CN105606509A - Measuring method of high-temperature oil-water relative permeability of heavy oil reservoir - Google Patents

Abstract

The invention discloses a measuring method of high-temperature oil-water relative permeability of a heavy oil reservoir. A method for replacing high-temperature oil-water relative permeability of the heavy oil reservoir with oil-water relative permeability under the low-temperature oil-water system condition is put forward for the first time, reduces the measuring difficulty of the high-temperature oil-water permeability of the heavy oil reservoir, avoids potential safety hazards caused by high-temperature and high-pressure experiment conditions and simplifies experiment processes and operation requirements, and the oil-water relative permeability obtained with the two measuring methods is basically identical on the premise that the oil-water viscosity ratio is equal, thus, simple, time-saving, safe and accurate measurement of the high-temperature heavy oil relative permeability is realized with the method.

Description

A kind of measuring method of heavy crude reservoir high temperature oil-water relative permeability

Technical field

The present invention relates to a kind of measuring method of heavy crude reservoir high temperature oil-water relative permeability, belong to the skill of oil-gas field developmentArt field.

Background technology

Viscous crude aboundresources, Exploitation Potential is huge, and along with the becoming increasingly conspicuous of contradiction between oil supply and demand, Development of Viscous Crude Oil mustThe focus of oil exploitation from now on will be become. Steam injection oil recovery by heating is the main approach of Development of Viscous Crude Oil, common exploitationMode has steam soak, steam flooding, SAGD etc. In thermal process, the common seepage flow of the multielement hot fluids such as viscous crude and steam, hot waterProcess is very complicated, is familiar with and analyzes the seepage flow to research steam injection oil recovery by heating of oil-water relative permeability under high-temperature and high-pressure conditionsFeature and mechanism of oil displacement are most important.

Relative permeability is when saturated while having heterogeneous fluid in blowhole, the effective permeability of rock to each phase fluidRatio with rock absolute permeability. Be called relative permeability by the definite relative permeability of experiment and the relation curve of saturation degreeCurve. The method of directly measuring permeability saturation curve mainly contains steady state method and unstable state method. Steady state method is surveyed relative permeability songThe principle of line is based on Darcy's law, with permanent oil-water ratio displacement rock sample, until set up the poised state of saturation degree and pressure isOnly, try to achieve saturation degree, pressure and flow under this poised state, then directly calculate with Darcy's law that can to try to achieve profit relativePermeability. Unstable state method is taking Berkeley-Lie Weierte displacement of reservoir oil theory as basis, and supposes oil, water saturation in water drive oil processThe distribution of degree in rock core is the function of time and distance. As long as in water drive oil process, can measure exactly profit flow andPressure, can calculate the variation numerical value of two-phase relative permeability with saturation degree. Unstable state method is that to overcome steady state method consuming time longPutting forward, is current most popular method.

Heavy crude reservoir high temperature relative permeability influence factor is numerous, wherein temperature and viscosity ratio of oil and water be two topmostInfluence factor. Research discovery, heavy crude reservoir relative permeability is to responsive to temperature, and temperature change causes viscosity ratio of oil and water to change, fromAnd relative permeability is had to impact. Temperature is to realize by affecting viscosity ratio of oil and water on the impact of relative permeability in essence. In the time ensureing that viscosity ratio of oil and water equates, the oil-water relative permeability under different temperatures system is basically identical, therefore heavy crude reservoirHigh temperature oil-water relative permeability can replace by the relative permeability of the low viscous oil water system of the low temperature with identical viscosity ratio of oil and water.

The measurement of heavy crude reservoir high temperature oil-water relative permeability is mainly according to standard SY/T6384-1999 " viscous crude at presentOil reservoir high-temperature-phase is to permeability determination " carry out, measure and require the experiment condition of HTHP to simulate actual reservoir mediaAnd injection condition. But this measuring method is had relatively high expectations to experimental provision, measuring process very complicated, and HTHPThere is certain risk in experiment condition, these have all increased the experiment difficulty of the measurement of heavy crude reservoir high temperature oil-water relative permeabilityDegree. Meanwhile, in the data such as existing domestic and foreign literature, patent, there is no easier, safe measuring method.

Summary of the invention

For the deficiencies in the prior art, the invention provides a kind of measurement side of heavy crude reservoir high temperature oil-water relative permeabilityMethod, the method, according to the relation of viscosity ratio of oil and water and relative permeability, proposes the relative permeability with the low viscous oil water system of low temperatureReplace the method for heavy crude reservoir high temperature oil water to permeability determination, survey thereby greatly reduce heavy crude reservoir high temperature relative permeabilityFixed experiment difficulty, realizes that heavy crude reservoir high temperature oil-water relative permeability is simple and convenient, measurement fast and safely.

