CN104453842A - 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 diagnostic method thereof

Technical field

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

Background technology

In drilling process, can the fault that occurs of prediction down-hole promptly and accurately if do not had, just may cause down hole problem or accident, suffer huge economic loss.Down-hole fault mainly comprises leakage, well kick, drill stem washout, borehole well instability etc.Just because of the multiple and seriousness of the accidents such as leakage, well kick, drill stem washout, borehole well instability, Chinese scholars has carried out a large amount of theories and experimental exploring.

Comprehensive mud logging technology is that the collection grown up on geological logging basis is measured as comprehensive site mud logging technology integrally with boring geologic observations analysis, gas detect, drilling liquid parameter measurement, prediction of formation pressure and drilling engineering parameter.Compound logging can provide well logging geological section, lithology data, formation fluid data etc. for geological research personnel, and for drilling technology personnel provide terminal monitor, monitoring and analysis drilling well situation are the important means of Real-Time Monitoring drilling failure.Petroleum science and technology worker both domestic and external has utilized compound logging equipment, the tracking of shaft building process drilling safety, monitoring are carried out, and drilling well down-hole fault (comprise well kick, leakage, drill stem washout, fall water nozzle, water blockoff eye, drilling string not well braked, bit freezing, drilling well are hampered, oil gas water enchroachment (invasion), fall drilling tool etc.) prediction, prediction research practice, for the drilling well that ensures safety has played important function.While guarantee drilling safety, well logging engineering parameter is carried in effect, Drilling optimization in speed-raising, also serves positive effect.Along with the development of engineering parameter well logging, define a series of technology gradually.

But for a long time, China payes attention to the emphasis of compound logging both at home and abroad in the application in geological logging and discovery hydrocarbon information etc., enough attention is not caused in engineering, despise the application of compound logging in drilling engineering, compound logging is mainly applied also effect and is concentrated in prospect pit aspect, seldom adopts in the drillng operation of development well with other type well.Emphasis is also to catch hydrocarbon information in drilling process in time, and it is its Function Extension booster action that the application for drilling engineering aspect is only played.Simultaneously, judge and predict that the method for drilling well down-hole fault mainly relies on one-parameter Threshold Alerts and carries out subjective judgement according to field experience, this not only needs Field Force to have the sense of responsibility of height, and need that there is certain know-how and practical experience, the situation such as often there is erroneous judgement, fail to judge.In addition, with regard to drilling engineering application, the sample rate of compound logging is often too low, and poor real causes the potential larger risk of the predictive diagnosis work of Drilling Troubles and error.As can be seen here, want that it is more difficult for utilizing employing Comprehensive mud logging technology to carry out Oil/gas Well down-hole fault diagnosis, exists significant limitation.

Summary of the invention

The technical problem to be solved in the present invention is: the poor real existed for existing down-hole fault diagnosis system, apply the deficiencies such as limited, the invention provides a kind of real-time, for the Oil/gas Well down-hole fault Multifunction diagnosing system of drilling engineering and diagnostic method thereof.

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 borehole pump, described Oil/gas Well is provided with drill string and borehole pump, described drill string is supported by rig floor and derrick, described rig floor comprises one deck rig floor be positioned at bottom derrick, be positioned at the quadruple board platform at middle part, described borehole pump is connected with borehole pump pipeline, described borehole pump pipeline comprises discharge line and suction line, described discharge line passes through manifold of ground, and be connected with hose with the standpipe that manifold of ground is connected, described suction line connects mud pit, described hose connecting tap, described derrick is installed with standpipe, drilling fluid return pipe or mud ditch is provided with between the well head of described Oil/gas Well and mud pit, Oil/gas Well down-hole fault diagnosis system has drilling fluid inlet flow rate sensor, drilling fluids outlet flow sensor, pressure sensor, multi-channel signal acquiring and dispensing device, multi channel signals receiving system and computer system, described drilling fluid inlet flow rate sensor is fixed on manifold of ground or standpipe, described drilling fluids outlet flow sensor is fixed on drilling fluid return pipe or mud ditch, described pressure sensor is arranged on manifold of ground or standpipe, described multi-channel signal acquiring and dispensing device arrange on one deck rig floor, described drilling fluid inlet flow rate sensor, drilling fluids outlet flow sensor, pressure sensor is all connected with dispensing device with multi-channel signal acquiring, described multi-channel signal acquiring is wired or wireless connection with dispensing device and multi channel signals receiving system, multi channel signals receiving system and computer system are wired connection.

