CN104453842B - Oil gas well down-hole fault diagnosis system and method - Google Patents

Abstract

The invention relates to an oil gas well down-hole fault diagnosis system and method. The diagnosis system is provided with a well drilling liquid inlet flow sensor, a well drilling liquid outlet flow sensor, a pressure sensor, a multi-channel signal collecting and sending device, a multi-channel signal receiving device and a computer system. The well drilling liquid inlet flow sensor is fixed on a ground manifold or a stand pipe. The well drilling liquid outlet flow sensor is fixed at a well drilling liquid backflow pipe or a mud ditch at a well opening of an oil gas well. The pressure sensor is arranged on the stand pipe. The multi-channel signal collecting and sending device is arranged on a drilling table of a well frame. Down-hole fault forecasting, locating and quantification diagnosis can be achieved, the accuracy and the identifying effect of fault diagnosis are greatly improved, changing of well drilling liquid flow and pressure is grasped timely and accurately, early-stage diagnosis of well leakage, well kicking and drilling rig washout is achieved, cost is low, mounting is convenient, a mounting position is reasonable, and the safety factor is high.

Description

Oil/gas Well down-hole fault diagnosis system and its diagnostic method

Technical field

The present invention relates to oil-well drilling equipment technical field, more particularly to a kind of Oil/gas Well down-hole fault diagnosis system and its Diagnostic method.

Background technology

In drilling process, if the failure that prediction down-hole that can be not promptly and accurately occurs, it is possible to cause down-hole Complex situations or accident, suffer huge economic loss.Down-hole failure mainly includes leakage, well kick, drill stem washout, borehole well instability Deng.Just because of the multiple and seriousness of the accident such as leakage, well kick, drill stem washout, borehole well instability, Chinese scholars have been carried out Substantial amounts of theoretical and experimental exploring.

Comprehensive mud logging technology is that the item collection grown up on the basis of geological logging is examined with geologic observations analysis, gas is bored The comprehensive site mud logging technology that survey, drilling liquid parameter measurement, prediction of formation pressure and drilling engineering parameter measurement are integrated.It is comprehensive Closing well logging can provide well logging geologic section, lithology data, formation fluid data etc. for geological research personnel, be drilling technology personnel It is the important means of real-time monitoring drilling failure there is provided terminal monitor, monitoring and analysis drilling well situation.Oil both domestic and external Scientific worker has utilized compound logging equipment, has carried out tracking, the monitoring of shaft building process drilling safety, and drilling well down-hole Failure (including well kick, leakage, drill stem washout, falls water nozzle, water blockoff eye, drilling string not well braked, bit freezing, drilling well and is hampered, oil gas water enchroachment (invasion), falls drilling tool Deng) prediction, prediction research practice, the drilling well to ensure safety played important function.While drilling safety is ensured, well logging Engineering parameter also plays positive effect in terms of speed-raising puies forward effect, optimization drilling well.With the development of engineering parameter well logging, by Gradually define a series of technologies.

But for a long time, China payes attention to both at home and abroad the emphasis of compound logging square with discovery hydrocarbon information etc. in geological logging In the application in face, enough attention is not caused in terms of engineering, despise application of the compound logging in terms of drilling engineering, comprehensive record Well is mainly concentrated in prospect pit aspect using also effect, is seldom adopted in the drillng operation of development well and other type wells.Weight Point lies also in and catch in time hydrocarbon information in drilling process, for drilling engineering in terms of application only to only serve be its function Extension assosting effect.Meanwhile, judge and predict the method for drilling well down-hole failure mainly by one-parameter Threshold Alerts and according to Field experience carries out subjective judgment, and this not only needs Field Force to have the responsibility of height, and needs to know with certain Knowledge level and practical experience, situations such as often there is erroneous judgement, fail to judge.Additionally, for drilling engineering application, compound logging is adopted Sample rate is often too low, and poor real causes the potential larger risk of predictive diagnosis work and error of Drilling Troubles.As can be seen here, Want that using Oil/gas Well down-hole fault diagnosis is carried out using Comprehensive mud logging technology be relatively difficult, there is significant limitation.

The content of the invention

The technical problem to be solved in the present invention is：For existing down-hole fault diagnosis system exist poor real, should Wait not enough with limited, the present invention provides a kind of real-time, for drilling engineering Oil/gas Well down-hole failure Multifunction diagnosing system System and its diagnostic method.

