AU2019202097A1 - Drilling fluid density online regulation device - Google Patents
Drilling fluid density online regulation device Download PDFInfo
- Publication number
- AU2019202097A1 AU2019202097A1 AU2019202097A AU2019202097A AU2019202097A1 AU 2019202097 A1 AU2019202097 A1 AU 2019202097A1 AU 2019202097 A AU2019202097 A AU 2019202097A AU 2019202097 A AU2019202097 A AU 2019202097A AU 2019202097 A1 AU2019202097 A1 AU 2019202097A1
- Authority
- AU
- Australia
- Prior art keywords
- filter cartridge
- drilling fluid
- backflow
- wall
- drilling
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000005553 drilling Methods 0.000 title claims abstract description 168
- 239000012530 fluid Substances 0.000 title claims abstract description 119
- 230000033228 biological regulation Effects 0.000 title claims abstract description 61
- 238000001914 filtration Methods 0.000 claims abstract description 19
- 230000000149 penetrating effect Effects 0.000 claims description 12
- 230000003247 decreasing effect Effects 0.000 claims description 4
- 238000006396 nitration reaction Methods 0.000 claims description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 abstract description 20
- 238000011161 development Methods 0.000 description 9
- 230000018109 developmental process Effects 0.000 description 9
- 239000007789 gas Substances 0.000 description 9
- 230000015572 biosynthetic process Effects 0.000 description 5
- 238000005755 formation reaction Methods 0.000 description 5
- 238000002347 injection Methods 0.000 description 5
- 239000007924 injection Substances 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- 238000005516 engineering process Methods 0.000 description 4
- 230000005484 gravity Effects 0.000 description 4
- 230000001276 controlling effect Effects 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- 230000001105 regulatory effect Effects 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 2
- 230000000903 blocking effect Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 150000004677 hydrates Chemical class 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 239000013535 sea water Substances 0.000 description 2
- 235000019738 Limestone Nutrition 0.000 description 1
- 239000004568 cement Substances 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 230000005465 channeling Effects 0.000 description 1
- 238000005056 compaction Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 239000006028 limestone Substances 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 239000003345 natural gas Substances 0.000 description 1
- 239000003129 oil well Substances 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 239000011435 rock Substances 0.000 description 1
- 238000007711 solidification Methods 0.000 description 1
- 230000008023 solidification Effects 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 239000003643 water by type Substances 0.000 description 1
Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B21/00—Methods or apparatus for flushing boreholes, e.g. by use of exhaust air from motor
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B21/00—Methods or apparatus for flushing boreholes, e.g. by use of exhaust air from motor
- E21B21/08—Controlling or monitoring pressure or flow of drilling fluid, e.g. automatic filling of boreholes, automatic control of bottom pressure
Landscapes
- Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Mining & Mineral Resources (AREA)
- Mechanical Engineering (AREA)
- Physics & Mathematics (AREA)
- Environmental & Geological Engineering (AREA)
- Fluid Mechanics (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Earth Drilling (AREA)
Abstract
Abstract The present invention relates to a drilling fluid density online regulation device, comprising an outer barrel and a plurality of hollow spheres, a central hole is provided in the outer barrel, a layered filtering structure is sleeved in the central hole, the layered filtering structure comprises a filter cartridge structure slidable and capable of layer-based filtrations of the hollow spheres, a plurality of fluid discharge through-holes are provided on a sidewall of the outer barrel, with a hole diameter larger than an outer diameter of the hollow sphere. Deep-water variable-gradient drilling can be realized by the device, which well solves the problem that excessive layers of casings are set in the single-gradient drilling, and the problem that a large equipment is required in the dual-gradient drilling, thereby reducing the drilling cost, and solving the problem of the narrow-density window in deep-water drilling. 1 / l 3-0-33-13 1- 1
Description
Cross-reference to related applications [0001] This application claims priority to Chinese Patent Application No. 201810263801.5 , filed on March 28,2018, which is incorporated herein by reference in its entirety.
Technical Field [0002] The present invention relates to the technical field of oil drilling, and in particular to a drilling fluid density online regulation device.
Background Art [0003] In recent years, 50% of the major oil and gas explorations and developments in the world are carried out in the ocean, mainly in the deep-water areas, which have become the important substitution areas for international oil and gas explorations and developments. The deep-water oil and gas exploration and development is becoming a main growth point of the oil on earth and a frontier of technological innovation, and the deep-water areas will become the main battlefield for future competitions in oil and gas resources.
