Bypass multi-point injection type gravel filling screen pipe

Abstract

The invention relates to a bypass multi-point jet type gravel filling screen pipe which comprises a base pipe, a plurality of filter sand filling units arranged outside the base pipe in a sleeving mode and sand blasting rings arranged among the filter sand filling units, and each filter sand filling unit comprises a bypass pipe used for conveying mortar. And the sand blasting ring is constructed to enable the two adjacent bypass pipes to be communicated with each other and enable the two adjacent bypass pipes to be communicated with the annular space outside the screen pipe, so that mortar conveyed in the bypass pipes is shunted at the sand blasting ring. The sand blasting ring is used for filling the annular space outside the screen pipe, and the bypass pipe is completely used for conveying mortar, so that the overflowing section of the bypass pipe is completely utilized, and the conveying capacity of the bypass pipe is effectively improved. When construction enters a mortar bypass conveying stage, circulating pressure drop of mortar is stable due to the fact that the conveying capacity of the bypass pipe is high. Therefore, the mortar flow does not need to be properly reduced, the construction time is shortened, and the pollution of liquid components in the mortar to the stratum is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of oil extraction, in particular to a bypass multi-point injection type gravel packing screen pipe. Background Art

[0002] Gravel packing is a commonly used sand control method in horizontal wells. A filling tool is used to force slurry into the annulus (the annular space outside the screen) of the screen. The solid components in the slurry are trapped outside the screen, while the liquid components enter the screen. The screen blocks the solid components, which in turn blocks the formation sand, ultimately achieving sand control.

[0003] The Chinese invention patent with publication number CN110593825A provides an erosion-resistant filling bypass screen for oil field development, which is integrated with five bypass pipes, and at least two of the five bypass pipes are provided with one or more filling channels. By screwing the upper joint and the lower joint, multiple screens can be used in series, and the bypass pipes of each screen can be connected. At the beginning of construction, the outer annulus of the screen in the upper well section of the bridge plug (or desanding point) is first filled. Then the mortar bypass transportation stage begins, at which time the bypass pipe guides the mortar over the bridge plug (or desanding point) and continues to transport it to the front, thereby eliminating the filling deficit area and effectively improving the circulation filling efficiency.

[0004] The above patent has many limitations in actual use. First, at least two bypass pipes are provided with more than one filling channel, resulting in low utilization of the flow cross-section of the bypass pipe and limited mortar conveying capacity of the bypass pipe. Secondly, although the five bypass pipes can ensure the overall conveying capacity of the mortar, due to the limitation of the size of the screen pipe, the five bypass pipes have the problem of excessively blocking the filtering surface of the screen pipe. Finally, since the main body of the screen pipe is independent of each other and the mortar in the bypass pipe is only collected at the end of the screen pipe, it is easy to cause uneven distribution of mortar flow in each bypass pipe. Moreover, when the construction enters the mortar bypass conveying stage, the circulation pressure drop of the mortar increases significantly because the flow cross-section of the bypass pipe is smaller than the annular cross-section outside the screen pipe. In order to avoid fracturing the reservoir and channeling the water layer, the mortar flow must be appropriately reduced, which leads to excessively long construction time and aggravates the contamination of the formation by the liquid components in the mortar. Summary of the Invention

[0005] Based on the above-mentioned problems existing in the prior art, the present invention provides a bypass multi-point injection gravel packing screen pipe with a larger flow cross-section, strong mortar conveying capacity and anti-clogging ability, which can avoid the construction time of the gravel packing bypass conveying stage being too long and effectively reduce formation pollution.

[0006] The technical solution adopted by the present invention to solve the technical problem is: to provide a gravel pack screen, comprising a base pipe, a plurality of filter sand filling units sleeved outside the base pipe, and a sand blasting ring arranged between two adjacent filter sand filling units, each of the filter sand filling units including a bypass pipe for conveying mortar,

[0007] The sandblasting ring is configured to enable the bypass pipes to communicate with each other and to connect the bypass pipes with the annular space outside the screen pipe, so that the slurry transported in the bypass pipes of the upstream sand filter filling unit can be diverted at the sandblasting ring, resulting in a portion of the slurry flowing into the annular space and another portion of the slurry entering the bypass pipes of the downstream sand filter filling unit.

[0008] Furthermore, the sandblasting ring includes a first limiting portion, a second limiting portion arranged outside the first limiting portion, and a connecting portion arranged between the first limiting portion and the second limiting portion, the connecting portion is provided with a fourth through hole connecting two adjacent bypass pipes and extending axially, and the second limiting portion is provided with a fifth through hole connecting the fourth through hole and the annular space outside the screen pipe and extending radially.

[0009] Furthermore, the first limiting portion and the second limiting portion define receiving grooves at both side end surfaces of the connecting portion that can be plugged into the ends of the sand filter filling units, so that the sandblasting ring can be installed between two adjacent sand filter filling units.

[0010] Furthermore, an annular flow channel connected to the fourth through hole is provided in the connecting portion, and the flow channel is configured to converge the mortar in each of the bypass pipes located upstream of the sandblasting ring to distribute the mortar to the fifth through hole and each of the bypass pipes located downstream of the sandblasting ring.

