CN102508317A - Method for identifying fracture-cavity carbonate reservoir fluid properties - Google Patents

Abstract

The invention relates to a method for identifying fracture-cavity carbonate reservoir fluid properties. The method comprises the following steps: acquiring conventional logging information, formation water information and drilling fluid information; calculating the mud content V of the mud-containing seam hole well section_shAnd effective porosity phi_e(ii) a Calculating resistivity of the whole well section with the influence of mud deductionAnd resistivity R of apparent formation water of whole well section_wai^*(ii) a Counting the mean value and the root-mean-square difference of the resistivity of the visual formation water of a reservoir section to be identified; drawing the mean value and the root-mean-square difference of the apparent formation water resistivity of a plurality of reservoir sections with determined fluid properties of the tested oil on a log-log coordinate, and establishing a fluid property judgment standard of a research area; and comparing the mean value and the root-mean-square difference of the resistivity of the visual formation water of the reservoir section to be identified with the established judgment standard of the fluid property of the research area, so as to judge the fluid property of the reservoir. The invention takes valueThe method avoids the influence of hole diameter expansion on logging data, and achieves the purpose of identifying the fluid properties of the fracture-cave carbonate reservoir.

Description

A kind of method of discerning seam hole type carbonate reservoir fluid properties

Technical field

The present invention relates to the logging technology of oil, gas prospecting, be specifically related to a kind of method of discerning seam hole type carbonate reservoir fluid properties.

Background technology

In oil, gas prospecting process, utilize well-log information to judge that fluid properties is the main task that well-log information is estimated in the reservoir.The method that is used for the properties of fluid in bearing stratum differentiation at present is the experimental formula-Archie equation that obtains according to sandstone reservoir, introduces an index that is called saturation degree, is oil gas or local water through fluid properties in the size evaluation reservoir that calculates intensity value.The basic problem that this classic method exists is:

1), this method can not be eliminated the shale additional guide well electrically to the influence of saturation computation;

2), existing method is applicable to sandstone formation, and is not exclusively suitable for seam hole type carbonate formation;

3), when filling shale seam hole type carbonate reservoir well section hole diameter condition is bad, well-log information has distortion, influences the well-log information evaluation.

Summary of the invention

The object of the present invention is to provide a kind of method of discerning seam hole type carbonate reservoir fluid properties, solve in the oil-gas exploration process, the identification problem of fluid properties in the type carbonate reservoir of seam hole.

In order to achieve the above object, the technical scheme of the present invention's employing is:

A kind of method of discerning seam hole type carbonate reservoir fluid properties comprises the steps:

(1) obtains conventional logging data, local water data, drilling fluid data;

(2) calculate the shale index V that contains mud seam hole well section_ShAnd net porosity Φ_e

(3) according to the said shale index V that contains mud seam hole well section_ShAnd net porosity Φ_e, calculate the resistivity of full well section deduction shale influence

And full well section apparant formation water resistivity R_Wai^*

(4) the apparant formation water resistivity average and the root-mean-square deviation of statistics one reservoir section to be identified;

(5) formation testing has been confirmed that a plurality of reservoir section apparant formation water resistivity averages and the root-mean-square deviation of fluid properties are plotted on the log-log coordinate, and set up the fluid properties criterion of survey region;

(6) the said survey region fluid properties criterion that reservoir section apparant formation water resistivity average said to be identified that step (4) is obtained and root-mean-square deviation and step (5) are set up relatively can be differentiated said reservoir section fluid properties to be identified.

In the such scheme, said step (5) also comprises before, according to the whether expansion of hole diameter, chooses the average of the apparant formation water resistivity that corresponding well section calculates and the fluid properties that the root-mean-square deviation evaluation contains mud seam hole section;

If hole diameter is not expanded, directly choose the average of the apparant formation water resistivity that stitches the hole section and the fluid properties that root-mean-square deviation is estimated this section;

If hole diameter expansion, then choose average and the fluid properties that root-mean-square deviation goes to assess this seam hole that seam section top, hole or bottom have been proofreaied and correct the apparant formation water resistivity of shale conduction influence.

