CN112836406B - Drilling process weight-on-bit modeling method considering uncertain damping coefficient - Google Patents

Drilling process weight-on-bit modeling method considering uncertain damping coefficient Download PDF

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CN112836406B
CN112836406B CN202110045008.XA CN202110045008A CN112836406B CN 112836406 B CN112836406 B CN 112836406B CN 202110045008 A CN202110045008 A CN 202110045008A CN 112836406 B CN112836406 B CN 112836406B
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吴敏
马斯科
曹卫华
陈略峰
陆承达
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Abstract

The invention discloses a drilling process weight on bit modeling method considering uncertain damping coefficients, aiming at the field of geological drilling engineering, which comprises the following steps: firstly, modeling a drilling machine lifting system, a drilling string system and a drill bit-rock action mechanism, constructing a drilling string longitudinal motion equation, obtaining a state space model depending on uncertain damping coefficients, solving model parameters by using field drilling tool parameters and historical data, and finally setting the uncertain feeding damping coefficients. The method of the invention considers the characteristic that the actual drill string system is composed of discrete units, and based on a finite element method, a high-freedom model with equivalent freedom degree to the actual drilling tool number is invented. The introduced damping model can reflect the drill bit-rock action in the current environment by setting the damping coefficient, so that a drilling pressure dynamic model suitable for different environments is established. The field data shows that the model is able to better fit the dynamic response from the drawworks rotational speed input to the weight-on-bit output.

Description

Drilling process bit pressure modeling method considering uncertain damping coefficient
Technical Field
The invention relates to the field of geological drilling engineering, in particular to a drilling pressure modeling method in a drilling process considering uncertain damping coefficients.
Background
The drilling process is an important way of deep resource energy exploration, the bit pressure is one of key operating parameters in the drilling process, and the bit pressure is controlled and maintained at a preset expected value in the drilling process, so that the safety and the high efficiency of the whole drilling process are ensured. The weight on bit is a function of the longitudinal stress to which the drill string is subjected and the longitudinal movement of the drill string. Deep geological drilling often requires traversing multiple complex formations to reach a target area and obtain a complete core. In the process, the drill string is typically tens or hundreds of centimeters in diameter and extends continuously to thousands of meters in length to reach the target horizon. Although a single drill rod is very rigid, the overall slenderness ratio of a drill string consisting of hundreds of drill rods is extremely small, and the flexibility characteristic is not negligible. In addition, as the drilling process is a process of driving a drilling tool to interact with the stratum, the dynamic change of the rock breaking of the drill bit can be caused by the change of the lithology of the stratum, and the drilling engineering parameters (such as the rotating speed of a turntable, the pump amount, the mud density and the like) and the model of the drilling tool (such as the size of the drill bit, the type of the drill bit and the like) can influence the rock breaking process of the drill bit, so that the drilling process has uncertainty.
At present, the work of many scholars and related drilling companies in the aspect of bit pressure control is developed based on low-order models, most of the models are generated by system identification, the structural parameters are fixed, the flexibility is low, real-time adjustment and reaction of high-frequency dynamic and stratum environment influence cannot be realized by combining actual drilling tool types and drilling data, and the practical physical significance is avoided. Although the model can reflect the trend of the low-frequency response of the weight on bit, the high-order dynamic characteristics brought to the system by the flexible drill string are not considered. Meanwhile, none of the parameters in the model can directly reflect the characteristics of the stratum which is currently drilled and encountered, so that the parameters of the whole model need to be changed according to different stratum environments, and the model is not convenient to adjust and analyze in a complex and changeable geological environment. Therefore, on one hand, the establishment of a high-freedom drill string motion model is an effective means for considering the flexible high-frequency characteristics of the drill string, and can help us to analyze the high-order dynamic characteristics of the bit pressure response; on the other hand, the model can use the drill bit-rock effect considering the uncertain damping coefficient as a boundary condition, and the stratum uncertainty can be effectively considered. The established model can guide the design of the weight-on-bit controller, help to understand the weight-on-bit dynamics in different stratums and under different drilling tool combinations, realize the high-precision control of the weight-on-bit, and guarantee the safety and high efficiency of the drilling process, so the establishment of the dynamic weight-on-bit model in the drilling process has practical significance.
Disclosure of Invention
The invention discloses a drilling pressure modeling method considering uncertain damping coefficients in a drilling process, and aims to solve the technical problems that in the prior art, models are mostly based on system identification, structural parameters are fixed, flexibility is low, and real-time adjustment and reaction of high-frequency dynamic and stratum environment influence cannot be realized by combining actual drilling tool types and drilling data.