[0011] Furthermore, the sand filter filling unit also includes a sand filter net arranged outside the base pipe, a first protective tube arranged outside the sand filter net and used to protect the sand filter net, and a second protective tube for protecting the screen pipe. The sand filter filling unit is configured to allow the liquid component in the mortar to pass through the second protective tube and several sixth through holes on the first protective tube, the sand filter net, and several third through holes on the base pipe in sequence into the base pipe.

[0012] Furthermore, the sand filter filling unit also includes a support frame arranged between the first protective tube and the second protective tube, and the support frame is configured to radially support the first protective tube and the second protective tube so that the first protective tube and the second protective tube always remain coaxial, and the support frame is also configured to circumferentially support at least two of the bypass tubes so that the bypass tubes are always connected to the fourth through hole.

[0013] Furthermore, the support frame includes several axially extending connecting rods and several support plates arranged axially along the connecting rods. The side of the support plate close to the bypass pipe is provided with a concave surface that can abut against the bypass pipe, and the inner surface of the support plate is provided with a connecting groove so that the liquid component in the mortar can flow axially through the support plate.

[0014] Furthermore, the screen pipe further comprises an upper connecting assembly connected to the upper end of the base pipe and a lower connecting assembly connected to the lower end of the base pipe. The upper connecting assembly and the lower connecting assembly are configured to be interconnected and to allow the bypass pipes of two adjacent screen pipes to be fluidically connected.

[0015] Furthermore, the upper connecting assembly includes a coupling for connecting the lower connecting assembly, an upper joint connected to the upper end of the base pipe, and an upper ring sleeve connected to the upper joint and the first sand filter filling unit. The outer diameter of the first conveying part of the upper joint is smaller than the inner diameter of the upper ring sleeve, so that a first channel for mortar circulation is formed between the upper ring sleeve and the upper joint.

[0016] Furthermore, a radially extending first through hole is provided on the first conveying part, and an axially extending second through hole is provided on the first boss of the first conveying part. The first channel connects the first through hole and the second through hole, so that the slurry from the upstream adjacent screen pipe can flow from the first through hole through the first channel and the second through hole in sequence into the bypass pipe of the first filter sand filling unit.

[0017] Furthermore, the lower connecting assembly includes a central cannula connected to the lower end of the base pipe, a lower joint connected to the central cannula, and a lower ring sleeve connected to the lower joint and the last of the sand filter filling units. The outer diameter of the second conveying part of the lower joint is smaller than the inner diameter of the lower ring sleeve, so that a fourth channel for mortar circulation is formed between the lower ring sleeve and the lower joint.

[0018] Furthermore, a seventh through hole extending axially is provided on the second boss of the second conveying part, and an eighth through hole extending radially is also provided on the second conveying part. The fourth channel connects the seventh through hole and the eighth through hole, so that the mortar in the bypass pipe of the last sand filter filling unit can flow from the seventh through hole through the fourth channel and the eighth through hole in sequence into the downstream adjacent screen pipe.

[0019] Furthermore, the central cannula is configured to be inserted into the upper joint and to form a second channel and a third channel that are interconnected with the upper joint and the lower joint, respectively, so that when two adjacent sieve tubes are connected, the eighth through hole of the upstream sieve tube and the first through hole of the downstream sieve tube are connected through the second channel and the third channel.

[0020] Beneficial Effects of the Present Invention: The bypass multi-point injection gravel pack screen provided by the present invention has at least the following benefits. First, the sandblasting ring is used to fill the annular space outside the screen, while the bypass pipe is entirely used to transport slurry. This fully utilizes the bypass pipe's flow cross-section and effectively improves the bypass pipe's conveying capacity. Furthermore, due to this effective improvement in the bypass pipe's conveying capacity, even if the screen pipe's size is limited, the bypass pipe will not excessively obstruct the screen's filtering surface.

[0021] Secondly, the mortar in the bypass pipes is collected at the sandblasting ring, which makes the mortar flow in each bypass pipe evenly distributed, thus effectively improving the conveying efficiency of the bypass pipes. If a bypass pipe is blocked, the mortar can be sandblasted around the blocked bypass pipe and then conveyed forward through other unblocked bypass pipes.

[0022] Finally, when construction entered the mortar bypass delivery phase, the bypass pipe's high delivery capacity kept the mortar circulation pressure drop relatively stable. Therefore, there was no need to reduce the mortar flow rate, thus shortening construction time and reducing contamination of the mortar's liquid components to the formation. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention will be further described below with reference to the accompanying drawings and examples.

[0024] Figure 1 Shown is a structural cross-sectional view of a bypass multi-point injection gravel packing screen.

[0025] Figure 2 Shown Figure 1 Cross-sectional view of the AA section of the mid-bypass multi-point injection gravel pack screen.

[0026] Figure 3 Shown is a structural cross-sectional view of the coupling.

[0027] Figure 4 Shown is a structural cross-sectional view of the upper joint.

[0028] Figure 5 Shown is a structural cross-sectional view of the upper ring sleeve.

