CN104389592A - Oil loss evaluation experiment test method for water flooded layer of bottom water condensate gas reservoir with oil rim - Google Patents

Abstract

The invention discloses an oil loss evaluation experiment test method for a water flooded layer of a bottom water condensate gas reservoir with an oil rim. The method comprises the following steps that: (1) injection water, in-place oil and condensate gas samples are prepared; (2) rock core sampling and process establishment are carried out, and all blocks of rock cores are combined into a long rock core by a harmonic average mode; (3) original conditions of the bottom water condensate gas reservoir with the oil rim are established; (4) a water body is established, and the establishment is carried out according to known original gas reservoir data; (5) bottom water reservoir oil displacement loss evaluation is carried out, and a formula is established through oil-gas-water three-phase saturation degree data for calculating the oil loss quantity; (6) graphs are drawn according to oil-containing saturation degree data, and quantitative evaluation can be made on the oil loss condition of the water flooded layer of the bottom water condensate gas reservoir, with the oil rim and the oil rim distribution condition of a gas cap region and the like through combining an oil loss quantity calculation formula. The oil loss evaluation experiment test method has the advantages that a physical simulation scheme of the bottom water drive of the bottom water condensate gas reservoir with the oil rim under the prime stratum actual conditions is established, and an effective tool and an effective experiment test method are provided for the oil loss evaluation of the water flooded layer.

Description

End water gas condensate reservoir with oil rim Water Flooding Layer oil loss assessment experimental test procedures

Technical field

The present invention relates to the experimental test procedures of water gas condensate reservoir with oil rim Water Flooding Layer oil loss assessment at the bottom of petroleum natural gas exploration field.

Background technology

Due to end liter waterborne, water gas condensate reservoir with oil rim oil ring is easily by water logging at the end, makes recovery percent of reserves general lower, how to improve the key issue that oil ring recovery ratio is this kind of oil-gas reservoir.Carried out at present related experiment and the research of bottom water reservoir water drive and bottomwater gas field water drive, but end water-band oil ring Water Flooding Gas Condensate Reservoir also not have comparatively ripe evaluation experimental method of testing, and the problem of this field engineering technician care just.At present about the experiment of bottom water reservoir water drive or bottomwater gas field water drive, pressure and temp does not generally reach physical condition or reservoir fluid is not real fluid, a key technology difficult problem how to record oil, gas, water saturation distribution in laboratory conditions and how to set up the physical analogy scheme close with oil-gas reservoir physical condition, and the present invention is exactly the experimental test procedures set up on the long-core test equipment with linear saturation ratio on-line testing function.

Summary of the invention

The object of the present invention is to provide end water gas condensate reservoir with oil rim Water Flooding Layer oil loss assessment experimental test procedures, the method principle is reliable, easy and simple to handle, effectively can simulate and waterbornely at the bottom of end water gas condensate reservoir with oil rim rise the displacement of reservoir oil, purging process, and Measurement accuracy oil saturation and gas saturation are along the distribution situation of rock core vertical direction, provide effective instrument and means for evaluating end water gas condensate reservoir with oil rim Water Flooding Layer oil damaed cordition.

For reaching above technical purpose, the invention provides following technical scheme.

End water gas condensate reservoir with oil rim Water Flooding Layer oil loss assessment experimental test procedures, comprises the following steps successively:

(1) water, in-place oil, condensate gas sample are injected in preparation

Under formation temperature pressure, prepare by relevant criterion.The crude oil PVT report that in-place oil sample provides according to scene is prepared, and condensate gas sample is prepared according to pneumatic jack PVT sampling, injects water sample and prepares at ambient temperature according to actual formation water ion content analysis data.

(2) boring sample and flow process are set up

Coring by reservoir longitudinal direction, test degree of porosity φ and the permeability K of every block rock core by standard method respectively, in order to make long cores have better representativeness, (namely pressing formula L/K=L by permeability harmonic average mode _i/ K _icalculate the mean permeability K of each block of rock core, then permeability is chosen and the comparatively close rock core of K value is arranged in order from the port of export of core holding unit) each block of rock core is combined into long cores, length is L (cm), in the long rock core holder of tape loaded oil gas water three phase saturation ratio test function, vertical placement, by system warm-up to predetermined formation temperature, until temperature stabilization, fluctuate within ± 0.5.

