CN1015661B - Experiment method for measuring relative penetration of oil, gas and water in reservoir core - Google Patents

Abstract

The present invention relates to a method for measuring the three phase relative penetration rate of oil, gas and water in an oil reservoir rock core. The method comprises an experimental device and a test program. By using the method, curves of three phase relative penetration of oil, gas and water of the oil reservoir rock core are measured when water saturation is increased, oil saturation is decreased and gas saturation is increased.

Description

Experiment method for measuring relative penetration of oil, gas and water in reservoir core

The present invention relates to a kind of experimental technique that is used to measure oil reservoir column rock core oil, gas, water three-phase relative permeability.The invention of this method has special meaning to the oil reservoir development experimental study.

Oil in the porous medium, gas, water three-phase relative permeability measuring research start from early forties, M.C. Lai Furuite (M.C.Leverett) at first on the artificial sand sample, utilized stable state determination of experimental method oil, gas, water three-phase relative permeability.The mensuration of oil, gas, water saturation has adopted resistivity method.The experiment of Lai Furuite does not consider to overcome two effects that influence experimental precision, i.e. lag-effect and end effect.Also there is certain problem in the measuring technology of saturation degree.In 1 or nine years on May Day, B.H. examines people such as moral, and (B.H.Caudle et.al) has proposed to utilize the way of distillation to measure oil and water saturation degree in the three-phase relative permeability experiment.Ignored the influence of lag-effect and end effect in the experiment, because fluid loss in the test process is affected the measuring accuracy of saturation degree.A.T. (A.T.Corey) and S. Reed (S.Reid) you can well imagine out distinct methods in one nine five six the fraction of the year in the section, have obtained oil, gas, water three-phase relative permeability.Experimentation in the section exists certain not enough, and the experiment of Reed does not overcome lag-effect.In 1962, R.W. Si Naier (R.W.Snell) utilized the stable state method on the artificial sand sample, obtained three-phase relative permeability.The method that the measuring technology of saturation degree has adopted RCL oscillatory circuit and neutron bombardment to combine, the deficiency of experimental technique are that experimentation is too complicated, and there are bigger difference in sample and oil reservoir actual sample.In 1966, E.C. Donaldson people such as (E.C.Donaldson) and A.M. Sa Ruimu (A.M.Sarem) utilized the expansion of astable two-phase relative permeability experiment to calculate three-phase relative permeability respectively.Obviously, this method lacks the mobile jointly condition of oil, gas, water.In 1967 and in 1983, D.N. Sa pressgang (D.N.Saraf) proposes two kinds of distinct methods, one, utilize nuclear magnetic resonance technique to determine each phase saturation in the rock core, because the costliness of experimental facilities, experiment condition and reservoir condition differ greatly, and promote so be difficult in the real work; Its two, the method for utilizing stable state and non-steady state to combine has been measured oil, gas, water three-phase relative permeability, the material balance method of the circulation system has been adopted in the test of saturation degree.Because his experiment condition is limit, and makes lag-effect not overcome well.In 1982, E.V. this profit gloomy (E.V.Spronsen) has proposed a kind of hydro-extractor method of utilizing and has measured three-phase relative permeability, the mensuration of saturation degree adopts the gravitational difference method, and this method does not constitute oil, gas, water and flows in porous medium, so the three-phase relative permeability curve does not have representativeness.In 1988, M.J. gram difficult to understand (M.J.Oak) people of etc.ing utilized X-light adsorption technology to measure heterogeneous saturation degree in Baily (Berea) sandstone, although equipment is advanced, lag-effect is not still overcome in they test.