[0029] Figure 6 Shown is a structural cross-sectional view of the base pipe.

[0030] Figure 7 Shown is a cross-sectional view of the structure of the sandblasting ring.

[0031] Figure 8 Shown is a structural cross-sectional view of a filter sand filling unit.

[0032] Figure 9 Shown is a schematic structural diagram of the support frame.

[0033] Figure 10 Shown is a schematic diagram of the flow of mortar between the filter sand filling units (arrows indicate the flow direction of the mortar).

[0034] Figure 11 Shown is a cross-sectional view of the structure of the central cannula.

[0035] Figure 12 Shown is a cross-sectional view of the lower joint structure

[0036] Figure 13 Shown is a structural cross-sectional view of the lower ring sleeve.

[0037] Figure 14 Shown is a schematic diagram of the flow of mortar between the screen pipes (arrows indicate the flow direction of the mortar).

[0038] In the figures, reference numerals are as follows: 100, screen pipe; 10, upper connecting assembly; 11, coupling; 111, first thread; 112, second thread; 12, upper joint; 121, first connecting portion; 122, first conveying portion; 123, third thread; 124, fourth thread; 125, fifth thread; 126, first through hole; 127, first boss; 128, second through hole; 129, sealing groove; 1291, sealing ring; 13, upper ring; 131, sixth thread; 132, groove;

[0039] 20. Base pipe; 21. Seventh thread; 22. Eighth thread; 23. Third through hole;

[0040] 30. Sandblasting ring; 31. First limiting portion; 32. Connecting portion; 321. Fourth through hole; 322. Flow channel; 33. Second limiting portion; 331. Fifth through hole; 34. Receiving groove;

[0041] 40. Sand filter filling unit; 41. Sand filter screen; 42. First protective tube; 421. Sixth through hole; 43. Bypass tube; 44. Support frame; 441. Connecting rod; 442. Support plate; 4421. Concave surface; 4422. Connecting groove; 45. Second protective tube;

[0042] 50. Lower connecting assembly; 51. Central cannula; 511. Ninth thread; 52. Lower connector; 521. Second delivery portion; 5211. Second boss; 5212. Seventh through hole; 5213. Eighth through hole; 5214. Stabilizing nail hole; 522. Second connecting portion; 5221. Tenth thread; 5222. Eleventh thread; 523. Stabilizing nail; 53. Lower collar; 531. Twelfth thread;

[0043] 61, first channel; 62, second channel; 63, third channel; 64, fourth channel. DETAILED DESCRIPTION

[0044] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention clearer, the present invention is now described in detail with reference to the accompanying drawings. This figure is a simplified schematic diagram, which only illustrates the basic structure of the present invention in a schematic manner, and therefore only shows the components related to the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0045] It should be noted that the directional terms or qualifiers "upper" and "lower" used in this application are all directed to the referenced Figure 1 As used herein, the directional terms "inward" refer to a direction closer to the central axis of the gravel pack screen, and "outward" refer to a direction away from the central axis of the gravel pack screen. "Upstream" refers to a direction closer to the upper connecting assembly, and "downstream" refers to a direction closer to the lower connecting assembly. "Axial" refers to a direction parallel to the axis of the gravel pack screen, and "radial" refers to a direction parallel to the diameter of the gravel pack screen.

[0046] refer to Figure 1 and Figure 2As shown, a bypass multi-point injection gravel pack screen 100 provided by the present invention includes a base pipe 20, an upper connecting assembly 10 mounted on the upper end of the base pipe 20, a plurality of sand filter filling units 40 sleeved on the outside of the base pipe 20, a sand blasting ring 30 disposed between the plurality of sand filter filling units 40, and a lower connecting assembly 50 mounted on the lower end of the base pipe 20. The upper connecting assembly 10 is used to connect to a sand supply device (not shown) or the lower connecting assembly 50 of another screen pipe 100. Through the upper connecting assembly 10, slurry in the sand supply device or another screen pipe 100 can be transported to a bypass pipe 43 within the sand filter filling unit 40. After being transported through the bypass pipe 43, the slurry can be sprayed out by the sand blasting rings 30 between the plurality of sand filter filling units 40. The sprayed mortar is filtered by the filter sand filling unit 40, and the liquid components in the mortar re-enter the base pipe 20, while the solid components in the mortar remain in the annular space outside the screen pipe 100, thereby filling the annular space outside the screen pipe 100. The lower connecting assembly 50 can be used to install a plug (not shown) or to connect to the upper connecting assembly 10 of another screen pipe 100.

[0047] refer to Figure 1 and Figure 3-5 As shown, the upper connection assembly 10 includes a coupling 11 for connecting to the lower connection assembly 50 of a sand supply device or another screen pipe 100, an upper joint 12 connected to the coupling 11, and an upper ring 13 that is sleeved over the upper joint 12 and the first sand filter filling unit 40. The coupling 11 is a hollow cylindrical structure with both ends open. The coupling 11 is provided with a first thread 111 for connecting to the lower connection assembly 50 of a sand supply device or another screen pipe 100, and a second thread 112 for connecting to the upper joint 12. The first thread 111 is provided on the inner wall of the upper end of the coupling 11, and the second thread 112 is provided on the inner wall of the lower end of the coupling 11. In other embodiments not shown, the connection between the coupling 11 and the sand supply device can also be a snap-on or bolted connection, and the connection between the coupling 11 and the upper joint 12 can also be a snap-on or bolted connection.

