a certain pre-tension for the ground contact riser, which increases the stiffness of the ground contact riser to reduce fatigue damage; at the same time, the movement of the drilling platform structure will form a vertical tension on the contact point, making the contact point bend When the stress reaches the peak value, the tension can be evenly transmitted to the standpipe of the ground contact section through the axially extending support spring, so as to reduce the damage to the standpipe of the ground contact section caused by instantaneous excessive stress.

The radial spring group arranged along the length direction of the standpipe, on the one hand, reduces the movement range of the standpipe in the radial direction, prevents the collision and damage of the standpipe and casing in the ground contact section, and on the other hand forms a "three-dimensional seabed" with a certain rigidity , the riser of the touchdown section is no longer in direct contact with the seabed soil, and the radial spring forms a "flexible seabed", and the fatigue damage of the seabed to the "touchdown point" of the touchdown section riser will be greatly reduced.

Therefore, the utility model has the following beneficial effects: the direct contact between the oil delivery riser and the seabed soil is avoided, the service life of the ground contact riser and the entire oil delivery riser is improved; the vortex around the casing is effectively suppressed The formation reduces the erosion of the bottom of the pipe by the sea current, and reduces the adverse effect of the groove formed by the erosion on the contact point; the structure is simple, easy to transform, and the cost is low.

It should be understood that this embodiment is only used to illustrate the utility model but not to limit the scope of the utility model. In addition, it should be understood that after reading the content taught by the utility model, those skilled in the art can make various changes or modifications to the utility model, and these equivalent forms also fall within the scope defined by the appended claims of the application.

Claims (6)

1. the segment protect structure of contacting to earth of oil transportation standpipe, described oil transportation standpipe comprises the horizontal segment standpipe (1) being connected with the oil-out of sub-sea drilled wells, the section of the dangling standpipe (2) being connected with offshore boring island (16) and the section of the contacting to earth standpipe (3) between horizontal segment standpipe and the section of dangling standpipe; It is characterized in that, described in contact to earth segment protect structure comprise be located at the section of contacting to earth standpipe outside sleeve pipe (4), be located at the ringwise cavity of cross section (5) between sleeve pipe and the section of contacting to earth standpipe and be positioned at the axial support spring (6) that the section of contacting to earth standpipe is outside and contact with internal surface of casing; Between sleeve pipe and the section of contacting to earth standpipe, be provided with several radial spring groups (7) along the axial distribution of the section of contacting to earth standpipe, each radial spring group comprises several radial springs distributing radially (8), and radial spring two ends are connected with sleeve pipe with the section of contacting to earth standpipe respectively.

2. the segment protect structure of contacting to earth of oil transportation standpipe according to claim 1, is characterized in that, the tube wall of described sleeve pipe is provided with several staggered container cavities (9), and container cavity is perpendicular to sleeve pipe outer peripheral face; In container cavity, be provided with tube wall spring (10) and ball (11), tube wall spring outer end contacts with ball; Expose outside sleeve pipe outer peripheral face ball one end.

3. the segment protect structure of contacting to earth of oil transportation standpipe according to claim 1, is characterized in that, the outer peripheral face of described sleeve pipe is provided with the spiral strake that some block gaps arrange.

4. the segment protect structure of contacting to earth of oil transportation standpipe according to claim 1, is characterized in that, the quantity of the radial spring in described radial spring group is 4 to 8, and radial spring is uniformly distributed along the circumferencial direction of the cross section of the section of contacting to earth standpipe.

5. the segment protect structure of contacting to earth of oil transportation standpipe according to claim 1, is characterized in that, described sleeve pipe comprises the flaring pipe (12) of being located at sleeve pipe two ends, and flaring pipe is connected with the section of contacting to earth standpipe by flange (17).

6. according to the segment protect structure of contacting to earth of the oil transportation standpipe described in claim 1 or 2 or 3 or 4 or 5; it is characterized in that; each radial spring group is connected with the section of contacting to earth standpipe by the standpipe collar (13) of being located on the section of contacting to earth standpipe outer peripheral face, is connected with sleeve pipe by the sleeve pipe collar (18) of being located on sleeve pipe inner peripheral surface.