(3) end water gas condensate reservoir with oil rim initial condition is set up

Long cores is carried out finding time to reach below 200Pa, the saturated injection water sample from long cores bottom, under the condition keeping formation temperature, water is pressurized to stratum reset pressure, again the condensate gas sample prepared directly is injected the saturated injection water of displacement long cores from top, until production end not water outlet, obtain irreducible water saturation S _wi(%); The in-place oil sample configured is injected into long cores from bottom, injects the oil ring thickness H formed _o(cm) determined by following formula: H _o=L*H _oi/ (H _oi+ H _gi).

H in formula _gi(m): the original pneumatic jack thickness of gas condensate reservoir with oil rim, H _oi(m): gas condensate reservoir with oil rim original reservoir thickness.

Oil ring thickness H _ocontrolled by three-phase saturation watch-dog.

Oil ring oil saturation S can be obtained by three-phase saturation test _o, calculate and adopt H _ovalue should be the pure oil ring thickness of actual test, if D (cm) is core diameter, and original pure oil ring oil volume V _o(ml):

V _o＝1/4πD ²φH _oS _o

Oil gas intermediate zone oil volume V in pneumatic jack _o' (ml): ${V_o}^{\′}=1/4\mathrm{\π}{D}^2\mathrm{\φ}\underset{j=1}{\overset{N}{\mathrm{\Σ}}}{\mathrm{\ΔH}}_{\mathrm{ogj}}{S}_{\mathrm{ogj}}$

Δ H in formula _ogj: oil gas intermediate zone jth section section length size, j=1 ~ N, total segments N are the hop counts will obtained after average for intermediate zone thickness segmentation, optional 0.1 ~ 0.5cm; S _ogj: test obtains pneumatic jack district oil gas intermediate zone jth section oil saturation (%);

After initial condition is set up, obtained along the oil in rock core vertical direction, gas, water three-phase saturation S by the test of X-ray saturation ratio In-circiut tester _ok, S _gk, S _wkdistribution situation.

(4) foundation of water body

Set up according to known primitive arts data.According to the original water body volume of gas condensate reservoir with oil rim and original hydro carbons volume ratio N _w(zero dimension) is prepared, the water body volume V for setting up in rock core under HTHP _wi(ml) can determine by following formula:

V _wi＝(V _oi+V _gi)*N _w

Gas condensate reservoir with oil rim initial oil volume V in formula _oiwith original gassiness volume V _giand N _wbeing given data, in order to ensure the accuracy of water body volume, processing one and V _withe rigid container of the high temperature high voltage resistant that volume is equally large is connected on the vertical lower of long cores, under water body being pressurized to oil-gas reservoir initial pressure at the formation temperature by external intermediate receptacle.

(5) bottom water drive oil loss assessment

Intermediate receptacle is adopted to fill injection water sample, constant voltage bottom water drive is carried out by injection pump from long cores bottom water injection under setting pressure, record different injected water volume HCPV (HCPV, the injected water volume multiple of HCPV represents, as namely 0.15HCPV represents that injected water volume is 0.15 times that underground hydro carbons occupies voids volume) oil of bottom water drive in the vertical direction, gas, water three-phase saturation S under condition _ok, S _gk, S _wksituation of change.End water gas condensate reservoir with oil rim Water Flooding Layer oil damaed cordition carries out quantitative assessment by following two aspects:

1) the oily loss amount in pure oil ring district.

The different oily loss amount V injecting HCPV water yield Xia Chun oil ring district ₁, with original pure oil ring thickness H _ofor boundary line, lower than H _ofollowing region is pure oil ring district, is calculated as follows:

$V_1=1/4\mathrm{\π}{D}^2\mathrm{\φ}\underset{j=1}{\overset{N}{\mathrm{\Σ}}}{\mathrm{\ΔH}}_{\mathrm{ojk}}{S}_{\mathrm{ojk}}$

Δ H in formula _ojk: jth section section length size under oil ring K level HCPV, j=1 ~ N, total segments N is by H _oobtain after average segmentation, the optional 0.1 ~ 0.5cm of every compute segment; S _ojk: test pure oil ring jth section oil saturation (%) obtained;

2) the oily loss amount in pneumatic jack district.