[0048] Combine Figure 1 and Figure 4As shown, in some embodiments, the upper joint 12 is generally a hollow cylindrical structure with both ends open. The upper joint 12 includes a first connecting portion 121 and a first conveying portion 122 located below the first connecting portion 121. The first connecting portion 121 is provided with a third thread 123 for threaded connection with the second thread 112 and a fourth thread 124 for connecting to the upper ring 13. The end of the first conveying portion 122 close to the first connecting portion 121 is provided with a plurality of first through holes 126 penetrating the side wall of the upper joint 12. The plurality of first through holes 126 are evenly arranged along the circumference of the upper joint 12. The inner wall of the end of the first conveying portion 122 away from the first connecting portion 121 is provided with a fifth thread 125 for connecting to the base pipe 20. The outer wall of the end of the first conveying portion 122 away from the first connecting portion 121 is provided with a first boss 127, which extends radially outward from the upper joint 12. At least two second through holes 128 are evenly arranged on the first boss 127 along its circumference. The second through holes 128 penetrate the first boss 127 along the axial direction of the upper joint 12 .

[0049] refer to Figure 5 As shown, in some embodiments, the upper inner wall of the upper collar 13 is provided with a sixth thread 131 for threaded engagement with the fourth thread 124, and the lower inner wall of the upper collar 13 is provided with a groove 132 corresponding to the first boss 127. The inner diameter of the groove 132 is the same as the outer diameter of the first boss 127, so that the groove wall of the groove 132 can slide with the circumferential side wall of the first boss 127. The groove surface of the groove 132 can also abut against the surface of the first boss 127, ensuring that the upper collar 13 and the upper joint 12 are properly installed.

[0050] Combine Figure 1 and Figure 14 As shown, when the upper connection assembly 10 is in the assembled state, the coupling 11 is connected to the lower connection assembly 50 of the sand supply device or another screen pipe 100 through the first thread 111. The coupling 11 is connected to the upper joint 12 by screwing together the second thread 112 and the third thread 123. The upper joint 12 is connected to the upper collar 13 by screwing together the fourth thread 124 and the sixth thread 131. Since the inner diameter of the upper collar 13 is larger than the outer diameter of the first conveying portion 122 of the upper joint 12, a first channel 61 for connecting the first through hole 126 and the second through hole 128 is formed between the upper collar 13 and the first conveying portion 122 of the upper joint 12. The slurry conveyed by the sand supply device can pass through the first through hole 126, the first channel 61 and the second through hole 128 in sequence and enter the bypass pipe 43 in the filter sand filling unit 40.

[0051] Recombination Figure 1 and Figure 4As shown, in some embodiments, a sealing groove 129 is further defined on the inner wall of the first conveying portion 122 of the upper connector 12, with a sealing ring 1291 disposed within the sealing groove 129. The sealing ring 1291 seals the sand supply device and the lower end of the first conveying portion 122 of the upper connector 12, preventing the liquid components of the refluxed mortar from mixing with the mortar conveyed by the sand supply device. The sealing ring 1291 also seals the lower connecting assembly 50 of another screen pipe 100 to the upper connector 12, preventing the liquid components of the refluxed mortar from mixing with the mortar conveyed by the other screen pipe 100.

[0052] Combine Figure 6 As shown, in some embodiments, the upper end of the base tube 20 is provided with a seventh thread 21 for threaded engagement with the fifth thread 125 on the inner wall of the first delivery portion 122. The lower end of the base tube 20 is provided with an eighth thread 22 for connection to the lower connection assembly 50. The sidewall of the base tube 20 is also provided with a plurality of third through holes 23 for passage of liquid components. In some embodiments, the base tube 20 may be a split or integral structure depending on actual production or manufacturing requirements.

[0053] refer to Figure 7 As shown, in some embodiments, the longitudinal cross-section of the sandblasting ring 30 is generally I-shaped. The sandblasting ring 30 includes a first stopper 31 located near the base pipe 20, a second stopper 33 located away from the base pipe 20, and a connecting portion 32 disposed between the first stopper 31 and the second stopper 33. The connecting portion 32 defines a fourth through-hole 321 for inserting a bypass pipe 43. A fifth through-hole 331 is defined on the circumferential sidewall of the second stopper 33, extending radially along the sandblasting ring 30. The fifth through-hole 331 connects to the fourth through-hole 321. Because both ends of the first and second stopper 31, 33 are higher than the end surface of the connecting portion 32, a receiving groove 34 is formed between the first and second stopper 31, 33, and connecting portion 32 to accommodate the ends of adjacent sand filter filling units 40, thereby improving the stability of the connection between the sand filter filling units 40 and the sandblasting ring 30.

