CN108222865B - Self-feedback three-phase system drilling fluid mixing system and method for mixing drilling fluid - Google Patents

Self-feedback three-phase system drilling fluid mixing system and method for mixing drilling fluid Download PDF

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CN108222865B
CN108222865B CN201810007757.1A CN201810007757A CN108222865B CN 108222865 B CN108222865 B CN 108222865B CN 201810007757 A CN201810007757 A CN 201810007757A CN 108222865 B CN108222865 B CN 108222865B
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seawater
density
base slurry
additive
flow
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CN108222865A (en
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孙宝江
何伟
张贺恩
魏士鹏
梅天林
刘华清
蔡德军
李相鹏
高永海
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China University of Petroleum East China
CNPC Offshore Engineering Co Ltd
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China University of Petroleum East China
CNPC Offshore Engineering Co Ltd
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    • 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
    • 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
    • E21B21/10—Valve arrangements in drilling-fluid circulation systems
    • E21B21/106—Valve arrangements outside the borehole, e.g. kelly valves

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Abstract

本发明涉及一种自反馈三相体系钻井液混合系统，包括：混合器、海水池、基浆池、添加剂池；海水池通过第一管路与混合器相连，基浆池通过第二管路与混合器相连，添加剂池通过第三管路与混合器相连；其中，海水池容纳海水，用于给第一管路提供海水原料；基浆池容纳基浆池，用于给第二管路提供基浆原料；添加剂池容纳添加剂，用于给第三管路提供添加剂原料；海水、基浆、添加剂进入混合器混合后经密度自反馈模块进入泥浆池或者泥浆泵管汇。添加自反馈钻井液混合系统的密度自反馈模块可以使混合液密度更加精确，还可以通过检测密度与设置或设计密度对比校准流量计，并可以使系统在不控制泵功率的情况下实现各种比例原料的混合。

Figure 201810007757

The invention relates to a self-feedback three-phase system drilling fluid mixing system. Connected to the mixer, the additive pool is connected to the mixer through a third pipeline; wherein, the seawater pool accommodates seawater for supplying seawater raw materials to the first pipeline; the base slurry pool accommodates the base slurry pool for supplying the second pipeline The base slurry raw material is provided; the additive pool accommodates the additive for supplying the additive raw material to the third pipeline; the seawater, the base slurry and the additive enter the mixer to be mixed and then enter the mud pool or the mud pump manifold through the density self-feedback module. Adding the density self-feedback module of the self-feedback drilling fluid mixing system can make the density of the mixed fluid more accurate, and can also calibrate the flowmeter by comparing the detected density with the set or designed density, and the system can achieve various Proportional mix of raw materials.