The technical solution adopted for the present invention to solve the technical problems is：Oil/gas Well is provided with well head, drill string and drilling pump, institute State Oil/gas Well and be provided with drill string and drilling pump, the drill string is supported by rig floor and derrick, and the rig floor includes being located at derrick bottom One layer of rig floor, positioned at the quadruple board platform at middle part, the drilling pump is connected with drilling well pump conduit, and the drilling well pump conduit includes discharge pipe Road and suction line, the discharge line is by manifold of ground, and is connected with rotary hose with the standpipe that manifold of ground is connected, The suction line connects mud pit, and the rotary hose connects faucet, standpipe, the oil gas are installed with the derrick Drilling fluid return pipe or mud ditch are provided between the well head and mud pit of well, Oil/gas Well down-hole fault diagnosis system has drilling fluid Inlet flow rate sensor, drilling fluids outlet flow sensor, pressure transducer, multi-channel signal acquiring and dispensing device, lead to more Road signal receiving device and computer system, the drilling fluid inlet flow rate sensor is fixed on manifold of ground or standpipe, institute State drilling fluids outlet flow sensor to be fixed on drilling fluid return pipe or mud ditch, the pressure transducer is arranged on ground line In remittance or standpipe, the multi-channel signal acquiring is arranged on one layer of rig floor with dispensing device, the drilling fluid inlet flow rate sensing Device, drilling fluids outlet flow sensor, pressure transducer are connected with multi-channel signal acquiring with dispensing device, the multichannel Signals collecting is wired or wireless connection, multi channel signals reception device and meter with dispensing device and multi channel signals reception device Calculation machine system is wired connection.

Multi-channel signal acquiring and dispensing device are arranged on one layer of rig floor, this position can cause each sensor with it is many Channel signal is gathered and the connection cables between dispensing device obtain most reasonably distributing.Drilling fluid inlet flow rate sensor is used for Collection is injected into the mud flow rate signal inside drill string from ground；Drilling fluids outlet flow sensor is used for gathering well head backflow The flow signal of drilling fluid in pipeline；Pressure transducer is used for measuring the pressure of pipeline inner part drilling well liquid；Multi-channel signal acquiring The conditioning process such as the flow of the measuring point and pressure signal are acquired, are amplified, being filtered with dispensing device, and to described stream Amount carries out longer-distance transmission and pick-up with pressure signal；Multi channel signals reception device is received in a wireless or wired way From the multi-channel signal acquiring and the flow and pressure signal of dispensing device.Present inventor is to required sensor The position that species and sensor are placed is made that rational arrangement, is entered using the drilling fluid on being arranged on manifold of ground or standpipe Mouth flow transducer and pressure transducer, the drilling fluids outlet flow sensor of wellhead drilling fluid reflux pipe, for measuring not Data parameters are sent to computer system by flow in the same time and pressure signal, combining wireless or wired R-T unit, by counting Calculation machine system carries out the analysis of signal and processes.The Oil/gas Well down-hole fault diagnosis system of the present invention utilizes drilling-fluid circulation system Pepeline characteristic differentiating underground working.For example, for entrance, the contrast of rate of discharge signal, can be used to predict leakage, well Gush；And mud flow rate can realize drill string thorn leakage, drillling tool twisting off, drill bit water blockoff eye, well cleaning, annular space with standpipe pressure signal The forecast of the operating modes such as flow condition, power drilling tool state analysiss, and the detection of bit operation state；With reference to entrance, outlet stream Amount signal can realize being accurately positioned for the failures such as underground drill stem thorn leakage, well kick, leakage with standpipe pressure signal.

The drilling fluid inlet flow rate sensor be fixed on manifold of ground or standpipe on close derrick position.

Drilling fluids outlet flow sensor is fixed on the drilling fluid return pipe or mud ditch.

The pressure transducer is arranged on manifold of ground or standpipe near the position of one layer of rig floor.

The drilling fluid inlet flow rate sensor, drilling fluids outlet flow sensor, pressure transducer by cable with Multi-channel signal acquiring is connected with dispensing device.

The multi-channel signal acquiring is not less than 3000Hz and can gather full frequency band with dispensing device for signal sampling rate The multi-channel signal acquiring and dispensing device of channel signal.

A kind of diagnostic method of described Oil/gas Well down-hole fault diagnosis system, comprises the following steps：

Step S1：Drilling fluid inlet flow rate sensor, drilling fluids outlet flow sensor and pressure transducer are collected In the not flow signal and pressure signal of each measuring point in the same time, pretreatment obtains the pressure value and flow value of intervals, And it is designated as drilling fluid inlet flow rate Q_i, rate of discharge Q_oWith standpipe pressure P_L；The pretreatment of data include delete dissimilarity, filtration, It is averaging, is the conventional meanses of field of signal processing, does not repeat here.

Step S2：In the case where keeping rate of discharge and inlet flow rate constant, standpipe pressure P_LWith drill bit place depth L Between regression treatment is carried out using linear relationship, i.e.,

P_L=A × L+B (1)

In formula, P_L：Standpipe pressure, unit is MPa；L：Well depth, unit is m；A, B are constant coefficient, A, B actual measurement standpipe pressure The preprocessed data of power carries out linear regression processing acquisition with well depth L changes；

Step S3：After the coefficient A and B of acquisition formula (1), then from simultaneous equations (2), constant b and c are calculated：

In formula, L₁、L₂、L₃、L₄、L_dc、L_dpRespectively high pressure line, standpipe, rotary hose, kelly bar, drill collar and drilling rod are long Degree, unit is m；d₁、d₂、d₃、d₄、d_dc、d_dcRespectively high pressure line, standpipe, rotary hose, kelly bar, drill collar and drilling rod is interior Footpath, unit is cm；D_h、D_dc、D_dpRespectively well, drill collar and drilling rod external diameter, unit is cm；A₀：Drill bit equivalent nozzle area, it is single Position is cm²；Q：Inlet flow rate or rate of discharge when operating mode is normal, unit is L/s；In the normal condition without any failure Under, inlet flow rate is equal to rate of discharge, i.e. Q=Q_iOr Q=Q_o；BB：The coefficient relevant with interior pipeline state；C：Nozzle flow system Number, relevant with the resistance coefficient of nozzle, the value of C is always less than 1；B values in the range of 1.75～1.8；