[0054] In some embodiments, an annular flow channel 322 is further provided within the connecting portion 32. The flow channel 322 connects all fourth through-holes 321, thereby connecting all bypass pipes 43 on both sides of the sandblasting ring 30. The fifth through-hole 331 can be directly connected to the fourth through-hole 321, or indirectly connected to the fourth through-hole 321 via the flow channel 322. Because the sandblasting ring 30 connects to all bypass pipes 43 located upstream and downstream of the sandblasting ring 30 via the fourth through-holes 321 and the flow channel 322, slurry transported in the bypass pipe 43 located upstream of the sandblasting ring 30 can be promptly and evenly distributed to the bypass pipes 43 located downstream of the sandblasting ring 30 via the fourth through-holes 321 and the flow channel 322, thereby effectively improving the transport efficiency of the bypass pipes 43. If a bypass pipe 43 becomes clogged, the slurry can bypass the clogged bypass pipe 43 through the sandblasting ring 30 and continue to be transported forward through the remaining unblocked bypass pipes 43.

[0055] In other embodiments not shown, the fourth through hole 321 and the fifth through hole 331 are arranged 90 degrees apart in the circumferential direction of the sandblasting ring 30. When the screen 100 is lowered into the horizontal wellbore, impurities such as mud cake or rock debris adhering to the wellbore wall can be prevented from directly entering the bypass pipe 43 through the fifth through hole 331 and the fourth through hole 321, thereby preventing the bypass pipe 43 from being blocked.

[0056] refer to Figure 8 As shown, the sand filter filling unit 40 includes a sand filter screen 41 sleeved over the base pipe 20, a first protective tube 42 disposed outside the sand filter screen 41, a bypass pipe 43 and a support frame 44 disposed outside the first protective tube 42, and a second protective tube 45 disposed on the side of the bypass pipe 43 and support frame 44 away from the first protective tube 42. Slurry delivered by a sand supply device or another screen pipe 100 passes sequentially through the first through-hole 126, the first channel 61, and the second through-hole 128 into the bypass pipe 43 within the sand filter filling unit 40. A portion of the slurry passes through the fourth through-hole 321 of the sand blasting ring 30 and is ejected through the fifth through-hole 331. Another portion of the slurry passes through the fourth through-hole 321 and flow channel 322 of the sand blasting ring 30 and enters the bypass pipe 43 within the adjacent sand filter filling unit 40. The ejected slurry is filtered by the sand filter screen 41 within the sand filter filling unit 40, and the solid components in the slurry fill the annular space outside the screen pipe 100. The liquid components in the mortar then pass through the second protective tube 45, the first protective tube 42, and the sand filter 41, into the base pipe 20, and then flow back for reuse. This not only fills the annular space outside the screen 100, achieving the purpose of sand control, but also prevents a large amount of liquid components in the mortar from entering the formation, thereby preventing formation contamination.

[0057] In some embodiments, the sand filter 41 is a cylindrical body made of a material having a filtering function, and the circumferential sidewalls of the sand filter 41 serve as filtering surfaces. When the sand filter 41 is mounted on the base pipe 20, the upper end surface of the sand filter 41 can abut against the lower end surface of the upper joint 12 or the lower end surface of the first stopper 31 of the sandblasting ring 30. The lower end surface of the sand filter 41 can also abut against the upper end surface of the lower connecting assembly 50 or the upper end surface of the first stopper 31 of another adjacent sandblasting ring 30.

[0058] In some embodiments, the circumferential sidewalls of the first and second protective tubes 42 and 45 are each provided with a plurality of sixth through-holes 421 for passage of liquid components. Both the first and second protective tubes 42 and 45 are preferably made of a hard material, such as ferrous metal or an iron alloy, so that they can protect the sand filter 41 and the entire screen 100, respectively. It will be appreciated that by controlling the size of the sixth through-holes 421 relative to the size of the solid components in the mortar, the first and second protective tubes 42 and 45 can provide a preliminary filtration of the mortar. When installed on the screen 100, the upper end surfaces of the first and second protective tubes 42 and 45 can abut against the lower end surface of the first boss 127 or the lower end surface of the connecting portion 32 of the sandblasting ring 30. Alternatively, the lower end surfaces of the first and second protective tubes 42 and 45 can abut against the upper end surface of the lower connecting assembly 50 or the upper end surface of the connecting portion 32 of another adjacent sandblasting ring 30. That is, the upper ends or lower ends of the first protection tube 42 and the second protection tube 45 can be inserted into the receiving groove 34 of the adjacent sandblasting ring 30 , thereby improving the stability of the connection between the sand filter filling unit 40 and the sandblasting ring 30 .

[0059] Recombination Figure 8 As shown, in some embodiments, the bypass tube 43 has a waist-shaped cross-section. One side of the bypass tube 43 abuts against the outer wall of the first protective tube 42, while the other side abuts against the inner wall of the second protective tube 45. The end of the bypass tube 43 can be inserted into the second through-hole 128 of the first boss 127 or the fourth through-hole 321 of the sandblasting ring 30. To ensure a tight connection between the bypass tube 43 and the second through-hole 128, the second through-hole 128 on the first boss 127 is a waist-shaped hole.

