CN103726815B - A kind of CO 2drive produced well pit shaft fluidised form is determined and parameter optimization method - Google Patents

Abstract

The invention provides a kind of CO ₂drive produced well pit shaft fluidised form is determined and parameter optimization method, belongs to oil reservoir exploitation field.Said method comprising the steps of: (1) CO ₂drive produced well Production development is simulated, and obtains CO ₂the Production development of drive produced well, draws and injects wellbore pressure, temperature, density and the viscosity regularity of distribution along pit shaft; (2) CO will obtained in step (1) ₂the pressure and temperature of drive produced well is plotted in CO along the regularity of distribution of pit shaft ₂on phasor, draw CO ₂the pressure-plotting of extraction well shaft and temperature profile, can directly find so in the drawings along pit shaft diverse location place CO ₂phase; (3) preferred manufacturing parameter: under the prerequisite keeping casing programme data constant, change creation data, then repeat step (1) and (2), and according to field demand, preferred best production technology and working system.Utilization present invention achieves CO ₂drive the Simulation and analysis of producing well Production development.

Description

A kind of CO 2drive produced well pit shaft fluidised form is determined and parameter optimization method

Technical field

The invention belongs to oil reservoir exploitation field, be specifically related to a kind of CO ₂drive produced well pit shaft fluidised form is determined and parameter optimization method, for improving recovery ratio.

Background technology

Along with the industrialized fast development of human society, greenhouse gas emission is increasing to climatic influences, CO ₂reduction of discharging be more and more subject to the extensive concern of international community, note CO ₂drive and be considered to improve one of most effective method of oil recovery factor, meet the demand of geological storage simultaneously, realize the doulbe-sides' victory of Social benefit and economic benefit, be widely used abroad.Domesticly carry out CO ₂drive pilot test, be still in the exploratory stage at present.At note CO ₂drive in recovery process, due to CO ₂there is very high solubility in reservoir fluid, cause crude oil volume expansion, significantly reduce viscosity of crude and interfacial tension, form more favourable crude oil flow, very favourable with raising recovery ratio to oil extraction.But with the CO that shows loving care for ₂drive deepening continuously in recovery process, CO ₂likely break through in oil reservoir and arrive extraction well shaft bottom, CO afterwards ₂together can be plucked out of along with profit.How to judge CO rapidly and accurately ₂along temperature in wellbore, pressure and Phase velocity map feature in drive produced well pit shaft, be CO ₂drive Production Wells system formulation, parameter optimization and corrosive pipeline and process for protecting design in problem demanding prompt solution.

Summary of the invention

The object of the invention is to solve the difficult problem existed in above-mentioned prior art, a kind of CO is provided ₂drive produced well pit shaft fluidised form is determined and parameter optimization method, realizes CO ₂the Simulation and analysis of drive produced well Production development, quantitative analysis, simulation note CO ₂the Production development of drive produced well, draws the regularity of distribution of the parameters such as extraction wellbore pressure, density, viscosity along pit shaft, and according to CO ₂the Production development analog result of drive produced well, at CO ₂on phasor, draw CO ₂the pressure of extraction pit shaft, temperature profile, can directly find in the drawings along pit shaft diverse location place CO ₂phase, for the working system that different technique is preferably best, rational oil production technology measure and corrosion protection steps can be taked by guide field, obtain higher economic benefit.

The present invention is achieved by the following technical solutions:

A kind of CO ₂drive produced well pit shaft fluidised form is determined and parameter optimization method, said method comprising the steps of:

(1) CO ₂drive produced well Production development is simulated, and obtains CO ₂the Production development of drive produced well, draws and injects wellbore pressure, temperature, density and the viscosity regularity of distribution along pit shaft;

(2) CO will obtained in step (1) ₂the pressure and temperature of drive produced well is plotted in CO along the regularity of distribution of pit shaft ₂on phasor, draw CO ₂the pressure-plotting of extraction well shaft and temperature profile, can directly find so in the drawings along pit shaft diverse location place CO ₂phase;

(3) preferred manufacturing parameter: under the prerequisite keeping casing programme data constant, change creation data, then repeat step (1) and (2), and according to field demand, preferred best production technology and working system.