Figure 201810007757

Description

Self-feedback three-phase system drilling fluid mixing system and method for mixing drilling fluid
Technical Field
The invention belongs to the technical field of drilling, and particularly relates to a self-feedback three-phase system drilling fluid mixing system and a method for mixing drilling fluid.
Background
The drilling fluid balance drilling is the mature drilling technology in the world at present, and the balance drilling technology utilizes the static pressure of the drilling fluid to balance the bottom pressure so as to ensure the normal operation of drilling. However, deep water surface layer drilling faces shallow geological disaster risks such as shallow flow and shallow gas, and drilling problems such as narrow pressure window caused by weak stratum:
1. the safety density window is narrow, the well structure design is difficult, and the casing cannot be lowered to a preset depth. In deep water drilling, seawater exerts much less overburden pressure than rock on land because seawater has a lower density than rock. Therefore, since the fracture pressure gradient of the deep sea formation is smaller than that of the land formation with the same well depth, the safety margin between the formation pressure gradient and the fracture pressure gradient is very small, the safety density window becomes narrower as the water depth increases, the design difficulty of the well structure becomes greater, and the casing cannot be lowered to the predetermined well depth.
2. Drilling is in high-pressure shallow laminar flow, and well control is difficult to effectively implement. Deep water seafloor often contains a large amount of high pressure shallow laminar flow, including shallow water flow and shallow gas flow. The kick of shallow water flow is represented by difficulty in drilling and casing well cementation, and can cause borehole collapse and even seabed settlement in severe cases and possibly cause oil well abandonment; when drilling and meeting shallow layer air current, because the stratum is more shallow, do not have lower surface casing usually, fail to install wellhead assembly, in case take place the kick of shallow layer air current, gas can a large amount of entering into the pit shaft annular space, reduces the annular space effective pressure. In this case, the annulus pressure cannot be timely controlled without the wellhead.
A special kill method is therefore needed to address this challenge. During the drilling operation, as long as the measurement while drilling device monitors that the underground stratum has abnormal high pressure, the required high-density drilling fluid can be pumped out by manually inputting a working instruction or automatically operating the working instruction without circulating and waiting for preparing the high-density drilling fluid, so that the dynamic drilling operation with operation and weighting is realized.
In the prior art, a self-feedback device is not provided, the mixed liquid which cannot meet the requirement cannot be detected and adjusted again, the long-time use of the system can cause the reading deviation of a flowmeter, further cause the deviation of the proportion of the base slurry, the seawater and the additive and the preset parameter or the design parameter, and finally cause the density of the mixed liquid which cannot meet the requirement and cause the well killing failure, which is very fatal in the implementation of the technology; in the prior art, no pumping pressure protection device is arranged, so that mixing of various mixing ratios cannot be realized, or the safety and reliability of a pump cannot be ensured.
The existing mixer has the problems of complex structure, large volume, difficult installation and the like. And the high-speed fluid sprayed out of the nozzle can generate inelastic collision in the cabin, particularly when the inlet flow of the two-phase fluid is close, the two-phase fluid collision can form radial flow and directly flows out of the mixer, the collision also causes the momentum loss of the high-speed fluid, the high-speed low-speed shearing of the fluid is an important factor of mixing, the momentum loss also influences the high efficiency of mixing, and the uniform mixing under various discharge capacities and mixing ratios cannot be ensured.
Disclosure of Invention
In order to solve the defects in the engineering problems and adjust the drilling fluid in real time, the invention provides a self-feedback drilling fluid mixing system.
In order to achieve the purpose, the technical scheme adopted by the invention is as follows:
self-feedback three-phase system drilling fluid mixing system includes: a mixer, a seawater pool, a base slurry pool and an additive pool; the seawater pool is connected with the mixer through a first pipeline, the base slurry pool is connected with the mixer through a second pipeline, and the additive pool is connected with the mixer through a third pipeline; wherein the seawater pool contains seawater and is used for providing seawater raw materials for the first pipeline; the base slurry tank is used for accommodating the base slurry tank and supplying a base slurry raw material to the second pipeline and destroying the net structure of the high-viscosity fluid; the additive pool contains additives and is used for providing additive raw materials for the third pipeline; seawater, base slurry and additives enter a mixer to be mixed and then enter a slurry pool or a slurry pump manifold through a density self-feedback module.
Compared with the prior art, the invention has the following beneficial effects:
1. the density self-feedback module of the self-feedback three-phase system drilling fluid mixing system is added, so that the density of the mixed liquid is more accurate, and the flowmeter can be calibrated by comparing the detected density with the set or designed density.
2. The overflow valve arranged between the pump and the flowmeter can lead the system to realize the mixing of raw materials with various proportions under the condition of not controlling the power of the pump. When the opening degree of the control valve is too small, the pump pressure is increased, the overflow valve is opened to enable the fluid to flow back to the pool, the mixing of the seawater and the base slurry in all proportions is realized, the working safety of the pump is protected, and the reliability of the whole system is improved.
3. The shearing pump is adopted in the basic slurry conveying pump, the mesh structure of high-viscosity fluid is broken, the two-phase fluid can be mixed with each other, and the mixing is more efficient.
4. The nozzle of the mixer of the self-feedback three-phase system drilling fluid mixing system is in a T shape with the cabin body, the two nozzles are opposite to each other, are perpendicular to the axial line of the cabin body and are positioned at the eccentric position where the nozzles are just staggered, the nozzles adopt a reducing torsion structure, the torsion angle is 15-25 degrees, the reducing can accelerate the increase of turbulence degree of fluid, the torsion enables the fluid to form a primary vortex and increase the shearing contact area, and the mixing is more facilitated; the nozzle is directly welded to the cabin body, and the nozzle is directly welded to the cabin body, so that the size of the mixer can be reduced, and the turbulence degree is reduced due to the fact that the high-speed fluid is inefficiently mixed with the similar fluid in the flow channel behind the nozzle after being ejected out of the nozzle and the flow speed is reduced; the nozzle eccentric design can avoid inelastic collision of two fluids of the right-handed T-shaped mixer in the mixer, reduce the momentum loss and the radial flow generated after collision, lead to the direct outflow of the fluid from the mixer, be more favorable for the direct shearing of the ejected high-speed fluid and the low-speed fluid in the cabin, and form a secondary vortex, increase the mixing time of the fluid in the mixer, and lead the fluid to be efficiently mixed, and the mixer is not influenced by factors such as the discharge capacity mixing ratio and the like.