Technical scheme of the present invention is as follows:

A measuring method for heavy crude reservoir high temperature oil-water relative permeability, comprises that concrete steps are as follows:

1) oil for preparing experiment;

2) prepare rock core: will rock core be installed in sand-filling tube model, the dimensional parameters of rock core comprises: long L, cross-sectional diameter d,Cross section sectional area A, volume V_f; Described rock core size is sand-filling tube model size, and rock core described herein is according to actual formationThe parameter such as porosity, permeability, select quartz sand close with actual formation rock sample distribution of particles and that wetability is consistent fill and present andBecome;

3) sealing of inspection sand-filling tube model, if described sand-filling tube model sealing is good, remembers by gas survey methodRecord the absolute permeability K of described rock core; Described sand-filling tube model is vacuumized to rear saturation water, while recording saturation water, suck the body of waterLong-pending V_p, i.e. the pore volume of rock core; Calculate the porosity of described rock core $\mathrm{\φ}=\frac{V_p}{V_f}\×100\%$

4) described sand-filling tube model is connected to experimental provision, set experimental temperature T₂; Use oily with constant speed Q with experiment_oDriveFor the saturation water in described rock core, until displacement pressure reduction is stable, record pressure differential deltap P now_o, displacement in metering sand-filling tube modelThe accumulated water volume V going out_o, calculate irreducible water saturation $S_{wc}=1-\frac{V_o}{V_p}\×100\%,$ Oil phase under irreducible water saturation effectively permeates $K_{o\left(S_{wc}\right)}=\frac{Q_o{\mathrm{\μ}}_{o}L}{{\mathrm{A\ΔP}}_o},$ Wherein, described μ_oFor experiment oil viscosity, mPas;

5) after saturated oils, stablize 10-20h, with water drive speed Q_wCarry out water drive oil, in water drive oil process writing time t,Corresponding with described time t: until cumulative oil production V when displacement fluid water breakthrough_o(t), accumulative total production fluid amount V_(t), displacement velocity Q_wDisplacement pressure differential deltap p with rock core two ends_(t); The displacement fluid water breakthrough initial stage, scrambled record is suitable according to how many selections of oil pump capacityThe time interval, with the continuous decline of oil pump capacity, gradually extend record the time interval;

6) in the time that the moisture content of described rock core reaches 99.95% or water injection rate be after the rock pore volume of 30 times, displacementFinish, record now cumulative oil productionDisplacement pressure differential deltap P_w；

Calculate residual oil saturationWater effective permeability under residual oil saturationWherein said μ_wFor the viscosity of water, mPas;

7) utilize existing JBN method calculation procedure 5) under each moment t different saturation oil phase, water relatively to oozingRate thoroughly, computing formula is as follows:

$K_{ro\left(S_w\right)}=f_{o\left(S_w\right)}\frac{d\[\frac{1}{{\stackrel{\‾}{V}}_{\left(t\right)}}\]}{d\[\frac{1}{I_r{\stackrel{\‾}{V}}_{o\left(t\right)}}\]};$

$K_{rw\left(S_w\right)}=K_{ro\left(S_w\right)}\frac{{\mathrm{\μ}}_w}{{\mathrm{\μ}}_o}\frac{f_{w\left(S_w\right)}}{f_{o\left(S_w\right)}};$

$S_{we}=S_{wc}+{\stackrel{\‾}{V}}_{o\left(t\right)}-f_{o\left(S_w\right)}{\stackrel{\‾}{V}}_{\left(t\right)};$

$f_{w\left(S_w\right)}=\frac{1}{1+\frac{K_{ro}}{K_{rw}}\frac{{\mathrm{\μ}}_w}{{\mathrm{\μ}}_o}};$

$I_r=\frac{{\mathrm{\Δp}}_0}{{\mathrm{\Δp}}_{\left(t\right)}}$

-oil relative permeability, decimal;

-oil content, decimal;

S_w-water saturation, decimal;

-dimensionless accumulative total water injection rate (V/V_p，V_pFor pore volume), decimal;

-dimensionless cumulative recovery (V/V_p), decimal;

I_r-fluid ability ratio, decimal;

-water relative permeability, decimal;

S_we-rock core exit-end water saturation, decimal;

S_wc-irreducible water saturation, decimal;

μ_wThe viscosity of-water, mPas;

μ_o-oil viscosity, mPas;

-moisture content, decimal;

Δp₀-initial pressure reduction, MPa;

Δp_(t)-t moment pressure reduction, Mpa;

And taking water saturation as X-axis, relative permeability is Y-axis, draw oil-water relative permeability curve; Wherein saidJBN method comes from " method of unstable state method calculation of water gas relative permeability is inquired into " literary composition.