Described step (1) is realized by the analog computation of pit shaft dynamic parameter, as shown in Figure 6, specifically comprises the following steps:

(A) data input step: input creation data and casing programme data; Described creation data comprises extraction well yield, moisture content, gas liquid ratio, temperature, pressure, stroke and jig frequency; Described casing programme data comprise that casing diameter, depth of setting, tubing diameter and depth of setting, pump are dark, pump footpath and sucker rod combination;

(B) extraction well data processing step;

Described step (B) comprises the following steps:

(B1) fluidised form judges: the flow pattern judging extraction well shaft inner fluid;

(B2) data computing: successively the height of the frictional resistant coefficient of oil volume factor, viscosity of crude, gas liquid two-phase flow, pressure drop, temperature and correspondence is calculated according to different described flow patterns and described creation data;

(B3) oil well height iteration: carry out height iteration from the well head of oil well to destination layer, namely from the well head of oil well, step (B1) and (B2) is repeated to each height, until reach the height of destination layer, finally obtain injection wellbore pressure, temperature, density and viscosity under the given working condition regularity of distribution along pit shaft.

Compared with prior art, the invention has the beneficial effects as follows:

(1) achieve CO ₂drive the Simulation and analysis of producing well Production development;

(2) quantitative analysis, simulation CO is achieved ₂drive the Production development of producing well, draw the regularity of distribution of the parameters such as extraction temperature in wellbore, pressure and density along pit shaft;

(3) according to CO ₂drive the Production development analog result of producing well, at CO ₂on phasor, under drawing given manufacturing parameter, the pressure of extraction well shaft, temperature profile, directly can find the CO along pit shaft diverse location place in the drawings ₂phase;

(4) the present invention is utilized can to obtain optimized producing parameter, best CO ₂extraction well casing rod structure;

(5) rational extraction technique can be taked by guide field, obtain higher economic benefit;

(6) utilize result of calculation of the present invention, can be corrosive pipeline and process for protecting design provides theoretical foundation.

Accompanying drawing explanation

Fig. 1 is CO of the present invention ₂drive produced well pit shaft fluidised form is determined and the step block diagram of parameter optimization method.

Fig. 2 is the temperature in pit shaft.

Fig. 3 gives producing well pressure, flow pattern along the pit shaft regularity of distribution.

Fig. 4 is pressure, temperature and CO in extraction well shaft ₂gas phase in the wellbore.

Fig. 5 is hole deviation curve.

Fig. 6 is extraction well Production development analog computation block diagram.

Fig. 7 is pressure distribution curve.

Fig. 8 is temperature distribution history.

Fig. 9 is density profile.

Detailed description of the invention

Below in conjunction with accompanying drawing, the present invention is described in further detail:

As shown in Figure 1, the calculating used is specific as follows for step of the present invention:

One, the present invention establishes compressible multicomponent fluid pit shaft oil-gas-water three-phase flow pressure-drop model, gives the computational methods of flow pattern discrimination criterion and corresponding resistance coefficient, solves CO ₂drive produced well wellbore pressure computational problem, specific as follows:

Described compressible multicomponent fluid pit shaft oil-gas-water three-phase flow pressure-drop model is as follows:

Pressure-drop model adopts single model to calculate in the past, and its drawback is the difference because of fluidised form, and computational accuracy is not high.The present invention adopts the computation model of comprehensive pressure drop, and namely for the feature of different flow pattern, adopt the pressure-drop model corresponded respectively, its advantage is closer to reality, and improves computational accuracy.

Pressure drop in described step (B2) be adopt homogeneous flow calculation of pressure model respectively for different fluidised forms, phase-splitting flowing pressure computation model calculates;

Homogeneous flow calculation of pressure model is:

Phase-splitting flowing pressure calculates flow model:

$-\frac{\mathrm{dp}}{\mathrm{dz}}=\frac{\mathrm{\λ}{V_l}^{\′}}{2D}{\left(\frac{M}{A}\right)}^2{\mathrm{\φ}}_0^2+{\left(\frac{M}{A}\right)}^2\frac{d}{\mathrm{dz}}[\frac{x^2{V_g}^{\′}}{\mathrm{\φ}}+\frac{{(1-x)}^2{V_l}^{\′}}{1-\mathrm{\φ}}]+{\mathrm{\ρ}}_{\mathrm{TP}}g\sin \mathrm{\θ}---\left(2\right)$

In formula:

The pressure (definitely) of p-mixture, Pa; The distance of z-axial flow, m; ρ _l-density of liquid phase, kg/m ³; ρ _g-density of gas phase, kg/m ³; H _l-liquid holdup, m ³/ m ³; G-acceleration of gravity, m/s ²; The angle of θ-pipeline and horizontal direction, °; The frictional resistant coefficient of λ-two-phase flow, zero dimension; The mass flow of G-mixture, kg/s; The flow velocity of v-mixture, m/s; v _sgthe specific speed of-gas phase, m/s; D-pipe diameter, m; A-pipeline section amasss, m ².