To drilling fluid inlet flow rate Q_iWith rate of discharge Q_oIt is compared, in the case where other conditions are constant, if Q_i≈ Q_oAnd standpipe pressure obeys the change of formula (1), then be determined as drilling condition normal；Otherwise, if Q_i≈Q_oAnd standpipe pressure it is unexpected on Rise or suppress pump, be then determined as drill bit water blockoff eye；If the fluctuation of pipeline circular flow is abnormal, and is pumped unstable or suppresses pump, then sentence Wei not annular space exception or cave-in；If Q_i≈Q_oAnd significantly declining occurs in standpipe pressure, it is assumed that by under original normal pressure It is reduced to P_L1, then it is determined as tubing string thorn leakage；Proceed to low discharge Q_i2Circulation, measures now corresponding standpipe pressure P_L2, and then carry out pipe The identification and diagnosis of post thorn leakage；

In drilling process, if drilling fluid inlet flow rate Q_iMore than rate of discharge Q_o, and super threshold values, then carry out the knowledge of leakage Not with diagnosis；If drilling fluids outlet flow Q_oMore than inlet flow rate Q_i, and during more than threshold values, then it is judged as well kick.

The identification and diagnosis of tubing string thorn leakage are carried out using formula (4)：

In formula, k_b：Bit pressuredrop coefficient,Q_i、Q_i2：The drilling fluid inlet flow rate of different periods, unit For L/s；μ：The discharge coefficient in thorn leakage crack, can value be approximately μ=0.62；Q₁、Q₂For correspondence difference drilling fluid inlet flow rate Q_i、Q_i2When thorn leak source with mud flow rate inside and outside lower tubular column, unit is L/s；A：Thorn leakage flaw area, unit is cm²；k_f1： Loine pressure loss factor inside and outside thorn leak source drilling rod and inside and outside drill collar；k_f2：Pipe inside and outside the following drilling rod of leak source and inside and outside drill collar Road pressure loss coefficient, k_f1And k_f2Determined according to leak source position.

If leak source is in drilling rod, there is k_f1、k_f2Computing formula it is as follows：

By k_f1、k_f2Computing formula substitute in formula (4), wherein, L_sTo pierce leak source well depth, k_f1、k_f2To pierce leak source as boundary Line, unknown quantity is L_s, A (or μ A), Q₁、Q₂, formula (4) simultaneous equations being solved, can obtain piercing leak source depth L_sAnd thorn leakage fracture surface Product A.

It is assumed that when there is leakage, drilling fluid inlet flow rate is Q_i；Returned out either with or without drilling fluid according to well head, phase is carried out respectively The process answered：If there is drilling fluid to return out, drilling fluids outlet flow is Q_o；Otherwise make Q_o=0；

Determine and find the standpipe pressure P after leakage_L, and carry out following judgement：

(1) P is calculated according to the following formula_L′、P_L"：

(2) if P_L＜ P_L', show leakage points in the bottom of drill bit；

If P_L' ＜ P_L＜ P_L", show leakage points in drill collar section, determine Well leakage position L by formula (6)₁；

If P_L≥P_L", show leakage points in drill pipe section, determine Well leakage position L by formula (7)₁；

Because the calculating of b is more complicated, for reduced equation, b=1.8 is taken, formula (2) is reduced to：

For streamline tool joint and annular space, BB=0.575；For internal flush joint, BB=0.517；For streamlined Nozzle, C=0.98.

In the present invention, drilling fluid inlet flow rate sensor, drilling fluids outlet flow sensor can respectively collect entrance Flow signal and rate of discharge signal, pressure transducer collects standpipe pressure signal, can be with according to the change of flow signal Realize underground working detection and leakage, the diagnosis of well kick.The pressure transducer collects standpipe pressure signal, can be with sensitive The various failures that ground record, display well blood circulation inside occur, it is clear to drill string thorn leakage, drillling tool twisting off, drill bit water blockoff eye, well Wash, the operating mode such as inventionannulus flow situation carries out accurate prediction.By analyzing drilling fluid entrance and exit flow, drilling hydraulic Relation between power and down-hole failure depth, and then realize being accurately positioned for down-hole failure.

The invention has the beneficial effects as follows, the Oil/gas Well down-hole fault diagnosis system and its diagnostic method of the present invention, to drilling well Liquid inlet flow rate sensor, drilling fluids outlet flow sensor and pressure transducer have carried out rational layout, and measurement is obtained not Data parameters are sent to computer system by flow in the same time and pressure signal, combining wireless or wired R-T unit, by counting Calculation machine system carries out the analysis of signal and processes, it is possible to achieve the positioning of failure is diagnosed with quantification, drastically increases failure The accuracy rate and recognition effect of diagnosis, realizes the early diagnosiss of the failures such as leakage, well kick, drill stem washout；And only with several The sensor commonly used on the market, low cost is easy for installation, and installation site is rationally, and safety coefficient is high.