[0004] The drilling is a key link in deep-water oil and gas exploration and development, and the deep-water drilling faces many challenges and risks: 1) The challenge brought by the water depth. With the increase of the water depth, higher requirements are imposed on the drilling tool, the drilling fluid, the marine riser, the platform bearing capacity, the drilling rig load, the deck space, etc., and the cost is correspondingly increased. 2) The challenge brought by the wind waves. The wind waves in the deep-water environment will cause the movement of the drilling ship, resulting in the deformation and vortex-induced vibration of the marine riser, so a higher fatigue strength design is required; the wind waves current can also affect the connection between the marine riser system and the underwater blowout preventer; and the ocean storms are even catastrophic damages to the drilling platform. 3) The challenge brought by the low temperature. The seawater temperature decreases as the well depth increases and the seabed temperature is generally about 4 °C; the rock formations of several hundred meters below the seabed mud line are also affected, as a result, the rheological properties of the drilling fluid in the marine riser are changed, the viscosity and density of the drilling fluid are increased, and the gel effect occurs, which makes it difficult to control the wellbore pressure; in addition, the low temperature prolongs the solidification time of the drilling fluid, and the fluid channeling is liable to occur, resulting in a decrease of the cement strength. 4) The challenge brought by hydrates. Hydrates are very easy to occur if the well contains natural gases during the drilling. As a result, the throttle manifold, the kill manifold, the liquid-gas separator, and the blowout preventer are blocked, which hinders the pressure monitoring of i
2019202097 27 Mar 2019 the oil well. 5) The challenge brought by a narrow drilling fluid safety density window. The under-compaction caused by the deep waters leads to a narrow window between the fracture pressure gradient and the formation pore pressure gradient, which can easily cause accidents such as leakage, blowout, collapse and blocking, resulting in an increase of the casing layers, and it is even impossible to reach the target layer, so the drilling depth and the construction cycle are greatly affected. In which, the problem of formation narrow safety density window is the most prominent, which can easily cause complex accidents such as leakage, blowout, collapse, and blocking, and bring great potential safety hazards to the deep-water oil and gas exploration and development during the drilling. For example, the reservoirs of the Amu Darya gas field are composed of reef limestone with developed cracks, excellent permeability, and very narrow formation pressure window, so the vicious leakage will occur during drilling due to the excessive drilling fluid density.
[0005] At present, deep-water drilling uses the conventional single-gradient drilling technology. In order to deal with the narrow-density window of the formation, usually the operational risk is only reduced by increasing the casing layers to maintain the drilling. The disadvantages lie in that the single open hole section is short, the number of casing layers is large, and it is difficult to reach the target layer for deep wells. The dual-gradient drilling technology occurred in the 1990s solves the problem of narrow-density window in the deep-water drilling to some extent. The dual-gradient drilling technology is to inject a low-density light medium into a bottom portion of a marine riser annulus, and reduce a drilling fluid density in the marine riser annulus to make it be equal to the seawater density, so that two liquid column pressure gradients are formed in the wellbore, and the drilling fluid density below the seabed can be adjusted within a wider range. Although the dual-gradient drilling is more advantages than the single-gradient drilling, it still disadvantageous in that large equipment (such as the submarine lift pump) is needed, and the drilling cost is increased; in addition, with the increase of development depth of the oil and gas resources, the dual-gradient drilling technology can not completely solve the problem of narrow-density window in deep-water drilling, and its limitation is also increasingly prominent.
[0006] Therefore, by virtue of years of experiences and practices in related industries, the inventor proposes a drilling fluid density online regulation device to overcome the defects of the prior art.
Summary of the Invention [0007] An objective of the present invention is to provide a drilling fluid density online regulation device. Deep-water variable-gradient drilling can be realized by the device, which well solves the problem that excessive layers of casings are set in the single-gradient drilling, and the problem that the large equipment is required in the dual-gradient drilling, thereby reducing the drilling cost, and finally solving the problem of narrow-density window in the deep-water drilling.
[0008] The objective of the present invention is achieved by a drilling fluid density online regulation
2019202097 27 Mar 2019 device, comprising an outer barrel and a plurality of hollow spheres having a density less than a drilling fluid density, a central hole penetrating from top to bottom is provided in the outer barrel, the central hole comprises a backflow cavity having a bottom portion communicated with a diameter-decreasing drilling fluid via-hole, a layered filtering structure allowing drilling fluid to flow downward is sleeved in the central hole, the layered filtering structure can allow layer-based entries of the hollow spheres into the backflow cavity, the layered filtering structure comprises a filter cartridge structure slidable and capable of layer-based nitrations of the hollow spheres, a plurality of fluid discharge through-holes penetrating radially are provided to be spaced apart from each other circumferentially on a sidewall of the outer barrel on the bottom portion of the backflow cavity, with a hole diameter larger than an outer diameter of the hollow sphere; a bottom portion of the layered filtering structure can be sealed and slidable to pass through the drilling fluid via-hole.