The criterion of the flow pattern in described step (B1) is as follows:

In the flow pattern research of multiphase pipe flow, J.Orkiszewski (Ao Qisizesiji) method is applied comparatively extensive, and the boundary of the flow pattern in the method employing table 1 divides various fluidised form, and the computational methods of each parameter are as described below.

Table 1

In table 1, N _vgthe accurate number of-gas phase velocity, the volume flow of Q-mixture, m ³/ s; Q _gthe volume flow of-gas phase, m ³/ s; (L) _b-bubble flow boundary number, (L) _s-slug flow boundary number, (L) _m-mist flow boundary number.

Void content

Beggs-Brill has shown that the void content of tipping tube stream is after deliberation:

φ(θ)＝φ(0)ψ＝φ(0)[1+1.2418sin(0.4θ)-2.3412sin ³(0.4θ)]

The related law of frictional resistant coefficient

The frictional resistant coefficient of the gas liquid two-phase flow in described step (B2) adopts following formula to calculate:

λ＝λ′·e ^s

In formula

The frictional resistant coefficient of λ '-" without slippage ", zero dimension; S-index.

λ ' in above formula can be calculated by following formula

${\mathrm{\λ}}^{\′}={\left[21g\left(\frac{{R_e}^{\′}}{4.52231g{R_e}^{\′}-3.8215}\right)\right]}^{-2}$

Wherein

In formula

R _e'-", is without slippage " Reynolds number; μ _l, μ _gthe viscosity of-liquid phase, gas phase, Pas.And

$s=\frac{\ln Y}{-0.0523+3.182\ln Y-0.8725{\left(\ln Y\right)}^2+0.01853{\left(\ln Y\right)}^4}$

Wherein

$Y=\frac{E_l}{{\left[H_l\left(\mathrm{\θ}\right)\right]}^2}$

It may be noted that as 1 < Y < 1.2, following formula should be used to ask s

s＝ln(2.2Y-1.2)

The computational methods of physical parameter

A, dissolves oil-gas ratio

Dissolve oil-gas ratio also known as solution gas coefficient.The research of Vazquez and Beggs shows: the relative density of natural gas is the important parameter that oil-gas ratio is dissolved in impact.Due in 100 pounds per inch ²(689.5kPa), under gauge pressure, the shrinkage factor of crude oil is minimum, and close to the actual conditions of oil well separator pressure, therefore can using the natural gas relative density under this pressure as benchmark.

$S_s=0.1781C_1{\mathrm{\&delta;}}_{\mathrm{gs}}{\left(0.1450p\right)}^{C_2}\exp \left\{C_3\right[\frac{{{\mathrm{\&delta;}}_o}^{\mathrm{API}}}{1.8t+492}\left]\right\}---\left(3\right)$

Wherein

${\mathrm{\&delta;}}_{\mathrm{gs}}={\mathrm{\&delta;}}_{{\mathrm{gp}}^{\&prime;}}[1+5.912\&times;{10}^{-5}{{\mathrm{\&delta;}}_o}^{\mathrm{API}}(1.8t^{\&prime;}+32)\lg \left(0.001265p^{\&prime;}\right)]$

${{\mathrm{\&delta;}}_o}^{\mathrm{API}}=\frac{141.5-131.5{\mathrm{\&delta;}}_o}{{\mathrm{\&delta;}}_o}$

In formula

S _s-dissolve oil-gas ratio, m ³/ m ³; P-pressure (definitely), kPa; T-temperature, DEG C; δ _ounder-the status of criterion, the relative density of crude oil; δ _{gp '}the relative density of-pressure p ' (definitely) and the lower natural gas of temperature t '; δ _gsthe relative density of natural gas under-689.5kPa gauge pressure.

Dissolve the coefficient C in oil-gas ratio design formulas ₁, C ₂and C ₃value as shown in table 2.