5. The additive inlet adopts a shunting structure, so that the additive can be shunted to the wall of the mixer, the additive is converged into the seawater and the base slurry flowing out at high speed and is mixed in the vortex in the cabin, the additive is prevented from directly flowing through the center of the mixer, the mixing time is shortened, and the three phases are mixed more uniformly.
Drawings
FIG. 1 is a schematic structural diagram of a self-feedback three-phase system drilling fluid mixing system;
FIG. 2 is a schematic flow diagram of a self-feedback three-phase system drilling fluid mixing system;
FIG. 3 is a schematic cross-sectional view of a mixer;
FIG. 4 is a schematic right-view of the mixer;
FIG. 5 is a schematic view of a mixer nozzle;
FIG. 6 is a schematic cross-sectional view of a mixer nozzle;
FIG. 7 is a schematic cross-sectional view of a mixer additive inlet;
FIG. 8 is a schematic diagram showing the variation of density in the axial direction of the mixer;
FIG. 9 shows the average density and the mean square error of different mixing ratios at the outlet of the mixer;
FIG. 10 is a schematic diagram of the three-phase mixing density variation of the mixer;
in the figure: 1a, a seawater pool, 1b, a base slurry pool, 1c, an additive pool, 2a, a mortar pump, 2b, a shear pump, 2c, a centrifugal pump, 3a, a first overflow valve, 3b, a second overflow valve, 3c, a third overflow valve, 4a, a first flow meter, 4b, a second flow meter, 4c, a third flow meter, 5a, a first control valve, 5b, a second control valve, 5c, a third control valve, 6, a mixer, 7, a density self-feedback module, 8, an on-site control box, 9, a remote hydraulic parameter design calculation control module, a seawater nozzle 601a, a base slurry nozzle 601b, a cabin 602, a seawater inlet 603, a base slurry inlet 604, an additive inlet 605, a mixed liquid outlet 606 and a diversion structure 607.
Detailed Description
As shown in fig. 1, the self-feedback three-phase system drilling fluid mixing system comprises: a mixer 6, a seawater tank 1a, a base slurry tank 1b and an additive tank 1 c; the seawater pool 1a is connected with the mixer 6 through a first pipeline, the base slurry pool 1b is connected with the mixer 6 through a second pipeline, and the additive pool 1c is connected with the mixer 6 through a third pipeline; wherein the seawater pool 1a contains seawater for providing a seawater raw material to the first pipeline; the base slurry tank 1b accommodates a base slurry tank for supplying a base slurry raw material to the second pipeline and breaking the network structure of the high-viscosity fluid; the additive tank 1c contains an additive for supplying an additive raw material to the third pipeline; seawater, base slurry and additives enter a mixer 6 to be mixed and then enter a slurry pool or a slurry pump manifold through a density self-feedback module 7.
A mortar pump 2a, a first flow meter 4a and a first control valve 5a are sequentially arranged on the first pipeline from the seawater pool 1a to the mixer 6; an overflow return bypass is arranged between the mortar pump 2a and the first flowmeter 4a, the overflow return bypass is connected to the seawater pool 1a, and a first overflow valve 3a is arranged on the overflow return bypass; the mortar pump 2a pumps seawater and enters the first pipeline, the first flowmeter 4a measures seawater flow in the first pipeline, the first overflow valve 3a is opened when in work, and the seawater overflows back to the seawater pool 1 a.
A shear pump 2b, a second flow meter 4b and a second control valve 5b are sequentially arranged on the second pipeline from the basic slurry tank 1b to the mixer 6; an overflow return bypass is arranged between the shear pump 2b and the second flowmeter 4b, a second overflow valve 3b is arranged on the overflow return bypass, and the overflow return bypass is connected to the base slurry tank 1 b; the shear pump 2b pumps the base slurry to enter the second pipeline, the second flowmeter 4b measures the flow of the base slurry in the second pipeline, the second overflow valve 3b is opened when working, and the base slurry overflows back to the base slurry pool 1 b.
A centrifugal pump 2c, a third flow meter 4c and a third control valve 5c are sequentially arranged on the third pipeline from the additive tank 1c to the mixer 6; an overflow return bypass is arranged between the centrifugal pump 2c and the third flow meter 4c, the overflow return bypass is connected to the additive tank 1c, and a third overflow valve 3c is arranged on the overflow return bypass; the centrifugal pump 2c pumps the additive into a third pipeline, a third flow meter 4c measures the flow of the additive in the third pipeline, a third overflow valve 3c is opened when working, and the additive overflows back into an additive pool.
The first flowmeter 4a in the first pipeline, the second flowmeter 4b in the second pipeline and the third flowmeter 4c in the third pipeline are connected with the field control box 8 in a wired or wireless mode; a first control valve meter 5a in a first pipeline, a second flow meter 5b in a second pipeline and a third flow meter 5c in a third pipeline are connected with a field control box 8 in a wired or wireless mode; the density self-feedback module 7 is connected with the field control box 8 in a wired or wireless mode; the field control box 8 is connected with a remote hydraulic parameter design calculation control module 9 in a wired or wireless mode. A first flowmeter 4a in the first pipeline transmits a seawater flow signal to a field control box 8, and the field control box 8 transmits the seawater flow signal to a remote hydraulic parameter design calculation control module 9; the remote hydraulic parameter design calculation control module 9 transmits a control signal to the field control box 8, and the field control box 8 transmits the control signal to the first control valve 5a to adjust the flow of the seawater. The second flowmeter 4b in the second pipeline transmits a base slurry flow signal to the field control box 8, the field control box 8 transmits the base slurry flow signal to the remote hydraulic parameter design calculation control module 9, the remote hydraulic parameter design calculation control module 9 transmits a control signal to the field control box 8, and the field control box 8 transmits the control signal to the second control valve 5b to adjust the base slurry flow. A third flow meter 4c in the third pipeline transmits an additive flow signal to a field control box 8, and the field control box 8 transmits the additive flow signal to a remote hydraulic parameter design calculation control module 9; the remote hydraulic parameter design calculation control module 9 transmits a control signal to the field control box 8, and the field control box 8 transmits the control signal to the third control valve 5c to adjust the additive flow. The density self-feedback module 7 transmits the density signal of the outlet of the mixer to the field control box 8, and the field control box 8 transmits the density signal to the remote hydraulic parameter design calculation control module 9.
The field control box 8 can read the flow rates of the seawater, the base slurry and the additive and the density of the mixed liquid at the outlet of the mixer, and can manually adjust the opening of the control valve. The remote hydraulic parameter design and calculation module 9 can manually input a command of required drilling fluid density, and can also calculate the required drilling fluid density according to the formation pressure and calculate the required discharge capacity of seawater, base slurry and additives according to the drilling fluid density.