[0060] Combine Figure 2As shown, when the bypass pipe 43 is installed on the screen pipe 100, the sidewall of the bypass pipe 43 will partially cover the filtering surface of the sand filter 41, affecting the filtering efficiency of the sand filter 41. In this embodiment, two bypass pipes 43 are provided, and the two bypass pipes 43 are evenly arranged along the circumference of the screen pipe 100. Because the two bypass pipes 43 transport the slurry to the sandblasting ring 30, the sandblasting ring 30 sprays the slurry into the annular space outside the screen pipe 100. Therefore, the flow cross-section of the two bypass pipes 43 is fully utilized, without increasing the flow cross-section by increasing the number of bypass pipes 43. This prevents the filtering surface of the sand filter 41 from being excessively covered, thereby maintaining a stable pressure drop in the slurry circulation.

[0061] In some embodiments, taking into account the cross-sectional dimensions of the screen 100 and actual construction requirements, three, four, or six bypass pipes 43 may be provided, as long as the slurry circulation pressure drop is stable. It is understood that in other embodiments, the circumferential span of the bypass pipe 43 relative to the screen 100 may be increased, while the thickness of the filling pipe 43 is reduced, so that the flow cross-section of the filling pipe 43 remains unchanged. This allows the size of the base pipe 20 to be increased while maintaining a reasonable outer diameter of the screen 100, thereby meeting the requirements of some oil production and well repair operations for a large-diameter screen 100.

[0062] Combine Figure 2 、 Figure 8 and Figure 9 As shown, in some embodiments, the support frame 44 includes a plurality of connecting rods 441 extending parallel to the axial direction of the screen tube 100 and a plurality of support plates 442 evenly arranged along the axial direction of the connecting rods 441. The support plates 442 are generally arc-shaped, with one side of the support plates 442 abutting against the outer wall of the first protective tube 42 and the other side of the support plates 442 abutting against the inner wall of the second protective tube 45. The sides of the support plates 442 proximate the bypass tube 43 are provided with concave surfaces 4421, which are capable of abutting against the longitudinal end surface of the bypass tube 43. The sides of the support plates 442 proximate the first protective tube 42 are also provided with connecting grooves 4422, allowing the liquid component in the slurry to flow freely through the support plates 442 along the axial direction of the sand filter 41, thereby improving the filtration efficiency of the sand filter 41. The support frame 44 supports the first and second protective tubes 42, 45 in the radial direction of the screen tube 100, ensuring that the first and second protective tubes 42, 45 are always well coaxial. The support frame 44 can also support the bypass pipe 43 in the circumferential direction of the screen pipe 100 , so that the bypass pipe 43 is always in communication with the second through hole 128 of the first boss 127 or the fourth through hole 321 of the sandblasting ring 30 .

[0063] Combine Figure 10As shown, the first process of mortar flowing from the filter sand filling unit 40a to the filter sand filling unit 40b is as follows. The mortar in the bypass pipe 43a flows to the fourth through-hole 321 of the sandblasting ring 30. A portion of the mortar enters the annular space outside the screen pipe 100 through the fifth through-hole 331, while another portion directly passes through the fourth through-hole 321 and enters the bypass pipe 43b of the filter sand filling unit 40b. Similarly, each time the mortar passes through a sandblasting ring 30, a portion of the mortar enters the annular space outside the screen pipe 100 through the fifth through-hole 331 and fills the space, thereby achieving multi-point injection filling. The remaining portion of the mortar is evenly distributed through the flow channel 332 to the bypass pipes 43b of the filter sand filling unit 40b before continuing downstream.

[0064] refer to Figure 1 and Figure 11-14 As shown, the lower connection assembly 50 includes a central cannula 51 connected to the base pipe 20, a lower joint 52 connected to the central cannula 51, and a lower ring 53 sleeved on the lower joint 52 and the last filter sand filling unit 40. The central cannula 51 is a hollow cylindrical structure with both ends open. The inner wall of the upper end of the central cannula 51 is provided with a ninth thread 511 for threaded engagement with the eighth thread 22 at the lower end of the base pipe 20. The lower end of the central cannula 51 can be inserted into the coupling 11 and the upper joint 12 of the upper connection assembly 10 of another adjacent screen pipe 100, and is sealed with the upper joint 12 through a sealing ring 1291. Since the inner diameter of the upper joint 12 is larger than the outer diameter of the central cannula 51, a second channel 62 for mortar circulation is formed between the central cannula 51 and the upper joint 12.

[0065] Combine Figure 12 As shown, in some embodiments, the lower joint 52 is also generally a hollow cylindrical structure with both ends open. The lower joint 52 includes a second conveying portion 521 and a second connecting portion 522 located below the second conveying portion 521. A second boss 5211 is provided on the outer wall of one end of the second conveying portion 521 away from the second connecting portion 522. The second boss 5211 extends radially outward from the lower joint 52 and is provided with a seventh through hole 5212 for inserting the bypass pipe 43. The second conveying portion 521 is also provided with an eighth through hole 5213 for mortar circulation and a stabilizing nail hole 5214 for installing a stabilizing nail 523. The second connecting portion 522 is provided with a tenth thread 5221 for connecting to the lower ring 53 and an eleventh thread 5222 for threaded engagement with the first thread 111 of the coupling 11.