[0009] In a preferred embodiment of the present invention, the layered filtering structure comprises a hollow fixed barrel fixedly provided in the central hole, an upper portion of an outer wall of the fixed barrel is in a sealed and fixed connection with a sidewall of the central hole, the outer wall of the fixed barrel in the backflow cavity is spaced apart from a sidewall of the backflow cavity, a fixed barrel bottom plate is provided at a bottom portion of the fixed barrel, and a penetrating fixed barrel bottom hole is provided on the fixed barrel bottom plate; a plurality of backflow through-grooves are provided to be spaced apart from each other circumferentially on a sidewall of the fixed barrel in the backflow cavity;
[0010] the filter cartridge structure comprises a hollow first filter cartridge that is sealed, slidable, and sleeved in the fixed barrel, a first strainer is provided in the first filter cartridge, a bottom end of the first filter cartridge is sealed and slidable to pass through the fixed barrel bottom hole, the first filter cartridge can block each of the backflow through-grooves and move downward to expose the same, a first spring is sleeved on an outer wall of the first filter cartridge, a top end of the first spring is abutted against a top portion of the outer wall of the first filter cartridge, and a bottom end of the first spring is abutted against the fixed barrel bottom plate; a first filter cartridge bottom plate is provided at a bottom portion of the first filter cartridge, and a penetrating first filter cartridge bottom hole is provided on the first filter cartridge bottom plate;
[0011] a plurality of second backflow through-grooves are provided to be spaced apart from each other circumferentially on a sidewall of the first filter cartridge below the first strainer; the filter cartridge structure further comprises a hollow second filter cartridge that is sealed, slidable, and sleeved in the first filter cartridge, a second strainer is provided in the second filter cartridge, a bottom end of the second filter cartridge is sealed and slidable to pass through the first filter cartridge bottom hole and then slidable to pass through the drilling fluid via-hole, the second filter cartridge can block each of the second backflow through-groove and move downward to expose the same, a second spring is sleeved on an outer wall of the second filter cartridge, a top end of the second spring is abutted against a top portion of the outer wall
2019202097 27 Mar 2019 of the second filter cartridge, and a bottom end of the second spring is abutted against the first filter cartridge bottom plate;
[0012] a cross-sectional size of the first backflow through-groove is larger than a mesh size of the first strainer; the mesh size of the first strainer is larger than a cross-sectional size of the second backflow through-groove, and the cross-sectional size of the second backflow through-groove is larger than a mesh size of the second strainer.
[0013] In a preferred embodiment of the present invention, a diameter-increasing first step portion is provided at the top portion of the outer wall of the first filter cartridge, an outer wall of the first step portion can be sealed and slidable along an inner wall of the fixed barrel, and the top end of the first spring is abutted against the first step portion.
[0014] In a preferred embodiment of the present invention, a diameter-increasing second step portion is provided at the top portion of the outer wall of the second filter cartridge, an outer wall of the second step portion can be sealed and slidable along an inner wall of the first filter cartridge, and the top end of the second spring is abutted against the second step portion.
[0015] In a preferred embodiment of the present invention, a diameter-decreasing third step portion is provided on the sidewall of the central hole, and a diameter-increasing fourth step portion is provided at a top portion of the outer wall of the fixed barrel and can be abutted against the third step portion.
[0016] In a preferred embodiment of the present invention, a first connection taper-thread portion is provided at a top portion of the sidewall of the central hole, a tapered surface having a diameter decreasing downward is provided at a bottom portion of an outer wall of the outer barrel, and a second connection taper-thread portion is provided on the tapered surface.
[0017] As can be seen from the above description, the drilling fluid density online regulation device provided by the present invention has the following beneficial effects:
[0018] 1) the drilling fluid density online regulation device of the present invention can regulate densities of drilling fluids arriving at different depths of a wellbore annulus by injecting hollow spheres of corresponding sizes into the drilling fluid, thereby more flexibly and accurately controlling the wellbore pressure, and achieving the multi-gradient drilling to solve the problem of narrow-density window in the deep-water drilling;
[0019] 2) the drilling fluid density online regulation device of the present invention can well solve the problem that excessive layers of casings are set in a short single-gradient drilling, while benefiting the well control to reduce the probability of dangerous accidents;
[0020] 3) any large equipment is not required when the drilling fluid density online regulation device of the present invention is used for the wellbore pressure segmented control, which reduces the drilling cost; at the same time, with the increase of development depth, under the limited layers of casing, the problem that it is difficult to reach the target layer in the single-gradient and double-gradient drilling can be
2019202097 27 Mar 2019 well solved.
Brief Description of the Drawings [0021] The following drawings are only intended to illustrate and explain the present invention, rather than limiting the scope of the present invention. In which, [0022] Fig. 1 is a structural schematic diagram of a drilling fluid density online regulation device without a sphere injection in the present invention;
[0023] Fig. 2 is a structural schematic diagram of a drilling fluid density online regulation device during a sphere injection in the present invention;
[0024] Fig. 3 is a use state schematic diagram of a drilling fluid density online regulation device during dual-gradient drilling in the present invention;
[0025] Fig. 4 is a use state schematic diagram of a drilling fluid density online regulation device during multi-gradient drilling in the present invention.
[0026] In the drawings:
[0027] 100: drilling fluid density online regulation device;
[0028] 1: outer barrel;
[0029] 111: backflow cavity; 112: drilling fluid via-hole;
[0030] 12: fluid discharge through-hole;
[0031] 13: third step portion;
[0032] 141: first connection taper-thread portion; 142: second connection taper-thread portion;
[0033] 15: tapered surface;
[0034] 2: hollow sphere;
[0035] 30: fixed barrel;
[0036] 301: fixed barrel bottom plate; 302: first backflow through-groove; 303: fourth step portion;
[0037] 31: first filter cartridge;
[0038] 311: first filter cartridge bottom plate; 312: second backflow through-groove; 313: first step portion;
[0039] 32: second filter cartridge;
[0040] 321: second step portion;
[0041] 41: first strainer; 42: second strainer;
[0042] 51: first spring; 52: second spring;
[0043] 81: wellbore annulus;
[0044] 9: drill stem.
