CN104594834A - Method for monitoring drilling overflow condition of deepwater oil-based drilling fluid - Google Patents

Abstract

The invention relates to the technical field of oil and gas development, in particular to a method for monitoring the drilling overflow condition of deepwater oil-based drilling fluid. According to the method for monitoring the drilling overflow condition of the deepwater oil-based drilling fluid, based on the shaft annular space multiphase flow theory, the flashing theory and the phase change characteristics of the shaft annular space oil-based drilling fluid, the influences of an inner liquid membrane, an outer liquid membrane and the dip angle of an annular space structure and liquid drops contained in a gaseous core are considered, the influence of the flow pattern on hydrodynamic parameters and the influence of the annular space structure and the flow pattern on mass transfer, heat transfer and momentum transfer modes are considered, a shaft annular space transient multiphase flow model during deepwater overflow well killing is established to determine distribution of shaft annular space transient multiphase flow parameters along the well depth, an accurate monitoring result is provided for the early overflow condition of a deepwater oil-gas well, and a theoretical basis is provided for subsequent well killing construction modes and the like.

Description

A kind of monitoring method of deep water oil base drilling fluid drilling well flooded conditions

Technical field

The present invention relates to oil and gas development art field, be specifically related to a kind of monitoring method of deep water oil base drilling fluid drilling well flooded conditions.

Background technology

After entering 21 century, the oil-gas exploration of China has started from land to sea transfer, and deepwater petroleum exploration exploitation has become current focus.Marine oil and gas drilling well is bored and is met having a big risk of abnormal pressure oil-gas Layer, and the probability that overflow occurs is large.Due to fluid pressure temperature Changing Pattern in deep water mineshaft annulus and landly have larger difference, overflow rule identification under oil base drilling fluid condition has himself feature, invade gas to be likely dissolved in completely under suitable condition in oil base drilling fluid, in pit shaft, fluid is liquid phase; Along with the reduction of pressure, temperature, gas can be separated out again, and form free gas, in pit shaft, fluid shows as gas-liquid two-phase.Oil base drilling fluid phase Characteristics is complicated, is unfavorable for the monitoring of the early stage flooded conditions of overflow.

Overflow simultaneously mostly occurs in mineshaft annulus, mostly the mineshaft annulus transient multi-phase flow model of current description deep water flooding process is on the basis of pipe biphase gas and liquid flow empirical formula, adopt the method establishment of hydraulics equivalent diameter to get up, this method is inapplicable when lower gas-liquid flow velocity, and error is larger.This method can not embody annular space and pipeline otherness structurally simultaneously, and usually ignore the impact of flow pattern on parameter distribution, two phase flow is regarded as plan single-phase flow, its applicability is subject to the restriction of experiment condition.

Summary of the invention

Be subject to the defect of the restriction of experiment condition for the monitoring result error of the flooded conditions existed in prior art compared with applicability during Datong District, the invention provides a kind of monitoring method of deep water oil base drilling fluid drilling well flooded conditions.

On the one hand, the monitoring method of a kind of deep water oil base drilling fluid drilling well flooded conditions provided by the invention, comprising:

Obtain the monitored data in deep water oil base drilling fluid bored shaft annular space;

According to described monitored data and the phase equilibrium model set up in advance, judge whether the phase in mineshaft annulus is gas-liquid two-phase;

If gas-liquid two-phase, then determine the flow pattern of biphase gas and liquid flow in mineshaft annulus;

The distribution along well depth of the transient temperature of mineshaft annulus fluid, void fraction and pressure is calculated according to the mineshaft annulus transient multi-phase flow model set up in advance and annular fluid steady state heat transfer model corresponding to this flow pattern and Stationary Water kinetic model;

The distribution of mineshaft annulus transient multi-phase flow parameter along well depth is determined along the distribution of well depth according to described transient temperature, void fraction and pressure;

Drilling well flooded conditions is determined along the distribution of well depth according to described mineshaft annulus transient multi-phase flow parameter.

Further, described according to described monitored data and the phase equilibrium model set up in advance, judge that whether phase in mineshaft annulus is that the step of gas-liquid two-phase comprises:

By mineshaft annulus along well depth direction discrete formation grid configuration;

According to the mineshaft annulus fluid pressure p of described monitored data estimation current grid;

The fluid bubble point pressure p under current pressure is solved according to described phase equilibrium model _b;

If p<p _b, then the phase in mineshaft annulus is gas-liquid two-phase.

Further, in described mineshaft annulus, the flow pattern of biphase gas and liquid flow comprises dispersed bubble flow, bubble flow, annular flow and slug flow.

Further, the described mineshaft annulus transient multi-phase flow model set up in advance comprises mass-conservation equation, momentum conservation equation and energy conservation equation.

Further, described mass-conservation equation comprises:

Free gas mass-conservation equation:

$\frac{\&PartialD;}{\&PartialD;t}\left[A_c{H}_g{\mathrm{\&rho;}}_g\right]=-\frac{\&PartialD;\left(A_c{H}_g{\mathrm{\&rho;}}_g{v}_g\right)}{\&PartialD;z}-A_c{\stackrel{.}{m}}_g$

Wherein, t is overflow time, A _cfor annular space sectional area, H _gfor free gas void fraction, ρ _gfor density of gas phase in annular space, v _gfor the gas phase velocity in annular space, z is the vertical degree of depth, for the mass transfer velocity between free gas and solution gas;

Solution gas mass-conservation equation:

$\frac{\&PartialD;}{\&PartialD;t}\left[A_c(1-H_g)x{\mathrm{\&rho;}}_m\right]=-\frac{\&PartialD;\left(A_c(1-H_g)x{\mathrm{\&rho;}}_m{v}_m\right)}{\&PartialD;z}+A_c{\stackrel{.}{m}}_g$

Wherein, ρ _mfor oil base drilling fluid density, v _mfor the speed of oil base drilling fluid, x is the mass fraction of solution gas in oil base drilling fluid;

Liquid phase quality conservation equation:

$\frac{\&PartialD;}{\&PartialD;t}\left[A_c(1-H_g){\mathrm{\&rho;}}_m\right]=-\frac{\&PartialD;\left(A_c(1-H_g){\mathrm{\&rho;}}_m{v}_m\right)}{\&PartialD;z}+A_c{\stackrel{.}{m}}_g.$

Further, the mass transfer velocity between described free gas and solution gas for:

${\stackrel{.}{m}}_g=M_{g}p{k}_{g}a(y-y_e)\&times;{10}^3$

Wherein, M _gfor amount of substance, p is annular pressure, k _gfor mass tranfer coefficient, y is the gas molar mark in current system, y _efor the gas molar mark at system pressure, temperature during vapor liquid equilibrium, drawn by PR Solving Equation of State, a is gas-liquid contact interfacial area, in bubble flow situation:

$a=\frac{6H_g}{d_c}$

Wherein, d _cfor bubble diameter, Guan Liuzhong, mass tranfer coefficient can be solved by Sherwood number:

$S{h}_g=\frac{k_g{D}_r}{D_g}$

Wherein, D _rfor the equivalent diameter of annular space, D _gfor the coefficient of molecular diffusion of methane and diesel oil;

Work as reynolds number Re _gduring <2100, flowing belongs to laminar flow:

${\mathrm{Sh}}_g=\frac{8}{3}=\frac{k_g{D}_r}{D_g}$

$k_g=\frac{8D_g}{3D_r}$

Work as reynolds number Re _gduring >2100, flowing belongs to turbulent flow:

${\mathrm{Sh}}_g=0.023{{\mathrm{Re}}_g}^{0.8}{{\mathrm{Sc}}_g}^{1/3}=\frac{k_g{D}_r}{D_g}$

$k_g=\frac{0.023{{\mathrm{Re}}_g}^{0.8}{{\mathrm{Sc}}_g}^{1/3}{D}_g}{D_r}$

Wherein, Sc _gfor gas phase Schmidt number.