Multi-channel signal acquiring and dispensing device are arranged on one deck rig floor, and this position can make each sensor and the connection cable between multi-channel signal acquiring and dispensing device obtain the most reasonably distributing.Drilling fluid inlet flow rate sensor is used for gathering the mud flow rate signal being injected into drill string inside from ground; Drilling fluids outlet flow sensor is used for gathering the flow signal of drilling fluid in well head return line; Pressure sensor is used for measuring the pressure of pipeline inner part drilling well liquid; Multi-channel signal acquiring and dispensing device gather the flow of described measuring point and pressure signal, amplify, filtration etc. is nursed one's health and processed, and carry out longer-distance transmission to described flow and pressure signal and change is sent; Multi channel signals receiving system receives flow from described multi-channel signal acquiring and dispensing device and pressure signal in a wireless or wired way.Present inventor has made rational arrangement to the position that the kind of required sensor and sensor are placed, adopt the drilling fluids outlet flow sensor of the drilling fluid inlet flow rate sensor that is arranged on manifold of ground or standpipe and pressure sensor, wellhead drilling fluid return line, be used for measuring not flow in the same time and pressure signal, data parameters is sent to computer system by combining wireless or wired R-T unit, is carried out the analysis and treament of signal by computer system.Oil/gas Well down-hole of the present invention fault diagnosis system utilizes the pepeline characteristic of drilling-fluid circulation system to differentiate underground working.Such as, for the contrast of entrance, rate of discharge signal, can be used for predicting leakage, well kick; And mud flow rate and standpipe pressure signal can realize drill string sting leak, the forecast of the operating mode such as drillling tool twisting off, drill bit water blockoff eye, well are cleaned, inventionannulus flow situation, power drilling tool state analysis, and the detection of bit operation state; In conjunction with entrance, rate of discharge signal and standpipe pressure signal can realize underground drill stem sting leak, the accurate location of the fault such as well kick, leakage.

Described drilling fluid inlet flow rate sensor is fixed on the position of the close derrick on manifold of ground or standpipe.

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

Described pressure sensor is arranged on the position near one deck rig floor on manifold of ground or standpipe.

Described drilling fluid inlet flow rate sensor, drilling fluids outlet flow sensor, pressure sensor are all connected with dispensing device with multi-channel signal acquiring by cable.

Described multi-channel signal acquiring and dispensing device are that signal sampling rate is not less than 3000Hz and can gathers multi-channel signal acquiring and the dispensing device of full frequency band channel signal.

A diagnostic method for 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 sensor collect at the not flow signal of each measuring point and pressure signal in the same time, pretreatment obtains force value and the flow value at certain hour interval, and is designated as drilling fluid inlet flow rate Q _i, rate of discharge Q _owith standpipe pressure P _l; The pretreatment of data comprises deletion dissimilarity, filters, is averaging, and is the conventional means in signal transacting field, does not repeat here.

Step S2: when keeping rate of discharge and inlet flow rate is constant, standpipe pressure P _land adopt linear relationship to carry out recurrence between the degree of depth L of drill bit place to process, namely

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 the preprocessed data that A, B survey standpipe pressure carries out linear regression processing acquisition with well depth L change;

Step S3: after obtaining coefficient A and B of formula (1), then from simultaneous equations (2), calculate constant b and c:

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

In formula, L ₁, L ₂, L ₃, L ₄, L _dc, L _dpbe respectively high pressure line, standpipe, hose, kelly bar, drill collar and run of steel, unit is m; d ₁, d ₂, d ₃, d ₄, d _dc, d _dcbe respectively the internal diameter of high pressure line, standpipe, hose, kelly bar, drill collar and drilling rod, unit is cm; D _h, D _dc, D _dpbe respectively well, drill collar and drilling rod external diameter, unit is cm; A ₀: drill bit equivalent nozzle area, unit is cm ²; Q: inlet flow rate when operating mode is normal or rate of discharge, unit is L/s; Without any fault under normal circumstances, inlet flow rate equals rate of discharge, i.e. Q=Q _ior Q=Q _o; BB: the coefficient relevant with interior pipeline state; C: nozzle orifice coeficient, relevant with the resistance coefficient of nozzle, the value of C is always less than 1; B is value in 1.75 ~ 1.8 scopes;