Firstly, based on a finite element method, regarding each drill rod unit as a discrete unit, constructing a finite element equation of drill string motion, and taking an uphole hoisting system model and a downhole drill bit-rock action model as boundary conditions; converting a finite element equation into a parameter dependent state space model with the input of the rotating speed of a winch drum and the output of the on-well drilling pressure by selecting a proper state variable; solving parameters in the model by combining parameters of a drilling machine and a drilling tool of an actual well site; and finally, selecting a section of appropriate field data, and determining the undetermined feeding damping coefficient in the model by utilizing a dichotomy.
The invention relates to a drilling process weight on bit modeling method considering uncertain damping coefficients, which comprises the following steps:
considering that a drill string system is formed by splicing drill rod units, dividing the drill string system into discrete units of the number of drilling tools according to the number of the drilling tools such as the drill rods, the drill collars and the like, defining two ends of each section of the drill rods and the drill collars as generalized nodes, acquiring a mass matrix, a rigidity matrix and a damping matrix corresponding to each section of the drilling tool units, combining the mass matrix, the rigidity matrix and the damping matrix into a global parameter matrix, and establishing a finite element model of the drill string system;
establishing a drilling machine lifting system model and a drill bit-rock action model, taking the drilling machine lifting system model and the drill bit-rock action model as boundary conditions into the finite element model of the drill column system, and constructing a longitudinal motion equation of the drill column;
selecting the on-well drilling pressure, the speed and the speed difference of each generalized node as state variables of the longitudinal motion equation of the drill string, and calculating a parameter dependence state space equation from the input of the rotating speed of the winch to the output of the on-well drilling pressure;
solving the determined parameters in the parameter-dependent state space equation according to the sizes and material parameters of the drill rod and the drill collar, the radius of the winch and the parameters of the drilling rope;
adjusting the feeding damping coefficient in the parameter-dependent state space equation by using a bisection method according to the winch rotating speed and the on-well drilling pressure data in the drilling process;
and establishing a drilling pressure dynamic model in the current environment drilling process according to the parameter-dependent state space equation, the determined parameters and the feeding damping coefficient.
The invention has the following beneficial effects: the method can effectively realize the modeling of the drilling pressure in the drilling process by utilizing the parameters of the field drilling tool and the historical engineering data, and reveal the dynamic change characteristic of the drilling pressure under the current condition, thereby guiding the design of the controller, improving the control precision, ensuring the safety and the efficiency of the drilling process, and having practicability and applicability.
Drawings
FIG. 1 is a flow chart of a weight-on-bit modeling method of the present invention for a drilling process that takes into account an uncertain damping coefficient;
FIG. 2 is a schematic diagram of the model architecture of the present invention;
FIG. 3 is a frequency response curve of a model of the longitudinal motion of the drill string of the present invention;
FIG. 4 is a step response curve of a model of the longitudinal motion of the drill string of the present invention;
FIG. 5 is an iterative tuning process of the feed damping coefficient in the drill string longitudinal movement model of the present invention;
FIG. 6 is a comparison of weight-on-bit response and actual weight-on-bit data in a model of longitudinal movement of the drill string of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention will be further described with reference to the accompanying drawings.
Referring to fig. 1, fig. 1 is a flow chart of a weight-on-bit modeling method for a drilling process considering uncertain damping coefficients according to the present invention, which specifically comprises the following steps:
s1: establishing finite element model of drill column system
Referring to fig. 2, a drill string system is a key component connecting the uphole and downhole. Based on the field process, the drill string is made up of different drill tool combinations, usually including differentA size drill pipe, a weighted drill pipe and a drill collar. The length of each drilling tool is about 9 meters, and hundreds of drilling tools are needed to reach target layers with the depth of thousands of meters. The finite element method is a method of discretizing a continuous system into discrete elements and approximately solving the system motion. Considering the characteristic that the drill string system is composed of discrete units, the invention directly considers each drilling tool as one discrete unit, considers the connection point of the discrete units as a generalized node and establishes a finite element equation. The number of each discrete unit of the drill string system consisting of N drilling tools is 1 to N from top to bottom, and the total number of the discrete units is N +1 generalized nodes. Cell mass matrix M for each cell taking into account only node longitudinal displacementi∈R2×2And a stiffness matrix Ki∈R2×2A matrix can be represented in the form:
Figure BDA0002896895980000031
the matrix can construct generalized node motion equations at two ends of a single unit, all drilling tools such as drill rods and drill collars are considered to be connected end to end, generalized nodes at the connection positions are combined into a node, and then a global mass matrix and a stiffness matrix for constructing a finite element equation can be deduced from the unit mass matrix and the stiffness matrix:
Figure BDA0002896895980000032
Figure BDA0002896895980000041
obtaining a global quality matrix M E R(N+1)×(N+1)And the stiffness matrix K ∈ R(N+1)×(N+1)And describing the structural damping of the drill string system by adopting Rayleigh damping, wherein a damping matrix of the Rayleigh damping can be expressed as a linear combination form of a mass matrix and a rigidity matrix as follows:
C＝αM+βK (4)
where α and β are the coefficients of the mass matrix and stiffness matrix, respectively.