Detailed Description of the Preferred Embodiments
2019202097 27 Mar 2019 [0045] In order to more clearly understand the technical features, objectives and effects of the present invention, now the embodiments of the present invention are described with reference to the drawings.
[0046] As illustrated in Figs. 1 to 4, the present invention provides a drilling fluid density online regulation device 100; in use, the drilling fluid density online regulation device 100 is connected to a hollow drill stem 9 (prior art) in series; the drilling fluid density online regulation device 100 comprises an outer barrel 1 and a plurality of hollow spheres 2 (low density light mediums) having a density less than a drilling fluid density; the plurality of hollow spheres 2 are used for a sphere injection operation when the drilling fluid density is regulated, and sizes of the hollow spheres 2 are determined based on the practical application; since a wellbore annulus 81 is filled with the hollow spheres 2, the amount of drilling fluid contained therein is reduced, thereby decreasing the drilling fluid density in the wellbore annulus 81 of corresponding well section.
[0047] As illustrated in Figs. 1 and 2, a central hole penetrating from top to bottom is provided in the outer barrel 1, the central hole comprises a backflow cavity 111 having a bottom portion communicated with a diameter-decreasing drilling fluid via-hole 112, a layered filtering structure allowing drilling fluid to flow downward is sleeved in the central hole, the layered filtering structure can allow layer-based entries of the hollow spheres 2 into the backflow cavity 111, the layered filtering structure comprises a filter cartridge structure slidable and capable of layer-based nitrations of the hollow spheres 2, the layered filtering structure performs layer-based nitrations according to the sizes of the hollow spheres 2, respectively, and the hollow sphere 2 with a larger outer diameter is located above the hollow sphere 2 with a smaller outer diameter; a plurality of fluid discharge through-holes 12 penetrating radially are provided to be spaced apart from each other circumferentially on a sidewall of the outer barrel 1 at the bottom portion of the backflow cavity 111, with a hole diameter larger than an outer diameter of the hollow sphere 2; a bottom portion of the layered filtering structure can be sealed and slidable to pass through the drilling fluid via-hole 112.
[0048] The drilling fluid density online regulation device 100 of the present invention can regulate densities of drilling fluids arriving at different depths of a wellbore annulus by injecting hollow spheres of corresponding sizes into the drilling fluid, thereby more flexibly and accurately controlling the wellbore pressure, and achieving the multi-gradient drilling to solve the problem of narrow-density window in the deep-water drilling. The drilling fluid density online regulation device 100 of the present invention can well solve the problem that excessive layers of casings are set in a short single-gradient drilling, while benefiting the well control to reduce the probability of dangerous accidents. Any large equipment is not required when the drilling fluid density online regulation device 100 of the present invention is used for the wellbore pressure segmented control, which reduces the drilling cost; at the same time, with the increase of the development depth, under the limited layers of casing, the problem that it is difficult to reach the
2019202097 27 Mar 2019 target layer in the single-gradient and double-gradient drilling can be well solved.
[0049] Further, as illustrated in Figs. 1 and 2, the layered filtering structure comprises a hollow fixed barrel 30 fixedly provided in the central hole, an upper portion of an outer wall of the fixed barrel 30 is in a sealed and fixed connection with a sidewall of the central hole, the outer wall of the fixed barrel 30 in the backflow cavity 111 is spaced apart from a sidewall of the backflow cavity 111, a fixed barrel bottom plate 301 is provided at a bottom portion of the fixed barrel 30, and a penetrating fixed bottom hole is provided on the fixed barrel bottom plate 301; a plurality of backflow through-grooves 302 are provided to be spaced apart from each other circumferentially on a sidewall of the fixed barrel 30 in the backflow cavity
111.
[0050] The filter cartridge structure comprises a hollow first filter cartridge 31 that is sealed, slidable, and sleeved in the fixed barrel 30; a first strainer 41 is provided in the first filter cartridge 31; a bottom end of the first filter cartridge 31 is sealed and slidable to pass through the fixed barrel bottom hole; the first filter cartridge 31 can block each of the backflow through-grooves 302 and move downward to expose the same; in the normal drilling state and when the hollow spheres on the first strainer 41 are insufficient to cause the first filter cartridge 31 to move downward, the first filter cartridge 31 blocks each of the first backflow through-grooves 302 from a radial inner side of the fixed barrel 30; and when the hollow spheres on the first strainer 41 cause the first filter cartridge 31 to move downward, each of the first backflow through-grooves 302 can communicate the inner cavity of the fixed barrel 30 with the backflow cavity 111.
[0051] A first spring 51 is sleeved on an outer wall of the first filter cartridge 31, a top end of the first spring 51 is abutted against a top portion of the outer wall of the first filter cartridge 31, and a bottom end of the first spring 51 is abutted against the fixed barrel bottom plate 301; a first filter cartridge bottom plate 311 is provided at a bottom portion of the first filter cartridge 31, and a penetrating first filter cartridge bottom hole is provided on the first filter cartridge bottom plate 311.