Description of the drawings

With reference to the accompanying drawings and examples the present invention is further described.

Fig. 1 is the structural representation of the Oil/gas Well down-hole fault diagnosis system most preferred embodiment of the present invention.

Fig. 2 is the diagnostic method flow chart of the Oil/gas Well down-hole fault diagnosis system of the present invention.

1, drill bit in figure, 2, down-hole equipment, 3, drill string, 4, one layer of rig floor, 5, derrick, 6, kelly bar, 7, multi channel signals Collection and dispensing device, 8, multi channel signals reception device, 9, quadruple board platform, 10, computer system, 11, faucet, 12, drilling well Liquid return duct or mud ditch, 13, mud vibrating screen, 14, mud pit, 15, well head, 16, drilling fluids outlet flow sensor, 17, Drilling pump, 18, discharge line, 19, standpipe, 20, drilling fluid inlet flow rate sensor, 21, rotary hose, 22, pressure transducer, 23rd, manifold of ground, 24, cable, 25, suction line, 26, drilling fluid return out pipeline, 27, sleeve pipe.

Specific embodiment

In conjunction with the accompanying drawings, the present invention is further detailed explanation.These accompanying drawings are simplified schematic diagram, only with Schematic diagram mode illustrates the basic structure of the present invention, therefore it only shows the composition relevant with the present invention.

As shown in figure 1, the drill string 3 is supported by rig floor and derrick 5, the rig floor includes being located at one layer of brill of derrick bottom Platform 4, positioned at the quadruple board platform 9 at middle part, the drilling pump 17 is connected with drilling well pump conduit, and the drilling well pump conduit includes discharge line 18 and suction line 25, the discharge line 18 by manifold of ground 23, and the standpipe 19 being connected with manifold of ground 23 with Rotary hose 21 connects, the connection mud pit 14 of the suction line 25, and the rotary hose connects faucet 11, solid on the derrick 5 Dingan County is equipped with standpipe 19, and the Oil/gas Well down-hole fault diagnosis system of the present invention has drilling fluid inlet flow rate sensor 20, drilling well Liquid outlet flow sensor 16, pressure transducer 22, multi-channel signal acquiring and dispensing device 7, multi channel signals reception device 8 With computer system 10, the drilling fluid inlet flow rate sensor 20 be fixed on manifold of ground 23 or standpipe 19 on close derrick 5 position.Sleeve pipe 27 is provided with the well head 15 of Oil/gas Well, described sleeve pipe 27 is set in outside drill string 3, between sleeve pipe 27 and drill string 3 Annular space return out passage 26 for drilling fluid, be provided with drilling fluid return pipe or mud between the well head 15 and mud pit 14 of Oil/gas Well Stock tank 12, drilling fluids outlet flow sensor 16 is fixed on the drilling fluid return pipe or mud ditch 12.The pressure sensing Device 22 is arranged on manifold of ground 23 or standpipe 19 near the position of one layer of rig floor 4.The multi-channel signal acquiring is filled with sending Put on 7 setting, one layer of rig floor 4, the drilling fluid inlet flow rate sensor 20, drilling fluids outlet flow sensor 16, pressure sensing Device 22 is connected by cable 24 with multi-channel signal acquiring with dispensing device 7, and the multi-channel signal acquiring is filled with sending It is wired or wireless connection to put with multi channel signals reception device 8, and multi channel signals reception device 8 is have with computer system 10 Line connects.

Multi-channel signal acquiring is not less than 3000Hz with the signal sampling rate of dispensing device 7, and it is logical to gather full frequency band Road signal.

2 flow transducers (16,20) and 1 pressure transducer 22 measure respectively not each measuring point flow signal in the same time and Pressure signal.Abundant down-hole fault status information is contained in the change of flow signal and standpipe pressure signal.The oil of the present invention The diagnostic method of gas well down-hole fault diagnosis system, comprises the following steps：

Step S1：Drilling fluid inlet flow rate sensor 20, drilling fluids outlet flow sensor 16 and pressure transducer 22 are adopted Collection is obtained in not drilling pump inlet flow rate signal, rate of discharge signal and standpipe pressure signal in the same time.

Step S2：Multi-channel signal acquiring is with dispensing device 7 is by drilling pump inlet flow rate signal, rate of discharge signal and stands Pipe pressure signal is acquired, amplifies and Filtering Processing.

Step S3：Multi-channel signal acquiring transmits in a wireless or wired way the flow for collecting with dispensing device 7 With pressure signal.

Step S4：Multi channel signals reception device 8 receives the number sent from multi-channel signal acquiring and dispensing device 7 According to.

Step S5：Computer system 10 receives the multichannel flow signal and pressure from multi channel signals reception device 8 Force signal.

Step S6：The pressure obtained using collection and flow signal, carry out the prediction of down-hole string thorn leakage, leakage and well kick Forecast, concrete handling process following steps S6.1～S6.5：

Step S6.1：The pressure obtained using collection and data on flows, pretreatment obtains intervals (0.1～1s) Pressure value and flow value, and be designated as drilling fluid inlet flow rate Q_i, rate of discharge Q_oWith standpipe pressure P_L；The pretreatment of data Including deletion dissimilarity, filter, be averaging.