S2: constructing a longitudinal equation of motion for a drill string
Referring to fig. 2, the drill string is subjected to hook loading and bottom hole weight at the top and bottom, respectively. The finite element equation of the drill string takes the hook load on the well and the weight on the drill bit at the bottom of the well as boundary conditions. The finite element motion equation comprising N +1 generalized nodes is constructed as follows:
Figure BDA0002896895980000042
where x ∈ [ x ]1,x2,…,xN+1]T∈RN+1Represents the displacement of N +1 generalized nodes; the superscript of x denotes the first derivative, which denotes the second derivative, i.e.
Figure BDA0002896895980000043
Which is indicative of the speed of the node,
Figure BDA0002896895980000044
representing node acceleration; the coefficients M, K and C are respectively a mass matrix, a rigidity matrix and a damping matrix of N +1 units of the drill string system, FhE.R represents hook load, FdE R represents the downhole weight-on-bit resulting from the bit-rock interaction, both by the factor E1∈[1,0,…,0]T∈RN+1And E2∈[0,0,…,1]T∈RN+1Respectively acting on the top and bottom of the drill string and hooked with FhThe epsilon R is specifically as follows:
Fh＝nFl
Figure BDA0002896895980000045
Xdl＝∫RdwΩdwdt (6)
wherein, FlThe tension on the single drilling string can be measured by a dead string tension sensor. n is the number of ropes wound on the crown block and the travelling block, KlIs a well drilling lineAn equivalent stiffness coefficient. x is the number of1And XdlRespectively the displacement of the generalized node at the top of the drill string and the total elongation of the drill string. R isdwAnd ΩdwRespectively winch radius and angular velocity. Weight-on-bit F downhole when considering all initial conditions as zeros＝-Fh。
Bottom hole weight on bit FdThe epsilon R is specifically as follows:
Figure BDA0002896895980000051
wherein the content of the first and second substances,
Figure BDA0002896895980000052
is the speed of the generalized node at the bottom most end of the drill string and represents the rate at which the drill bit is fed through the formation. k is a radical ofrThe feed damping coefficient has different values according to different stratum environments.
S3: establishing a parameter dependent state space model
Based on a finite element equation of a drill string system, a state space model from winch rotating speed input to on-well bit pressure output is constructed, and proper state variables are selected firstly.
Selecting the state variable as
Figure BDA0002896895980000053
The model constructed was of the form:
Figure BDA0002896895980000054
u:＝Ωdwe R represents the system input, i.e. the winch drum angular velocity.
ys:＝FsE R is the system output, namely the drilling pressure on the well.
The model state matrix A depends linearly on the uncertain feed damping coefficient krMatrix B represents the winch speed input matrix, matrix CsRepresenting the system weight-on-hole output matrix.
Figure BDA0002896895980000055
A，B，Cs，H，H1And H2The method specifically comprises the following steps:
Figure BDA0002896895980000056
Figure BDA0002896895980000057
wherein O isi×jIs a zero matrix of i rows and j columns, KtIs a transformation matrix of the global stiffness matrix K.
S4: solving the determined parameters
The method mainly utilizes the parameters of the drilling machine and the drilling tool to calculate the parameters of the aboveground lifting system and the drilling column system.
For a certain well site, six drilling tools, namely a phi 89mm drill pipe (dp1), a phi 127mm drill pipe (dp2), a phi 127mm weighted drill pipe (hdp), a phi 158mm drill collar (dc1), a phi 178mm drill collar (dc2) and a phi 203mm drill collar (dc3), are used at the well site.