Coefficient	δ o≥0.8762	δ o＜0.8762
			C 1	0.0362	0.0178
C 2	1.0937	1.1870
			C 3	25.7240	23.9310

Table 2

In actual applications, the present invention adopts following methods correction

C _i ^k＝K _i·C _i(i＝1，2，3)(4)

In formula

K _i-correction factor; C _i ^k-revised coefficient value.

Statistics shows: coefficient C ₁to S _simpact more remarkable.Usually, only C is revised ₁just the simulation curve comparatively conformed to PVT can be obtained.

B, oil volume factor

(1) Standing formula

B _o＝0.972+0.000147F ^1.175

Wherein

$F=5.615{\left(\frac{{\mathrm{\&delta;}}_{\mathrm{ng}}}{{\mathrm{\&delta;}}_o}\right)}^{0.5}+2.25t+40$

In formula

B _o-oil volume factor, m ³/ m ³; δ _ngunder-the status of criterion, the relative density of natural gas.

(2) Vazquez-Beggs formula

As p≤p _btime

$B_o=1+5.615C_1{S}_s+(C_2+5.615C_3{S}_s)(1.8t-28)\frac{{{\mathrm{\&delta;}}_o}^{\mathrm{API}}}{{\mathrm{\&delta;}}_{\mathrm{gs}}}$

As p > p _btime

B _o＝B _obexp[-C ₀(p-p _b)]

Wherein

$C_0=\frac{6.895}{a_{6}p}[a_1+5.615a_2{S}_s+a_3(1.8t+32)+a_4{\mathrm{\&delta;}}_{\mathrm{gs}}+a_5{{\mathrm{\&delta;}}_o}^{\mathrm{API}}]$

$\left\{\begin{array}{ccc}{a}_1=-1433.0,& a_2=5.0,& a_3=17.2,\\ a_4=-1180.0,& a_5=12.61,& a_6={10}^5\end{array}\right.$

In formula

B _ob-saturation pressure p _bunder oil volume factor, m ³/ m ³; Coefficient C in oil volume factor design formulas ₁, C ₂and C ₃as shown in table 3.

Coefficient	δ o≥0.8762	δ o＜0.8762
			C 1	4.677×10 -4	4.670×10 -4
C 2	1.751×10 -5	1.100×10 -5
			C 3	-1.811×10 -8	1.337×10 -9

Table 3

Statistics shows: as pressure p≤p _btime, with the simulation curve that Vazquez-Beggs formula obtains, there is similar Changing Pattern according to Standing formula, but a certain constant of approximate difference; As pressure p > p _btime, because Vazquez-Beggs formula considers saturation pressure p _bimpact, at p _bthere is turnover in place's curve, and Standing curve does not exist turning point.Meanwhile, also oil volume factor B is found _owith saturation pressure p _bthere is correlation.

Comprehensive Standing formula and Vazquez-Beggs formula, consider saturation pressure p _bimpact, and after correction factor is provided, the oil volume factor B that the present invention obtains _oanalog computation formula can be expressed as

$B_o=\frac{{B_o}^S+{B_o}^V}{2}+[0.0892(1-\frac{p_b}{12})-0.0035]---\left(5\right)$

In formula

B _o ^sthe oil volume factor that-Standing formulae discovery goes out, m ³/ m ³; B _o ^vthe oil volume factor that-Vazquez-Beggs formulae discovery goes out, m ³/ m ³.

Oil volume factor B in described step (B2) _o(5) formula is above adopted to obtain.

Needs are noted that, although the present invention has done a large amount of research work to the simulation of dissolving oil-gas ratio and oil volume factor, but in actual applications, in order to can better simulate effect be obtained, present invention also adds the correction to simulation curve shape and translation, namely theoretical curves and measured data contrast, and apply formulae discovery B above after obtaining correction factor _o.

C, the viscosity of crude in described step (B2) is adopted and is calculated in the following method:

(1) Chew-Connaly formula

μ _o＝Aμ _on ^B(6)

Wherein

$A=0.2+\frac{0.8}{{10}^{0.004544S_s}}$

$B=0.43+\frac{0.57}{{10}^{0.004089S_s}}$

In formula

μ _o-saturated former oil viscosity, mPas; μ _onthe viscosity of-stock tank oil, mPas.