[0052] A plurality of second backflow through-grooves 312 are provided to be spaced apart from each other circumferentially on a sidewall of the first filter cartridge 31 below the first strainer 41; the filter cartridge structure further comprises a hollow second filter cartridge 32 that is sealed, slidable, and sleeved in the first filter cartridge 31; a second strainer 42 is provided in the second filter cartridge 32, a bottom end of the second filter cartridge 32 is sealed and slidable to pass through the first filter cartridge bottom hole and then slidable to pass through the drilling fluid via-hole 112, and the second filter cartridge 32 can block each of the second backflow through-groove 312 and move downward to expose the same; in the normal drilling state and when the hollow spheres on the second strainer 42 are insufficient to cause the second filter cartridge 32 to move downward, the second filter cartridge 32 blocks each of the second backflow through-grooves 312 from a radial inner side of the first filter cartridge 31; and when the hollow spheres on the second strainer 42 cause the second filter cartridge 32 to move downward,
2019202097 27 Mar 2019 each of the second backflow through-grooves 312 can communicate the inner cavity of the first filter cartridge 31 with the backflow cavity 111.
[0053] A second spring 52 is sleeved on an outer wall of the second filter cartridge 32, a top end of the second spring 52 is abutted against a top portion of the outer wall of the second filter cartridge 32, and a bottom end of the second spring 52 is abutted against the first filter cartridge bottom plate 311.
[0054] A cross-sectional size of the first backflow through-groove 302 is larger than a mesh size of the first strainer 41; the mesh size of the first strainer 41 is larger than a cross-sectional size of the second backflow through-groove 312; and the cross-sectional size of the second backflow through-groove 312 is larger than a mesh size of the second strainer 42. When two sizes of hollow spheres are injected into the drilling fluid, the bigger hollow spheres are intercepted by the first strainer 41 and accumulated in the first filter cartridge 31; when the first filter cartridge 31 moves downward to expose the first backflow through-groove 302, the bigger hollow spheres flow into the backflow cavity 111 via the first backflow through-grooves 302; the smaller hollow spheres flow downward via the meshes on the first strainer 41 and are intercepted by the second strainer 42 and accumulated in the second filter cartridge 32; when the second filter cartridge 32 moves downward to expose the second backflow through-groove 312, the smaller hollow spheres flow into the backflow cavity 111 via the second backflow through-grooves 312.
[0055] The cross-sectional size of the first backflow through-groove 302, the mesh size of the first strainer 41, the cross-sectional size of the second backflow through-groove 312, and the mesh size of the second strainer 42 shall be set to match the sizes of the hollow spheres.
[0056] Further, a diameter-increasing first step portion 313 is provided at the top portion of the outer wall of the first filter cartridge 31, an outer wall of the first step portion 313 can be sealed and slidable along an inner wall of the fixed barrel 30, and the top end of the first spring 51 is abutted against the first step portion 313.
[0057] Further, as shown in Figs. 1 and 2, a diameter-increasing second step portion 321 is provided at the top portion of the outer wall of the second filter cartridge 32, an outer wall of the second step portion can be sealed and slidable along an inner wall of the first filter cartridge 31, and the top end of the second spring 52 is abutted against the second step portion 321.
[0058] Further, as shown in Figs. 1 and 2, a diameter-decreasing third step portion 13 is provided on the sidewall of the central hole, and a diameter-increasing fourth step portion 303 is provided at a top portion of the outer wall of the fixed barrel 30 and can be abutted against the third step portion 13.
[0059] Further, as shown in Figs. 1 and 2, a first connection taper-thread portion 141 is provided at the top portion of the sidewall of the central hole, a tapered surface 15 having a diameter decreasing downward is provided at the bottom portion of the outer wall of the outer barrel 1, and a second connection taper-thread portion 142 is provided on the tapered surface 15.