In the such scheme, calculating contains mud seam hole well section V in the said step (2)_ShAnd net porosity Φ_e, be to come out through the density response Equation for Calculating of many mineral group model, the density response equation of said many mineral group model is:

${\mathrm{\ρ}}_b=\underset{i}{\mathrm{\Σ}}{v}_i{\mathrm{\ρ}}_{\mathrm{mai}}+v_{\mathrm{sh}}{\mathrm{\ρ}}_{\mathrm{sh}}+\underset{j}{\mathrm{\Σ}}{v}_j{\mathrm{\ρ}}_{\mathrm{fj}}$

ρ in the formula_bIt is the density value of measuring; v_iBe the percentage composition of i kind skeleton, ρ_MaiIt is i kind skeletal density; v_jBe the percentage composition of j kind fluid, ρ_FjBe the density of j kind fluid; v_ShBe wet shale index, ρ_ShBe the density of wet shale; Find the solution each mineral constituent, total porosity by multimineral model

Calculate net porosity φ_eFormula is:

φ_e＝φ-φ_bw

φ is a total porosity in the formula; φ_BwThe factor of porosity of shale irreducible water.

In the such scheme, the resistivity

of the full well section deduction of said calculating shale influence specifically comprises the steps:

A. with the shale index V that contains mud seam hole well section of linear conductance Model Calculation_ShDeduction shale additional guide is electrical;

B. said linear conductance model formation does

$\sqrt{C_t}=\sqrt{C_t^{*}}+\sqrt{C_{\mathrm{bw}}}\×V_{\mathrm{sh}}\×\mathrm{WCLP}$

C in the formula_tBe the measurement conductivity of original well logging,

Be the conductivity of deduction shale electric conductivity, C_BwBe irreducible water conductivity value in the shale, WCLP is the porosity value of shale;

Can deduct the resistivity value of shale additional conductive by following formula

$R_t^{*}=1/{(\sqrt{1/R_t}-\sqrt{C_{\mathrm{bw}}}*V_{\mathrm{sh}}*\mathrm{WCLP})}^2.$

In the such scheme, said full well section apparant formation water resistivity R_Wai^*Calculate through following formula,

$R_{\mathrm{wa}}={\mathrm{\Φ}}_e\·R_t^{*}={\mathrm{\Φ}}_e/C_t^{*}$

Φ in the formula_eBe the net porosity on stratum,

Be the resistivity of having eliminated shale additional conductive influence in the stratum,It is the corresponding conductivity of eliminating shale additional conductive influence in the stratum.

In the such scheme, said step (4) is the average and the root-mean-square deviation of adding up apparant formation water resistivity in the said reservoir section to be identified through following computing formula,

$\stackrel{\‾}{{R_{\mathrm{wa}}}^{*}}=\frac{\underset{i=1}{\overset{N}{\mathrm{\Σ}}}{R_{\mathrm{wai}}}^{*}}{N},$${\mathrm{\σ}}_{{R_{\mathrm{wa}}}^{*}}=\sqrt{\frac{\underset{i=1}{\overset{N}{\mathrm{\Σ}}}{({R_{\mathrm{wai}}}^{*}-\stackrel{\‾}{{R_{\mathrm{wa}}}^{*}})}^2}{N}},$

and

is respectively the average and the root-mean-square deviation of the apparant formation water resistivity of said reservoir section to be identified in the formula, and N is a hits in the said reservoir section to be identified.

In the such scheme; The fluid properties criterion is in the said step (5); When the apparant formation water resistivity average of reservoir section to be identified and root-mean-square deviation respectively greater than apparant formation water resistivity average boundary value and root-mean-square deviation boundary value, this well section properties of fluid in bearing stratum is a hydrocarbon zone so; When the apparant formation water resistivity average of reservoir section to be identified and root-mean-square deviation respectively less than apparant formation water resistivity average boundary value and root-mean-square deviation boundary value, this well section properties of fluid in bearing stratum is a water layer so.