The experimental technique and the device that the purpose of this invention is to provide a kind of mensuration oil of avoiding above-mentioned shortcoming, gas, water three-phase relative permeability

The method that solves this task is the experimental technique and the device of oil, gas, water three-phase relative permeability, and this device is made up of from metering system injected system, pressure-measuring system, three sections rock core system, little heavy saturation degree test macro and oil, gas, moisture.Injected system is by constant speed waterflood pump 1, constant speed filling pump 2 and compressed-air actuated steel cylinder 4 is housed forms.Pressure-measuring system is by inlet pressure table 21, DP15 pressure transducer 25, delivery gauge 29, and pressure combination box 30 and bench teat registering instrument 31 are formed.Three sections core holding units are by stable section 26, test section 27, and end segment 28 is formed.Little heavy saturation degree test macro is made up of electronical reading balance 36 and microwave instrument 37; Oil, gas, moisture are to be made up of oil, gas, separator 32 and soap bubble flowmeter 35 from metering system.

Experimental technique of the present invention is:

1. synthetic core or reservoir cores are got in test specimen preparation, and being drilled to diameter is 2.5cm, and length is the garden post sample of 9cm.The reservoir cores sample cleans with the potpourri that benzene adds alcohol, the organic substance in the flush away rock core.Adopt technological process that 87214736 patents narrate with rock core organic glass good seal, being processed into diameter then is 4.5cm, (comprising organic glass shell), longly being 8.5cm, thickness is the laboratory sample of 2.8cm.As shown in Figure 2, experiment is a colony with 10～15 in sample.

2. claim its every dried rock core weight, measure air permeability.The laboratory sample of finding time, and to its saturation water, the example weight after claiming it saturated is calculated the volume of voids of sample.

3. the typical curve of working sample microwave attenuation voltage and water cut relation (V-Gw).The mensuration of V-Gw typical curve is carried out according to gas/water diphasic flow experiment.The sample of saturation water is installed in (No. 27 position in the accompanying drawing 1) on the core holding unit, carries out the experiment of gas drive water then.In fact, gas drive water is meant that the injection rate of gas changes from small to big, and the injection rate of water from large to small.In the mensuration process, adopted the stable state experiment, promptly work as G﹠W according to a certain percentage by stable section 26, test section 27, end segment 28 flows out, and treats that flow state is stable, unloads test section 27.Be placed on its weight of title Gw on the electronical reading balance 36, the evanescent voltage value V. that utilizes microwave instrument 37 to measure sample then so just constitutes example weight and evanescent voltage value corresponding point.Change gas injection, water ratio, repeat said process, just can obtain many gravimetric values and magnitude of voltage one-to-one point, these corresponding point are plotted in the common coordinate system, then constituted the typical curve of V-Gw.

4. the mensuration of oil, gas, water three-phase relative permeability

Find time to measure the sample of typical curve, saturation water again.The oil expelling water produces irreducible water, measures permeability to oil under the irreducible water condition, surveys three points, and difference gets final product with interior 5% between each value.According to the saturated course that is thought out in advance, carry out oil, gas, water three-phase relative permeability determination test.After oil, gas, water are injected into test section sample 27 according to a certain percentage, oil, gas, water flow jointly and reach 8 hours and can make flow state reach stable, inlet pressure table 21 from the experimental section two ends, with delivery gauge 29, the pressure at record test section 27 two ends, and the flow of the oil of output, gas, water.In the stable state experiment,, can think oil, the water yield injected to equate with oil, the water yield of output as long as flow state reaches stable.Gas is by Oil, Water, Gas separation vessel 32, measures by soap bubble flowmeter 35 after separating.After having write down pressure and output, can utilize Darcy formula to calculate the effective permeability of fuel-displaced, gas, water, calculate its relative permeability then.The computing formula of oil, gas, water effective permeability is:

For oil phase:

Ko＝ (μo.Qo.L)/(A.△p.t) （1）

For gas phase:

$\mathrm{Kg\; =}\frac{{\mathrm{2\; L.Qg.po.Za\; \mu }}_g}{{\mathrm{A\; (\; <figure-callout\; id="2"\; label="P"\; filenames="88108655\_DRIMG2.png"\; state="\{\{state\}\}">P</figure-callout>}}^2{}_1{\mathrm{-\; <figure-callout\; id="2"\; label="P"\; filenames="88108655\_DRIMG2.png"\; state="\{\{state\}\}">P</figure-callout>}}^2{}_2\mathrm{)Zo.\; t}}\mathrm{(2)}$