The oily loss amount V in pneumatic jack district under the different injection HCPV water yield ₂, with original pure oil ring thickness H _ofor boundary line, higher than H _oabove region is gas cap region, is calculated as follows:

$V_2=1/4\mathrm{\π}{D}^2\mathrm{\φ}\underset{j=1}{\overset{N}{\mathrm{\Σ}}}{\mathrm{\ΔH}}_{\mathrm{ogjk}}{S}_{\mathrm{ogjk}}-{V_o}^{\′}$

Δ H in formula _ogjk: gas cap oil invades jth section section length size under district K level HCPV, and j=1 ~ N, obtains after the average segmentation of total segments N Shi Jiangyouqin district thickness, optional 0.1 ~ 0.5cm; S _ogjk: test obtains pneumatic jack Zhong Youqin district oil saturation (%).(6) according to oil saturation Plotting data figure

According to testing the data obtained, draw out before constant voltage bottom water drive and after constant voltage bottom water drive different when injecting the HCPV water yield along the oil in rock core vertical direction, gas, water three-phase saturation scatter chart, the oily loss amount design formulas according to the curve map integrating step (5) of drawing can make quantitative assessment to the oil ring distribution situation etc. in end water gas condensate reservoir with oil rim Water Flooding Layer oil damaed cordition and pneumatic jack district.

Compared with prior art, the present invention has following beneficial effect:

(1) under true formation temperature and pressure condition, condensate gas, crude oil and the formation water sample prepared by strict standard is adopted to test, can the displacement process of water gas condensate reservoir with oil rim bottom water drive at the bottom of accurate simulation, reflect the production performance of primitive arts objectively;

(2) under true formation temperature and pressure condition, evaluate end water direct displacement condition water gas condensate reservoir with oil rim water logging oil ring of going to the bottom and rise and damaed cordition;

Accompanying drawing explanation

Fig. 1 is oil, gas, water three-phase saturation linear distribution schematic diagram before bottom water drive.

Fig. 2 is oil after bottom water drive, gas, water three-phase saturation linear distribution schematic diagram.

Detailed description of the invention

The present invention is further illustrated with reference to the accompanying drawings below with example.

End water-band oil ring gas reservoir Water Flooding Layer oil loss assessment experimental test procedures, follows these steps to carry out:

(1) water, in-place oil, condensate gas sample are injected in preparation

At formation temperature 80, under pressure 30MPa, prepare by relevant criterion.The crude oil PVT report that in-place oil sample provides according to scene is prepared, and condensate gas sample is prepared according to pneumatic jack PVT sampling, injects water sample and prepares at ambient temperature according to actual formation water ion content analysis data.

(2) boring sample and flow process are set up

Core by reservoir longitudinal direction, by standard method test porosity and permeability, average pore 18%, mean permeability 50mD, is combined into long cores by permeability harmonic average mode, length is L=16cm, in the long rock core holder of tape loaded oil gas water three phase saturation ratio test, vertically place, by system warm-up to predetermined formation temperature, until whole system temperature stabilization, fluctuate within ± 0.5.

(3) end water gas condensate reservoir with oil rim initial condition is set up

Long cores is carried out finding time to reach below 200Pa, the saturated injection water sample prepared from long cores bottom, close top gate, under the condition keeping formation temperature, water is pressurized to stratum reset pressure, again the condensate gas prepared directly is injected the injection water driving saturation from long cores top, until production end is less than water, the water yield displaced in record, obtains irreducible water saturation S _wi=35%; The in-place oil sample configured is injected into long cores from bottom, according to reservoir oil ring height account for total oil-gas reservoir high 25% to calculate oil ring height in long cores be 4cm, under three-phase saturation monitoring condition, inject and form the pure oil ring of 4cm (not containing intermediate zone), be i.e. H _o=4cm, can obtain oil ring oil saturation S by three-phase saturation test _o=65%, D=2.54cm, oil gas transition tape thickness 1cm.

Original pure oil ring oil volume V _o: V _o=1/4 π D ²φ H _os _o, can be calculated oil ring volume by oil ring thickness 4cm is 2.33ml.