In the case where keeping rate of discharge and inlet flow rate constant (from from the viewpoint of engineering, rate of discharge and entrance Flow is constant to refer to rate of discharge and inlet flow rate is constant or its change is in the fluctuation range for allowing), standpipe pressure P_LWith Regression treatment is carried out using linear relationship between depth L of drill bit place, i.e.,

P_L=A × L+B (1)

In formula, P_L：Standpipe pressure, unit is MPa；L：Well depth, unit is m；A, B are constant coefficient, A, B actual measurement standpipe pressure The preprocessed data of power carries out linear regression processing acquisition with well depth L changes；

After the coefficient A and B of acquisition formula (1), then from simultaneous equations (2), constant b and c are calculated：

In formula, L₁、L₂、L₃、L₄、L_dc、L_dpRespectively high pressure line, standpipe, rotary hose, kelly bar, drill collar and drilling rod are long Degree, unit is m；d₁、d₂、d₃、d₄、d_dc、d_dcRespectively high pressure line, standpipe, rotary hose, kelly bar, drill collar and drilling rod is interior Footpath, unit is cm；D_h、D_dc、D_dpRespectively well, drill collar and drilling rod external diameter, unit is cm；A₀：Drill bit equivalent nozzle area, it is single Position is cm²；Q：Inlet flow rate or rate of discharge when operating mode is normal, unit is L/s；BB：The coefficient relevant with interior pipeline state； For streamline tool joint and annular space, BB=0.575；For internal flush joint, BB=0.517；C：Nozzle orifice coeficient, with spray The resistance coefficient of mouth is relevant, and the value of C is always less than 1；For Streamline Nozzles, C=0.98.

Generally, b values in the range of 1.75～1.8.If taking b=1.8, formula (2) can be reduced to：

Step S6.2：To drilling fluid inlet flow rate Q_iWith rate of discharge Q_oIt is compared, in the situation that other conditions are constant Under, if Q_i≈Q_oAnd standpipe pressure obeys the change of formula (1), then be determined as drilling condition normal；Otherwise, if Q_i≈Q_oAnd it is vertical Pipe pressure flies up or suppresses pump, then be determined as drill bit water blockoff eye；If the fluctuation of pipeline circular flow is abnormal, and is pumped unstable Or suppress pump, then it is determined as annular space exception or cave-in；If Q_i≈Q_oAnd significantly declining occurs in standpipe pressure, it is assumed that by original Normal pressure drop to P_L1, then it is determined as tubing string thorn leakage；Proceed to low discharge Q_i2Circulation, measures now corresponding standpipe pressure P_L2, and then carry out the identification and diagnosis of tubing string thorn leakage.

Step S6.3：The identification and diagnosis of tubing string thorn leakage are carried out using following formula (4)：

In formula, k_b--- bit pressuredrop coefficient,

Q_i、Q_i2--- the drilling fluid inlet flow rate of different periods, L/s；

μ --- the discharge coefficient in thorn leakage crack, can value be approximately μ=0.62；

Q₁、Q₂--- corresponding thorn leak source is with mud flow rate inside and outside lower tubular column, L/s under different flow；

A --- thorn leakage flaw area, cm²；

k_f1、k_f2--- the loine pressure loss factor more than thorn leak source and inside and outside the following drilling rod of leak source and inside and outside drill collar, root Determine according to leak source position.For example, if leak source is in drilling rod, have：

In formula (4), four equations, L_sTo pierce leak source well depth, k_f1、k_f2To pierce leak source as demarcation line, unknown quantity is L_s、A (or μ A), Q₁、Q₂, it is also four, there is unique solution.Therefore, formula (4) simultaneous equations are solved, can obtains piercing leak source depth L_sAnd thorn Leakage area A.

Step S6.4：In drilling process, if drilling fluid inlet flow rate Q_iMore than rate of discharge Q_o, and super threshold values, outlet stream Amount is reduced or well head does not have drilling fluid to return out, drilling liquid level declines, it is possible to be leakage；Well is carried out by below step The identification of leakage and diagnosis.

It is assumed that when there is leakage, drilling fluid inlet flow rate is Q_i；Returned out either with or without drilling fluid according to well head, phase is carried out respectively The process answered：If there is drilling fluid to return out, drilling fluids outlet flow is Q_o；Otherwise make Q_o=0；

Step S6.5：Determine and find the standpipe pressure P after leakage_L, and carry out following judgement：

(1) P is calculated according to the following formula_L′、P_L"：

(2) if P_L＜ P_L', show leakage points in the bottom of drill bit；

If P_L' ＜ P_L＜ P_L", show leakage points in drill collar section, determine Well leakage position L by formula (6)₁；

If P_L≥P_L", show leakage points in drill pipe section, determine Well leakage position L by formula (7)₁；

Step S6.6：If drilling fluids outlet flow Q_oMore than inlet flow rate Q_i, and during more than threshold values, then it is judged as well kick.

Step S7：The display of down-hole fault diagnosis result and warning.