The parameters of the drilling machine and the types of the parameters of the drilling tool are shown in the table I:
table-drilling machine parameter kind and drilling tool parameter kind
Figure BDA0002896895980000061
Note: subscript theta represents six drilling tools of dp1, dp2, hdp, dc1, dc2 and dc3
From the above parameters, the total number N of drill string model elements is:
N＝ndp1+ndp2+nhdp+ndc1+ndc2+ndc3 (11)
cross-sectional area S of each drillΘComprises the following steps:
Figure BDA0002896895980000062
the obtained unit mass matrix and the obtained rigidity matrix are respectively as follows:
Figure BDA0002896895980000063
the corresponding relationship between the drill type Θ and the unit number i is shown in the table two:
table two drilling tool type and unit number i corresponding relation
Figure BDA0002896895980000064
S5: setting feed damping coefficient
In the drilling process, the feeding damping coefficient is an undetermined parameter determined by a stratum to be met, and the feeding damping coefficient needs to be set by using historical bit pressure and drilling speed data of a current well section when a drill string longitudinal motion model under the current stratum condition is established. In the invention, the drilling rate data is used as the model input, and the mean square error between the output of the model and the filtered drilling pressure data is optimized so as to obtain the feeding damping coefficient according with the current stratum environment. The method comprises the following specific steps:
(1) first, a section of data of the on-site weight-on-bit and the drilling rate in the starting process is selected, namely a section of data including data from the drilling process to the final weight-on-bit stabilizing near the expected value. Filtering the bit pressure data, and obtaining the drilling speed data D according to the number of ropes and the radius of a winch drumropConverting into model input, namely the winch drum angular velocity;
Figure BDA0002896895980000071
(2) using converted winch drum angular velocity data as model input to obtain simulated bit pressure data, comparing the final stable amplitude with actual data, and preliminarily judging a feeding damping coefficient krUpper and lower boundaries k ofhAnd klIf the final stable bit pressure is larger overall, the currently selected k is indicatedrLarger, otherwise, k is selectedrIs small;
(3) carry-in khAnd klConstructing a boundary model, using the converted winch drum angular speed as the model input, and solving the output weight D of the upper boundary model and the lower boundary modelhwob、DlwobAnd filtering the weight-on-bit data D in situwobMean square error J betweenhAnd Jl；
Figure BDA0002896895980000072
Figure BDA0002896895980000073
(4) And updating the upper and lower boundaries of the parameters. If Jh(k)≥Jl(k) Then k is updatedhIs kh(k+1)＝[kh(k)+kl(k)]/2，klRemain unchanged. Otherwise, update klIs kl(k+1)＝[kh(k)+kl(k)]/2，khRemain unchanged. Wherein k is the number of iterations;
(5) repeating the steps (3) and (4) until the parameters converge to a satisfactory error precision, and if the range satisfies:
Figure BDA0002896895980000074
obtaining the finally determined feeding damping coefficient krIs kr＝(kh+kl)/2。
From the step 1 to the step 5, a drilling pressure dynamic model of the drilling process under the current stratum environment can be established for any well site using the electric drive drilling machine, and the method has better universality. Taking the well site and drill assembly mentioned in step 4 as an example, referring to FIG. 3, FIG. 3 shows the resulting model from the input winch speed ΩdwWeight on bit F to the wellsThe frequency response of the frequency response can be found that a plurality of resonance modes exist in a high-frequency part, the bit weight control effect can be influenced in practical situations, and meanwhile, different feeding damping coefficients bring great difference to the gain of a low-frequency part of the frequency response. Referring to fig. 4, it can be seen from the step response of the model in fig. 4 that the models with different feed damping coefficients have different gains and time constants. The model in the invention considers the high-frequency characteristic and uncertain feeding damping coefficient brought by the flexible drill string.
The initial upper and lower bounds at a given feed damping coefficient are kh＝2×108And kl＝1.5×108While, iteratively adjusting krReferring to fig. 5, a smaller range for determining k is obtained after 10 iterationsrThe value of (a). And substituting the finally determined feeding damping coefficient to obtain a dynamic model of the bit pressure under the current stratum environment. Referring to fig. 6, the actual drilling rate data is used as the model input, and the obtained simulated weight-on-bit output and the filtered weight-on-bit data show better consistency in the variation trend and the time scale. 0-150 s in the selected data is the drilling down process, the drill bit does not contact the well bottom, and the well bottom drilling pressure F is obtained at the momentdIs 0; and then the drill bit contacts the bottom of the well within 150-2000 s to start rock breaking, and the drilling pressure continuously rises and is finally stabilized around a set value.