In the such scheme, said apparant formation water resistivity average boundary value and root-mean-square deviation boundary value are to calculate out according to the apparant formation water resistivity average and the root-mean-square deviation of the reservoir section of the definite fluid properties of the some formation testings of survey region.

Compare with the prior art scheme, the beneficial effect that the technical scheme that the present invention adopts produces is following:

The present invention avoids the influence of hole diameter hole enlargement to well-log information on obtaining value method; Calculate the average and the root-mean-square deviation of apparant formation water resistivity parameter; Reach the purpose of identification seam hole type carbonate reservoir fluid properties; Solve in the oil-gas exploration process, the identification problem of fluid properties is remarkable to the effect of individual well in the type carbonate reservoir of seam hole.

Description of drawings

The process flow diagram of the method that Fig. 1 provides for the embodiment of the invention;

Fig. 2 contains mud seam hole many wells of type reservoir apparant formation water resistivity average and root-mean-square deviation X plot (log-log coordinate) for northern somewhere, embodiment of the invention Tarim Basin;

Fig. 3 does not contain many wells of mud reservoir apparant formation water resistivity average and root-mean-square deviation X plot (log-log coordinate) for northern somewhere, Tarim Basin;

Embodiment

Below in conjunction with accompanying drawing and embodiment technical scheme of the present invention is described in detail.

As shown in Figure 1, the embodiment of the invention provides a kind of method of discerning seam hole type carbonate reservoir fluid properties, comprises the steps:

(1) obtains conventional logging data, local water data, drilling fluid data;

(2) calculate the shale index V that contains mud seam hole well section_ShAnd net porosity Φ_e

The shale index V that contains mud seam hole well section_ShAnd net porosity Φ_eBe to come out through the density response Equation for Calculating of many mineral group model, the density response equation of said many mineral group model is:

${\mathrm{\ρ}}_b=\underset{i}{\mathrm{\Σ}}{v}_i{\mathrm{\ρ}}_{\mathrm{mai}}+v_{\mathrm{sh}}{\mathrm{\ρ}}_{\mathrm{sh}}+\underset{j}{\mathrm{\Σ}}{v}_j{\mathrm{\ρ}}_{\mathrm{fj}}$

ρ in the formula_bIt is the density value of measuring; v_iBe the percentage composition of i kind skeleton, ρ_MaiIt is i kind skeletal density; v_jBe the percentage composition of j kind fluid, ρ_FjBe the density of j kind fluid; v_ShBe wet shale index, ρ_ShBe the density of wet shale; Find the solution each mineral constituent, total porosity by multimineral modelCalculate net porosity φ_eFormula is:

φ_e＝φ-φ_bw

φ is a total porosity in the formula; φ_BwThe factor of porosity of shale irreducible water.

(3) according to the shale index V that contains mud seam hole well section_ShAnd net porosity Φ_e, calculate the resistivity of full well section deduction shale influence

And full well section apparant formation water resistivity R_Wai^*

A. with the shale index V that contains mud seam hole well section of linear conductance Model Calculation_ShDeduction shale additional guide is electrical;

B. said linear conductance model formation does

$\sqrt{C_t}=\sqrt{C_t^{*}}+\sqrt{C_{\mathrm{bw}}}\×V_{\mathrm{sh}}\×\mathrm{WCLP}$

C in the formula_tBe the measurement conductivity of original well logging,Be the conductivity of deduction shale electric conductivity, C_BwBe irreducible water conductivity value in the shale, WCLP is the porosity value of shale;

Can deduct the resistivity value of shale additional conductive by following formula

$R_t^{*}=1/{(\sqrt{1/R_t}-\sqrt{C_{\mathrm{bw}}}*V_{\mathrm{sh}}*\mathrm{WCLP})}^2$

Full well section apparant formation water resistivity R_Wai^*Calculate through following formula,

$R_{\mathrm{wa}}={\mathrm{\Φ}}_e\·R_t^{*}={\mathrm{\Φ}}_e/C_t^{*}$

Φ in the formula_eBe the net porosity on stratum,

Be the resistivity of having eliminated shale additional conductive influence in the stratum,

It is the corresponding conductivity of eliminating shale additional conductive influence in the stratum.