To drilling fluid inlet flow rate Q _iwith rate of discharge Q _ocompare, when other conditions are constant, if Q _i≈ Q _oand standpipe pressure obeys the change of formula (1), be then determined as drilling condition normal; Otherwise, if Q _i≈ Q _oand standpipe pressure rises suddenly or suppresses pump, be then determined as drill bit water blockoff eye; If the fluctuation of pipeline circular flow is abnormal, and pump pressure is unstable or suppress pump, be then determined as annular space exception or cave-in; If Q _i≈ Q _oand significantly declining, assuming that drop to P by original normal pressure appears in standpipe pressure _l1, be then determined as tubing string thorn and leak; Proceed to low discharge Q _i2circulation, measures now corresponding standpipe pressure P _l2, and then carry out the detection and diagnosis of tubing string thorn leakage;

In drilling process, if drilling fluid inlet flow rate Q _ibe greater than rate of discharge Q _o, and super threshold values, then carry out the detection and diagnosis of leakage; If drilling fluids outlet flow Q _obe greater than inlet flow rate Q _i, and when exceeding threshold values, be then judged as well kick.

Formula (4) is utilized to carry out the detection and diagnosis of tubing string thorn leakage:

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

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: thorn leaks the discharge coefficient in crack, and can be similar to value is μ=0.62; Q ₁, Q ₂for correspondence different drilling fluid inlet flow rate Q _i, Q _i2time thorn leak source with mud flow rate inside and outside lower tubular column, unit is L/s; A: thorn leaks flaw area, and unit is cm ²; k _f1: the loine pressure loss factor inside and outside thorn leak source drilling rod and inside and outside drill collar; k _f2: the loine pressure loss factor inside and outside the following drilling rod of leak source and inside and outside drill collar, k _f1and k _f2determine according to leak source position.

If leak source is in drilling rod, then there is k _f1, k _f2design formulas as follows:

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

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

By k _f1, k _f2design formulas substitute in formula (4), wherein, L _sfor thorn leak source well depth, k _f1, k _f2to sting leak source for line of demarcation, unknown quantity is L _s, A (or μ A), Q ₁, Q ₂, solve formula (4) simultaneous equations, thorn leak source degree of depth L can be obtained _sand thorn leaks flaw area A.

Assuming that when there is leakage, drilling fluid inlet flow rate is Q _i; Whether there is drilling fluid to return out according to well head, process accordingly respectively: if there is drilling fluid to return out, drilling fluids outlet flow is Q _o; Otherwise make Q _o=0;

Measure the standpipe pressure P after finding leakage _l, and carry out following judgement:

(1) P is calculated according to the following formula _l', P _l":

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

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

(2) if P _l< P _l', show the bottom of leakage points at drill bit;

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

If P _l>=P _l", show that leakage points is in drill pipe section, determine Well leakage position L by formula (7) ₁;

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

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

Due to the calculating more complicated of b, in order to reduced equation, get b=1.8, formula (2) is reduced to:

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

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

In the present invention, drilling fluid inlet flow rate sensor, drilling fluids outlet flow sensor can collect inlet flow rate signal and rate of discharge signal respectively, pressure sensor collects standpipe pressure signal, according to the change of flow signal can realize underground working detect and leakage, well kick diagnosis.Described pressure sensor collects standpipe pressure signal, can record delicately, various faults that display well circulating system inside occurs, prediction is accurately carried out to operating mode such as drill string thorn leakage, drillling tool twisting off, drill bit water blockoff eye, well cleaning, inventionannulus flow situation etc.By analyzing drilling fluid entrance and exit flow, relation between drilling liquid pressure and the down-hole fault degree of depth, and then realize the accurate location of down-hole fault.