As shown in fig. 1 and 2, the remote hydraulic parameter designing and calculating module 9 may manually input a command of a required drilling fluid density, or design and calculate the drilling fluid density by using the remote hydraulic parameter designing and calculating module 9 according to the formation pressure, design the proportion and the required displacement of the base slurry, the seawater and the additive, merge the base slurry and the additive into the mixer 6 by the first manifold and the second manifold, adjust the opening of the first control valve 5a to adjust the seawater flow rate according to the calculated data, adjust the opening of the second control valve 5b to adjust the base slurry flow rate, and adjust the opening of the third control valve 5c to adjust the additive flow rate. The first flow meter 4a transmits the seawater flow, the second flow meter 4b transmits the base slurry flow and the third flow meter 4c transmits the additive flow data to the control module 9 to compare with the design parameters, and the opening of the control valve is further adjusted until the seawater, the base slurry and the additive reach the calculated displacement. When the mixing ratio of the seawater is small, the opening degree of the first control valve 5a is small, the pump pressure is increased, the first overflow valve 3a is opened, and the seawater flows back to the seawater pool 1 a; when the base slurry mixing ratio is small, the opening degree of the second control valve 5b is small, the pump pressure is increased, the second overflow valve 3b is opened, and the base slurry flows back to the base slurry tank 1 b; when the mixing ratio of the additive is small, the opening degree of the third control valve 5c is small, the pump pressure is increased, the third overflow valve 3c is opened, and the additive flows back to the additive tank 1c, so that the mixing of the seawater, the base slurry and the additive in various proportions and discharge capacities is realized; the density self-feedback module 7 transmits a density signal of the outlet of the mixer to the field control box 8, the field control box 8 transmits the density signal to the remote hydraulic parameter design calculation control module 9 to be compared with an instruction or a designed density, the discharge capacity of seawater, base slurry and an additive is recalculated when the expected value is not reached, a closed loop is formed until the density meets the requirement, the field drilling requirement is met, and the error of the flowmeter can be found in time according to the density feedback value to be corrected.
It can be understood that when no additive is needed, the additive inlet 12 in the third pipeline can be closed, the proportion of the base slurry and the seawater and the required discharge capacity are designed, the seawater and the base slurry are converged into the mixer 6 through the first manifold, the opening of the first control valve 5a is adjusted according to the calculated data to adjust the flow of the seawater, and the opening of the second control valve 5b is adjusted to adjust the flow of the base slurry. The first flowmeter 4a transmits the seawater flow and the second flowmeter 4b transmits the base slurry flow data to the control module 9 to be compared with design parameters, and the opening of the control valve is further adjusted until the seawater and the base slurry reach the calculated displacement. When the mixing ratio of the seawater is small, the opening degree of the first control valve 5a is small, the pump pressure is increased, the first overflow valve 3a is opened, and the seawater flows back to the seawater pool 1 a; when the base slurry mixing ratio is small, the opening degree of the second control valve 5b is small, the pump pressure is increased, the second overflow valve 3b is opened, and the base slurry flows back into the base slurry tank 1b, so that the mixing of the seawater and the base slurry in various proportions and discharge capacities is realized; the density self-feedback module 7 transmits a density signal of the outlet of the mixer to the field control box 8, the field control box 8 transmits the density signal to the remote hydraulic parameter design calculation control module 9 to be compared with an instruction or a designed density, the discharge capacity of seawater, base slurry and an additive is recalculated when the expected value is not reached, a closed loop is formed until the density meets the requirement, the field drilling requirement is met, and the error of the flowmeter can be found in time according to the density feedback value to be corrected.
As shown in fig. 3, the mixer 6 includes: a cabin 602, a seawater inlet 603, a base slurry inlet 604, an additive inlet 605 and a mixed liquid outlet 606; the additive inlet 605 and the mixed liquid outlet 606 are respectively connected with two ends of the cabin 602, and the seawater inlet 603 and the base slurry inlet 604 are positioned at one end of the cabin 602 close to the additive 605 inlet and are respectively divided at two sides of the cabin 602; a seawater nozzle 601a is arranged between the cabin 602 and the seawater inlet 603, a base slurry nozzle 601b is arranged between the cabin 602 and the base slurry inlet 603, and a flow dividing structure 607 is arranged between the cabin 602 and the additive inlet 605; as shown in fig. 4, the seawater nozzle 601a and the base slurry nozzle 601b are both arranged opposite to the cabin body in an eccentric manner, and the optimal eccentric distance is the distance when no intersection part exists on the projection of the vertical mixing cabin; seawater inlet 603, base slurry inlet 604 and additive inlet 605 are used for mixing seawater, base slurry and additives which are gathered into the cabin body through a nozzle; wherein the additive inlet 605 can be closed when the additive is not needed, so as to complete the mixing of the base slurry and the seawater; the mixed liquor is discharged through outlet 606.
As shown in fig. 5, the seawater nozzle 601a and the base slurry nozzle 601b have the same structure and are both dumbbell-shaped, the dumbbell-shaped can increase the shearing area, and the nozzle shape belongs to the prior art; as shown in fig. 6, inlets of the seawater nozzle 601a and the base slurry nozzle 601b adopt a dumbbell-shaped twisting reducing structure, the twisting angle is 15-25 degrees, the reducing structure accelerates the fluid to increase the turbulence, the twisting can increase the shearing area, and primary vortex is formed; the shortest thickness of the seawater nozzle 601a and the base slurry nozzle 601b is 8-10cm, so that high-speed fluid and vortex can be formed, and the size can be smaller; the seawater nozzle 601a and the base slurry nozzle 601b are directly connected with the cabin body, so that an inefficient mixing area at an outlet is saved, the turbulence degree of high-speed fluid is ensured, and the structure is more compact; the eccentric structure enables the two fluids to form secondary vortex in the mixer, and the vortex is beneficial to increasing the contact time and the contact area of the two components in the cabin; the structure is beneficial to the movement of two components in the mutual occupied space in a volume diffusion mode, the fluid is subjected to the actions of shearing, extruding, stretching and the like to achieve uniform distribution, the inelastic collision of the high-speed fluid in the cabin is avoided, the high-speed fluid is directly sheared and mixed with the low-speed fluid in the cabin, the momentum loss is reduced, the mixing time of the fluid in the mixer is prolonged, the two fluids are mixed more efficiently, and the requirements of various discharge capacities and mixing ratios can be met. The invention has more compact structure, does not affect the installation mode (horizontal and vertical), saves the space of the ocean platform, can make the installation more convenient and saves the installation time.
As shown in fig. 7, the additive entry adopts reposition of redundant personnel structure 607, the inside round platform shape that is of reposition of redundant personnel structure 607, it is the hemisphere to be close to additive entry position, the outside is empty round platform shape, outside small head is connected with the additive entry, the major part is connected with the mixing cabin, the inside 4 rectangular blocks that link together with the outside of reposition of redundant personnel structure, the reposition of redundant personnel structure can shunt the additive to blender wall department, make the additive converge into high-speed outflow's sea water and base stock, mix in the inboard swirl, avoid the additive directly to flow through from the blender center and reduce the mix time, it is more even to make the three-phase mix.