With the above-mentioned desirable embodiment according to the present invention as enlightenment, by above-mentioned description, relevant staff is complete Entirely various change and modification can be carried out in the range of without departing from this invention technological thought.The technology of this invention Property scope is not limited to the content in description, it is necessary to its technology is determined according to right.

Claims (9)

1. a kind of diagnostic method of Oil/gas Well down-hole fault diagnosis system, the Oil/gas Well is provided with well head (15), drill string (3) and bores Well pump (17), the drill string (3) is supported by rig floor and derrick (5), and the rig floor includes being located at one layer of rig floor of derrick bottom (4), positioned at the quadruple board platform (9) at middle part, the drilling pump (17) is connected with drilling well pump conduit, and the drilling well pump conduit includes discharging Pipeline (18) and suction line (25), the discharge line (18) by manifold of ground (23), and with manifold of ground (23) phase The standpipe (19) of connection is connected with rotary hose (21), the suction line (25) connection mud pit (14), the rotary hose connection Faucet (11), is installed with standpipe (19) on the derrick (5), the well head (15) and mud pit (14) of the Oil/gas Well it Between be provided with drilling fluid return pipe or mud ditch (12), Oil/gas Well down-hole fault diagnosis system has drilling fluid inlet flow rate sensor (20), drilling fluids outlet flow sensor (16), pressure transducer (22), multi-channel signal acquiring and dispensing device (7), lead to more Road signal receiving device (8) and computer system (10), the drilling fluid inlet flow rate sensor (20) is fixed on manifold of ground (23) or on standpipe (19), the drilling fluids outlet flow sensor (16) is fixed on drilling fluid return pipe or mud ditch (12) On, the pressure transducer (22) is arranged on manifold of ground (23) or standpipe (19), the multi-channel signal acquiring with send Device (7) is arranged on one layer of rig floor (4), the drilling fluid inlet flow rate sensor (20), drilling fluids outlet flow sensor (16), pressure transducer (22) is connected with multi-channel signal acquiring with dispensing device (7), the multi-channel signal acquiring with send out Device and multi channel signals reception device (8) is sent to be wired or wireless connection, multi channel signals reception device (8) and department of computer science System (10) is wired connection, it is characterised in that comprised the following steps：

Step S1：Drilling fluid inlet flow rate sensor (20), drilling fluids outlet flow sensor (16) and pressure transducer (22) Collect in the not flow signal and pressure signal of each measuring point in the same time, pretreatment obtain the pressure value of intervals and Flow value, and it is designated as drilling fluid inlet flow rate Q_i, rate of discharge Q_oWith standpipe pressure P_L；

Step S2：In the case where keeping rate of discharge and inlet flow rate constant, standpipe pressure P_LBetween depth L of drill bit place Regression treatment is carried out using linear relationship, i.e.,

P_L=A × L+B (1)

In formula, P_L：Standpipe pressure, unit is MPa；L：Well depth, unit is m；A, B are constant coefficient, and A, B are by surveying standpipe pressure Preprocessed data with well depth L change carry out linear regression processing acquisition；

Step S3：After the coefficient A and B of acquisition formula (1), then from simultaneous equations (2), constant b and c are calculated：

$\left\{\begin{array}{c}A=c\×\left(\frac{BB}{{d_{dp}}^{3+b}}+\frac{0.575}{{(D_h-D_{dp})}^3{(D_h+D_{dp})}^b}\right)Q^b\\ B=c\×\left\{\begin{array}{c}0.517\×\left(\frac{L_1}{{d_1}^{3+b}}+\frac{L_2}{{d_2}^{3+b}}+\frac{L_3}{{d_3}^{3+b}}+\frac{L_4}{{d_4}^{3+b}}\right)+\\ L_{dc}\×\left(\frac{0.517}{{d_{dc}}^{3+b}}+\frac{0.575}{{(D_h-D_{dc})}^3{(D_h+D_{dc})}^b}\right)-\\ L_{dp}\×\left(\frac{BB}{{d_{dp}}^{3+b}}+\frac{0.575}{{(D_h-D_{dp})}^3{(D_h+D_{dp})}^b}\right)\end{array}\right\}\×Q^b+\frac{0.05\×{\mathrm{\ρ}}_d}{C^2{A_0}^2}\×Q^2\end{array}\right.---\left(2\right)$

In formula, L₁、L₂、L₃、L₄、L_dc、L_dpRespectively high pressure line, standpipe, rotary hose, kelly bar, drill collar and run of steel, single Position is m；d₁、d₂、d₃、d₄、d_dc、d_dcThe respectively internal diameter of high pressure line, standpipe, rotary hose, kelly bar, drill collar and drilling rod, unit For cm；D_h、D_dc、D_dpRespectively well, drill collar and drilling rod external diameter, unit is cm；A₀：Drill bit equivalent nozzle area, unit is cm²；Q：Inlet flow rate or rate of discharge when operating mode is normal, unit is L/s；BB：The coefficient relevant with interior pipeline state；C：Spray Mouth discharge coefficient, relevant with the resistance coefficient of nozzle, the value of C is always less than 1；B values in the range of 1.75～1.8；