Further, described momentum conservation equation comprises:

Gas phase momentum conservation equation:

$\begin{array}{c}\frac{\&PartialD;}{\&PartialD;t}\left(A_c{H}_g{\mathrm{\&rho;}}_g{v}_g\right)=-\frac{\&PartialD;\left(A_c{H}_{g}p\right)}{\&PartialD;z}-\frac{\&PartialD;\left(A_c{H}_g{\mathrm{\&rho;}}_g{v}_g^2\right)}{\&PartialD;z}-f_I{\mathrm{\&rho;}}_g\frac{v_r^2}{2}{S}_I\\ -f_g{\mathrm{\&rho;}}_g\frac{v_g^2}{2}{S}_g-A_c{H}_g{\mathrm{\&rho;}}_{g}g-A_c{\stackrel{.}{m}}_g{v}_a\end{array}$

Wherein, t is overflow time, A _cfor annular space sectional area, H _gfor free gas void fraction, ρ _gfor density of gas phase in annular space, v _gfor the gas phase velocity in annular space, z is the vertical degree of depth, and p is annular pressure, f _ithe friction factor of gas phase and liquid interface, f _gthe friction factor of gas phase and tube wall, S _ithe girth of gas phase and liquid phase contact surface, S _gthe girth of gas phase and tube wall contact surface, v _rthe relative velocity of gas phase and liquid phase, v _abe the speed of mass transfer phase, g is gravity acceleration constant, for the mass transfer velocity between free gas and solution gas;

Liquid phase momentum conservation equation:

$\begin{array}{c}\frac{\&PartialD;}{\&PartialD;t}\left(A_c(1-H_g){\mathrm{\&rho;}}_L{v}_L\right)=-\frac{\&PartialD;\left(A_c(1-H_g)p\right)}{\&PartialD;z}-\frac{\&PartialD;\left(A_c(1-H_g){\mathrm{\&rho;}}_L{v}_L^2\right)}{\&PartialD;z}-f_L{\mathrm{\&rho;}}_L\frac{v_L^2}{2}{S}_L\\ -f_I{\mathrm{\&rho;}}_L\frac{v_r^2}{2}{S}_I-A_c(1-H_g){\mathrm{\&rho;}}_{L}g+A_c{\stackrel{.}{m}}_g{v}_a\end{array}$

Wherein, ρ _lfor density of liquid phase in annular space, v _lfor the liquid velocity in annular space, f _lfor the friction factor of liquid phase and tube wall, S _lfor the girth of liquid phase and tube wall contact surface;

Aggregated momentum conservation equation:

$\begin{array}{c}\frac{\&PartialD;}{\&PartialD;t}(A_c(1-H_g){\mathrm{\&rho;}}_L{v}_L+A_c{H}_g{\mathrm{\&rho;}}_g{v}_g)=-\frac{\&PartialD;\left(A_{c}p\right)}{\&PartialD;z}-\frac{\&PartialD;(A_c(1-H_g){\mathrm{\&rho;}}_L{v}_L^2+A_c{H}_g{\mathrm{\&rho;}}_g{v}_g^2)}{\&PartialD;z}-f_L{\mathrm{\&rho;}}_L\frac{v_L^2}{2}{S}_L\\ -f_g{\mathrm{\&rho;}}_g\frac{v_g^2}{2}{S}_g-A_c((1-H_g){\mathrm{\&rho;}}_{L}g+H_g{\mathrm{\&rho;}}_{L}g)\end{array}.$

Further, described energy conservation equation comprises:

Heat conservation equation in mineshaft annulus:

$\begin{array}{c}\frac{\&PartialD;}{\&PartialD;t}({\mathrm{\&rho;}}_g{H}_g(c_{\mathrm{pg}}{T}_c+{\mathrm{\&eta;}}_g{c}_{\mathrm{pg}}p+\frac{1}{2}{v}_g^2+\mathrm{gdz})+{\mathrm{\&rho;}}_L{H}_L(c_{\mathrm{pL}}{T}_c+{\mathrm{\&eta;}}_L{c}_{\mathrm{pL}}p+\frac{1}{2}{v}_L^2+\mathrm{gdz}))\\ +\frac{\&PartialD;({\mathrm{\&rho;}}_g{v}_g{H}_g(c_{\mathrm{pg}}{T}_c+{\mathrm{\&eta;}}_g{c}_{\mathrm{pg}}p+\frac{1}{2}{v}_g^2+\mathrm{gdz})+{\mathrm{\&rho;}}_L{v}_L{H}_L(c_{\mathrm{pL}}{T}_c+{\mathrm{\&eta;}}_L{c}_{\mathrm{pL}}p+\frac{1}{2}{v}_L^2+\mathrm{gdz}))}{\&PartialD;z}\\ =\frac{\mathrm{\&Delta;}{Q}_g+\mathrm{\&Delta;}{Q}_L}{A_c\mathrm{dz}}=\frac{1}{A_c}(\frac{(T_{\mathrm{dp}}-T_c)}{A_{\mathrm{dpc}}^{\&prime;}}+\frac{(T_{\mathrm{ei}}-T_c)}{A_{\mathrm{cw}}^{\&prime;}})\end{array}$

Wherein, t is overflow time, A _cfor annular space sectional area, H _gfor free gas void fraction, ρ _gfor density of gas phase in annular space, v _gfor the gas phase velocity in annular space, z is the vertical degree of depth, and p is annular pressure, c _pgfor gas phase specific heat capacity, T _cfor the fluid temperature (F.T.) in annular space, η _gfor gas phase joule thomson effect coefficient, g is gravity acceleration constant, ρ _lfor density of liquid phase in annular space, H _lfor liquid holdup, v _lfor the liquid velocity in annular space, η _lfor liquid phase joule thomson effect coefficient, c _pLfor liquid phase specific heat capacity, Δ Q _gfor the thermal change amount of gas phase in micro unit, Δ Q _lfor the thermal change amount of liquid phase in micro unit, T _dpfor drilling fluid temperature in drilling rod, T _eifor surrounding formation temperature,

$A_{\mathrm{dpc}}^{\&prime;}=\frac{c_{\mathrm{pdp}}{w}_{\mathrm{Ldp}}{A}_{\mathrm{dpc}}}{c_{\mathrm{pc}}{w}_{\mathrm{Lc}}}$

$A_{\mathrm{cw}}^{\&prime;}=\frac{1}{A_{\mathrm{cw}}{A}_c{\mathrm{\&rho;}}_L{c}_{\mathrm{pdp}}}$