As shown in fig. 1 and 2, the method for mixing drilling fluid by using the self-feedback three-phase system drilling fluid mixing system comprises the following steps:
1. the hydraulic parameter design calculation control module 9 obtains a required drilling fluid density instruction, or the hydraulic parameter design and calculation module 9 is used for designing and calculating the drilling fluid density according to the formation pressure, and the proportion and the required discharge capacity of seawater, base slurry and an additive are designed;
the hydraulic parameter design calculation control module 9 of the drilling fluid mixing system calculates the mud density and the discharge capacity required by killing the well according to the formation pressure according to the principle that: under the density and the discharge capacity, the pressure of a flowing circulating frictional resistance liquid adding column in the well is equal to the pore pressure of the stratum but less than the fracture pressure of the stratum; according to the conditions of offshore drilling, the density of the well killing fluid meets the following requirements:
Pr≤Pwf＝ρmgh+Pfr+ρswghsw
in the formula:
Pr-formation pressure, Pa;
Pwf-bottom hole pressure, Pa;
ρm-density of drilling fluid in kg/m after mixing3；
h-depth of mud line from bottom hole, m;
Pfr-annulus friction, Pa;
ρswsea water density, kg/m3；
hsw-water depth, m;
the annular friction resistance is calculated by the following formula:
Figure BDA0001539210140000111
in the formula:
Dwi-section i wellbore diameter, m;
Dp-drill rod outer diameter, cm;
dc-drill collar outside diameter, cm;
ρm-density of drilling fluid in kg/m after mixing3；
Mu-slurry plastic viscosity, Pa · s;
q-displacement, L/s;
Hi-an ith wellbore length;
b is constant, the inner flat drill rod B is 0.51655, and the through hole drill rod B is 0.57503;
the maximum final mud density is calculated from the formation fracture pressure:
Figure BDA0001539210140000121
in the formula:
h-depth of mud line from bottom hole, m;
ρswsea water density, kg/m3；
hsw-water depth, m;
ρ′mend slurry Density, kg/m3；
Pf-formation fracture pressure, MPa;
control of the dynamic kill volume is required while adjusting the drilling mud density. The discharge capacity of drilling fluid required for realizing well killing is as follows:
Figure BDA0001539210140000122
in the formula:
Figure BDA0001539210140000123
Pr-formation pressure, Pa;
ρswsea water density, kg/m3；
ρm-density of drilling fluid in kg/m after mixing3；
hsw-water depth, m;
h-depth of mud line from bottom hole, m;
mu-slurry plastic viscosity, Pa · s;
Dwi-section i wellbore diameter, m;
Dp-drill rod outer diameter, cm;
Dc-drill collar outer diameter, cm;
hi-an ith wellbore length;
b is constant, the inner flat drill rod B is 0.51655, and the through hole drill rod B is 0.57503;
the maximum drilling displacement for ensuring the safety of the shaft is as follows:
Figure BDA0001539210140000131
the discharge capacity of the drilling fluid also meets the requirement of carrying rocks, and the minimum discharge capacity required for meeting the requirement of carrying rocks is as follows:
Figure BDA0001539210140000132
in the formula:
Qa-minimum displacement, L/s, to meet the requirement for carrying rock.
Dw-wellbore diameter, cm;
Dp-drill rod outer diameter, cm;
ρm-density of drilling fluid in kg/m after mixing3；
The displacement of weighted drilling fluid and seawater can be calculated by the following formula:
ρm(Q1+Q2+Q3)＝ρ0Q1+ρswQ2+ρtjQ3
Q＝Q1+Q2+Q3
Q2＝aQ3
Figure BDA0001539210140000133
in the formula:
a is the required preset ratio of seawater to additive, and has no dimension;
ρ0base slurry density of weighted drilling fluid in kg/m3；
ρtjDensity of additive, kg/m3；
Q1In order to increase the discharge capacity of the base slurry of the drilling fluid, L/s;
Q2the discharge capacity of seawater is L/s;
Q3is the additive displacement, L/s;
2. adjusting the seawater flow controlled by a first control valve, the base slurry flow controlled by a second control valve and the additive flow controlled by a third control valve according to the displacement and proportion data calculated by the remote hydraulic parameter design and calculation module 9;
3. when the required flow of the seawater is small, the opening degree of the first control valve 5a is reduced, the pump pressure of the mortar pump 2a is increased, the first overflow valve 3a is opened to release the pressure, and the seawater flows back to the seawater pool 1 a; when the required flow of the base slurry is small, the opening degree of the second control valve 5b is reduced, the pump pressure of the shear pump 2b is increased, the second overflow valve 3b is opened to release the pressure, and the base slurry flows back to the base slurry tank 1 b; when the required flow of the additive is small, the opening degree of a third control valve 5c is reduced, the pump pressure of a centrifugal pump 2c is increased, a third overflow valve 3c is opened to release pressure, and the additive flows back to an additive tank 1 c;
4. the first flow meter 4a transmits the seawater flow, the second flow meter 4b transmits the base slurry flow and the third flow meter 4c transmits the additive flow data to the control module 9 to compare with the design parameters, and the opening of the control valve is further adjusted until the seawater, the base slurry and the additive reach the calculated displacement;
5. the seawater passes through a first control valve 5a, the base slurry passes through a second control valve 5b and the additive passes through a third control valve 5c and then is mixed in a mixer;
6. the mixer outlet density self-feedback module 7 feeds the measured density back to the control module to be compared with the instruction or the designed density, the opening of the control valve is adjusted again when the measured density cannot reach the expected value, a closed loop is formed until the density meets the requirement, the field drilling requirement is met, and the error of the flowmeter can be found in time according to the density feedback value and corrected.
Experiment and simulation verification: as shown in FIG. 8, the density of the base slurry was 2.0g/cm3Sea water density 1.025g/cm3And the density change chart on the mixer axis is obtained after the base slurry and the seawater are mixed by the mixer under the condition of 3:2 mixing ratio under different discharge capacities. And the well killing requirement is met according to the equivalent density of the drilling fluid and the annular circulation friction resistance during well killing. The circulation friction is closely related to the discharge capacity, so the mixer must be capable of meeting the requirement of mixing drilling fluids with different discharge capacities. Especially, when the large displacement is needed in an emergency, the reliability of the mixer is tested. From fig. 8, the mixer can rapidly mix the base slurry and the seawater uniformly and stably in the mixer under the discharge capacity of 20L/s-100L/s. As shown in fig. 9: under the condition that the discharge capacity is 50L/s and under the condition of different mixing ratios of the basic slurry and the seawater, the density after theoretical mixing and the mixing density and the mean square error of a simulation experiment show that the error between the outlet density of the mixer and a theoretical value is small and stable, and the field requirement can be met. As shown in fig. 10: and (3) uniformly taking x, x1, x2, x3 and x4 as a mixing effect diagram when the seawater is 30L/s, the base slurry is 20L/s and the additive is 5L/s, respectively representing different axial linear density change curves in the mixer, wherein the length of the mixer is 0.5m, and the density at a mixing outlet is uniformly mixed.