Original oil gas intermediate zone oil volume V _o': ${V_o}^{\′}=1/4\mathrm{\π}{D}^2\mathrm{\φ}\underset{j=1}{\overset{N}{\mathrm{\Σ}}}{\mathrm{\ΔH}}_{\mathrm{ogj}}{S}_{\mathrm{ogj}}$

Δ H in formula _ogj: oil gas intermediate zone jth section section length size, j=1 ~ N, according to Fig. 1, oil gas intermediate zone is the 1cm between 4-5cm, and total segments N=10 obtains after 1cm is equally divided into 10 sections; S _ogj: oil gas intermediate zone is the intensity value that the every 0.1cm between 4-5cm is corresponding, if averaging is 32.5%; Intermediate zone oil volume 0.29ml.

After initial condition is set up, obtained along the oil in rock core vertical direction, gas, water three-phase saturation S by the test of X-ray saturation ratio In-circiut tester _ok, S _gk, S _wkdistribution situation.

(4) foundation of water body

Set up according to known primitive arts data.According to the original water body volume of gas condensate reservoir with oil rim and original hydro carbons volume ratio N _w(zero dimension) is prepared, the water body volume V for setting up in rock core under HTHP _wi(ml) can determine by following formula:

V _wi＝(V _oi+V _gi)*N _w

In order to ensure the accuracy of water body volume, process one and V _withe rigid container of the high temperature high voltage resistant that volume is equally large is connected on the vertical lower of long cores, under water body being pressurized to oil-gas reservoir initial pressure at the formation temperature by external intermediate receptacle.

(5) bottom water drive oil loss assessment

Adopting intermediate receptacle to fill injection water sample, under setting pressure, carry out constant voltage bottom water drive, obtaining along rock core vertical direction upper base water drive oil, gas, water three-phase saturation situation of change S when injecting 0.15HCPV _ok, S _gk, S _wk.End water gas condensate reservoir with oil rim Water Flooding Layer oil damaed cordition carries out quantitative assessment by following two aspects:

1) the oily loss amount in pure oil ring district.

Be that boundary line is measured with 4cm, oily loss amount V in pure oil ring district within this ₁:

$V_1=1/4\mathrm{\π}{D}^2\mathrm{\φ}\underset{j=1}{\overset{N}{\mathrm{\Σ}}}{\mathrm{\ΔH}}_{\mathrm{ojk}}{S}_{\mathrm{ojk}}$

Δ H in formula _ojk: jth section section length size under oil ring K level HCPV, j=1 ~ N, total segments N obtain after average for 4cm segmentation, the optional 0.1 ~ 0.5cm of every compute segment; S _ojk: test pure oil ring jth section oil saturation (%) obtained;

2) the oily loss amount in pneumatic jack district

The region being more than boundary line higher than 4cm is pneumatic jack district, can be calculated as follows the oily loss amount V in pneumatic jack district ₂:

$V_2=1/4\mathrm{\π}{D}^2\mathrm{\φ}\underset{j=1}{\overset{N}{\mathrm{\Σ}}}{\mathrm{\ΔH}}_{\mathrm{ogjk}}{S}_{\mathrm{ogjk}}-{V_o}^{\′}$

Δ H in formula _ogjk: gas cap oil invades district K level HCPV jth section section length size, j=1 ~ N, obtains, optional 0.1 ~ 0.5cm between total segments N Shi Jiangyouqin district height 4-8cm after average segmentation; S _ogjk: test obtains pneumatic jack Zhong Youqin district jth section oil saturation (%).

(6) according to oil saturation Plotting data figure

According to testing the data obtained, can obtain before constant voltage bottom water drive and after constant voltage bottom water drive different when injecting the HCPV water yield along the oil gas water three phase saturation distribution curve map in rock core vertical direction, contrast accompanying drawing 1,2 can obviously be found out, have a very large change along the oil in rock core vertical direction, gas, water three-phase saturation before and after bottom water drive, the oily loss amount design formulas according to the data integrating step (5) in figure can make quantitative assessment to the oil ring distribution situation etc. in end water gas condensate reservoir with oil rim Water Flooding Layer oil damaed cordition and pneumatic jack district.