The invention has the beneficial effects as follows, Oil/gas Well down-hole fault diagnosis system of the present invention and diagnostic method thereof, to drilling fluid inlet flow rate sensor, drilling fluids outlet flow sensor and pressure sensor have carried out rational layout, measure and obtain not flow in the same time and pressure signal, data parameters is sent to computer system by combining wireless or wired R-T unit, the analysis and treament of signal is carried out by computer system, the location and relative quantityization diagnosis of fault can be realized, drastically increase accuracy rate and the recognition effect of fault diagnosis, realize leakage, well kick, the early diagnosis of the faults such as drill stem washout, and only adopt several sensor conventional on the market, cost is low, easy for installation, and installation site is reasonable, and safety factor is high.

Accompanying drawing explanation

Below in conjunction with drawings and Examples, the present invention is further described.

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

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

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

Detailed description of the invention

In conjunction with the accompanying drawings, the present invention is further detailed explanation.These accompanying drawings are the schematic diagram of simplification, only basic structure of the present invention are described schematically, and therefore it only shows the formation relevant with the present invention.

As shown in Figure 1, described drill string 3 is supported by rig floor and derrick 5, described rig floor comprises one deck rig floor 4 be positioned at bottom derrick, be positioned at the quadruple board platform 9 at middle part, described borehole pump 17 is connected with borehole pump pipeline, described borehole pump pipeline comprises discharge line 18 and suction line 25, described discharge line 18 is by manifold of ground 23, and be connected with hose 21 with the standpipe 19 that manifold of ground 23 is connected, described suction line 25 connects mud pit 14, described hose connecting tap 11, described derrick 5 is installed with standpipe 19, Oil/gas Well down-hole of the present invention fault diagnosis system has drilling fluid inlet flow rate sensor 20, drilling fluids outlet flow sensor 16, pressure sensor 22, multi-channel signal acquiring and dispensing device 7, multi channel signals receiving system 8 and computer system 10, described drilling fluid inlet flow rate sensor 20 is fixed on the position of the close derrick 5 on manifold of ground 23 or standpipe 19.Well head 15 place of Oil/gas Well is provided with sleeve pipe 27, described sleeve pipe 27 is set in outside drill string 3, annular space between sleeve pipe 27 and drill string 3 is that drilling fluid returns out passage 26, be provided with drilling fluid return pipe or mud ditch 12 between the well head 15 of Oil/gas Well and mud pit 14, drilling fluids outlet flow sensor 16 is fixed on described drilling fluid return pipe or mud ditch 12.Described pressure sensor 22 is arranged on the position near one deck rig floor 4 on manifold of ground 23 or standpipe 19.Described multi-channel signal acquiring and dispensing device 7 arrange on one deck rig floor 4, described drilling fluid inlet flow rate sensor 20, drilling fluids outlet flow sensor 16, pressure sensor 22 are all connected with dispensing device 7 with multi-channel signal acquiring by cable 24, described multi-channel signal acquiring is connected for wired or wireless with multi channel signals receiving system 8 with dispensing device, and multi channel signals receiving system 8 and computer system 10 are wired connection.

The signal sampling rate of multi-channel signal acquiring and dispensing device 7 is not less than 3000Hz, and can gather full frequency band channel signal.

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

Step S1: drilling fluid inlet flow rate sensor 20, drilling fluids outlet flow sensor 16 and pressure sensor 22 collect at not borehole pump inlet flow rate signal, rate of discharge signal and standpipe pressure signal in the same time.

Step S2: borehole pump inlet flow rate signal, rate of discharge signal and standpipe pressure signal carry out gathering, amplifying and filtering process by multi-channel signal acquiring and dispensing device 7.

Step S3: multi-channel signal acquiring and dispensing device 7 transmit the flow and pressure signal that collect in a wireless or wired way.

Step S4: multi channel signals receiving system 8 receives the data sent from multi-channel signal acquiring and dispensing device 7.

Step S5: computer system 10 receives multichannel flow signal from multi channel signals receiving system 8 and pressure signal.