To drilling fluid inlet flow rate Q_iWith rate of discharge Q_oIt is compared, in the case where other conditions are constant, if Q_i≈Q_oAnd Standpipe pressure obeys the change of formula (1), then be determined as normal drilling condition；Otherwise, if Q_i≈Q_oAnd standpipe pressure fly up or Pump is suppressed, is then determined as drill bit water blockoff eye；If the fluctuation of pipeline circular flow is abnormal, and is pumped unstable or suppresses pump, then it is determined as Annular space exception or cave-in；If Q_i≈Q_oAnd significantly declining occurs in standpipe pressure, it is assumed that dropped to by original normal pressure P_L1, then it is determined as tubing string thorn leakage；Proceed to low discharge Q_i2Circulation, measures now corresponding standpipe pressure P_L2, and then carry out tubing string thorn The identification of leakage and diagnosis；

In drilling process, if drilling fluid inlet flow rate Q_iMore than rate of discharge Q_o, and super threshold values, then carry out the identification of leakage with Diagnosis；If drilling fluids outlet flow Q_oMore than inlet flow rate Q_i, and during more than threshold values, then it is judged as well kick.

2. diagnostic method as claimed in claim 1, it is characterised in that：The identification and diagnosis of tubing string thorn leakage are carried out using formula (4)：

$\left\{\begin{array}{c}{P}_{L1}=k_{f1}{Q_i}^b+k_{f2}{Q_1}^b+k_b{Q_1}^2\\ P_{L2}=k_{f1}{Q_{i2}}^b+k_{f2}{Q_2}^b+k_b{Q_2}^2\\ k_{f_2}{Q}_1^b+k_b{Q}_1^2-\frac{{(Q_i-Q_1)}^2}{{\mathrm{\μ}}^2{A}^2}=0\\ k_{f_2}{Q}_2^b+k_b{Q}_2^2-\frac{{(Q_{i2}-Q_2)}^2}{{\mathrm{\μ}}^2{A}^2}=0\end{array}\right.---\left(4\right)$

In formula, k_b：Bit pressuredrop coefficient,Q_i、Q_i2：The drilling fluid inlet flow rate of different periods, unit is L/ s；μ：The discharge coefficient in thorn leakage crack, can value be approximately μ=0.62；Q₁、Q₂For correspondence difference drilling fluid inlet flow rate Q_i、Q_i2 When thorn leak source with mud flow rate inside and outside lower tubular column, unit is L/s；A is thorn leakage flaw area, and unit is cm²；k_f1：Thorn leakage Loine pressure loss factor inside and outside point drilling rod and inside and outside drill collar；k_f2：Pipeline pressure inside and outside the following drilling rod of leak source and inside and outside drill collar Power loss factor, k_f1And k_f2Determined according to leak source position.

3. diagnostic method as claimed in claim 2, it is characterised in that：If leak source is in drilling rod, there is k_f1、k_f2Computing formula It is as follows：

$k_{f1}=c\×\[0.517\left(\frac{L_1}{d_1^{3+b}}+\frac{L_2}{d_2^{3+b}}+\frac{L_3}{d_3^{3+b}}+\frac{L_4}{d_4^{3+b}}\right)+L_s\left(\frac{BB}{d_{dp}^{3+b}}+\frac{0.575}{{(D_h-D_{dp})}^3{(D_h+D_{dp})}^b}\right)\]$

$k_{f2}=c\×\[(L_{dp}-L_s)\left(\frac{BB}{d_{dp}^{3+b}}+\frac{0.575}{{(D_h-D_{dp})}^3{(D_h+D_{dp})}^b}\right)+L_{dc}\left(\frac{0.517}{d_{dc}^{3+b}}+\frac{0.575}{{(D_h-D_{dc})}^3{(D_h+D_{dc})}^b}\right)\]$

By k_f1、k_f2Computing formula substitute in formula (4), wherein, L_sTo pierce leak source well depth, k_f1、k_f2To pierce leak source as demarcation line, Unknown quantity is L_s, A or μ A, Q₁、Q₂, formula (4) simultaneous equations being solved, can obtain piercing leak source depth L_sAnd thorn leakage flaw area A.

4. diagnostic method as claimed in claim 1, it is characterised in that：It is assumed that when there is leakage, drilling fluid inlet flow rate is Q_i； Returned out either with or without drilling fluid according to well head, processed accordingly respectively：If there is drilling fluid to return out, drilling fluids outlet flow is Q_o；Otherwise make Q_o=0；

Determine and find the standpipe pressure P after leakage_L, and carry out following judgement：

(1) P is calculated according to the following formula_L′、P_L"：

$\begin{array}{c}{P_L}^{\′}=\[0.517\×(\frac{L_1}{{d_1}^{3+b}}+\frac{L_2}{{d_2}^{3+b}}+\frac{L_3}{{d_3}^{3+b}}+\frac{L_4}{{d_4}^{3+b}}+\frac{L_{dc}}{{d_{dc}}^{3+b}})+\frac{BB\×L_{dp}}{{d_{dp}}^{3+b}}\]\×{Q_i}^b\\ +\frac{0.575L_{dp}\×{Q_o}^b}{{(D_h-D_{dp})}^3{(D_h+D_{dp})}^b}+\frac{0.575L_{dc}\×{Q_o}^b}{{(D_h-D_{dc})}^3{(D_h+D_{dc})}^b}+k_b{Q_i}^2\end{array}---\left(5a\right)$