[0066] Combine Figure 13 As shown, in some embodiments, the inner wall of the lower end of the lower ring sleeve 53 is provided with a twelfth thread 531 threadedly engaged with the tenth thread 5221.

[0067] Combine Figure 1 and Figure 14 As shown, when the lower connecting assembly 50 is assembled, the central cannula 51 is connected to the lower end of the base pipe 20 via the threaded engagement of the ninth thread 511 and the eighth thread 22. The lower joint 52 is connected to the central cannula 51 via a stabilizing pin 523 installed in the stabilizing pin hole 5214, forming a third passage 63 for mortar circulation between the central cannula 51 and the lower joint 52. The lower joint 52 is connected to the lower collar 53 via the threaded engagement of the tenth thread 5221 and the twelfth thread 531. Because the inner diameter of the lower collar 53 is larger than the outer diameter of the second conveying portion 521 of the lower joint 52, a fourth passage 64 is formed between the lower collar 53 and the second conveying portion 521 of the lower joint 52, connecting the seventh through hole 5212 and the eighth through hole 5213. Mortar in the bypass pipe 43 can enter the third passage 63 between the central cannula 51 and the lower joint 52 through the seventh through hole 5212, the fourth passage 64, and the eighth through hole 5213, in sequence.

[0068] Combine Figure 14 As shown, the second process of mortar flowing from screen pipe 100c to screen pipe 100d is as follows: the mortar passes through the bypass pipe 43c in the upper screen pipe 100c, through the seventh through hole 5212c of the lower joint 52c, and into the fourth channel 64. Then, the mortar passes through the eighth through hole 5213c of the lower joint 52c, sequentially enters the third channel 63 and the second channel 62. The mortar then passes through the first through hole 126d of the upper joint 12d, enters the first channel 61 of the screen pipe 100d, and finally passes through the second through hole 128d of the upper joint 12d and enters the bypass pipe 43d of the screen pipe 100d.

[0069] During the actual construction process, technicians first connect several bypass multi-point jet gravel pack screens 100 in series to form a production string, which is then lowered into the designated location within the horizontal wellbore. Once the filling process begins, the mortar is preferentially transported forward through the annular space outside the screens 100 until it reaches the bridge point. In the annular space outside the screens 100 in front of the bridge point, the solid components in the mortar continue to deposit until the annular space in front of the bridge point is densely filled, forming a filling zone. At this point, the mortar is forced into the bypass pipe 43 of the screen 100 at the front end of the horizontal wellbore, crossing the formed filling zone and entering the annular space outside the screen 100 behind the bridge point. This marks the beginning of the bypass transport phase. During this phase, the mortar undergoes the first and second stages multiple times within the string of screens 100 behind the bridge point. The mortar enters the annular space and continuously deposits solid components until the annular space outside the screens 100 throughout the horizontal wellbore is densely filled.

[0070] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; they may refer to mechanical connections; they may refer to direct connections or indirect connections through an intermediate medium; they may refer to internal communication between two components or the interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0071] It should be understood that the terms "length", "width", "up", "down", "front and back", "left and right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0072] The above description is based on the ideal embodiment of the present invention. Based on the above description, relevant personnel can make various changes and modifications without departing from the scope of the present invention. The technical scope of this invention is not limited to the content of the specification, but must be determined according to the scope of the claims.

Claims

1. A gravel pack screen comprising a base pipe (20), a plurality of filter sand filling units (40) sleeved outside the base pipe (20), and a sand blasting ring (30) arranged between two adjacent filter sand filling units (40), each of the filter sand filling units (40) comprising a bypass pipe (43) for conveying mortar. in, The sandblasting ring (30) is configured to enable the bypass pipes (43) to communicate with each other and to enable the bypass pipe (43) to communicate with the annular space outside the screen pipe (100), so that the slurry transported in the bypass pipe (43) of the upstream sand filter filling unit (40) can be split at the sandblasting ring (30), resulting in a portion of the slurry flowing into the annular space and another portion of the slurry entering the bypass pipe (43) of the downstream sand filter filling unit (40).

2. The gravel pack screen according to claim 1, wherein: The sandblasting ring (30) comprises a first limiting portion (31), a second limiting portion (33) arranged outside the first limiting portion (31), and a connecting portion (32) arranged between the first limiting portion (31) and the second limiting portion (33); the connecting portion (32) is provided with a fourth through hole (321) connecting two adjacent bypass pipes (43) and extending in the axial direction; the second limiting portion (33) is provided with a fifth through hole (331) connecting the fourth through hole (321) and the annular space outside the screen tube (100) and extending in the radial direction.

3. The gravel pack screen according to claim 2, wherein: The first limiting portion (31) and the second limiting portion (33) define receiving grooves (34) at both side end surfaces of the connecting portion (32) that can be plugged into the ends of the sand filter filling units (40), so that the sandblasting ring (30) can be installed between two adjacent sand filter filling units (40).