Step S6: utilize the pressure versus flow signal gathering and obtain, carries out that down-hole string thorn leaks, the prediction of leakage and well kick, concrete handling process following steps S6.1 ~ S6.5:

Step S6.1: utilize the pressure and data on flows that gather and obtain, pretreatment obtains force value and the flow value at certain hour interval (0.1 ~ 1s), and is designated as drilling fluid inlet flow rate Q _i, rate of discharge Q _owith standpipe pressure P _l; The pretreatment of data comprises deletion dissimilarity, filters, is averaging.

When keep rate of discharge and inlet flow rate constant (from the viewpoint of engineering, rate of discharge and inlet flow rate constant refer to rate of discharge and inlet flow rate is constant or its change allow fluctuation range in), standpipe pressure P _land adopt linear relationship to carry out recurrence between the degree of depth L of drill bit place to process, namely

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 the preprocessed data that A, B survey standpipe pressure carries out linear regression processing acquisition with well depth L change;

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

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

In formula, L ₁, L ₂, L ₃, L ₄, L _dc, L _dpbe respectively high pressure line, standpipe, hose, kelly bar, drill collar and run of steel, unit is m; d ₁, d ₂, d ₃, d ₄, d _dc, d _dcbe respectively the internal diameter of high pressure line, standpipe, hose, kelly bar, drill collar and drilling rod, unit is cm; D _h, D _dc, D _dpbe respectively well, drill collar and drilling rod external diameter, unit is cm; A ₀: drill bit equivalent nozzle area, unit is cm ²; Q: inlet flow rate when operating mode is normal or rate of discharge, 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, relevant with the resistance coefficient of nozzle, the value of C is always less than 1; For Streamline Nozzles, C=0.98.

Generally, b value in 1.75 ~ 1.8 scopes.If get b=1.8, then formula (2) can be reduced to:

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

Step S6.2: to drilling fluid inlet flow rate Q _iwith rate of discharge Q _ocompare, when other conditions are constant, if Q _i≈ Q _oand standpipe pressure obeys the change of formula (1), be then determined as drilling condition normal; Otherwise, if Q _i≈ Q _oand standpipe pressure rises suddenly or suppresses pump, be then determined as drill bit water blockoff eye; If the fluctuation of pipeline circular flow is abnormal, and pump pressure is unstable or suppress pump, be then determined as annular space exception or cave-in; If Q _i≈ Q _oand significantly declining, assuming that drop to P by original normal pressure appears in standpipe pressure _l1, be then determined as tubing string thorn and leak; Proceed to low discharge Q _i2circulation, measures now corresponding standpipe pressure P _l2, and then carry out the detection and diagnosis of tubing string thorn leakage.

Step S6.3: utilize following formula (4) to carry out the detection and diagnosis of tubing string thorn leakage:

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

In formula, k _b---bit pressuredrop coefficient,

Q _i, Q _i2---the drilling fluid inlet flow rate of Different periods, L/s;

μ---thorn leaks the discharge coefficient in crack, and can be similar to value is μ=0.62;

Q ₁, Q ₂---thorn leak source corresponding under different flow with mud flow rate inside and outside lower tubular column, L/s;

A---thorn leaks flaw area, cm ²;

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, determine according to leak source position.Such as, if leak source is in drilling rod, then have:

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

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

In formula (4), four equations, L _sfor thorn leak source well depth, k _f1, k _f2to sting leak source for line of demarcation, unknown quantity is L _s, A (or μ A), Q ₁, Q ₂, be also four, have unique solution.Therefore, solve formula (4) simultaneous equations, thorn leak source degree of depth L can be obtained _sand thorn leaks area A.

Step S6.4: in drilling process, if drilling fluid inlet flow rate Q _ibe greater than rate of discharge Q _o, and super threshold values, rate of discharge reduces or well head does not have drilling fluid to return out, drilling liquid level declines, and may be just leakage; The detection and diagnosis of leakage is carried out by step below.