(2) Beggs-Robinson formula

μ _o＝Aμ _on ^B

Wherein

$A={(1+\frac{5.615}{100}{S}_s)}^{-0.515}$

$B={(1+\frac{5.615}{150}{S}_s)}^{-0.338}$

In the multiphase pipe flow of petroleum production engineering calculates, former oil viscosity is a very important parameter.With dissolving oil-gas ratio and oil volume factor similar, also need when practical application to revise.But former oil viscosity is with pressure, the changing greatly of temperature, and its change with pressure is often only tested at scene.In other words, by the correction to PVT viscograph, the impact of temperature often cannot be reflected.

Research shows, former oil viscosity is general only directly by the impact of dissolving oil-gas ratio, and the impact of the factor such as pressure, temperature lies in the calculating of dissolving oil-gas ratio.Like this, by the former oil viscosity of matching and the related law dissolving oil-gas ratio, just good viscograph can be obtained.

Two, the present invention establishes CO ₂the drive produced well pit shaft equation of heat conduction, and give the computational methods of wellbore fluids thermodynamic properties and the constraint equation of condition discrimination.

A, energy equation:

$\begin{array}{cc}\frac{\mathrm{dh}}{\mathrm{dz}}=-\frac{u_2}{G}(T-T_{\&infin;})& \frac{\mathrm{dh}}{\mathrm{dz}}=-\frac{K_L}{G}(T-T_{\&infin;})\end{array}$

Constraint equation: h=h (p, T); Medium is carbon dioxide liquid or overheated carbon dioxide.

B, heat transfer equation

According to assumed condition, wellbore heat is stable, so

dQ＝2πr ₂u ₂(T _s-T _h)dz(7)

In formula

R ₂-oil pipe outer radius, m; u ₂the overall coefficient of heat transfer of-oil pipe external surface, W/ (m ²k); T _s-vapor (steam) temperature, K; T _hthe temperature at-cement sheath and interface place, stratum, K.

Meanwhile, this heat equals outer by cement sheath and stratum interface is not extremely influenced by heat the unsteady heat conduction amount on stratum.The latter is

$\mathrm{dQ}=\frac{2\mathrm{\&pi;}{\mathrm{\&lambda;}}_e(T_h-T_e)\mathrm{dz}}{f\left(t\right)}---\left(8\right)$

Wherein

$f\left(t\right)=\ln \frac{2\sqrt{\mathrm{\&beta;t}}}{r_h}-0.29$

In formula

λ _e-formation thermal conductivity, W/ (mK); T _e-the formation temperature that is not influenced by heat, K _ot _e=T _m+ α z; T _m-surface temperature, K; α-geothermal gradient, K/m; Z-degree of depth, m; The function of time of the instantaneous heat conduction in f (t)-stratum; β-stratum thermal diffusion coefficient, m ²/ h; T-steam injection time, h; r _h-cement sheath and stratum joint radius, m.

The temperature T of cement sheath and stratum interface can be obtained by (7) and (8) formula _h

$T_h=\frac{{\mathrm{\&lambda;}}_e{T}_e+T_s{u}_2{r}_{2}f\left(t\right)}{{\mathrm{\&lambda;}}_e+u_2{r}_{2}f\left(t\right)}$

Three, The present invention gives CO ₂the computational methods of the drive produced well pit shaft coefficient of heat conduction

The design formulas of pit shaft overall coefficient of heat transfer is

$u_2={[\frac{r_2\ln \left(\frac{r_3}{r_2}\right)}{{\mathrm{\&lambda;}}_{\mathrm{ins}}}+\frac{r_2}{r_4{h}_{\mathrm{rc},\mathrm{an}}}+\frac{r_2\ln \left(\frac{r_7}{r_6}\right)}{{\mathrm{\&lambda;}}_{\mathrm{cem}}}]}^{-1}$

As the heat-barrier material in insulated tubing, its coefficient of thermal conductivity λ _inschange with temperature, and coefficient of convective heat transfer h in annular space _{rc, an}also relevant with wall temperature with the corresponding time, and wall temperature is decided by heat output Q, so pit shaft overall coefficient of heat transfer u ₂to determine through iteration.

Four, The present invention gives the fluid computational methods that temperature raises after oil well pump compression

A, temperature rise in pump

The power output (effective power) of pump

In formula

ρ-density, kg/m ³; Q-volume flow, m ³/ s; H-pump lift, m; G-mass flow, kg/s.

B, the input power (shaft power) of pump

In formula

η _pumpthe efficiency of-pump.

C, the input power (power that pump and motor full device need) of motor

In formula

η _electricitythe efficiency of-motor; N _electricitythe power output of-motor.It equals the input power N of pump _axle.