The invention has the following beneficial effects after the concrete implementation: the method can effectively realize the modeling of the drilling pressure in the drilling process by utilizing the parameters of the field drilling tool and the historical engineering data, and reveal the dynamic change characteristic of the drilling pressure under the current condition, thereby guiding the design of the controller, improving the control precision, ensuring the safety and the efficiency of the drilling process, and having practicability and applicability.
While the present invention has been described with reference to the embodiments shown in the drawings, the present invention is not limited to the embodiments, which are illustrative and not restrictive, and it will be apparent to those skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope of the invention as defined in the appended claims.

Claims (8)

1. A drilling process weight-on-bit modeling method considering uncertain damping coefficients is characterized by comprising the following steps:
considering that a drill string system is formed by splicing drill tool units, acquiring the number of the drill tool units, dividing the drill string system into discrete units of the number of the drill tool units, defining two ends of each drill tool unit as generalized nodes, acquiring a mass matrix, a rigidity matrix and a damping matrix corresponding to each drill tool unit, combining the mass matrix, the rigidity matrix and the damping matrix into a global parameter matrix, and establishing a finite element model of the drill string system;
establishing a drilling machine lifting system model and a drill bit-rock action model, taking the drilling machine lifting system model and the drill bit-rock action model as boundary conditions to be brought into the finite element model of the drill string system, and establishing a longitudinal motion equation of the drill string;
selecting the on-well drilling pressure, the speed and the speed difference of each generalized node as state variables of the longitudinal motion equation of the drill string, and calculating a parameter dependence state space equation from the input of the rotating speed of the winch to the output of the on-well drilling pressure;
solving the determined parameters in the parameter-dependent state space equation according to the parameters of the lifting system of the drilling machine and the parameters of each drilling tool;
adjusting the feeding damping coefficient in the parameter-dependent state space equation by using a bisection method according to the winch rotating speed and the on-well drilling pressure data in the drilling process;
and establishing a drilling pressure dynamic model in the current environment drilling process according to the parameter-dependent state space equation, the determined parameters and the feeding damping coefficient.
2. The drilling process weight-on-bit modeling method considering the uncertain damping coefficient as recited in claim 1, wherein the drill string system is considered to be composed of spliced drill tool units, the number of the drill tool units is obtained, the drill string system is divided into discrete units of the number of the drill tool units, two ends of each drill tool unit are defined as generalized nodes, a mass matrix, a rigidity matrix and a damping matrix corresponding to each drill tool unit are obtained and combined into a global parameter matrix, and the step of establishing the finite element model of the drill string system comprises the following steps:
according to the type and the quantity of drilling tools, each drilling tool unit is considered as a discrete unit, two ends of each drilling tool unit are defined as generalized nodes, and a mass matrix and a rigidity matrix of each drilling tool unit are calculated;
according to the characteristics that each drilling tool unit is connected end to end, the mass and stiffness matrix of each drilling tool unit is combined into a global mass matrix and a global stiffness matrix, and a Rayleigh damping is used for describing a global damping matrix;
and establishing a finite element model of the drill string system according to the global mass matrix, the global rigidity matrix and the global damping matrix.
3. The drilling process weight-on-bit modeling method considering uncertain damping coefficients as claimed in claim 2, characterized in that the mass matrix M of each drill uniti∈R2×2And a stiffness matrix Ki∈R2×2Is a matrix of the form:
Figure FDA0003572528280000021
wherein N is the number of drilling tools.
4. The method of claim 1, wherein the step of establishing a drill rig hoist system model and a bit-rock interaction model, and introducing the drill rig hoist system model and the bit-rock interaction model as boundary conditions into the drill string system finite element model, and constructing a drill string longitudinal motion equation comprises:
considering a drilling machine lifting system as a multi-strand spring system, and establishing a spring model describing hook loading as a drilling machine lifting system model;
considering the bit-rock action as the bit is subjected to feed damping, and establishing a damping model describing the drilling pressure at the bottom of the well as a bit-rock action model;
and respectively acting on two ends of a drill string system according to hook load and bottom hole bit pressure, and taking the drill lifting system model and the drill bit-rock action model as boundary conditions to be brought into the finite element model of the drill string system to obtain a longitudinal motion equation of the drill string system.
5. The method of claim 4, wherein the drill string system longitudinal motion equation has the form:
Figure FDA0003572528280000022
where x ∈ [ x ]1,x2,…,xN+1]Τ∈RN+1Displacement representing N +1 generalized nodes; the superscript of x denotes the first derivative, which denotes the second derivative, i.e.