For water:

$K_W=\frac{{\mu }_w{\mathrm{·\; Q}}_W\mathrm{·\; L}}{\mathrm{A\; .\; △\; P\; .t}}\mathrm{(3)}$

Oil, gas, water three-phase relative permeability computing formula are by following various expression

For oil phase:

Kpo＝ (Ko)/(K) ×100%（4）

For gas phase:

Krg＝ (Kg)/(K) ×100%（5）

For water:

Krw＝ (Kw)/(K) ×100%（6）

In the formula:

Ko-oil effective permeability (* 10 ^-3μ m ²);

K-absolute permeability (* 10 ^-3μ m ²);

Krw-water relative permeability;

The Kro-oil relative permeability;

The F-core section amasss (cm ²);

P ₁-core entry pressure (MPa);

The Qg-atmospheric pressure flows out the gas flow (cm of rock core down ³/ s);

Za-is gas compressive coefficient under rock core mean pressure and experimental temperature;

μ _wThe viscosity of-water (mPas);

Kw-water effective permeability (* 10 ^-3μ m ²);

Krg-gas phase relative permeability;

L-rock core length;

Po-atmospheric pressure (MPa);

P ₂-rock core top hole pressure (MPa);

Qw-flows out the water yield (cm of rock core ³/ s);

Qo-flows out the oil mass (cm of rock core ³/ s);

Zo-is gas compressive coefficient under atmospheric pressure, experimental temperature;

μ g-gas viscosity (mPas);

μ ₀-oil viscosity (mPas).

After record pressure and each quantum of output mutually, carry out oil in the sample, gas, water saturation test, unload test section 27, claim its weight with electronical reading balance 36, this weight is that dry-eye disease, oil, water gross weight sum are designated as Gt, measure the evanescent voltage value of this moment in the sample with the microwave instrument again, find water cut Gw in the sample by this value on the V-Gw typical curve, weight oily in the sample can be calculated by following formula:

Go＝Gt-Gw-Gd（7）

Because the pore-body V of sample _{The hole}, oil, water density r _o, r _wBe known, then oil, gas, water saturation can be by various the calculating of example down.

Oil-phase saturation:

$S_O=\frac{V_O}{V_{}}\mathrm{\times \; 100\%\; =}\frac{G_O}{r_o{V}_{}}\mathrm{\times \; 100\%\; (8)}$

Water phase saturation:

$\frac{V_w}{V_{}}\mathrm{\times \; 100\%\; =}\frac{G_W}{r_W{V}_{}}\mathrm{\times \; 100\%\; (9)}$

Gas phase saturation: Sg=100-So-Sw

Change oil, gas, water and inject ratio, treat flow state reach stable after, the repetition said process can draw the corresponding relation of other one group of oil, gas, water three-phase relative permeability and three-phase saturation.According to saturated course, when the flow velocity of one phase flow body reached zero, experiment finished.In order to overcome the lag-effect in the experiment, every sample in colony's sample only carries out once complete saturated course experiment.After colony's sample (10-15 piece) is all finished oil, gas, the test of water three-phase relative permeability, test data can be drawn fuel-displaced, gas, water etc. and ooze on the line chart.Can decide according to test findings Deng the calibration that oozes line.

For the oil of finishing above-mentioned experiment usefulness, gas, water, can carry out the simulated experiment temperature at the oil reservoir practical problems is 20 ℃ ± 1 ℃.

Be described in further detail below with reference to 1 pair of this invention of accompanying drawing, accompanying drawing 1 is the process flow diagram that is used to measure reservoir cores oil, gas, water three-phase relative permeability.