For submersible electric pump, only has the power output N of pump _pumpavailable power, so power loss is

If think that power loss has all consumed with the form of heat energy, then

N _damage ^t=859.845N _damage

In formula

N _damage-power loss, kW; N _damage ^tthe power loss of-form of thermal energy, kcal/h.When liquid is plucked out of, these heats will be pulled away, so the heat that every kg liquid adds is

So temperature rise value is:

In formula

The specific heat of c-oil, gas-liquid mixture, kcal/ (kg DEG C).

By N _damagedesign formulas substitute into above formula,

If only consider pump efficiency, then above formula becomes

Because the mass flow of each phase remains unchanged, so the specific heat c of oil, gas-liquid mixture can calculate with following formula

$c=\frac{G_o{c}_o+G_g{c}_g+G_w{c}_w}{G}$

In formula

G _othe mass flow of-oil phase, kg/s; G _gthe mass flow of-gas phase, kg/s; G _wthe mass flow of-aqueous phase, kg/s; The mass flow of G-mixture, kg/s; c _othe specific heat of-crude oil, kcal/ (kg DEG C); c _gthe specific heat of-natural gas, kcal/ (kg DEG C); c _w-specific heat of water, kcal/ (kg DEG C).

Usually, crude oil and specific heat of water are respectively c _o=1.88kJ/ (kg DEG C)=0.45kcal/ (kg DEG C) and c _w=4.18kJ/ (kg DEG C)=1.0kcal/ (kg DEG C).The specific heat of natural gas is relevant with its component, and the main component of natural gas is methane, and the specific heat of methane is c _g=2.227kJ/ (kg DEG C)=0.53kcal/ (kg DEG C).

D, the temperature gradient in pit shaft

From Pump Suction Nozzle to pump discharge, except temperature gradient, also should consider the temperature rise in pump.As shown in Figure 2.So, have

$\left\{\begin{array}{c}{t}_o=t_h+K_1{H}_o\\ t_i=t_o-\mathrm{\&Delta;t}+K_2(H_i-H_o)\\ t_m=t_i+K_3(H_m-H_i)\end{array}\right.$

In formula

H _o-pump discharge vertical depth, m; H _i-Pump Suction Nozzle vertical depth, m; H _mvertical depth in the middle part of-oil reservoir, m; t _h-wellhead temperature, m; t _o-pump discharge temperature, DEG C; t _i-Pump Suction Nozzle temperature, DEG C; t _m-reservoir temperature, DEG C; Temperature rise in Δ t-pump, DEG C; K ₁temperature gradient on-pump, DEG C/m; K ₂-Pump Suction Nozzle to the temperature gradient of pump discharge well section, DEG C/m; K ₃temperature gradient under-pump, DEG C/m.

If suppose K ₁=K ₂=K ₃=K, then

$K=\frac{(t_m-t_h)+\mathrm{\&Delta;t}}{H_m}$

Five, The present invention gives CO ₂drive produced well pit shaft dynamic parameter simulation method.

CO ₂the particularity of drive produced well cylinder flowing:

(1) CO ₂gas is not broken through, containing solution gas

(2) CO ₂gas has breakthrough, and containing solution gas

(3) CO ₂gas has breakthrough, not containing solution gas

The present invention is at CO ₂phasor depicts CO ₂drive produced well Production development analog result, depicts the pressure of example pit shaft, temperature profile, can directly find in the drawings along pit shaft diverse location place CO ₂phase, wherein, Fig. 3 gives producing well pressure, flow pattern along the pit shaft regularity of distribution, and Fig. 4 gives pressure, temperature and CO in extraction well shaft ₂gas phase in the wellbore.

The present invention has begun to take shape the analysis of extraction well performance and Predicting Technique, and its result can carry out the optimal design of tubular column structure, manufacturing parameter and lower-continuous mapping by guide field.

Parameters in pit shaft all can regard the parameter of well depth as, and the effect of the different submersible electric pump of pump setting depth will be different.Therefore, how to determine that rational lower-continuous mapping is key technology wherein.