Figure FDA0003572528280000023
Which is indicative of the speed of the node,
Figure FDA0003572528280000024
representing node acceleration; the coefficients M, C and K are respectively a mass matrix, a rigidity matrix and a damping matrix of the N +1 units of the drill column system, FhE.R represents hook load, FdE R represents the downhole drilling pressure generated by the rock action of the drill bit and the passing coefficient E1∈[1,0,…,0]Τ∈RN+1And E2∈[0,0,…,1]Τ∈RN+1Respectively acting on the top and bottom of the drill string and hooked with FhThe epsilon R is specifically as follows:
Fh＝nFl
Figure FDA0003572528280000025
Xdl＝∫RdwΩdwdt
wherein, FlThe tension on the single drilling rope is measured by a dead rope tension sensor; n is the number of ropes wound on the crown block and the travelling block, KlIs the drilling line equivalent stiffness coefficient; x is the number of1And XdlRespectively the displacement of the generalized node at the top of the drill column and the total elongation of the drilling string; rdwAnd ΩdwWinch radius and angular velocity, respectively; weight-on-bit F downhole when considering all initial conditions as zeros＝-Fh；
Bottom hole weight on bit FdE.R is expressed as:
Figure FDA0003572528280000031
wherein, the first and the second end of the pipe are connected with each other,
Figure FDA0003572528280000032
is the speed of the generalized node at the bottommost end of the drill string, representing the rate at which the bit is fed in the formation, krThe feed damping coefficient has different values according to different stratum environments.
6. The drilling process weight-on-bit modeling method considering the uncertain damping coefficient as recited in claim 1, wherein the step of selecting the weight-on-bit, the generalized node speeds and the speed difference as state variables of the drill string longitudinal motion equation, and calculating the parameter-dependent state space equation from the winch rotation speed input to the weight-on-bit output comprises:
based on the finite element model of the drill string system, a parameter dependent state space model from winch rotating speed input to ground bit pressure output is constructed, and the selected state variables are as follows:
Figure FDA0003572528280000033
the parameter-dependent state space model has the form:
Figure FDA0003572528280000034
wherein u ═ Ωdwe.R represents the system input, i.e. the winch drum angular velocity, ys:＝FsE is R as the system output, namely the drilling pressure on the well, and the state matrix A depends on the uncertain feeding damping coefficient k linearlyrMatrix B represents the winch speed input matrix, matrix CsRepresenting the system weight-on-hole output matrix.
7. The method of claim 1, wherein the modeling of weight-on-bit for the drilling process is based on the uncertainty damping coefficient,
the rig hoist system parameters include: equivalent stiffness coefficient K of drilling ropelThe number n of drilling line ropes and the winch radius Rdw；
The drilling tool unit parameters comprise: diameter D, wall thickness DtLength l, modulus of elasticity E, density ρ and number ne；
The determining parameters in the parameter-dependent state-space equation include: the cross-sectional area, mass matrix and stiffness matrix of each drill unit.
8. The method of claim 1, wherein the step of adjusting the magnitude of the feed damping coefficient in the parameter-dependent state space equation using bisection based on the drilling process drawworks speed and the uphole weight data comprises:
s51, selecting data of the on-site drilling pressure and the drilling speed in a section of starting process, and converting the drilling speed into the angular speed of a winch drum according to the number of ropes and the radius of the winch drum;
s52, taking the winch drum angular velocity data as the input of the parameter dependence state space model to obtain the simulated bit weight and obtain the final stable amplitudeComparing the value with actual data to obtain a feeding damping coefficient k preliminarilyrUpper and lower boundaries k ofhAnd kl；
S53, band khAnd klConstructing an upper boundary model and a lower boundary model of the feeding damping coefficient, taking the winch drum angular velocity data as the input of the upper boundary model and the lower boundary model, and respectively solving the mean square error J between the output bit pressure and the field bit pressure data of the upper boundary model and the lower boundary modelhAnd Jl；
S54, according to JhAnd JlProceed to the upper and lower boundary khAnd klIs updated if Jh≥JlThen k is updatedhIs kh＝(kh+kl) /2, otherwise update klIs kl＝(kh+kl)/2；
S55, repeating the steps S53 and S54 until the upper and lower boundaries khAnd klConverging to a smaller range to obtain a finally determined feeding damping coefficient krIs kr＝(kh+kl)/2。
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