, described step 1 preferred according to the present invention) in oily compound method for experiment, comprise that step is as follows:

1.1) measure viscous crude to be measured in temperature T to be measured₁Under viscosity, mu_o1；

1.2) according to the viscosity of water in " chemical physical data handbook " and the relation table of temperature, check in water and treating thermometricDegree T₁Lower viscosity, mu_w1With experimental temperature T₂Under viscosity, mu_w2Thereby, calculate temperature T to be measured₁Under viscosity ratio of oil and water

1.3) utilize oil for viscous crude to be measured and naphtha preparation experiment, and experiments of measuring uses oil at experimental temperature T₂Under stickyDegree μ_o2, make experimental temperature T₂Under viscosity ratio of oil and waterWith temperature T to be measured₁Under viscosity ratio of oil and waterEquate, that is:

${\left(\frac{{\mathrm{\μ}}_{o1}}{{\mathrm{\μ}}_{w1}}\right)}_{T1}={\left(\frac{{\mathrm{\μ}}_{o2}}{{\mathrm{\μ}}_{w2}}\right)}_{T2}.$

The invention has the advantages that:

The measuring method of a kind of heavy crude reservoir high temperature oil-water relative permeability of the present invention, has proposed to use low temperature oil firstOil-water relative permeability under water system condition replaces the method for heavy crude reservoir high temperature oil-water relative permeability, and the method has reducedThe measurement difficulty of heavy crude reservoir high temperature profit permeability, the potential safety hazard of having avoided high temperature and pressure experiment condition to bring, simplifiesExperiment flow and operation requirements, and ensureing under the equal prerequisite of viscosity ratio of oil and water two kinds of profits that measuring method obtainsRelative permeability is basic identical, therefore the method realized high-heat heavy crude relative permeability simple, save time, safety and accurately surveyingAmount.

Brief description of the drawings

Fig. 1 is oil-water permeability saturation curve while using 20 DEG C that the method for the invention measures;

Fig. 2 is two kinds of method correlation curve figure, i.e. viscous crude-water relative permeability and this when conventional method record 250 DEG CInventive method records relative permeability.

Detailed description of the invention

According to embodiment and Figure of description, the present invention is described in detail below, but is not limited to this.

As shown in Figure 1, 2.

Embodiment 1,

A measuring method for heavy crude reservoir high temperature oil-water relative permeability, comprises that concrete steps are as follows:

1) oil for preparing experiment;

2) prepare rock core: will rock core be installed in sand-filling tube model, the dimensional parameters of rock core comprises: long L=60cm, cross sectionDiameter d=2.54cm, cross section sectional area A=5.07cm², volume V_f＝304.02cm³; Described rock core size is back-up sand pipe dieMolded dimension, rock core described herein, according to the parameter such as porosity, permeability of actual formation, is selected to divide with actual formation rock sample particleThe quartz sand that cloth is close and wetability is consistent is filled and presented and is formed;

3) sealing of inspection sand-filling tube model, if described sand-filling tube model sealing is good, remembers by gas survey methodRecord the absolute permeability K=2880mD of described rock core; Described sand-filling tube model is vacuumized to rear saturation water, while recording saturation water, inhaleEnter the volume V of water_p=95mL, the i.e. pore volume of rock core; Calculate the porosity of described rock core $\mathrm{\φ}=\frac{V_p}{V_f}\×100\%=31.26\%;$

4) described sand-filling tube model is connected to experimental provision, set experimental temperature T₂=20 DEG C; Use oily with constant with experimentSpeed Q_oSaturation water described in=0.1mL/min displacement in rock core, until displacement pressure reduction is stable, record pressure differential deltap P now_o＝0.033MPa, the accumulated water volume V that in metering sand-filling tube model, displacement goes out_o=85.3mL, calculates irreducible water saturationOil phase under irreducible water saturation effectively permeatesItsIn, described μ_oFor experiment oil viscosity, mPas;

5) after saturated oils, stablize 10-20h, with water drive speed Q_w=0.5mL/min carries out water drive oil, in water drive oil processWriting time t, corresponding with described time t: until cumulative oil production V when displacement fluid water breakthrough_o(t), accumulative total production fluid amount V_(t)、Displacement velocity Q_wDisplacement pressure differential deltap p with rock core two ends_(t); The displacement fluid water breakthrough initial stage, scrambled record, many according to oil pump capacitySelect less the suitable time interval, with the continuous decline of oil pump capacity, extend gradually the time interval of record; Table 1 for record timeBetween, accumulative total production fluid amount, cumulative oil production and displacement pressure reduction;