[0060] The use process of the drilling fluid density online regulation device 100 of the present
2019202097 27 Mar 2019 invention is as follows:
[0061] the drilling fluid density online regulation device 100 of the present invention is connected to a drill stem 9 in series and is set into a well in accompany with the drill stem 9;
[0062] during the normal drilling process, no hollow sphere 2 is required to be added into the drilling fluid injected from the wellhead, the first filter cartridge 31 blocks each of the first backflow through-grooves 302, the second filter cartridge 32 blocks each of the second backflow through-grooves 312, and the drilling fluid flows toward a drill bit via an inner cavity of the the drill stem 9 above the drilling fluid density online regulation device 100, the central hole, an inner cavity of the fixed barrel 30, an inner cavity of the first filter cartridge 31, an inner cavity of the second filter cartridge 32, the drilling fluid via-hole 112, and an inner cavity of the drill stem 9 below the drilling fluid density online regulation device 100;
[0063] when dual-gradient drilling is required, as illustrated in Fig. 3, one drilling fluid density online regulation device 100 is connected to the drill stem 9 in series, two sizes of hollow spheres 2 are orderly added into the drilling fluid injected from the wellhead, the hollow sphere 2 having a larger outer diameter is set as a first hollow sphere, the hollow sphere 2 having a smaller outer diameter is set as a second hollow sphere, an outer diameter of the first hollow sphere is set to match the mesh size of the first strainer 41, an outer diameter of the second hollow sphere is set to match the mesh size of the second strainer 42, the first hollow spheres are injected into the drilling fluid after the second hollow spheres have been injected, the second hollow spheres flow downward via the meshes on the first strainer 41 onto the second strainer 42 and then are intercepted by the second strainer 42 and accumulated in the second filter cartridge 32; when a sum of the gravity of the second hollow spheres, the gravity of the second filter cartridge 32 and the downward impact force of the drilling fluid is larger than an acting force of the second spring 52, the second filter cartridge 32 moves downward to expose the second backflow through-grooves 312, and the second hollow spheres flow into the backflow cavity 111 via the second backflow through-grooves 312; the first hollow spheres are intercepted by the first strainer 41 and accumulated in the first filter cartridge 31; when a sum of the gravity of the first hollow spheres, the gravity of the first filter cartridge 31 and the downward impact force of the drilling fluid is larger than an acting force of the first spring 51, the first filter cartridge 31 moves downward to expose the first backflow through-grooves 302, and the first hollow spheres flow into the backflow cavity 111 via the first backflow through-grooves 302; the first hollow spheres and the second hollow spheres in the backflow cavity 111 enter the wellbore annulus 81 via the fluid discharge through-holes 12, so as to effectively decrease the drilling fluid density in the wellbore annulus 81 above the drilling fluid density online regulation device 100; at that time, the drilling fluid densities in the wellbore annulus 81 have two values by taking the drilling fluid density online regulation device 100 as a boundary, and the drilling fluid density above the boundary is less than the drilling fluid density below the boundary, thereby achieving dual-gradient drilling.
[0064] When multi-gradient drilling is required to be performed, a plurality of drilling fluid density
2019202097 27 Mar 2019 online regulation devices 100 are connected to the drill stem 9 in series from top to bottom at intervals, and various sizes of hollow spheres 2 should be added into the drilling fluid injected from the wellhead. As illustrated in Fig. 4, in a specific application example of the present invention, two drilling fluid density online regulation devices 100 are connected to the drill stem 9 in series; it is set that the upper drilling fluid density online regulation device 100 is a first drilling fluid density online regulation device, and the lower drilling fluid density online regulation device 100 is a second drilling fluid density online regulation device in which mesh sizes of respective strainers are less than those of corresponding strainers in the first drilling fluid density online regulation device; when the drilling fluid density in the wellbore annulus 81 needs to be regulated, the outer diameters of the two sizes of hollow sphere 2 injected into the second drilling fluid density online regulation device are less than those of the hollow spheres 2 injected into the first drilling fluid density online regulation device, and less than the mesh size of the second strainer 42 in the first drilling fluid density online regulation device, which ensures that the two sizes of hollow spheres 2 can flow into the second drilling fluid density online regulation device, enter the backflow cavity 111 via the first backflow through-grooves 302 and second backflow through-grooves 312, respectively, and then enter the wellbore annulus 81 via the fluid discharge through-holes 12, thereby completing the density regulation in the wellbore annulus 81 above the second drilling fluid density online regulation device; after a hollow sphere injection operation in the second drilling fluid density online regulation device is completed, a hollow sphere injection operation in the first drilling fluid density online regulation device is performed, so as to complete the density regulation in the wellbore annulus 81 above the first drilling fluid density online regulation device, wherein the hollow spheres injected into the first drilling fluid density online regulation device are more than those injected into the second drilling fluid density online regulation device. The distributed densities of the hollow spheres 2 represent three values on the cross-section of the entire wellbore annulus 81, wherein a first level is above the first drilling fluid density online regulation device, a second level is between the first drilling fluid density online regulation device and the second drilling fluid density online regulation device, and a third level is below the second drilling fluid density online regulation device; a concentration of the hollow spheres in the first level is larger than a concentration of the hollow spheres in the second level, and the concentration of the hollow spheres in the second level is larger than a concentration of the hollow spheres in the third level, so that a drilling fluid density in the first level is less than a drilling fluid density in the second level, and the drilling fluid density in the second level is less than a drilling fluid density in the third level; the drilling fluid densities in wellbore annulus 81 are regulated based on the levels, thereby achieving multi-gradient drilling and solving the problem of narrow-density window in the deep-water drilling.
[0065] As can be seen from the above description, the drilling fluid density online regulation device provided by the present invention has the following beneficial effects:
[0066] 1) the drilling fluid density online regulation device of the present invention can regulate io
2019202097 27 Mar 2019 densities of drilling fluids arriving at different depths of a wellbore annulus by injecting hollow spheres of corresponding sizes into the drilling fluid, thereby more flexibly and accurately controlling the wellbore pressure, and achieving the multi-gradient drilling to solve the problem of narrow-density window in the deep-water drilling;
[0067] 2) the drilling fluid density online regulation device of the present invention can well solve the problem that excessive layers of casings are set in a short single-gradient drilling, while benefiting the well control to reduce the probability of dangerous accidents;
[0068] 3) any large equipment is not required when the drilling fluid density online regulation device of the present invention is used for the wellbore pressure segmented control, which reduces the drilling cost; at the same time, with the increase of development depth, under the limited layers of casing, the problem that it is difficult to reach the target layer in the single-gradient and double-gradient drilling can be well solved.