Assuming that when there is leakage, drilling fluid inlet flow rate is Q _i; Whether there is drilling fluid to return out according to well head, process accordingly respectively: if there is drilling fluid to return out, drilling fluids outlet flow is Q _o; Otherwise make Q _o=0;

Step S6.5: measure the standpipe pressure P after finding leakage _l, and carry out following judgement:

(1) P is calculated according to the following formula _l', P _l":

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

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

(2) if P _l< P _l', show the bottom of leakage points at drill bit;

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

If P _l>=P _l", show that leakage points is in drill pipe section, determine Well leakage position L by formula (7) ₁;

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

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

Step S6.6: if drilling fluids outlet flow Q _obe greater than inlet flow rate Q _i, and when exceeding threshold values, be then judged as well kick.

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

With above-mentioned according to desirable embodiment of the present invention for enlightenment, by above-mentioned description, relevant staff in the scope not departing from this invention technological thought, can carry out various change and amendment completely.The technical scope of this invention is not limited to the content on manual, must determine its technology according to right.

Claims (10)

1. an Oil/gas Well down-hole fault diagnosis system, described Oil/gas Well is provided with well head (15), drill string (3) and borehole pump (17), described drill string (3) is supported by rig floor and derrick (5), described rig floor comprises one deck rig floor (4) be positioned at bottom derrick, be positioned at the quadruple board platform (9) at middle part, described borehole pump (17) is connected with borehole pump pipeline, described borehole pump pipeline comprises discharge line (18) and suction line (25), described discharge line (18) is by manifold of ground (23), and be connected with hose (21) with the standpipe (19) that manifold of ground (23) is connected, described suction line (25) connects mud pit (14), described hose connecting tap (11), described derrick (5) is installed with standpipe (19), drilling fluid return pipe or mud ditch (12) is provided with between the well head (15) of described Oil/gas Well and mud pit (14), it is characterized in that: there is drilling fluid inlet flow rate sensor (20), drilling fluids outlet flow sensor (16), pressure sensor (22), multi-channel signal acquiring and dispensing device (7), multi channel signals receiving system (8) and computer system (10), described drilling fluid inlet flow rate sensor (20) is fixed on manifold of ground (23) or standpipe (19), described drilling fluids outlet flow sensor (16) is fixed on drilling fluid return pipe or mud ditch (12), described pressure sensor (22) is arranged on manifold of ground (23) or standpipe (19), described multi-channel signal acquiring and dispensing device (7) arrange on one deck rig floor (4), described drilling fluid inlet flow rate sensor (20), drilling fluids outlet flow sensor (16), pressure sensor (22) is all connected with dispensing device (7) with multi-channel signal acquiring, described multi-channel signal acquiring is connected for wired or wireless with multi channel signals receiving system (8) with dispensing device, multi channel signals receiving system (8) and computer system (10) are wired connection.

2. Oil/gas Well down-hole as claimed in claim 1 fault diagnosis system, is characterized in that: described 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).

3. Oil/gas Well down-hole as claimed in claim 1 fault diagnosis system, is characterized in that: drilling fluids outlet flow sensor (16) is fixed on described drilling fluid return pipe or mud ditch (12).

4. Oil/gas Well down-hole as claimed in claim 1 fault diagnosis system, is characterized in that: described pressure sensor (22) is arranged on manifold of ground (23) or the upper position near one deck rig floor (4) of standpipe (19).

5. Oil/gas Well down-hole as claimed in claim 1 fault diagnosis system, is characterized in that: described multi-channel signal acquiring and dispensing device (7) are not less than 3000Hz for signal sampling rate and can gather multi-channel signal acquiring and the dispensing device of full frequency band channel signal.

6. a diagnostic method for the Oil/gas Well down-hole fault diagnosis system according to any one of claim 1-5, is characterized in that, comprise the following steps:

Step S1: drilling fluid inlet flow rate sensor (20), drilling fluids outlet flow sensor (16) and pressure sensor (22) collect at the not flow signal of each measuring point and pressure signal in the same time, pretreatment obtains force value and the flow value at certain hour interval, and is designated as drilling fluid inlet flow rate Q _i, rate of discharge Q _owith standpipe pressure P _l;

Step S2: when keeping rate of discharge and inlet flow rate is constant, standpipe pressure P _land adopt linear relationship to carry out recurrence between the degree of depth L of drill bit place to process, namely

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 carry out linear regression processing acquisition by the preprocessed data of surveying standpipe pressure with well depth L change;