$\begin{array}{c}{P_L}^{\′\′}=\left[\begin{array}{c}0.517\×(\frac{L_1}{{d_1}^{3+b}}+\frac{L_2}{{d_2}^{3+b}}+\frac{L_3}{{d_3}^{3+b}}+\frac{L_4}{{d_4}^{3+b}}+\frac{L_{dc}}{{d_{dc}}^{3+b}})\\ +\frac{BB\×L_{dp}}{{d_{dp}}^{3+b}}+\frac{0.575L_{dc}}{{(D_h-D_{dp})}^3{(D_h+D_{dc})}^b}\end{array}\right]\×{Q_i}^b\\ +\frac{0.575L_{dp}\×{Q_o}^b}{{(D_h-D_{dc})}^3{(D_h+D_{dp})}^b}+k_b{Q_i}^2\end{array}---\left(5b\right)$

(2) if P_L＜ P_L', show leakage points in the bottom of drill bit；

If P_L' ＜ P_L＜ P_L", show leakage points in drill collar section, determine Well leakage position L by formula (6)₁；

If P_L≥P_L", show leakage points in drill pipe section, determine Well leakage position L by formula (7)₁；

$\begin{array}{c}{P}_L=\left[\begin{array}{c}0.517\×(\frac{L_1}{{d_1}^{3+b}}+\frac{L_2}{{d_2}^{3+b}}+\frac{L_3}{{d_3}^{3+b}}+\frac{L_4}{{d_4}^{3+b}}+\frac{L_{dc}}{{d_{dc}}^{3+b}})\\ +\frac{BB\×L_{dp}}{{d_{dp}}^{3+b}}+\frac{0.575(L_{dc}+L_{dp}-L_1)}{{(D_h-D_{dc})}^3{(D_h+D_{dc})}^b}\end{array}\right]\×{Q_i}^b\\ +0.575\[\frac{(L_1-L_{dp})}{{(D_h-D_{dc})}^3{(D_h+D_{dc})}^b}+\frac{L_{dp}}{{(D_h-D_{dp})}^3{(D_h+D_{dp})}^b}\]\×{Q_o}^b+k_b{Q_i}^2\end{array}---\left(6\right)$

$\begin{array}{c}{P}_L=\left[\begin{array}{c}0.517\×(\frac{L_1}{{d_1}^{3+b}}+\frac{L_2}{{d_2}^{3+b}}+\frac{L_3}{{d_3}^{3+b}}+\frac{L_4}{{d_4}^{3+b}}+\frac{L_{dc}}{{d_{dc}}^{3+b}})\\ +\frac{BB\×L_{dp}}{{d_{dp}}^{3+b}}+\frac{0.575L_{dc}}{{(D_h-D_{dc})}^3{(D_h+D_{dc})}^b}\end{array}\right]\×{Q_i}^b\\ +\frac{0.575(L_{dp}-L_1)\×{Q_i}^b}{{(D_h-D_{dp})}^3{(D_h+D_{dp})}^b}+\frac{0.575L_1\×{Q_o}^b}{{(D_h-D_{dp})}^3{(D_h+D_{dp})}^b}+k_b{Q_i}^2\end{array}---\left(7\right).$

5. diagnostic method as claimed in claim 1, it is characterised in that：B=1.8 is taken, formula (2) is reduced to：

$c=\frac{P_L-k_b{Q}^2}{\left[\begin{array}{c}0.517\×(\frac{L_1}{{d_1}^{3+b}}+\frac{L_2}{{d_2}^{3+b}}+\frac{L_3}{{d_3}^{3+b}}+\frac{L_4}{{d_4}^{3+b}}+\frac{L_{dc}}{{d_{dc}}^{3+b}})+\frac{BB\×L_{dp}}{{d_{dp}}^{3+b}}\\ +(\frac{0.575L_{dp}}{{(D_h-D_{dp})}^3{(D_h+D_{dp})}^b}+\frac{0.575L_{dc}}{{(D_h-D_{dc})}^3{(D_h+D_{dc})}^b})\end{array}\right]\×Q^b}---\left(3\right)$

For streamline tool joint and annular space, BB=0.575；For internal flush joint, BB=0.517；For Streamline Nozzles, C=0.98.

6. diagnostic method as claimed in claim 1, it is characterised in that：The drilling fluid inlet flow rate sensor (20) is fixed on The position of the close derrick (5) in manifold of ground (23) or standpipe (19).

7. diagnostic method as claimed in claim 1, it is characterised in that：Drilling fluids outlet flow sensor (16) is fixed on described On drilling fluid return pipe or mud ditch (12).

8. diagnostic method as claimed in claim 1, it is characterised in that：The pressure transducer (22) is arranged on manifold of ground (23) near the position of one layer of rig floor (4) or on standpipe (19).

9. diagnostic method as claimed in claim 1, it is characterised in that：The multi-channel signal acquiring is with dispensing device (7) Signal sampling rate is not less than 3000Hz and can gather the multi-channel signal acquiring and dispensing device of full frequency band channel signal.