(4) the apparant formation water resistivity average and the root-mean-square deviation of a reservoir section to be identified of statistics;

Through the average and the root-mean-square deviation of apparant formation water resistivity in following this reservoir section to be identified of computing formula statistics,

$\stackrel{\‾}{{R_{\mathrm{wa}}}^{*}}=\frac{\underset{i=1}{\overset{N}{\mathrm{\Σ}}}{R_{\mathrm{wai}}}^{*}}{N},$${\mathrm{\σ}}_{{R_{\mathrm{wa}}}^{*}}=\sqrt{\frac{\underset{i=1}{\overset{N}{\mathrm{\Σ}}}{({R_{\mathrm{wai}}}^{*}-\stackrel{\‾}{{R_{\mathrm{wa}}}^{*}})}^2}{N}},$

and is respectively the average and the root-mean-square deviation of the apparant formation water resistivity of reservoir section to be identified in the formula, and N is a hits in the reservoir section to be identified;

(5) consider the obtaining value method of hole diameter to the well-log information influence:

According to the whether expansion of hole diameter, choose the average of the apparant formation water resistivity that corresponding well section calculates and the fluid properties that the root-mean-square deviation evaluation contains mud seam hole section;

If hole diameter is not expanded, directly choose the average of the apparant formation water resistivity that stitches the hole section and the fluid properties that root-mean-square deviation is estimated this section;

If hole diameter expansion, then choose average and the fluid properties that root-mean-square deviation goes to assess this seam hole that seam section top, hole or bottom have been proofreaied and correct the apparant formation water resistivity of shale conduction influence.

(6) formation testing has been confirmed that the apparant formation water resistivity average and the root-mean-square deviation of a plurality of reservoir sections of fluid properties are plotted on the log-log coordinate; As shown in Figures 2 and 3; Set up the fluid properties criterion of survey region; When to be identified section apparant formation water resistivity average and root-mean-square deviation respectively greater than apparant formation water resistivity average boundary value and root-mean-square deviation boundary value, this well section properties of fluid in bearing stratum is a hydrocarbon zone so; When apparant formation water resistivity average to be identified and root-mean-square deviation respectively less than apparant formation water resistivity average boundary value and root-mean-square deviation boundary value, this well section properties of fluid in bearing stratum is a water layer so.Apparant formation water resistivity average boundary value and root-mean-square deviation boundary value are to calculate out according to the apparant formation water resistivity average and the root-mean-square deviation of the reservoir section of the definite fluid properties of the some formation testings of survey region, and boundary value can be different according to the actual conditions of survey region.

The present invention is as shown in Figure 2 to the fluid properties recognition effect of the northern 32 mouthfuls of wells in somewhere, 38 the acid fracturing formation testings section in Tarim Basin (explain 53 and contain mud reservoir section); The hole diameter condition contains the conventional apparant formation water resistivity average of mud seam hole type hydrocarbon zone preferably generally greater than 0.9 Ω M, and root-mean-square deviation is greater than 0.7 Ω M; The conventional apparant formation water resistivity average of water layer is generally less than 0.9 Ω M, and root-mean-square deviation is less than 0.7 Ω M.The hole diameter condition is relatively poor contains mud seam hole type hydrocarbon zone, and the conventional apparant formation water resistivity average of reservoir bottom is generally greater than 0.9 Ω M, and root-mean-square deviation is greater than 0.7 Ω M; The conventional apparant formation water resistivity average at water layer reservoir top is generally less than 0.9 Ω M, and root-mean-square deviation is less than 0.7 Ω M.Above-mentioned boundary is actual to can be used as the fluid evaluation criterion that this area contains mud seam hole type reservoir.