Claims (1)

1. end water gas condensate reservoir with oil rim Water Flooding Layer oil loss assessment experimental test procedures, comprises the following steps successively:

(1) water, in-place oil, condensate gas sample are injected in preparation;

(2) core by reservoir longitudinal direction, by permeability harmonic average mode, each block of rock core is combined into long cores, length is L, in the long rock core holder of tape loaded oil gas water three phase saturation ratio test function, vertical placement, by system warm-up to predetermined formation temperature;

(3) long cores is carried out finding time to reach below 200Pa, the saturated injection water sample from long cores bottom, under the condition keeping formation temperature, water is pressurized to stratum reset pressure, again the condensate gas sample prepared directly is injected the saturated injection water of displacement long cores from top, until production end not water outlet, obtain irreducible water saturation S _wi, the in-place oil sample configured is injected into long cores from bottom, injects the oil ring thickness H formed _odetermined by following formula:

H _o＝L*H _oi/(H _oi+H _gi)。

H in formula _gifor the original pneumatic jack thickness of gas condensate reservoir with oil rim, H _oifor gas condensate reservoir with oil rim original reservoir thickness,

Original pure oil ring oil volume V _o=1/4 π D ²φ H _os _o

Oil gas intermediate zone oil volume in pneumatic jack ${V_o}^{\′}=1/{4\mathrm{\πD}}^2\mathrm{\φ}\underset{j=1}{\overset{N}{\mathrm{\Σ}}}{\mathrm{\ΔH}}_{\mathrm{ogj}}{S}_{\mathrm{ogj}}$

In formula, D is core diameter, S _ofor oil ring oil saturation, Δ H _ogjfor oil gas intermediate zone jth section section length size, j=1 ~ N, total segments N are the hop counts will obtained after average for intermediate zone thickness segmentation, optional 0.1 ~ 0.5cm, S _ogjfor test obtains pneumatic jack district oil gas intermediate zone jth section oil saturation;

(4) water body is set up according to known primitive arts data, the water body volume V set up in rock core under HTHP _widetermine by following formula:

V _wi＝(V _oi+V _gi)*N _w

V in formula _oifor gas condensate reservoir with oil rim initial oil volume, V _gifor original gassiness volume, N _wfor the original water body volume of gas condensate reservoir with oil rim and original hydro carbons volume ratio;

(5) under setting pressure, carry out constant voltage bottom water drive by injection pump from long cores bottom water injection, record the oil of bottom water drive in the vertical direction under different injected water volume HCPV condition, gas, water three-phase saturation S _ok, S _gk, S _wksituation of change, the end water gas condensate reservoir with oil rim Water Flooding Layer oil damaed cordition carry out quantitative assessment by following two aspects:

1) the oily loss amount in pure oil ring district

With original pure oil ring thickness H _ofor boundary line, lower than H _ofollowing region is pure oil ring district, the different oily loss amount V injecting HCPV water yield Xia Chun oil ring district ₁be calculated as follows:

$V_1=1/{4\mathrm{\πD}}^2\mathrm{\φ}\underset{j=1}{\overset{N}{\mathrm{\Σ}}}{\mathrm{\ΔH}}_{\mathrm{ojk}}{S}_{\mathrm{ojk}}$

Δ H in formula _ojkfor jth section section length size under oil ring K level HCPV, j=1 ~ N, total segments N is by H _oobtain after average segmentation, every compute segment optional 0.1 ~ 0.5cm, S _ojkfor testing the pure oil ring jth section oil saturation obtained;

2) the oily loss amount in pneumatic jack district

With original pure oil ring thickness H _ofor boundary line, higher than H _oabove region is gas cap region, the oily loss amount V in pneumatic jack district under the different injection HCPV water yield ₂be calculated as follows:

$V_2=1/{4\mathrm{\πD}}^2\mathrm{\φ}\underset{j=1}{\overset{N}{\mathrm{\Σ}}}{\mathrm{\ΔH}}_{\mathrm{ogjk}}{S}_{\mathrm{ogjk}}-{V_o}^{\′}$

Δ H in formula _ogjkfor gas cap oil invades jth section section length size under district K level HCPV, j=1 ~ N, obtains after the average segmentation of total segments N Shi Jiangyouqin district thickness, optional 0.1 ~ 0.5cm, S _ogjkfor test obtains pneumatic jack Zhong Youqin district oil saturation;

(6) according to testing the data obtained, draw out before constant voltage bottom water drive and after constant voltage bottom water drive different when injecting the HCPV water yield along the oil in rock core vertical direction, gas, water three-phase saturation scatter chart, oily loss amount according to the curve map integrating step (5) of drawing calculates, and makes quantitative assessment to the oil ring distribution situation etc. in end water gas condensate reservoir with oil rim Water Flooding Layer oil damaed cordition and pneumatic jack district.