With reference to accompanying drawing 1, water is by constant speed waterflood pump 1, two logical gate 7, water filter 8, and water tensimeter 14 injects stable section 26, and oil is by constant speed filling pump 2, two logical gates 10, oil screen 9, oil phase tensimeter 15 is injected into stable section 26; Through decompression table 3, two logical gates 6, profit jar 5, two leads to gates 12 to gas from steel cylinder 4, gaseous pressure table 11, and gas control valve 16, gaseous pressure table 17, two logical gates 23, three-way gate 22 injects stable sections 26; Another of gas route is a gas process gas control valve 16, gaseous pressure table 17, and two logical gates 20, gas meter 19, two logical gates 18, receiver 13 enters stable section 26 behind the three-way gate 22.Oil, gas, water enter test section 27 after stable section 26 forms steady flow, end segment 28 flows into oil, gas, separator 32 again, and there, oil, gas, water separate by gravitational difference, and gas flows out through soap bubble flowmeter 35.Oil and water flow out through outage 38 and osculum 39.Beaker 34 and 33 is divided into the You Heshui that reclaims output.The pressure at test section two ends is by inlet pressure table 21, and delivery gauge 29 measures, and the pressure difference value signal is given pressure combination box 30 by DP15 pressure transducer 25, changes pressure signal into electric signal at this and gives desk-top registering instrument 31 again.In experiment, if the work track of desk-top registering instrument 31 is a straight line, inlet pressure table 21, delivery gauge 29, and the indication of pressure combination box 30 and reading are constant thinks under this oil, gas, water ratio condition flow state stable state in the sample, can be by the above-mentioned flow of measuring pressure and output, thereby in respect of imitating permeability and relative permeability.The mensuration of oil, gas, water saturation is finished by electronical reading balance 36 and microwave instrument 37.

The present invention has been used for Daqing oil field reservoir cores oil, gas, water three-phase relative permeability mensuration, obtained the water saturation increase, oil saturation minimizing and gas saturation increase the relation of oil, gas, water three-phase relative permeability and the three-phase saturation of saturated course.10 Daqing oil field oil reservoir samples have been used in experiment, and kerosene is oil phase, and distilled water is water, and pressurized air is gas phase, is under 20 ° of conditions in experimental temperature, and the viscosity of oil, gas, water is respectively 1.165,1.034 and 0.0181mPa.s.The density of oil and water is respectively 0.78g/cm ²And 1.01g/cm ³Experimental result shows that the water relative permeability only is the function of water saturation; And oil and gas phase relative permeability are the function of oil, gas, water saturation.Waters etc. ooze the reticule of its saturation degree of line parallel, and it is recessed to oil saturation 100% that oil phase etc. ooze line, and gas phase etc. to ooze line protruding in gas saturation 100%.This experimental result has been used for the numerical simulation of oil reservoir development.

Claims (2)

1, a kind of experimental technique that is used to measure reservoir cores oil, gas, water three-phase relative permeability may further comprise the steps:

A. synthetic core or reservoir cores are got in test specimen preparation, and being drilled to diameter is 2.5cm, and length is the garden post sample of 9cm;

B. the potpourri with benzene and alcohol cleans, organic substance in the flush away rock core, and the technological process of narrating with 87214736 patents is rock core organic glass good seal, being processed into diameter then is 4.5cm (comprising organic glass shell), long is 8.5cm, and thickness is the test specimen of 2.8cm;

C. the physical parameter of working sample (permeability, factor of porosity and volume of voids);

D. gas drive water injects flowing experiment, to obtain sample microwave attenuation voltage and water cut relation (V-G _w) typical curve;

E. oil, gas, water inject flowing experiment simultaneously, with the relation curve of the oil, gas, water three-phase relative permeability and the saturation degree that obtain sample;

F. write down and calculate measurement result.

2, a kind of device that is used to measure reservoir cores oil, gas, water three-phase relative permeability, by constituting with the lower part:

A. oil, water pump and compressed-air actuated gas cylinder is housed are respectively applied for and inject oil, water and gas in experiments;

B. pressure-measuring system is the pressure that is used for monitoring flow state and experiment with measuring sample two ends in experiment;

C. little heavy saturation degree test macro is to adopt microwave instrument and electronic balance to combine oil, gas, water saturation in the measuring samples;

D. oil, gas, moisture are to be used for separating and measuring from the fluid of test specimen output from metering system.

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