[0069] Those described above are just exemplary embodiments of the present invention, rather than limitations to the scope of the present invention. Any equivalent change or modification made by a person skilled in the art without deviating from the conception and principle of the present invention shall fall within the protection scope of the present invention.
[0070] It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in the art, in Australia or any other country.
[0071] In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word “comprise” or variations such as “comprises” or “comprising” is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.
Claims (6)
- ClaimsThe claims defining the invention are as follows:1. A drilling fluid density online regulation device, comprising an outer barrel and a plurality of hollow spheres having a density less than a drilling fluid density, a central hole penetrating from top to bottom is provided in the outer barrel, the central hole comprises a backflow cavity having a bottom portion communicated with a diameter-decreasing drilling fluid via-hole, a layered filtering structure allowing drilling fluid to flow downward is sleeved in the central hole, the layered filtering structure can allow layer-based entries of the hollow spheres into the backflow cavity, the layered filtering structure comprises a filter cartridge structure slidable and capable of layer-based nitrations of the hollow spheres, a plurality of fluid discharge through-holes penetrating radially are provided to be spaced apart from each other circumferentially on a sidewall of the outer barrel on the bottom portion of the backflow cavity, with a hole diameter larger than an outer diameter of the hollow sphere; a bottom portion of the layered filtering structure can be sealed and slidable to pass through the drilling fluid via-hole.
- 2. The drilling fluid density online regulation device according to claim 1, wherein the layered filtering structure comprises a hollow fixed barrel fixedly provided in the central hole, an upper portion of an outer wall of the fixed barrel is in a sealed and fixed connection with a sidewall of the central hole, the outer wall of the fixed barrel in the backflow cavity is spaced apart from a sidewall of the backflow cavity, a fixed barrel bottom plate is provided at a bottom portion of the fixed barrel, and a penetrating fixed barrel bottom hole is provided on the fixed barrel bottom plate; a plurality of backflow through-grooves are provided to be spaced apart from each other circumferentially on a sidewall of the fixed barrel in the backflow cavity;the filter cartridge structure comprises a hollow first filter cartridge that is sealed, slidable, and sleeved in the fixed barrel, a first strainer is provided in the first filter cartridge, a bottom end of the first filter cartridge is sealed and slidable to pass through the fixed barrel bottom hole, the first filter cartridge can block each of the backflow through-grooves and move downward to expose the same, a first spring is sleeved on an outer wall of the first filter cartridge, a top end of the first spring is abutted against a top portion of the outer wall of the first filter cartridge, and a bottom end of the first spring is abutted against the fixed barrel bottom plate; a first filter cartridge bottom plate is provided at a bottom portion of the first filter cartridge, and a penetrating first filter cartridge bottom hole is provided on the first filter cartridge bottom plate;a plurality of second backflow through-grooves are provided to be spaced apart from each other circumferentially on a sidewall of the first filter cartridge below the first strainer; the filter cartridge structure further comprises a hollow second filter cartridge that is sealed, slidable, and sleeved in the first filter2019202097 27 Mar 2019 cartridge, a second strainer is provided in the second filter cartridge, a bottom end of the second filter cartridge is sealed and slidable to pass through the first filter cartridge bottom hole and then slidable to pass through the drilling fluid via-hole, the second filter cartridge can block each of the second backflow through-groove and move downward to expose the same, a second spring is sleeved on an outer wall of the second filter cartridge, a top end of the second spring is abutted against a top portion of the outer wall of the second filter cartridge, and a bottom end of the second spring is abutted against the first filter cartridge bottom plate;a cross-sectional size of the first backflow through-groove is larger than a mesh size of the first strainer; the mesh size of the first strainer is larger than a cross-sectional size of the second backflow through-groove, and the cross-sectional size of the second backflow through-groove is larger than a mesh size of the second strainer.
- 3. The drilling fluid density online regulation device according to claim 2, wherein a diameter-increasing first step portion is provided at the top portion of the outer wall of the first filter cartridge, an outer wall of the first step portion can be sealed and slidable along an inner wall of the fixed barrel, and the top end of the first spring is abutted against the first step portion.
- 4. The drilling fluid density online regulation device according to claim 2 or 3, wherein a diameter-increasing second step portion is provided at the top portion of the outer wall of the second filter cartridge, an outer wall of the second step portion can be sealed and slidable along an inner wall of the first filter cartridge, and the top end of the second spring is abutted against the second step portion.
- 5. The drilling fluid density online regulation device according to claim 2, wherein a diameter-decreasing third step portion is provided on the sidewall of the central hole, and a diameter-increasing fourth step portion is provided at a top portion of the outer wall of the fixed barrel and can be abutted against the third step portion.