PIP and gas liquid ratio are the key factors of preferred pump setting depth.Wherein, gas liquid ratio refers to that the volume of free gas accounts for the percentage of oil, gas, water three-phase cumulative volume.According to its definition, can obtain

$R_i=\frac{(1-f_w)(S_p-S_s)B_g}{(1-f_w)B_o+(1-f_w)(S_p-S_s)B_g+f_w}$

Wherein

$B_g=0.000378\frac{Z(t+273)}{p_i}$

In formula

P _i-PIP, MPa; R _i-Pump Suction Nozzle gas liquid ratio, %; f _w-moisture content, decimal; T-temperature, DEG C; Z-gas compressive coefficient, generally between 0.81 ~ 0.91; S _p-producing gas-oil ratio, m ³/ m ³; S _s-dissolve oil-gas ratio, m ³/ m ³; B _o-oil volume factor, m ³/ m ³; B _g-gas volume factor, m ³/ m ³; B _wthe volume factor of-water, m ³/ m ³.Generally, B _w=1.

At Pump Suction Nozzle place, if provide pressure p _i, oil volume factor B can be obtained _o, gas volume factor B _g, dissolve oil-gas ratio S _s, the parameter such as temperature t, and then gas liquid ratio R can be calculated by formula (85) _i.In like manner, by gas liquid ratio R _ialso pressure p can be calculated _i.And pressure p _i, temperature t and gas liquid ratio R _iall again the function of pump setting depth etc. parameter, therefore according to required PIP p _ior gas liquid ratio R _ijust rational pump setting depth can be determined.

Based on the inventive method, carry out the application that 1 well is secondary, simplified working system, optimize manufacturing parameter.Result shows, utilize the party as compared with the past method compare, benefit significantly improves.The present invention is applicable to note CO ₂drive the oil field of recovering the oil and noting flue gas and recovering the oil.

One embodiment of the present of invention are as follows:

Well information in embodiment is as follows

1. " field basic data are as shown in table 4

Table 4

2. test data data are as shown in table 5:

Table 5

3. hole trajectory data is as shown in table 6:

Table 6

As shown in Figure 5, as shown in Figure 7, as shown in Figure 8, the density profile obtained as shown in Figure 9 for the temperature distribution history obtained for the pressure distribution curve obtained for the hole deviation curve utilizing the inventive method to obtain.

Along with oil field development process deepen continuously and the economy of fast development to the demand of crude oil, the exploitation share of viscous crude is increasing, need take CO both at home and abroad ₂the well driving and note flue gas heavy crude producing can get more and more, and therefore this invention at home and abroad all has broad application prospects.

Technique scheme is one embodiment of the present invention, for those skilled in the art, on the basis that the invention discloses application process and principle, be easy to make various types of improvement or distortion, and the method be not limited only to described by the above-mentioned detailed description of the invention of the present invention, therefore previously described mode is just preferred, and does not have restrictive meaning.

Claims (1)

1. a CO ₂drive produced well pit shaft fluidised form is determined and parameter optimization method, it is characterized in that: said method comprising the steps of:

(1) CO ₂drive produced well Production development is simulated, and obtains CO ₂the Production development of drive produced well, draws and injects wellbore pressure, temperature, density and the viscosity regularity of distribution along pit shaft;

(2) CO will obtained in step (1) ₂the pressure and temperature of drive produced well is plotted in CO along the regularity of distribution of pit shaft ₂on phasor, draw CO ₂the pressure-plotting of extraction well shaft and temperature profile;

(3) preferred manufacturing parameter: under the prerequisite keeping casing programme data constant, change creation data, then repeat step (1) and (2), and according to field demand, preferred best production technology and working system;

Described step (1) is realized by the analog computation of pit shaft dynamic parameter, specifically comprises the following steps:

(A) data input step: input creation data and casing programme data; Described creation data comprises extraction well yield, moisture content, gas liquid ratio, temperature, pressure, stroke and jig frequency; Described casing programme data comprise that casing diameter, depth of setting, tubing diameter and depth of setting, pump are dark, pump footpath and sucker rod combination;

(B) extraction well data processing step;

Described step (B) comprises the following steps:

(B1) fluidised form judges: the flow pattern judging extraction well shaft inner fluid;

(B2) data computing: successively the height of the frictional resistant coefficient of oil volume factor, viscosity of crude, gas liquid two-phase flow, pressure drop, temperature and correspondence is calculated according to different described flow patterns and described creation data;

(B3) oil well height iteration: carry out height iteration from the well head of oil well to destination layer, namely from the well head of oil well, step (B1) and (B2) is repeated to each height, until reach the height of destination layer, finally obtain injection wellbore pressure, temperature, density and viscosity under the given working condition regularity of distribution along pit shaft.