A _dpcfor drilling rod is to the local dimensionless constant that annular space conducts heat, c _pdpfor the specific heat capacity of fluid in drilling rod, w _ldpfor the unit mass flow velocity of fluid in drilling rod, w _ldp=A _dpρ _lv _ldp, A _dpfor drilling rod sectional area, v _ldpfor the liquid velocity in drilling rod, c _pcfor the specific heat capacity of fluid in annular space, w _lcfor the unit mass flow velocity of fluid in annular space, w _lc=A _cρ _lv _lc, v _lcfor the fluid velocity in annular space, A _cwfor the local dimensionless constant conducted heat in annular space and stratum, c _pdpfor the specific heat capacity of fluid in drilling rod;

Heat conservation equation in drilling rod:

$\begin{array}{c}\frac{\&PartialD;}{\&PartialD;t}\left({\mathrm{\&rho;}}_{\mathrm{Ldp}}(c_{\mathrm{pLdp}}{T}_{\mathrm{dp}}+{\mathrm{\&eta;}}_{\mathrm{Ldp}}{c}_{\mathrm{pLdp}}{p}_{\mathrm{dp}}+\frac{1}{2}{v}_{\mathrm{Ldp}}^2+\mathrm{gdz})\right)\\ +\frac{\&PartialD;\left({\mathrm{\&rho;}}_{\mathrm{Ldp}}{v}_{\mathrm{Ldp}}(c_{\mathrm{pLdp}}{T}_{\mathrm{dp}}+{\mathrm{\&eta;}}_{\mathrm{Ldp}}{c}_{\mathrm{pLdp}}{p}_{\mathrm{dp}}+\frac{1}{2}{v}_{\mathrm{Ldp}}^2+\mathrm{gdz})\right)}{\&PartialD;z}\\ =\frac{\mathrm{\&Delta;}{Q}_L}{A_{\mathrm{dp}}\mathrm{dz}}=\frac{1}{A_{\mathrm{dp}}}\frac{(T_c-T_{\mathrm{dp}})}{A_{\mathrm{dpc}}^{\&prime;}}\end{array}$

Wherein, ρ _ldpfor the density of liquid phase in drilling rod, c _pLdpfor the liquid phase specific heat capacity in annular space, η _ldpfor the liquid phase joule thomson effect coefficient in drilling rod, p _dpfor liquid phase pressure in drilling rod.

On the other hand, present invention also offers a kind of monitoring device of deep water oil base drilling fluid drilling well flooded conditions, comprising:

Acquisition module, for obtaining the monitored data in deep water oil base drilling fluid bored shaft annular space;

Judge module, for according to described monitored data and the phase equilibrium model set up in advance, judges whether the phase in mineshaft annulus is gas-liquid two-phase;

First determination module, if for gas-liquid two-phase, then determines the flow pattern of biphase gas and liquid flow in mineshaft annulus;

Computing module, for calculating the distribution along well depth of the transient temperature of mineshaft annulus fluid, void fraction and pressure according to the mineshaft annulus transient multi-phase flow model set up in advance and annular fluid steady state heat transfer model corresponding to this flow pattern and Stationary Water kinetic model; The distribution of mineshaft annulus transient multi-phase flow parameter along well depth is determined along the distribution of well depth according to described transient temperature, void fraction and pressure;

Second determination module, for determining drilling well flooded conditions according to described mineshaft annulus transient multi-phase flow parameter along the distribution of well depth.

Further, described judge module specifically for:

By mineshaft annulus along well depth direction discrete formation grid configuration;

According to the mineshaft annulus fluid pressure p of described monitored data estimation current grid;

The fluid bubble point pressure p under current pressure is solved according to described phase equilibrium model _b;

If p<p _b, then the phase in mineshaft annulus is gas-liquid two-phase.

The monitoring method of a kind of deep water oil base drilling fluid drilling well flooded conditions provided by the invention, the inventive method is theoretical based on mineshaft annulus Multiphase Flow, the phase-state change feature of flash distillation theory and mineshaft annulus oil base drilling fluid, consider liquid film in annular space structure, outer liquid film, impact containing drop in inclination angle and gaseous core, consider that flow pattern is on the impact on mass-and heat-transfer and Momentum Transfer mode of the impact of Hydrodynamic Parameters and annular space structure and flow pattern, mineshaft annulus transient multi-phase flow model during establishing deep water overflow kill-job, to determine the distribution of mineshaft annulus transient multi-phase flow parameter along well depth, for the early stage flooded conditions of deep water hydrocarbon well provides accurate monitoring result, and provide fundamental basis for follow-up kill-job form of construction work etc.

Accompanying drawing explanation

Can understanding the features and advantages of the present invention clearly by reference to accompanying drawing, accompanying drawing is schematic and should not be construed as and carry out any restriction to the present invention, in the accompanying drawings:

Fig. 1 is the schematic flow sheet of the monitoring method of deep water oil base drilling fluid drilling well flooded conditions in one embodiment of the invention;

Fig. 2 is that in one embodiment of the invention, during deep water oil base drilling fluid drilling well overflow kill-job, mineshaft annulus fluid phase state changes schematic diagram;

Fig. 3 is slug flow flow pattern schematic diagram in one embodiment of the invention;

Fig. 4 is annular flow flow pattern schematic diagram in one embodiment of the invention;

Fig. 5 is the structural representation of the monitoring device of deep water oil base drilling fluid drilling well flooded conditions in one embodiment of the invention.

Detailed description of the invention

Now in conjunction with the accompanying drawings and embodiments technical solution of the present invention is further elaborated.

Fig. 1 shows the schematic flow sheet of the monitoring method of a kind of deep water oil base drilling fluid drilling well flooded conditions in the present embodiment, and as shown in Figure 1, the monitoring method of a kind of deep water oil base drilling fluid drilling well flooded conditions that the present embodiment provides, comprising:

S1, obtains the monitored data in deep water oil base drilling fluid bored shaft annular space;

S2, according to described monitored data and the phase equilibrium model set up in advance, judges whether the phase in mineshaft annulus is gas-liquid two-phase;

S3, if gas-liquid two-phase, then determines the flow pattern of biphase gas and liquid flow in mineshaft annulus;

S4, calculates the distribution along well depth of the transient temperature of mineshaft annulus fluid, void fraction and pressure according to the mineshaft annulus transient multi-phase flow model set up in advance and annular fluid steady state heat transfer model corresponding to this flow pattern and Stationary Water kinetic model;

S5, determines the distribution of mineshaft annulus transient multi-phase flow parameter along well depth according to described transient temperature, void fraction and pressure along the distribution of well depth;

S6, determines drilling well flooded conditions according to described mineshaft annulus transient multi-phase flow parameter along the distribution of well depth.

According to described monitored data and the phase equilibrium model set up in advance, judge that whether phase in mineshaft annulus is that the step of gas-liquid two-phase comprises:

S21, by mineshaft annulus along well depth direction discrete formation grid configuration;

S22, according to the mineshaft annulus fluid pressure p of described monitored data estimation current grid;

S23, solves the fluid bubble point pressure p under current pressure according to described phase equilibrium model _b;

S24, if p<p _b, then the phase in mineshaft annulus is gas-liquid two-phase.

Described phase equilibrium model is based on PR state equation, considers the impact of different gas cut amount, considers the pressure of deep water mineshaft annulus, the impact of Temperature Distribution, and the basis of the phase-state change feature after considering deep water oil base drilling fluid drilling well overflow in mineshaft annulus is set up.