Claims (2)

1.一种自反馈三相体系钻井液混合系统，包括：混合器，海水池通过第一管路与混合器相连，基浆池通过第二管路与混合器相连，添加剂池通过第三管路与混合器相连，海水池给第一管路提供海水原料；基浆池给第二管路提供基浆原料，并破坏高粘流体的网状结构；添加剂池给第三管路提供添加剂原料；海水、基浆、添加剂进入混合器混合后经密度自反馈模块进入泥浆池或者泥浆泵管汇；其特征在于：1. A self-feedback three-phase system drilling fluid mixing system, comprising: a mixer, a seawater pool is connected to the mixer through a first pipeline, a base slurry pool is connected to the mixer through a second pipeline, and an additive pool is connected to the mixer through a third pipeline The road is connected to the mixer, the seawater pool provides seawater raw material for the first pipeline; the base slurry tank provides the base slurry raw material for the second pipeline, and destroys the network structure of high-viscosity fluid; the additive tank provides additive raw material for the third pipeline ; Seawater, base slurry and additives enter the mixer and enter into the mud pool or the mud pump manifold through the density self-feedback module after mixing; it is characterized in that: 第一管路上由海水池至混合器方向依次安装砂浆泵、第一流量计和第一控制阀；其中，砂浆泵和第一流量计间设有溢流回流旁路，溢流回流旁路连接至海水池，溢流回流旁路上设有第一溢流阀；砂浆泵抽取海水进入第一管路，第一流量计测量第一管路中海水流量，第一溢流阀工作时打开，海水溢流回海水池中；A mortar pump, a first flow meter and a first control valve are installed in sequence on the first pipeline from the seawater pool to the mixer; wherein, an overflow return bypass is arranged between the mortar pump and the first flow meter, and the overflow return bypass is connected To the seawater pool, there is a first overflow valve on the overflow and return bypass; the mortar pump draws seawater into the first pipeline, the first flowmeter measures the seawater flow in the first pipeline, the first overflow valve is opened when it is working, and the seawater overflow back into the sea pool; 第二管路上由基浆池至混合器方向依次安装剪切泵、第二流量计和第二控制阀；其中，剪切泵和第二流量计间装有溢流回流旁路，溢流回流旁路上设有第二溢流阀，溢流回流旁路连接至基浆池；剪切泵抽取基浆进入第二管路，第二流量计测量第二管路中基浆流量，第二溢流阀工作时打开，基浆溢流回基浆池中；The shear pump, the second flow meter and the second control valve are installed in sequence on the second pipeline from the base slurry tank to the mixer; among them, an overflow return bypass is installed between the shear pump and the second flow meter, and the overflow returns The bypass is provided with a second overflow valve, and the overflow return bypass is connected to the base slurry tank; the shear pump draws the base slurry into the second pipeline, the second flow meter measures the flow of the base slurry in the second pipeline, and the second overflow When the flow valve is open, the base slurry overflows back into the base slurry pool; 第三管路上由添加剂池至混合器方向依次安装离心泵、第三流量计和第三控制阀；其中，离心泵和第三流量计间设有溢流回流旁路，溢流回流旁路连接至添加剂池，溢流回流旁路上设有第三溢流阀；离心泵抽取添加剂进入第三管路，第三流量计测量第三管路中添加剂流量，第三溢流阀工作时打开，添加剂溢流回添加剂池中；A centrifugal pump, a third flow meter and a third control valve are installed in sequence on the third pipeline from the additive pool to the mixer; among them, an overflow return bypass is arranged between the centrifugal pump and the third flow meter, and the overflow return bypass is connected To the additive pool, there is a third overflow valve on the overflow return bypass; the centrifugal pump draws the additive into the third pipeline, the third flowmeter measures the flow of the additive in the third pipeline, the third overflow valve is opened when it is working, and the additive overflow back into the additive tank; 第一管路中的第一流量计、第二管路中的第二流量计、第三管路中的第三流量计通过有线或者无线的方式与现场控制箱连接；第一管路中的第一控制阀、第二管路中的第二控制阀、第三管路中的第三控制阀通过有线或者无线的方式与现场控制箱；密度自反馈模块通过有线或者无线的方式与现场控制箱连接；现场控制箱与远程水力参数设计计算控制模块通过有线或无线的方式连接；第一管路中的第一流量计向现场控制箱传输海水流量信号，现场控制箱将海水流量信号传输给远程水力参数设计计算控制模块；远程水力参数设计计算控制模块传输控制信号到现场控制箱，现场控制箱将控制信号传输至第一控制阀控制调节海水流量；第二管路中的第二流量计向现场控制箱传输基浆流量信号，现场控制箱将基浆流量信号传输给远程水力参数设计计算控制模块，远程水力参数设计计算控制模块传输控制信号到现场控制箱，现场控制箱将控制信号传输至第二控制阀控制调节基浆流量；第三管路中的第三流量计向现场控制箱传输添加剂流量信号，现场控制箱将添加剂流量信号传输给远程水力参数设计计算控制模块；远程水力参数设计计算控制模块传输控制信号到现场控制箱，现场控制箱将控制信号传输至第三控制阀控制调节添加剂流量；密度自反馈模块将混合器出口密度信号传输给现场控制箱，现场控制箱将密度信号传输给远程水力参数设计计算控制模块；The first flowmeter in the first pipeline, the second flowmeter in the second pipeline, and the third flowmeter in the third pipeline are connected to the field control box by wired or wireless means; The first control valve, the second control valve in the second pipeline, and the third control valve in the third pipeline communicate with the on-site control box through wired or wireless means; the density self-feedback module communicates with on-site control through wired or wireless means The on-site control box is connected with the remote hydraulic parameter design and calculation control module by wired or wireless means; the first flowmeter in the first pipeline transmits the seawater flow signal to the on-site control box, and the on-site control box transmits the seawater flow signal to the The remote hydraulic parameter design calculation control module; the remote hydraulic parameter design calculation control module transmits the control signal to the on-site control box, and the on-site control box transmits the control signal to the first control valve to control and adjust the seawater flow; the second flow meter in the second pipeline The base slurry flow signal is transmitted to the on-site control box. The on-site control box transmits the base slurry flow signal to the remote hydraulic parameter design calculation control module. The remote hydraulic parameter design calculation control module transmits the control signal to the on-site control box, and the on-site control box transmits the control signal. To the second control valve to control and adjust the flow rate of the base slurry; the third flow meter in the third pipeline transmits the additive flow signal to the on-site control box, and the on-site control box transmits the additive flow signal to the remote hydraulic parameter design and calculation control module; the remote hydraulic parameter The design calculation control module transmits the control signal to the on-site control box, and the on-site control box transmits the control signal to the third control valve to control and adjust the additive flow; the density self-feedback module transmits the mixer outlet density signal to the on-site control box, and the on-site control box transmits the density signal to the on-site control box. The signal is transmitted to the remote hydraulic parameter design calculation control module; 现场控制箱可以读取海水、基浆和添加剂流量以及混合器出口混合液密度，并能手动调节控制阀开度；远程水力参数设计与计算模块可手动输入所需钻井液密度指令，也可以根据地层压力计算所需钻井液密度，并根据钻井液密度计算出所需海水、基浆及添加剂排量；远程水力参数设计与计算模块可手动输入所需钻井液密度指令，或根据地层压力，利用远程水力参数设计与计算模块进行设计计算钻井液密度，设计出基浆、海水和添加剂的比例及所需排量，通过第一管汇将海水、第二管汇将基浆和第三管汇将添加剂汇入混合器，根据计算数据调整第一控制阀开度调节海水流量，调整第二控制阀开度调节基浆流量，调整第三控制阀开度调节添加剂流量；第一流量计将海水流量、第二流量计将基浆流量、第三流量计将添加剂流量数据传输给远程水力参数设计计算控制模块与设计参数对比，进一步调整控制阀开度，直至海水、基浆、添加剂达到计算排量；当海水混配比小时，第一控制阀开度小，泵压升高，第一溢流阀打开，海水回流至海水池中；当基浆混配比小时，第二控制阀开度小，泵压升高，第二溢流阀打开，基浆回流至基浆池中；当添加剂混配比小时，第三控制阀开度小，泵压升高，第三溢流阀打开，添加剂回流至添加剂池中，实现海水、基浆和添加剂各种配比和排量的混合；密度自反馈模块将混合器出口密度信号传输给现场控制箱，现场控制箱将密度信号传输给远程水力参数设计计算控制模块与指令或设计密度对比，达不到预期值重新计算海水、基浆和添加剂排量，形成闭环，直至密度达到要求，满足现场钻井需求，并可根据密度反馈值，及时发现流量计误差加以修正；The on-site control box can read the flow rates of seawater, base slurry and additives, and the density of the mixed liquid at the mixer outlet, and can manually adjust the opening of the control valve; the remote hydraulic parameter design and calculation module can manually input the required