4. The gravel pack screen according to claim 2, wherein: An annular flow channel (322) communicating with the fourth through hole (321) is further provided in the communicating portion (32). The flow channel (322) is configured to converge the mortar in each of the bypass pipes (43) located in the upstream direction of the sandblasting ring (30) so as to distribute the mortar to the fifth through hole (331) and each of the bypass pipes (43) located in the downstream direction of the sandblasting ring (30).

5. The gravel pack screen according to any one of claims 1 to 4, characterized in that: The sand filter filling unit (40) further comprises a sand filter screen (41) sleeved outside the base pipe (20), a first protective tube (42) arranged outside the sand filter screen (41) and used to protect the sand filter screen (41), and a second protective tube (45) used to protect the screen pipe (100). The sand filter filling unit (40) is configured to allow liquid components in the mortar to sequentially pass through the second protective tube (45), a plurality of sixth through holes (421) on the first protective tube (42), the sand filter screen (41), and a plurality of third through holes (23) on the base pipe (20) and enter the base pipe (20).

6. The gravel pack screen according to claim 5, characterized in that: The sand filter filling unit (40) further comprises a support frame (44) arranged between the first protection tube (42) and the second protection tube (45); the support frame (44) is configured to radially support the first protection tube (42) and the second protection tube (45), so that the first protection tube (42) and the second protection tube (45) always remain coaxial; the support frame (44) is further configured to circumferentially support at least two bypass tubes (43), so that the bypass tubes (43) always communicate with the fourth through hole (321).

7. The gravel pack screen according to claim 6, wherein: The support frame (44) includes a plurality of axially extending connecting rods (441) and a plurality of support plates (442) axially arranged along the connecting rods (441). The side of the support plate (442) close to the bypass pipe (43) is provided with a concave surface (4421) capable of abutting against the bypass pipe (43). The inner surface of the support plate (442) is provided with a connecting groove (4422), so that the liquid component in the mortar can flow axially through the support plate (442).

8. The gravel pack screen according to any one of claims 1 to 4, characterized in that: The screen pipe (100) further comprises an upper connecting assembly (10) connected to the upper end of the base pipe (20) and a lower connecting assembly (50) connected to the lower end of the base pipe (20); the upper connecting assembly (10) and the lower connecting assembly (50) are configured to be interconnected and to allow the bypass pipes (43) of two adjacent screen pipes (100) to be fluidically connected.

9. The gravel pack screen according to claim 8, wherein: The upper connection assembly (10) includes a coupling (11) for connecting to a lower connection assembly (50), an upper joint (12) connected to the upper end of the base pipe (20), and an upper ring sleeve (13) connected to the upper joint (12) and the first filter sand filling unit (40). The lower part of the upper joint (12) has a first conveying portion (122). The outer diameter of the first conveying portion (122) is smaller than the inner diameter of the upper ring sleeve (13), so that a first channel (61) for mortar circulation is formed between the upper ring sleeve (13) and the upper joint (12).

10. The gravel pack screen according to claim 9, wherein: The first conveying portion (122) is provided with a first through hole (126) extending radially, the first boss (127) of the first conveying portion (122) is provided with a second through hole (128) extending axially, and the first channel (61) is connected to the first through hole (126) and the second through hole (128), so that slurry from upstream can flow from the first through hole (126) through the first channel (61) and the second through hole (128) in sequence and enter the bypass pipe (43) of the first sand filter filling unit (40) of the screen pipe (100).

11. The gravel pack screen according to claim 10, wherein: The lower connection assembly (50) includes a central cannula (51) connected to the lower end of the base pipe (20), a lower joint (52) connected to the central cannula (51), and a lower ring sleeve (53) connected to the lower joint (52) and the last of the filter sand filling units (40). The upper part of the lower joint (52) has a second conveying portion (521). The outer diameter of the second conveying portion (521) is smaller than the inner diameter of the lower ring sleeve (53), so that a fourth channel (64) for mortar circulation is formed between the lower ring sleeve (53) and the lower joint (52).

12. The gravel pack screen according to claim 11, wherein: A seventh through hole (5212) extending axially is provided on the second boss (5211) of the second conveying portion (521), and an eighth through hole (5213) extending radially is also provided on the second conveying portion (521). The fourth channel (64) is connected to the seventh through hole (5212) and the eighth through hole (5213), so that the mortar in the bypass pipe (43) of the last sand filter filling unit (40) can flow from the seventh through hole (5212) through the fourth channel (64) and the eighth through hole (5213) in sequence and flow downstream.

13. The gravel pack screen according to claim 12, wherein: The central insert (51) is configured to be inserted into the upper joint (12) and to form a second channel (62) and a third channel (63) communicating with each other between the upper joint (12) and the lower joint (52), respectively, so that when two adjacent sieve tubes (100) are connected, the eighth through hole (5213) of the upstream sieve tube (100) and the first through hole (126) of the downstream sieve tube (100) are communicated through the second channel (62) and the third channel (63).

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