Wherein, as shown in Figure 2, the phase-state change feature during deep water oil base drilling fluid drilling well overflow kill-job in mineshaft annulus mainly contains:

In Fig. 2 A, do not exist degassed in mineshaft annulus, be always liquid phase.When gas cut amount is less, the bubble point condition of fluid-mixing is lower, and no matter how pressure, temperature change, wellbore annulus pressure temperature condition is in more than bubble point line all the time, until recycle well head from gas cut, there is not degassed phenomenon in whole pit shaft all the time, and fluid exists with liquid form all the time.

In Fig. 2 B, mineshaft annulus bottom is liquid phase, and top is gas-liquid two-phase.During medium gas cut amount, the pressure of the following annular space of a certain degree of depth of pit shaft is all greater than the bubble point pressure of the corresponding degree of depth, only there is solution gas, show as liquid form in annular space; And above pressure is all less than the bubble point pressure of the corresponding degree of depth, mineshaft annulus upper flow generation phase-state change, starts degassed, exists with the form of gas-liquid two-phase.Free tolerance in mineshaft annulus is one and grows out of nothing from shaft bottom to well head, and then the process increased gradually.

In Fig. 2 C, mineshaft annulus exists degassed all the time, is always gas-liquid two-phase.During larger gas cut amount, the bubble point pressure of fluid-mixing is higher, and wellbore annulus pressure is all less than the bubble point pressure of the corresponding degree of depth, exists degassed in annular space all the time.In whole flooding process, in annular space, be always gas-liquid mixture, from shaft bottom to well head, be always gas liquid two-phase flow.If pressure change is very fast, the free tolerance in mineshaft annulus increases gradually from shaft bottom to well head.If variations in temperature is very fast, the free tolerance in annular space can exist one from shaft bottom to well head first increases the process reduced afterwards.

Further, in described mineshaft annulus, the flow pattern of biphase gas and liquid flow comprises dispersed bubble flow, bubble flow, annular flow and slug flow.

As shown in Figure 3, the slug flow in the present embodiment in annular space two phase flow is different from ducted slug flow, first there is two-layer liquid film, and one is the casing tube film contacted with casing wall, and one is the drilling rod film contacted with drilling rod wall.Secondly, Taylor bubble does not occupy whole cross-sectional area, owing to there is a passage in direction, back, is connected to drilling rod film and casing tube film.Due to the existence of this passage, Taylor is steeped no longer symmetrical, high regions of turbulent flow can be there is after Taylor bubble.

As shown in Figure 4, the annular flow in the present embodiment in annular space is different from ducted, and under it occurs in very high gas flow rate, the gas phase velocity in gaseous core is very high, may contain drop.Around gaseous core, it is very thin liquid film.Due to the structure of annular space, also there are two kinds of liquid films, a kind of is the inner membrance contacted with drilling rod, and a kind of is the adventitia contacted with the borehole wall, and the thickness of adventitia is thicker than the thickness of inner membrance.

The existence of the double-deck liquid film of oil pipe film, casing tube film, makes the stressed of cell cube there occurs change, and the predicted impact of convection transition, liquid holdup, pressure drop etc. is comparatively large, needs to consider when studying annular space gas liquid two-phase flow rule.

Further, the described mineshaft annulus transient multi-phase flow model set up in advance comprises mass-conservation equation, momentum conservation equation and energy conservation equation.

Further, described mass-conservation equation comprises:

Free gas mass-conservation equation:

$\frac{\&PartialD;}{\&PartialD;t}\left[A_c{H}_g{\mathrm{\&rho;}}_g\right]=-\frac{\&PartialD;\left(A_c{H}_g{\mathrm{\&rho;}}_g{v}_g\right)}{\&PartialD;z}-A_c{\stackrel{.}{m}}_g$

Wherein, t is overflow time, A _cfor annular space sectional area, H _gfor free gas void fraction, ρ _gfor density of gas phase in annular space, v _gfor the gas phase velocity in annular space, z is the vertical degree of depth, for the mass transfer velocity between free gas and solution gas;

Solution gas mass-conservation equation:

$\frac{\&PartialD;}{\&PartialD;t}\left[A_c(1-H_g)x{\mathrm{\&rho;}}_m\right]=-\frac{\&PartialD;\left(A_c(1-H_g)x{\mathrm{\&rho;}}_m{v}_m\right)}{\&PartialD;z}+A_c{\stackrel{.}{m}}_g$

Wherein, ρ _mfor oil base drilling fluid density, v _mfor the speed of oil base drilling fluid, x is the mass fraction of solution gas in oil base drilling fluid;

Liquid phase quality conservation equation:

$\frac{\&PartialD;}{\&PartialD;t}\left[A_c(1-H_g){\mathrm{\&rho;}}_m\right]=-\frac{\&PartialD;\left(A_c(1-H_g){\mathrm{\&rho;}}_m{v}_m\right)}{\&PartialD;z}+A_c{\stackrel{.}{m}}_g.$

Further, the mass transfer velocity between described free gas and solution gas for:

${\stackrel{.}{m}}_g=M_{g}p{k}_{g}a(y-y_e)\&times;{10}^3$

Wherein, M _gfor amount of substance, p is annular pressure, k _gfor mass tranfer coefficient, y is the gas molar mark in current system, y _efor the gas molar mark at system pressure, temperature during vapor liquid equilibrium, drawn by PR Solving Equation of State, a is gas-liquid contact interfacial area, in bubble flow situation:

$a=\frac{6H_g}{d_c}$

Wherein, d _cfor bubble diameter, Guan Liuzhong, mass tranfer coefficient can be solved by Sherwood number:

$S{h}_g=\frac{k_g{D}_r}{D_g}$

Wherein, D _rfor the equivalent diameter of annular space, D _gfor the coefficient of molecular diffusion of methane and diesel oil;

Work as reynolds number Re _gduring <2100, flowing belongs to laminar flow:

${\mathrm{Sh}}_g=\frac{8}{3}=\frac{k_g{D}_r}{D_g}$

$k_g=\frac{8D_g}{3D_r}$

Work as reynolds number Re _gduring >2100, flowing belongs to turbulent flow:

${\mathrm{Sh}}_g=0.023{{\mathrm{Re}}_g}^{0.8}{{\mathrm{Sc}}_g}^{1/3}=\frac{k_g{D}_r}{D_g}$

$k_g=\frac{0.023{{\mathrm{Re}}_g}^{0.8}{{\mathrm{Sc}}_g}^{1/3}{D}_g}{D_r}$

Wherein, Sc _gfor gas phase Schmidt number.