Table 1

6) in the time that the moisture content of described rock core reaches 99.95% or water injection rate be after the rock pore volume of 30 times, displacementFinish, record now cumulative oil productionDisplacement pressure differential deltap P_w=0.016MPa; Calculate residual oil saturationWater effective permeability under residual oil saturationWherein said μ_wFor the viscosity of water, mPas;

7) utilize existing JBN method calculation procedure 5) under each moment t different saturation oil phase, water relatively to oozingRate thoroughly, computing formula is as follows:

$K_{ro\left(S_w\right)}=f_{o\left(S_w\right)}\frac{d\[\frac{1}{{\stackrel{\‾}{V}}_{\left(t\right)}}\]}{d\[\frac{1}{I_r{\stackrel{\‾}{V}}_{o\left(t\right)}}\]};$

$K_{rw\left(S_w\right)}=K_{ro\left(S_w\right)}\frac{{\mathrm{\μ}}_w}{{\mathrm{\μ}}_o}\frac{f_{w\left(S_w\right)}}{f_{o\left(S_w\right)}};$

$S_{we}=S_{wc}+{\stackrel{\‾}{V}}_{o\left(t\right)}-f_{o\left(S_w\right)}\stackrel{\‾}{V}\left(t\right);$

$f_{w\left(S_w\right)}=\frac{1}{1+\frac{K_{ro}}{K_{rw}}\frac{{\mathrm{\μ}}_w}{{\mathrm{\μ}}_o}};$

$I_r=\frac{{\mathrm{\Δp}}_0}{{\mathrm{\Δp}}_{\left(t\right)}}$

-oil relative permeability, decimal;

-oil content, decimal;

S_w-water saturation, decimal;

-dimensionless accumulative total water injection rate (V/V_p，V_pFor pore volume), decimal;

-dimensionless cumulative recovery (V/V_p), decimal;

I_r-fluid ability ratio, decimal;

-water relative permeability, decimal;

S_we-rock core exit-end water saturation, decimal;

S_wc-irreducible water saturation, decimal;

μ_wThe viscosity of-water, mPas;

μ_o-oil viscosity, mPas;

-moisture content, decimal;

Δp₀-initial pressure reduction, MPa;

Δp_(t)-t moment pressure reduction, Mpa;

And taking water saturation as X-axis, relative permeability is Y-axis, draw oil-water relative permeability curve; As shown in Figure 1.Wherein said JBN method comes from " method of unstable state method calculation of water gas relative permeability is inquired into " literary composition.

Result of calculation is as shown in table 2:

Table 2

Embodiment 2,

A measuring method for heavy crude reservoir high temperature oil-water relative permeability as described in Example 1, its difference is, instituteState step 1) in oily compound method for experiment, comprise that step is as follows:

1.1) measure viscous crude to be measured in temperature T to be measured₁Viscosity, mu at=250 DEG C_o1＝4.64mPa·s；

1.2) according to the viscosity of water in " chemical physical data handbook " and the relation table of temperature, check in water and treating thermometricDegree T₁Viscosity, mu at=250 DEG C_w1=0.11mPas and experimental temperature T₂Viscosity, mu at=20 DEG C_w2=1mPas, thus calculateGo out temperature T to be measured₁Viscosity ratio of oil and water at=250 DEG C

1.3) utilize oil for viscous crude to be measured and naphtha preparation experiment, and experiments of measuring uses oil at experimental temperature T₂＝20℃Under viscosity, mu_o2=42.2mPas, makes experimental temperature T₂Viscosity ratio of oil and water at=20 DEG CWith temperature T to be measured₁＝Viscosity ratio of oil and water at 250 DEG CEquate, that is:

${\left(\frac{{\mathrm{\μ}}_{o1}}{{\mathrm{\μ}}_{w1}}\right)}_{T1}={\left(\frac{{\mathrm{\μ}}_{o2}}{{\mathrm{\μ}}_{w2}}\right)}_{T2}=\mathrm{42.2.}$

Claims (2)

1. a measuring method for heavy crude reservoir high temperature oil-water relative permeability, is characterized in that, the method comprises concrete stepsAs follows:

1) oil for preparing experiment;

2) prepare rock core: will rock core be installed in sand-filling tube model, the dimensional parameters of rock core comprises: long L, cross-sectional diameter d, transversalFace sectional area A, volume V_f；

3) described sand-filling tube model is vacuumized to rear saturation water, while recording saturation water, suck the volume V of water_p, i.e. the pore-body of rock coreLong-pending; Calculate the porosity of described rock core