- 6. The drilling fluid density online regulation device according to claim 1, wherein a first connection taper-thread portion is provided at a top portion of the sidewall of the central hole, a tapered surface having a diameter decreasing downward is provided at a bottom portion of an outer wall of the outer barrel, and a second connection taper-thread portion is provided on the tapered surface.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810263801.5 | 2018-03-28 | ||
| CN201810263801.5A CN108425650B (en) | 2018-03-28 | 2018-03-28 | The online regulation device of drilling fluid density |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| AU2019202097A1 true AU2019202097A1 (en) | 2019-10-17 |
| AU2019202097B2 AU2019202097B2 (en) | 2020-07-09 |
Family
ID=63159406
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| AU2019202097A Active AU2019202097B2 (en) | 2018-03-28 | 2019-03-27 | Drilling fluid density online regulation device |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN108425650B (en) |
| AU (1) | AU2019202097B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111764850B (en) * | 2020-06-22 | 2022-02-25 | 中国石油大学(北京) | Hollow ball filtering and separating device and drilling string |
| CN113323610B (en) * | 2021-07-15 | 2024-05-28 | 中国海洋石油集团有限公司 | Drilling fluid injection device of submarine drilling machine, submarine drilling machine and injection method |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6530437B2 (en) * | 2000-06-08 | 2003-03-11 | Maurer Technology Incorporated | Multi-gradient drilling method and system |
| BRPI0708565A2 (en) * | 2006-03-06 | 2011-06-07 | Exxonmobil Upstream Res Co | system and method for drilling in wellbore, and method associated with hydrocarbon production |
| CN100412311C (en) * | 2006-10-12 | 2008-08-20 | 中国海洋石油总公司 | Method and apparatus for realizing double-gradient well drilling |
| US20100155063A1 (en) * | 2008-12-23 | 2010-06-24 | Pdti Holdings, Llc | Particle Drilling System Having Equivalent Circulating Density |
| CN105143600B (en) * | 2013-05-31 | 2018-11-16 | 哈利伯顿能源服务公司 | Well Monitoring, Sensing, Control and Mud Logging for Dual Gradient Drilling |
| US20160084083A1 (en) * | 2014-09-23 | 2016-03-24 | Gilbert Alan Hice | Borehole Mining System and Methods Using Sonic-Pulsed Jetting Excavation and Eductor Slurry Recovery Apparatus |
-
2018
- 2018-03-28 CN CN201810263801.5A patent/CN108425650B/en active Active
-
2019
- 2019-03-27 AU AU2019202097A patent/AU2019202097B2/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| AU2019202097B2 (en) | 2020-07-09 |
| CN108425650B (en) | 2019-06-14 |
| CN108425650A (en) | 2018-08-21 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101070755B (en) | Pressure-control well-drilling device based two gradients | |
| CN106285554B (en) | Wellbore pressure control system and method for the stage of cementing the well | |
| US6230824B1 (en) | Rotating subsea diverter | |
| US6325159B1 (en) | Offshore drilling system | |
| US9145753B2 (en) | Trapped pressure compensator | |
| CN101975041B (en) | Well cementing method for avoiding coal bed and device thereof | |
| CN201963231U (en) | Subsea mud suction system for realizing riser-free mud recovery drilling | |
| AU2019202097B2 (en) | Drilling fluid density online regulation device | |
| CN102155163A (en) | Deepwater multifunctional water pump drilling system and installation method thereof | |
| WO2017039649A1 (en) | Software simulation method for estimating fluid positions and pressures in the wellbore for a dual gradient cementing system | |
| CN208900028U (en) | A kind of double-gradient well drilling system | |
| RU2666562C2 (en) | Process for constructing well for exploiting reservoir under sea-bed or ocean-bed | |
| AU2019202100B2 (en) | Drilling fluid density segmented regulation device | |
| US20170370153A1 (en) | Piston assembly to reduce annular pressure buildup | |
| US20120306198A1 (en) | Mechanical-hydraulic subjection sectioned coupler, to seal wells for oil or gas | |
| CN100575659C (en) | A kind of insufficient balance well completion method | |
| CN106703743A (en) | Gel isolation well control method | |
| US4279307A (en) | Natural gas production from geopressured aquifers | |
| CN201705216U (en) | Clamp spring type salvageable bottom plug for expansion pipe | |
| CN111028648A (en) | Deep water drilling deep gas invasion simulation test system and method | |
| RU68588U1 (en) | THREE-PACK INSTALLATION FOR SIMULTANEOUSLY SEPARATE DOWNLOADING OF THE WORKING AGENT IN THREE STRAYS WITH THE COLUMN DISCONNECTOR | |
| CN202000892U (en) | Multi-functional deep-water undersea pump drilling system | |
| NO20181299A1 (en) | Artificial lift method | |
| GB2592937A8 (en) | Downhole apparatus and methods | |
| NO327689B1 (en) | Method of installing a rudder body in an oil / gas well and rudder body for carrying out the method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FGA | Letters patent sealed or granted (standard patent) |