Further, described momentum conservation equation comprises:

Gas phase momentum conservation equation:

$\begin{array}{c}\frac{\&PartialD;}{\&PartialD;t}\left(A_c{H}_g{\mathrm{\&rho;}}_g{v}_g\right)=-\frac{\&PartialD;\left(A_c{H}_{g}p\right)}{\&PartialD;z}-\frac{\&PartialD;\left(A_c{H}_g{\mathrm{\&rho;}}_g{v}_g^2\right)}{\&PartialD;z}-f_I{\mathrm{\&rho;}}_g\frac{v_r^2}{2}{S}_I\\ -f_g{\mathrm{\&rho;}}_g\frac{v_g^2}{2}{S}_g-A_c{H}_g{\mathrm{\&rho;}}_{g}g-A_c{\stackrel{.}{m}}_g{v}_a\end{array}$

Wherein, t is overflow time, A _cfor annular space sectional area, H _gfor free gas void fraction, ρ _gfor density of gas phase in annular space, v _gfor the gas phase velocity in annular space, z is the vertical degree of depth, and p is annular pressure, f _ithe friction factor of gas phase and liquid interface, f _gthe friction factor of gas phase and tube wall, S _ithe girth of gas phase and liquid phase contact surface, S _gthe girth of gas phase and tube wall contact surface, v _rthe relative velocity of gas phase and liquid phase, v _abe the speed of mass transfer phase, g is gravity acceleration constant, for the mass transfer velocity between free gas and solution gas;

Liquid phase momentum conservation equation:

$\begin{array}{c}\frac{\&PartialD;}{\&PartialD;t}\left(A_c(1-H_g){\mathrm{\&rho;}}_L{v}_L\right)=-\frac{\&PartialD;\left(A_c(1-H_g)p\right)}{\&PartialD;z}-\frac{\&PartialD;\left(A_c(1-H_g){\mathrm{\&rho;}}_L{v}_L^2\right)}{\&PartialD;z}-f_L{\mathrm{\&rho;}}_L\frac{v_L^2}{2}{S}_L\\ -f_I{\mathrm{\&rho;}}_L\frac{v_r^2}{2}{S}_I-A_c(1-H_g){\mathrm{\&rho;}}_{L}g+A_c{\stackrel{.}{m}}_g{v}_a\end{array}$

Wherein, ρ _lfor density of liquid phase in annular space, v _lfor the liquid velocity in annular space, f _lfor the friction factor of liquid phase and tube wall, S _lfor the girth of liquid phase and tube wall contact surface;

Aggregated momentum conservation equation:

$\begin{array}{c}\frac{\&PartialD;}{\&PartialD;t}(A_c(1-H_g){\mathrm{\&rho;}}_L{v}_L+A_c{H}_g{\mathrm{\&rho;}}_g{v}_g)=-\frac{\&PartialD;\left(A_{c}p\right)}{\&PartialD;z}-\frac{\&PartialD;(A_c(1-H_g){\mathrm{\&rho;}}_L{v}_L^2+A_c{H}_g{\mathrm{\&rho;}}_g{v}_g^2)}{\&PartialD;z}-f_L{\mathrm{\&rho;}}_L\frac{v_L^2}{2}{S}_L\\ -f_g{\mathrm{\&rho;}}_g\frac{v_g^2}{2}{S}_g-A_c((1-H_g){\mathrm{\&rho;}}_{L}g+H_g{\mathrm{\&rho;}}_{L}g)\end{array}.$

Further, described energy conservation equation comprises:

Heat conservation equation in mineshaft annulus:

$\begin{array}{c}\frac{\&PartialD;}{\&PartialD;t}({\mathrm{\&rho;}}_g{H}_g(c_{\mathrm{pg}}{T}_c+{\mathrm{\&eta;}}_g{c}_{\mathrm{pg}}p+\frac{1}{2}{v}_g^2+\mathrm{gdz})+{\mathrm{\&rho;}}_L{H}_L(c_{\mathrm{pL}}{T}_c+{\mathrm{\&eta;}}_L{c}_{\mathrm{pL}}p+\frac{1}{2}{v}_L^2+\mathrm{gdz}))\\ +\frac{\&PartialD;({\mathrm{\&rho;}}_g{v}_g{H}_g(c_{\mathrm{pg}}{T}_c+{\mathrm{\&eta;}}_g{c}_{\mathrm{pg}}p+\frac{1}{2}{v}_g^2+\mathrm{gdz})+{\mathrm{\&rho;}}_L{v}_L{H}_L(c_{\mathrm{pL}}{T}_c+{\mathrm{\&eta;}}_L{c}_{\mathrm{pL}}p+\frac{1}{2}{v}_L^2+\mathrm{gdz}))}{\&PartialD;z}\\ =\frac{\mathrm{\&Delta;}{Q}_g+\mathrm{\&Delta;}{Q}_L}{A_c\mathrm{dz}}=\frac{1}{A_c}(\frac{(T_{\mathrm{dp}}-T_c)}{A_{\mathrm{dpc}}^{\&prime;}}+\frac{(T_{\mathrm{ei}}-T_c)}{A_{\mathrm{cw}}^{\&prime;}})\end{array}$

Wherein, t is overflow time, A _cfor annular space sectional area, H _gfor free gas void fraction, ρ _gfor density of gas phase in annular space, v _gfor the gas phase velocity in annular space, z is the vertical degree of depth, and p is annular pressure, c _pgfor gas phase specific heat capacity, T _cfor the fluid temperature (F.T.) in annular space, η _gfor gas phase joule thomson effect coefficient, g is gravity acceleration constant, ρ _lfor density of liquid phase in annular space, H _lfor liquid holdup, v _lfor the liquid velocity in annular space, η _lfor liquid phase joule thomson effect coefficient, c _pLfor liquid phase specific heat capacity, Δ Q _gfor the thermal change amount of gas phase in micro unit, Δ Q _lfor the thermal change amount of liquid phase in micro unit, T _dpfor drilling fluid temperature in drilling rod, T _eifor surrounding formation temperature,

$A_{\mathrm{dpc}}^{\&prime;}=\frac{c_{\mathrm{pdp}}{w}_{\mathrm{Ldp}}{A}_{\mathrm{dpc}}}{c_{\mathrm{pc}}{w}_{\mathrm{Lc}}}$

$A_{\mathrm{cw}}^{\&prime;}=\frac{1}{A_{\mathrm{cw}}{A}_c{\mathrm{\&rho;}}_L{c}_{\mathrm{pdp}}}$

A _dpcfor drilling rod is to the local dimensionless constant that annular space conducts heat, c _pdpfor the specific heat capacity of fluid in drilling rod, w _ldpfor the unit mass flow velocity of fluid in drilling rod, w _ldp=A _dpρ _lv _ldp, A _dpfor drilling rod sectional area, v _ldpfor the liquid velocity in drilling rod, c _pcfor the specific heat capacity of fluid in annular space, w _lcfor the unit mass flow velocity of fluid in annular space, w _lc=A _cρ _lv _lc, v _lcfor the fluid velocity in annular space, A _cwfor the local dimensionless constant conducted heat in annular space and stratum, c _pdpfor the specific heat capacity of fluid in drilling rod;

Heat conservation equation in drilling rod:

$\begin{array}{c}\frac{\&PartialD;}{\&PartialD;t}\left({\mathrm{\&rho;}}_{\mathrm{Ldp}}(c_{\mathrm{pLdp}}{T}_{\mathrm{dp}}+{\mathrm{\&eta;}}_{\mathrm{Ldp}}{c}_{\mathrm{pLdp}}{p}_{\mathrm{dp}}+\frac{1}{2}{v}_{\mathrm{Ldp}}^2+\mathrm{gdz})\right)\\ +\frac{\&PartialD;\left({\mathrm{\&rho;}}_{\mathrm{Ldp}}{v}_{\mathrm{Ldp}}(c_{\mathrm{pLdp}}{T}_{\mathrm{dp}}+{\mathrm{\&eta;}}_{\mathrm{Ldp}}{c}_{\mathrm{pLdp}}{p}_{\mathrm{dp}}+\frac{1}{2}{v}_{\mathrm{Ldp}}^2+\mathrm{gdz})\right)}{\&PartialD;z}\\ =\frac{\mathrm{\&Delta;}{Q}_L}{A_{\mathrm{dp}}\mathrm{dz}}=\frac{1}{A_{\mathrm{dp}}}\frac{(T_c-T_{\mathrm{dp}})}{A_{\mathrm{dpc}}^{\&prime;}}\end{array}$

Wherein, ρ _ldpfor the density of liquid phase in drilling rod, c _pLdpfor the liquid phase specific heat capacity in annular space, η _ldpfor the liquid phase joule thomson effect coefficient in drilling rod, p _dpfor liquid phase pressure in drilling rod.