drilling fluid density instructions, or according to local conditions. The required drilling fluid density is calculated by the formation pressure, and the required displacement of seawater, base slurry and additives is calculated according to the drilling fluid density; the remote hydraulic parameter design and calculation module can manually input the required drilling fluid density command, or according to the formation pressure, use The remote hydraulic parameter design and calculation module is used to design and calculate the density of drilling fluid, design the ratio and required displacement of base slurry, seawater and additives, and use the first manifold to connect the seawater, the second manifold to the base slurry and the third manifold. Add the additive into the mixer, adjust the opening of the first control valve to adjust the flow of seawater according to the calculated data, adjust the opening of the second control valve to adjust the flow of the base slurry, and adjust the opening of the third control valve to adjust the flow of the additive; Flow, the second flowmeter transmits the base slurry flow, and the third flowmeter transmits the additive flow data to the remote hydraulic parameter design calculation control module to compare with the design parameters, and further adjust the opening of the control valve until the seawater, base slurry, and additives reach the calculated discharge rate. When the mixing ratio of seawater is small, the opening of the first control valve is small, the pump pressure increases, the first overflow valve is opened, and the seawater is returned to the seawater pool; when the mixing ratio of base slurry is small, the opening of the second control valve is small. When the additive mixing ratio is small, the opening of the third control valve is small, the pump pressure increases, and the third overflow valve is opened, The additive is returned to the additive tank to realize the mixing of seawater, base slurry and additives in various proportions and displacements; the density self-feedback module transmits the density signal of the mixer outlet to the on-site control box, and the on-site control box transmits the density signal to the remote hydraulic power The parameter design calculation control module is compared with the command or design density, and the displacement of seawater, base slurry and additives cannot be reached, and the displacement of seawater, base slurry and additives is recalculated to form a closed loop until the density reaches the requirements and meets the drilling needs on site. According to the density feedback value, it can be detected in time. The flowmeter error is corrected; 混合器，包括：舱体、海水入口、基浆入口、添加剂入口、混合液出口；添加剂入口、混合液出口分别与舱体两端相连，海水入口、基浆入口位于舱体靠近添加剂入口一端且分居舱体两侧；舱体与海水入口间设有海水喷嘴，舱体与基浆入口间设有基浆喷嘴，舱体与添加剂入口间设有分流结构；海水喷嘴、基浆喷嘴均与舱体正对偏心设置，偏心距为海水喷嘴和基浆喷嘴在垂直混合舱的投影上无相交部分时的距离；海水入口、基浆入口和添加剂入口将海水、基浆和添加剂通过喷嘴汇入舱体进行混合；其中不需要添加剂时可关闭添加剂入口，完成基浆和海水的混合；混合后的混合液通过出口排出；The mixer includes: a cabin, a seawater inlet, a base slurry inlet, an additive inlet, and a mixed liquid outlet; the additive inlet and the mixed liquid outlet are respectively connected to both ends of the cabin, and the seawater inlet and the base slurry inlet are located at one end of the cabin close to the additive inlet and Separated on both sides of the cabin; seawater nozzles are arranged between the cabin and the seawater inlet, base slurry nozzles are arranged between the cabin and the base slurry inlet, and a split flow structure is arranged between the cabin and the additive inlet; seawater nozzles and base slurry nozzles are connected to the tank. The body is eccentrically set, and the eccentric distance is the distance between the seawater nozzle and the base slurry nozzle when there is no intersection on the projection of the vertical mixing tank; the seawater inlet, the base slurry inlet and the additive inlet bring seawater, base slurry and additives into the tank through the nozzles When the additive is not needed, the inlet of the additive can be closed to complete the mixing of the base slurry and the seawater; the mixed liquid is discharged through the outlet; 海水喷嘴、基浆喷嘴结构相同，均为哑铃形状；海水喷嘴、基浆喷嘴入口采用哑铃型状扭转缩径结构，扭转角度为15-25度；The seawater nozzle and the base slurry nozzle have the same structure and are all in the shape of dumbbells; the inlet of the seawater nozzle and the base slurry nozzle adopts a dumbbell-shaped twisted diameter-reducing structure, and the twist angle is 15-25 degrees; 添加剂入口采用分流结构，分流结构内部为圆台形，靠近添加剂入口位置为半球形，外部为空圆台形，外部小头与添加剂入口连接，大头与混合器的舱体连接，分流结构内部与外部用四个矩形块连接在一起，分流结构可以将添加剂分流至混合器壁面处，使添加剂汇入高速流出的海水和基浆，在舱内漩涡内混合，避免添加剂直接从混合器中心流过减少混合时间，使三相混合更加均匀。The additive inlet adopts a shunting structure. The inside of the shunting structure is a truncated cone, the position near the additive inlet is hemispherical, and the outside is an empty truncated cone. The outer small head is connected to the additive inlet, and the large head is connected to the mixer. The four rectangular blocks are connected together, and the diverting structure can divert the additives to the wall of the mixer, so that the additives can be fed into the seawater and base slurry flowing out at a high speed, and mixed in the vortex in the cabin to avoid the additives flowing directly from the center of the mixer to reduce mixing. time to make the three-phase mixing more uniform. 2.采用权利要求1所述的自反馈三相体系钻井液混合系统进行混合钻井液的方法，其特征在于，步骤如下：2. adopt the self-feedback three-phase system drilling fluid mixing system according to claim 1 to carry out the method for mixing drilling fluid, it is characterized in that, step is as follows: (1)、远程水力参数设计计算控制模块得到所需钻井液密度指令，或根据地层压力，利用远程水力参数设计与计算模块进行设计计算钻井液密度，并设计出海水、基浆及添加剂的比例及所需排量；(1) The remote hydraulic parameter design and calculation control module obtains the required drilling fluid density command, or according to the formation pressure, the remote hydraulic parameter design and calculation module is used to design and calculate the drilling fluid density, and design the ratio of seawater, base mud and additives and the required displacement; 钻井液混合系统的远程水力参数设计计算控制模块，根据地层压力计算压井所需泥浆密度及排量的原则是：在该密度与排量下，井内的流动循环摩阻加液柱压力等于地层孔隙压力而小于地层破裂压力；根据海上钻井的条件，压井液密度满足：The remote hydraulic parameter design and calculation control module of the drilling fluid mixing system calculates the mud density and displacement required for well killing according to the formation pressure. The pore pressure is lower than the formation fracture pressure; according to the conditions of offshore drilling, the density of the killing fluid satisfies: Pr≤Pwf＝ρmgh+Pfr+ρswghsw P r ≤P wf =ρ m gh+P fr +ρ sw gh sw 式中：where: Pr——地层压力，Pa；P r — formation pressure, Pa; Pwf——井底压力，Pa；P wf ——bottom hole pressure, Pa; ρm——混合后钻井液密度，kg/m3；ρ m —— density of drilling fluid after mixing, kg/m 3 ; h——泥线距井底深度，m；h——the depth of the mud line from the bottom of the well, m; Pfr——环空摩阻，Pa；P fr — annular friction, Pa; ρsw——海水密度，kg/m3；ρ sw — density of seawater, kg/m 3 ; hsw——水深，m；h sw — water depth, m; 环空摩阻的计算用以下公式：The annular friction is calculated using the following formula:
Figure FDA0002699793960000051
Figure FDA0002699793960000051