4) described sand-filling tube model is connected to experimental provision, set experimental temperature T₂; Use oily with constant speed Q with experiment_oDisplacement instituteState the saturation water in rock core, until displacement pressure reduction is stable, record pressure differential deltap P now_o, in metering sand-filling tube model, displacement goes outAccumulated water volume V_o, calculate irreducible water saturation $S_{wc}=1-\frac{V_o}{V_p}\×100\%,$ Oil phase under irreducible water saturation effectively permeates $K_{o\left(S_{wc}\right)}=\frac{Q_o{\mathrm{\μ}}_{o}L}{{\mathrm{A\ΔP}}_o},$ Wherein, described μ_oFor experiment oil viscosity, mPas;

5) after saturated oils, stablize 10-20h, with water drive speed Q_wCarry out water drive oil, in water drive oil process writing time t, with described inTime, t was corresponding: until cumulative oil production V when displacement fluid water breakthrough_o(t), accumulative total production fluid amount V_(t), displacement velocity Q_wAnd rock coreThe displacement pressure differential deltap p at two ends_(t)；

6) in the time that the moisture content of described rock core reaches 99.95% or water injection rate be that after the rock pore volume of 30 times, displacement finishes,Record now cumulative oil productionDisplacement pressure differential deltap P_w；

Calculate residual oil saturationWater effective permeability under residual oil saturationWherein said μ_wFor the viscosity of water, mPas;

7) utilize existing JBN method calculation procedure 5) under each moment t different saturation oil phase, water relatively to infiltrationRate, computing formula is as follows:

$K_{ro\left(S_w\right)}=f_{o\left(S_w\right)}\frac{d\[\frac{1}{\stackrel{\‾}{V}\left(t\right)}\]}{d\[\frac{1}{I_r{\stackrel{\‾}{V}}_{o\left(t\right)}}\]};$

$K_{rw\left(S_w\right)}=K_{ro\left(S_w\right)}\frac{{\mathrm{\μ}}_w}{{\mathrm{\μ}}_o}\frac{f_{w\left(S_w\right)}}{f_{o\left(S_w\right)}};$

$S_{we}=S_{wc}+{\stackrel{\‾}{V}}_{o\left(t\right)}-f_{o\left(S_w\right)}\stackrel{\‾}{V}\left(t\right);$

$f_{w\left(S_w\right)}=\frac{1}{1+\frac{K_{ro}}{K_{rw}}\frac{{\mathrm{\μ}}_w}{{\mathrm{\μ}}_o}};$

$I_r=\frac{{\mathrm{\Δp}}_0}{{\mathrm{\Δp}}_{\left(t\right)}}$

-oil relative permeability, decimal;

-oil content, decimal;

S_w-water saturation, decimal;

-dimensionless accumulative total water injection rate (V/V_p，V_pFor pore volume), decimal;

-dimensionless cumulative recovery (V/V_p), decimal;

I_r-fluid ability ratio, decimal;

-water relative permeability, decimal;

S_we-rock core exit-end water saturation, decimal;

S_wc-irreducible water saturation, decimal;

μ_wThe viscosity of-water, mPas;

μ_o-oil viscosity, mPas;

-moisture content, decimal;

Δp₀-initial pressure reduction, MPa;

Δp_(t)-t moment pressure reduction, Mpa;

And taking water saturation as X-axis, relative permeability is Y-axis, draw oil-water relative permeability curve.

2. the measuring method of a kind of heavy crude reservoir high temperature oil-water relative permeability according to claim 1, is characterized in that,Described step 1) in oily compound method for experiment, comprise that step is as follows:

1.1) measure viscous crude to be measured in temperature T to be measured₁Under viscosity, mu_o1；

1.2) according to the viscosity of water in " chemical physical data handbook " and the relation table of temperature, check in water in temperature T to be measured₁Lower viscosity, mu_w1With experimental temperature T₂Under viscosity, mu_w2Thereby, calculate temperature T to be measured₁Under viscosity ratio of oil and water

1.3) utilize oil for viscous crude to be measured and naphtha preparation experiment, and experiments of measuring uses oil at experimental temperature T₂Under viscosityμ_o2, make experimental temperature T₂Under viscosity ratio of oil and waterWith temperature T to be measured₁Under viscosity ratio of oil and waterEquate, that is:

${\left(\frac{{\mathrm{\μ}}_{o1}}{{\mathrm{\μ}}_{w1}}\right)}_{T1}={\left(\frac{{\mathrm{\μ}}_{o2}}{{\mathrm{\μ}}_{w2}}\right)}_{T2}.$