For example, the transient temperature of mineshaft annulus fluid, void fraction and pressure is calculated according to the mineshaft annulus transient multi-phase flow model set up in advance and annular fluid steady state heat transfer model corresponding to this flow pattern and Stationary Water kinetic model as follows along the distribution concrete steps of well depth:

1. obtain and comprise well head pressure P _n1, wellhead temperature T _n1monitored data in interior deep water oil base drilling fluid bored shaft annular space;

2. by mineshaft annulus along well depth direction discrete formation grid configuration; According to mineshaft annulus fluid pressure initial value p (j, t+1), mineshaft annulus fluid temperature (F.T.) initial value T (j, t+1) in described monitored data estimation j point t+1 moment, wherein 0≤j≤N;

3. the density of gas phase in j point t+1 moment, viscosity, surface tension and specific speed is calculated, density of liquid phase, viscosity, surface tension and specific speed;

4. bubble point pressure p is solved according to described phase equilibrium model _bif, p (j, t+1) >p _b, be liquid phase in system, if p (j, t+1) <p _b, be gas-liquid two-phase in system; PR state equation is utilized to calculate the parameter such as density, viscosity, specific heat, compressibility factor, free tolerance that is single-phase or two-phase;

If 5. single-phase, single-phase heat transfer model is utilized to calculate the temperature value T ' (j, t+1) in j point t+1 moment; If two-phase, carry out flow pattern judgement according to mineshaft annulus multiphase flow pattern transition evaluation criterion; Calculate the temperature value T ' (j, t+1) in j point t+1 moment according to the heat transfer parameter computational methods under different flow pattern and energy equation, judge whether meet iteration precision with initial value, if meet, then continue; If do not meet, then using T ' (j, t+1) as new mineshaft annulus fluid j point t+1 moment temperature initial value return the 3. step recalculate;

6. the liquid holdup initial value H in j point t+1 moment is estimated _l(j, t+1), calculates the speed of each phase according to continuity equation, the hydraulic parameter computation model chosen under different flow pattern calculates liquid holdup H ' _l(j, t+1), judges whether to meet iteration precision, if meet, then continues; If do not meet, then by H ' _l(j, t+1) repeats this step as the liquid holdup initial value in j point t+1 moment;

7. the parameter obtained is brought into momentum conservation equation, and according to the hydraulic parameter computational methods under different flow pattern, solve pressure p ' (j, t+1), and judge whether to meet iteration precision, if meet, then p ' (j, t+1) is calculated the parameter such as pressure, temperature in j+1 point t+1 moment as j+1 point pressure initial value; If do not meet, then using p ' (j, t+1) as the pressure initial value in j point t+1 moment return the 2. step recalculate.

8. iteration carry out above-mentioned steps 2.-7., calculate well head pressure P _n1new, T _n1newand the Multiphase Flow parameter at each space nodes place in whole mineshaft annulus;

9. P is judged _n1with P _n1new, T _n1with T _n1newerror whether meet computational accuracy requirement;

The annular pressure P of the well head 8. calculated by step _n1new, T _n1new, judge this value and fixed well mouth pressure P _n1, wellhead temperature T _n1between error whether meet required precision; If met, the mineshaft annulus fluid pressure initial value p (j in description of step 2. j point t+1 moment, t+1), mineshaft annulus fluid temperature (F.T.) initial value T (j, t+1) reasonable, according to step 2.-the whole mineshaft annulus that 8. calculates in the Multiphase Flow parameter at each space nodes place effective; Otherwise return step 2. to recalculate, until meet the demands.

On the other hand, as shown in Figure 5, the present embodiment additionally provides a kind of monitoring device of deep water oil base drilling fluid drilling well flooded conditions, comprising:

Acquisition module 101, for obtaining the monitored data in deep water oil base drilling fluid bored shaft annular space;

Judge module 102, for according to described monitored data and the phase equilibrium model set up in advance, judges whether the phase in mineshaft annulus is gas-liquid two-phase;

First determination module 103, if for gas-liquid two-phase, then determines the flow pattern of biphase gas and liquid flow in mineshaft annulus;

Computing module 104, for calculating the distribution along well depth of the transient temperature of mineshaft annulus fluid, void fraction and pressure according to the mineshaft annulus transient multi-phase flow model set up in advance and annular fluid steady state heat transfer model corresponding to this flow pattern and Stationary Water kinetic model; The distribution of mineshaft annulus transient multi-phase flow parameter along well depth is determined along the distribution of well depth according to described transient temperature, void fraction and pressure;

Second determination module 105, for determining drilling well flooded conditions according to described mineshaft annulus transient multi-phase flow parameter along the distribution of well depth.

Further, described judge module 102 specifically for:

By mineshaft annulus along well depth direction discrete formation grid configuration;

According to the mineshaft annulus fluid pressure p of described monitored data estimation current grid;

The fluid bubble point pressure p under current pressure is solved according to described phase equilibrium model _b;

If p<p _b, then the phase in mineshaft annulus is gas-liquid two-phase.

The monitoring method of a kind of deep water oil base drilling fluid drilling well flooded conditions that the present embodiment provides, the present embodiment method is theoretical based on mineshaft annulus Multiphase Flow, the phase-state change feature of flash distillation theory and mineshaft annulus oil base drilling fluid, consider liquid film in annular space structure, outer liquid film, impact containing drop in inclination angle and gaseous core, consider that flow pattern is on the impact on mass-and heat-transfer and Momentum Transfer mode of the impact of Hydrodynamic Parameters and annular space structure and flow pattern, mineshaft annulus transient multi-phase flow model during establishing deep water overflow kill-job, to determine the distribution of mineshaft annulus transient multi-phase flow parameter along well depth, for the early stage flooded conditions of deep water hydrocarbon well provides accurate monitoring result, and provide fundamental basis for follow-up kill-job form of construction work etc.

Although describe embodiments of the present invention by reference to the accompanying drawings, but those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, such amendment and modification all fall into by within claims limited range.

Claims (10)

1. a monitoring method for deep water oil base drilling fluid drilling well flooded conditions, is characterized in that, described method comprises:

Obtain the monitored data in deep water oil base drilling fluid bored shaft annular space;

According to described monitored data and the phase equilibrium model set up in advance, judge whether the phase in mineshaft annulus is gas-liquid two-phase;

If gas-liquid two-phase, then determine the flow pattern of biphase gas and liquid flow in mineshaft annulus;

The distribution along well depth of the transient temperature of mineshaft annulus fluid, void fraction and pressure is calculated according to the mineshaft annulus transient multi-phase flow model set up in advance and annular fluid steady state heat transfer model corresponding to this flow pattern and Stationary Water kinetic model;

The distribution of mineshaft annulus transient multi-phase flow parameter along well depth is determined along the distribution of well depth according to described transient temperature, void fraction and pressure;

Drilling well flooded conditions is determined along the distribution of well depth according to described mineshaft annulus transient multi-phase flow parameter.