 式中：where: Dwi——第i段井筒直径，m； Dwi ——Diameter of the i-th section of the wellbore, m; Dp——钻杆外径，cm；D p - the outer diameter of the drill pipe, cm; Dc——钻铤外径，cm；Dc——Drill collar outer diameter, cm; ρm——混合后钻井液密度，kg/m3；ρ m —— density of drilling fluid after mixing, kg/m 3 ; μ——泥浆塑性粘度，Pa·s；μ——mud plastic viscosity, Pa s; Q——排量，L/s；Q——displacement, L/s; Hi——第i段井筒长度；H i ——the length of the i-th section of the wellbore; B——常数，内平钻杆B＝0.51655，贯眼钻杆B＝0.57503；B——constant, inner flat drill pipe B=0.51655, through hole drill pipe B=0.57503; 最大终了泥浆密度根据地层破裂压力求得：The maximum final mud density is obtained according to the formation fracture pressure:
Figure FDA0002699793960000052
Figure FDA0002699793960000052
 式中：where: h——泥线距井底深度，m；h——the depth of the mud line from the bottom of the well, m; ρsw——海水密度，kg/m3；ρ sw — density of seawater, kg/m 3 ; hsw——水深，m；h sw — water depth, m; ρ′m——终了泥浆密度，kg/m3；ρ′ m — final mud density, kg/m 3 ; Pf——地层破裂压力，MPa；P f — formation fracture pressure, MPa; 在调节钻井泥浆密度的同时，需要对动态压井排量进行控制；实现压井所需钻井液排量为：While adjusting the drilling mud density, it is necessary to control the dynamic killing displacement; the required drilling fluid displacement to achieve well killing is:
Figure FDA0002699793960000061
Figure FDA0002699793960000061
 式中：where:
Figure FDA0002699793960000062
Figure FDA0002699793960000062
 Pr——地层压力，Pa；P r — formation pressure, Pa; ρsw——海水密度，kg/m3；ρ sw — density of seawater, kg/m 3 ; ρm——混合后钻井液密度，kg/m3；ρ m —— density of drilling fluid after mixing, kg/m 3 ; hsw——水深，m；h sw — water depth, m; h——泥线距井底深度，m；h——the depth of the mud line from the bottom of the well, m; μ——泥浆塑性粘度，Pa·s；μ——mud plastic viscosity, Pa s; Dwi——第i段井筒直径，m； Dwi ——Diameter of the i-th section of the wellbore, m; Dp——钻杆外径，cm；D p - the outer diameter of the drill pipe, cm; Dc——钻铤外径，cm；D c - the outer diameter of the drill collar, cm; hi——第i段井筒长度；h i ——the length of the i-th section of the wellbore; B——常数，内平钻杆B＝0.51655，贯眼钻杆B＝0.57503；B——constant, inner flat drill pipe B=0.51655, through hole drill pipe B=0.57503; 保证井筒安全的最大钻井排量为：The maximum drilling displacement to ensure wellbore safety is:
Figure FDA0002699793960000063
Figure FDA0002699793960000063
 钻井液排量还应满足携岩要求，达到携岩要求所需最小排量为：The drilling fluid displacement should also meet the rock-carrying requirements, and the minimum displacement required to meet the rock-carrying requirements is:
Figure FDA0002699793960000064
Figure FDA0002699793960000064
 式中：where: Qa——满足携岩要求的最小排量，L/s；Q a ——the minimum displacement to meet the rock-carrying requirements, L/s; Dw——井筒直径，cm；D w — diameter of wellbore, cm; Dp——钻杆外径，cm；D p - the outer diameter of the drill pipe, cm; ρm——混合后钻井液密度，kg/m3；ρ m —— density of drilling fluid after mixing, kg/m 3 ; 加重钻井液与海水的排量可用如下公式进行计算：The displacement of the weighted drilling fluid and seawater can be calculated by the following formula: ρm(Q1+Q2+Q3)＝ρ0Q1+ρswQ2+ρtjQ3 ρ m (Q 1 +Q 2 +Q 3 )=ρ 0 Q 1 +ρ sw Q 2 +ρ tj Q 3 Q＝Q1+Q2+Q3 Q=Q 1 +Q 2 +Q 3 Q2＝aQ3 Q 2 =aQ 3
Figure FDA0002699793960000071
Figure FDA0002699793960000071
 式中：where: a为所需预设海水与添加剂比例，无因次；a is the required preset ratio of seawater and additives, dimensionless; ρ0为加重钻井液基浆密度，kg/m3；ρ 0 is the density of the weighted drilling fluid base slurry, kg/m 3 ; ρtj为添加剂密度，kg/m3；ρ tj is the density of the additive, kg/m 3 ; Q1为加重钻井液基浆排量，L/s；Q 1 is the displacement of the base slurry of the weighted drilling fluid, L/s; Q2为海水排量，L/s；Q 2 is the seawater displacement, L/s; Q3为添加剂排量，L/s；Q 3 is the additive displacement, L/s; (2)、根据远程水力参数设计计算控制模块计算出的排量、比例数据调整第一控制阀控制海水流量、第二控制阀控制基浆流量、第三控制阀控制添加剂流量；(2), adjust the first control valve to control the seawater flow, the second control valve to control the base slurry flow, and the third control valve to control the additive flow according to the displacement and proportional data calculated by the remote hydraulic parameter design calculation control module; (3)、当海水需求流量小时，第一控制阀开度变小，砂浆泵泵压升高，第一溢流阀打开泄压，回流海水至海水池中；当基浆需求流量小时，第二控制阀开度变小，剪切泵泵压升高，第二溢流阀打开泄压，回流基浆至基浆池中；当添加剂需求流量小时，第三控制阀开度变小，离心泵泵压升高，第三溢流阀打开泄压，回流添加剂至添加剂池中；(3) When the seawater demand flow is small, the opening of the first control valve becomes smaller, the pump pressure of the mortar pump increases, the first overflow valve is opened to release the pressure, and the seawater is returned to the seawater pool; when the base slurry demand flow is small, the first overflow valve is opened. The opening of the second control valve becomes smaller, the pump pressure of the shear pump increases, the second overflow valve is opened to release the pressure, and the base slurry is returned to the base slurry pool; when the required flow rate of the additive is small, the opening of the third control valve becomes smaller, and the centrifugal force When the pump pressure rises, the third relief valve is opened to release the pressure, and the additive is returned to the additive pool; (4)、第一流量计将海水流量、第二流量计将基浆流量、第三流量计将添加剂流量数据传输给远程水力参数设计计算控制模块与设计参数对比，进一步调整控制阀开度，直至海水、基浆、添加剂的流量达到计算排量；(4), the first flowmeter transmits the seawater flow, the second flowmeter the base slurry flow, and the third flowmeter the additive flow data to the remote hydraulic parameter design calculation control module to compare with the design parameters, and further adjust the control valve opening, Until the flow of seawater, base slurry and additives reaches the calculated displacement; (5)、海水通过第一控制阀、基浆通过第二控制阀及添加剂通过第三控制阀后在混合器混合；(5), the seawater passes through the first control valve, the base slurry passes through the second control valve, and the additives pass through the third control valve and are mixed in the mixer; (6)、混合器出口密度自反馈模块将所测密度反馈给远程水力参数设计计算控制模块与指令或设计密度对比，不能达到预期值时再次调整控制阀开度，形成闭环，直至密度达到要求，满足现场钻井需求，并可根据密度反馈值，及时发现流量计误差加以修正。(6) The self-feedback module of the outlet density of the mixer feeds back the measured density to the remote hydraulic parameter design calculation control module and compares it with the command or design density. When the expected value cannot be reached, adjust the opening of the control valve again to form a closed loop until the density meets the requirements. , to meet the needs of on-site drilling, and according to the density feedback value, the flowmeter error can be found and corrected in time.
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Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102797451A (en) * 2012-08-29 2012-11-28 中国海洋石油总公司 Automatic control system and method for underground annulus pressure of deep water surface layer drilling

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA2240580C (en) * 1998-06-12 2001-01-16 Roman Anthony Bilak Apparatus and method for subterranean injection of slurried wastes
AU762491C (en) * 1998-10-14 2005-02-17 Tracto-Technik Paul Schmidt Spezialmaschinen Mixing system
CN102029120B (en) * 2010-11-16 2013-04-03 中国海洋石油总公司 Mixing device for regulating density of drilling liquid
CN103894083B (en) * 2014-04-02 2016-04-13 重庆科技学院 A kind of dumb-bell shape nozzle drilling fluid mixed adjusting device

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102797451A (en) * 2012-08-29 2012-11-28 中国海洋石油总公司 Automatic control system and method for underground annulus pressure of deep water surface layer drilling

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
ZM-2钻井液密度调节混合装置的研制与应用;雷宗明等;《天然气工业》;20141130;第34卷(第11期);第82-87页 *
撞击流混合器微观混合性能的研究;李友凤等;《高校化学工程学报》;20120229;参见正文第2节 *

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