Step S3: after obtaining coefficient A and B of formula (1), then from simultaneous equations (2), calculate constant b and c:

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

In formula, L ₁, L ₂, L ₃, L ₄, L _dc, L _dpbe respectively high pressure line, standpipe, hose, kelly bar, drill collar and run of steel, unit is m; d ₁, d ₂, d ₃, d ₄, d _dc, d _dcbe respectively the internal diameter of high pressure line, standpipe, hose, kelly bar, drill collar and drilling rod, unit is cm; D _h, D _dc, D _dpbe respectively well, drill collar and drilling rod external diameter, unit is cm; A ₀: drill bit equivalent nozzle area, unit is cm ²; Q: inlet flow rate when operating mode is normal or rate of discharge, unit is L/s; BB: the coefficient relevant with interior pipeline state; C: nozzle orifice coeficient, relevant with the resistance coefficient of nozzle, the value of C is always less than 1; B is value in 1.75 ~ 1.8 scopes;

To drilling fluid inlet flow rate Q _iwith rate of discharge Q _ocompare, when other conditions are constant, if Q _i≈ Q _oand standpipe pressure obeys the change of formula (1), be then determined as normal drilling condition; Otherwise, if Q _i≈ Q _oand standpipe pressure rises suddenly or suppresses pump, be then determined as drill bit water blockoff eye; If the fluctuation of pipeline circular flow is abnormal, and pump pressure is unstable or suppress pump, be then determined as annular space exception or cave-in; If Q _i≈ Q _oand significantly declining, assuming that drop to P by original normal pressure appears in standpipe pressure _l1, be then determined as tubing string thorn and leak; Proceed to low discharge Q _i2circulation, measures now corresponding standpipe pressure P _l2, and then carry out the detection and diagnosis of tubing string thorn leakage;

In drilling process, if drilling fluid inlet flow rate Q _ibe greater than rate of discharge Q _o, and super threshold values, then carry out the detection and diagnosis of leakage; If drilling fluids outlet flow Q _obe greater than inlet flow rate Q _i, and when exceeding threshold values, be then judged as well kick.

7. diagnostic method as claimed in claim 6, is characterized in that: utilize formula (4) to carry out the detection and diagnosis of tubing string thorn leakage:

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

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: thorn leaks the discharge coefficient in crack, and can be similar to value is μ=0.62; Q ₁, Q ₂for correspondence different drilling fluid inlet flow rate Q _i, Q _i2time thorn leak source with mud flow rate inside and outside lower tubular column, unit is L/s; A is that thorn leaks flaw area, and unit is cm ²; k _f1: the loine pressure loss factor inside and outside thorn leak source drilling rod and inside and outside drill collar; k _f2: the loine pressure loss factor inside and outside the following drilling rod of leak source and inside and outside drill collar, k _f1and k _f2determine according to leak source position.

8. diagnostic method as claimed in claim 7, is characterized in that: if leak source is in drilling rod, then have k _f1, k _f2design formulas as follows:

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

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

By k _f1, k _f2design formulas substitute in formula (4), wherein, L _sfor thorn leak source well depth, k _f1, k _f2to sting leak source for line of demarcation, unknown quantity is L _s, A or μ A, Q ₁, Q ₂, solve formula (4) simultaneous equations, thorn leak source degree of depth L can be obtained _sand thorn leaks flaw area A.

9. diagnostic method as claimed in claim 6, is characterized in that: assuming that when there is leakage, drilling fluid inlet flow rate is Q _i; Whether there is drilling fluid to return out according to well head, process accordingly respectively: if there is drilling fluid to return out, drilling fluids outlet flow is Q _o; Otherwise make Q _o=0;

Measure the standpipe pressure PL after finding leakage, and carry out following judgement:

(1) P is calculated according to the following formula _l', P _l":

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

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

(2) if P _l< P _l', show the bottom of leakage points at drill bit;

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

If P _l>=P _l", show that leakage points is in drill pipe section, determine Well leakage position L by formula (7) ₁;

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

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

10. diagnostic method as claimed in claim 6, it is characterized in that: get b=1.8, formula (2) is reduced to:

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

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