2. method according to claim 1, is characterized in that, described according to described monitored data and the phase equilibrium model set up in advance, judges that whether phase in mineshaft annulus is that the step of gas-liquid two-phase comprises:

By mineshaft annulus along well depth direction discrete formation grid configuration;

According to the mineshaft annulus fluid pressure p of described monitored data estimation current grid;

The fluid bubble point pressure p under current pressure is solved according to described phase equilibrium model _b;

If p<p _b, then the phase in mineshaft annulus is gas-liquid two-phase.

3. method according to claim 1, is characterized in that, in described mineshaft annulus, the flow pattern of biphase gas and liquid flow comprises dispersed bubble flow, bubble flow, annular flow and slug flow.

4. method according to claim 1, is characterized in that, the described mineshaft annulus transient multi-phase flow model set up in advance comprises mass-conservation equation, momentum conservation equation and energy conservation equation.

5. method according to claim 4, is characterized in that, described mass-conservation equation comprises:

Free gas mass-conservation equation:

$\frac{\&PartialD;}{\&PartialD;t}\left[A_c{H}_g{\mathrm{\&rho;}}_g\right]=-\frac{\&PartialD;\left(A_c{H}_g{\mathrm{\&rho;}}_g{v}_g\right)}{\&PartialD;z}-A_c{\stackrel{\&CenterDot;}{m}}_g$

Wherein, t is overflow time, A _cfor annular space sectional area, H _gfor free gas void fraction, ρ _gfor density of gas phase in annular space, v _gfor the gas phase velocity in annular space, z is the vertical degree of depth, for the mass transfer velocity between free gas and solution gas;

Solution gas mass-conservation equation:

$\frac{\&PartialD;}{\&PartialD;t}\left[A_c(1-H_g)x{\mathrm{\&rho;}}_m\right]=-\frac{\&PartialD;\left(A_c(1-H_g)x{\mathrm{\&rho;}}_m{v}_m\right)}{\&PartialD;z}+A_c{\stackrel{\&CenterDot;}{m}}_g$

Wherein, ρ _mfor oil base drilling fluid density, v _mfor the speed of oil base drilling fluid, x is the mass fraction of solution gas in oil base drilling fluid;

Liquid phase quality conservation equation:

$\frac{\&PartialD;}{\&PartialD;t}\left[A_c(1-H_g){\mathrm{\&rho;}}_m\right]=-\frac{\&PartialD;\left(A_c(1-H_g){\mathrm{\&rho;}}_m{v}_m\right)}{\&PartialD;z}+A_c{\stackrel{\&CenterDot;}{m}}_g.$

6. method according to claim 5, is characterized in that, the mass transfer velocity between described free gas and solution gas for:

Wherein, M _gfor amount of substance, p is annular pressure, k _gfor mass tranfer coefficient, y is the gas molar mark in current system, y _efor the gas molar mark at system pressure, temperature during vapor liquid equilibrium, drawn by PR Solving Equation of State, a is gas-liquid contact interfacial area, in bubble flow situation:

$a=\frac{{6H}_g}{d_c}$

Wherein, d _cfor bubble diameter, Guan Liuzhong, mass tranfer coefficient can be solved by Sherwood number:

${\mathrm{Sh}}_g=\frac{k_g{D}_r}{D_g}$

Wherein, Dr is the equivalent diameter of annular space, D _gfor the coefficient of molecular diffusion of methane and diesel oil;

Work as reynolds number Re _gduring <2100, flowing belongs to laminar flow:

${\mathrm{Sh}}_g=\frac{8}{3}=\frac{k_g{D}_r}{D_g}$

$k_g=\frac{8D_g}{3D_r}$

Work as reynolds number Re _gduring >2100, flowing belongs to turbulent flow:

${\mathrm{Sh}}_g=0.023{{\mathrm{Re}}_g}^{0.8}{{\mathrm{Sc}}_g}^{1/3}=\frac{k_g{D}_r}{D_g}$

$k_g=\frac{0.023{{\mathrm{Re}}_g}^{0.8}{{\mathrm{Sc}}_g}^{1/3}{D}_g}{D_r}$

Wherein, Sc _gfor gas phase Schmidt number.

7. method according to claim 4, is characterized in that, described momentum conservation equation comprises:

Gas phase momentum conservation equation:

$\begin{array}{c}\frac{\&PartialD;}{\&PartialD;t}\left(A_c{H}_g{\mathrm{\&rho;}}_g{v}_g\right)=-\frac{\&PartialD;\left(A_c{H}_{g}p\right)}{\&PartialD;z}-\frac{\&PartialD;\left(A_c{H}_g{\mathrm{\&rho;}}_g{v}_g^2\right)}{\&PartialD;z}-f_I{\mathrm{\&rho;}}_g\frac{v_r^2}{2}{S}_I\\ -f_g{\mathrm{\&rho;}}_g\frac{v_g^2}{2}{S}_g-A_c{H}_g{\mathrm{\&rho;}}_{g}g-A_c{\stackrel{\&CenterDot;}{m}}_g{v}_a\end{array}$

Wherein, t is overflow time, A _cfor annular space sectional area, H _gfor free gas void fraction, ρ _gfor density of gas phase in annular space, v _gfor the gas phase velocity in annular space, z is the vertical degree of depth, and p is annular pressure, f _ithe friction factor of gas phase and liquid interface, f _gthe friction factor of gas phase and tube wall, S _ithe girth of gas phase and liquid phase contact surface, S _gthe girth of gas phase and tube wall contact surface, v _rthe relative velocity of gas phase and liquid phase, v _abe the speed of mass transfer phase, g is gravity acceleration constant, for the mass transfer velocity between free gas and solution gas;

Liquid phase momentum conservation equation:

$\begin{array}{c}\frac{\&PartialD;}{\&PartialD;t}\left(A_c(1-H_g){\mathrm{\&rho;}}_L{v}_L\right)=-\frac{\&PartialD;\left(A_c(1-H_g)p\right)}{\&PartialD;z}-\frac{\&PartialD;\left(A_c(1-H_g){\mathrm{\&rho;}}_L{v}_L^2\right)}{\&PartialD;z}-f_L{\mathrm{\&rho;}}_L\frac{v_L^2}{2}{S}_L\\ +f_I{\mathrm{\&rho;}}_L\frac{v_r^2}{2}{S}_I-A_c(1-H_g){\mathrm{\&rho;}}_{L}g+A_c{\stackrel{\&CenterDot;}{m}}_g{v}_a\end{array}$

Wherein, ρ _lfor density of liquid phase in annular space, v _lfor the liquid velocity in annular space, f _lfor the friction factor of liquid phase and tube wall, S _lfor the girth of liquid phase and tube wall contact surface;

Aggregated momentum conservation equation:

$\begin{array}{c}\frac{\&PartialD;}{\&PartialD;t}(A_c(1-H_g){\mathrm{\&rho;}}_L{v}_L+A_c{H}_g{\mathrm{\&rho;}}_g{v}_g)=-\frac{\&PartialD;\left(A_{c}p\right)}{\&PartialD;z}-\frac{\&PartialD;(A_c(1-H_g){\mathrm{\&rho;}}_L{v}_L^2+A_c{H}_g{\mathrm{\&rho;}}_g{v}_g^2)}{\&PartialD;z}-f_L{\mathrm{\&rho;}}_L\frac{v_L^2}{2}{S}_L\\ -f_g{\mathrm{\&rho;}}_g\frac{v_g^2}{2}{S}_g-A_c((1-H_g){\mathrm{\&rho;}}_{L}g+H_g{\mathrm{\&rho;}}_{L}g)\end{array}.$

8. method according to claim 4, is characterized in that, described energy conservation equation comprises:

Heat conservation equation in mineshaft annulus:

$\begin{array}{c}\frac{\&PartialD;}{\&PartialD;t}({\mathrm{\&rho;}}_g{H}_g(c_{\mathrm{pg}}{T}_c+{\mathrm{\&eta;}}_g{c}_{\mathrm{pg}}p+\frac{1}{2}{v}_g^2\mathrm{gdz})+{\mathrm{\&rho;}}_L{H}_L(c_{\mathrm{pL}}{T}_c+{\mathrm{\&eta;}}_L{c}_{\mathrm{pL}}p+\frac{1}{2}{v}_L^2+\mathrm{gdz}))\\ +\frac{\&PartialD;({\mathrm{\&rho;}}_g{v}_g{H}_g(c_{\mathrm{pg}}{T}_c+{\mathrm{\&eta;}}_g{c}_{\mathrm{pg}}p+\frac{1}{2}{v}_g^2+\mathrm{gdz})+{\mathrm{\&rho;}}_L{v}_L{H}_L\left(c_{\mathrm{pL}}{T}_c+{\mathrm{\&eta;}}_L{c}_{\mathrm{pL}}p+\frac{1}{2}{v}_L^2+\mathrm{gdz}\right))}{\&PartialD;z}\\ =\frac{\mathrm{\&Delta;}{Q}_g+\mathrm{\&Delta;}{Q}_L}{A_c\mathrm{dz}}=\frac{1}{A_c}(\frac{(T_{\mathrm{dp}}-T_c)}{A_{\mathrm{dpc}}^{\&prime;}}+\frac{(T_{\mathrm{ei}}-T_c)}{A_{\mathrm{cw}}^{\&prime;}})\end{array}$

Wherein, t is overflow time, A _cfor annular space sectional area, H _gfor free gas void fraction, ρ _gfor density of gas phase in annular space, v _gfor the gas phase velocity in annular space, z is the vertical degree of depth, and p is annular pressure, c _pgfor gas phase specific heat capacity, T _cfor the fluid temperature (F.T.) in annular space, η _gfor gas phase joule thomson effect coefficient, g is gravity acceleration constant, ρ _lfor density of liquid phase in annular space, H _lfor liquid holdup, v _lfor the liquid velocity in annular space, η _lfor liquid phase joule thomson effect coefficient, c _pLfor liquid phase specific heat capacity, Δ Q _gfor the thermal change amount of gas phase in micro unit, Δ Q _lfor the thermal change amount of liquid phase in micro unit, T _dpfor drilling fluid temperature in drilling rod, T _eifor surrounding formation temperature,

$A_{\mathrm{dpc}}^{\&prime;}=\frac{c_{\mathrm{pdp}}{w}_{\mathrm{Ldp}}{A}_{\mathrm{dpc}}}{c_{\mathrm{pc}}{w}_{\mathrm{Lc}}}$

$A_{\mathrm{cw}}^{\&prime;}=\frac{1}{A_{\mathrm{cw}}{A}_c{\mathrm{\&rho;}}_L{c}_{\mathrm{pdp}}}$

A _dpcfor drilling rod is to the local dimensionless constant that annular space conducts heat, c _pdpfor the specific heat capacity of fluid in drilling rod, w _ldpfor the unit mass flow velocity of fluid in drilling rod, w _ldp=A _dpρ _lv _ldp, A _dpfor drilling rod sectional area, v _ldpfor the liquid velocity in drilling rod, c _pcfor the specific heat capacity of fluid in annular space, w _lcfor the unit mass flow velocity of fluid in annular space, w _lc=A _cρ _lv _lc, v _lcfor the fluid velocity in annular space, A _cwfor the local dimensionless constant conducted heat in annular space and stratum, c _pdpfor the specific heat capacity of fluid in drilling rod;

Heat conservation equation in drilling rod:

$\begin{array}{c}\frac{\&PartialD;}{\&PartialD;t}\left({\mathrm{\&rho;}}_{\mathrm{Ldp}}(c_{\mathrm{pLdp}}{T}_{\mathrm{dp}}+{\mathrm{\&eta;}}_{\mathrm{Ldp}}{c}_{\mathrm{pLdp}}+\frac{1}{2}{v}_{\mathrm{Ldp}}^2+\mathrm{gdz})\right)\\ +\frac{\&PartialD;\left({\mathrm{\&rho;}}_{\mathrm{Ldp}}{v}_{\mathrm{Ldp}}(c_{\mathrm{pLdp}}{T}_{\mathrm{dp}}+{\mathrm{\&eta;}}_{\mathrm{pLdp}}{p}_{\mathrm{dp}}+\frac{1}{2}{v}_{\mathrm{ldp}}^2+\mathrm{gdz})\right)}{\&PartialD;z}\\ =\frac{\mathrm{\&Delta;}{Q}_L}{A_{\mathrm{dp}}\mathrm{dz}}=\frac{1}{A_{\mathrm{dp}}}\left(\frac{T_c-T_{\mathrm{dp}}}{A_{\mathrm{dpc}}^{\&prime;}}\right)\end{array}$

Wherein, ρ _ldpfor the density of liquid phase in drilling rod, c _pLdpfor the liquid phase specific heat capacity in annular space, η _ldpfor the liquid phase joule thomson effect coefficient in drilling rod, p _dpfor liquid phase pressure in drilling rod.

9. a monitoring device for deep water oil base drilling fluid drilling well flooded conditions, is characterized in that, described device comprises:

Acquisition module, for obtaining the monitored data in deep water oil base drilling fluid bored shaft annular space;

Judge module, for according to described monitored data and the phase equilibrium model set up in advance, judges whether the phase in mineshaft annulus is gas-liquid two-phase;

First determination module, if for gas-liquid two-phase, then determines the flow pattern of biphase gas and liquid flow in mineshaft annulus;

Computing module, for calculating the distribution along well depth of the transient temperature of mineshaft annulus fluid, void fraction and pressure according to the mineshaft annulus transient multi-phase flow model set up in advance and annular fluid steady state heat transfer model corresponding to this flow pattern and Stationary Water kinetic model; The distribution of mineshaft annulus transient multi-phase flow parameter along well depth is determined along the distribution of well depth according to described transient temperature, void fraction and pressure;

Second determination module, for determining drilling well flooded conditions according to described mineshaft annulus transient multi-phase flow parameter along the distribution of well depth.

10. device according to claim 9, is characterized in that, described judge module specifically for:

By mineshaft annulus along well depth direction discrete formation grid configuration;

According to the mineshaft annulus fluid pressure p of described monitored data estimation current grid;

The fluid bubble point pressure p under current pressure is solved according to described phase equilibrium model _b;

If p<p _b, then the phase in mineshaft annulus is gas-liquid two-phase.