Simultaneously, the present invention also is applicable to the situation of Vsh=0, does not promptly contain the reservoir of mud.As shown in Figure 3 to Tarim Basin 226 recognition effects that do not contain mud reservoir section fluid properties of northern 88 mouthfuls of wells in somewhere.Visible by figure, the average that does not contain mud reservoir hydrocarbons layer apparant formation water resistivity is generally greater than 4 Ω M, and root-mean-square deviation is generally greater than 3 Ω M; The apparant formation water resistivity average of water layer is generally less than 4 Ω M, and root-mean-square deviation is less than 3 Ω M.

The above is merely the preferred embodiments of the present invention, is not limited to the present invention, and for a person skilled in the art, the present invention can have various changes and variation.All within spirit of the present invention and principle, any modification of being done, be equal to replacement, improvement etc., all should be included within protection scope of the present invention.

Claims (8)

1. a method of discerning seam hole type carbonate reservoir fluid properties is characterized in that, comprises the steps:

(1) obtains conventional logging data, local water data, drilling fluid data;

(2) calculate the shale index V that contains mud seam hole well section_ShAnd net porosity Φ_e

(3) according to the said shale index V that contains mud seam hole well section_ShAnd net porosity Φ_e, calculate the resistivity of full well section deduction shale influence

And full well section apparant formation water resistivity R_Wai^*

(4) the apparant formation water resistivity average and the root-mean-square deviation of statistics one reservoir section to be identified;

(5) formation testing has been confirmed that a plurality of reservoir section apparant formation water resistivity averages and the root-mean-square deviation of fluid properties are plotted on the log-log coordinate, and set up the fluid properties criterion of survey region;

(6) the said survey region fluid properties criterion that reservoir section apparant formation water resistivity average said to be identified that step (4) is obtained and root-mean-square deviation and step (5) are set up relatively can be differentiated said reservoir section fluid properties to be identified.

2. the method for identification seam as claimed in claim 1 hole type carbonate reservoir fluid properties; It is characterized in that; Said step (5) also comprises before; According to the whether expansion of hole diameter, choose the average of the apparant formation water resistivity that corresponding well section calculates and the fluid properties that the root-mean-square deviation evaluation contains mud seam hole section;

If hole diameter is not expanded, directly choose the average of the apparant formation water resistivity that stitches the hole section and the fluid properties that root-mean-square deviation is estimated this section;

If hole diameter expansion, then choose average and the fluid properties that root-mean-square deviation goes to assess this seam hole that seam section top, hole or bottom have been proofreaied and correct the apparant formation water resistivity of shale conduction influence.

3. the method for identification seam as claimed in claim 1 hole type carbonate reservoir fluid properties is characterized in that, calculates in the said step (2) to contain mud seam hole well section V_ShAnd net porosity Φ_e, be to come out through the density response Equation for Calculating of many mineral group model, the density response equation of said many mineral group model is:

${\mathrm{\ρ}}_b=\underset{i}{\mathrm{\Σ}}{v}_i{\mathrm{\ρ}}_{\mathrm{mai}}+v_{\mathrm{sh}}{\mathrm{\ρ}}_{\mathrm{sh}}+\underset{j}{\mathrm{\Σ}}{v}_j{\mathrm{\ρ}}_{\mathrm{fj}}$

ρ in the formula_bIt is the density value of measuring; v_iBe the percentage composition of i kind skeleton, ρ_MaiIt is i kind skeletal density; v_jBe the percentage composition of j kind fluid, ρ_FjBe the density of j kind fluid; v_ShBe wet shale index, ρ_ShBe the density of wet shale; Find the solution each mineral constituent, total porosity by multimineral model

Calculate net porosity φ_eFormula is:

φ_e＝φ-φ_bw

φ is a total porosity in the formula; φ_BwThe factor of porosity of shale irreducible water.

4. the method for identification seam as claimed in claim 3 hole type carbonate reservoir fluid properties; It is characterized in that the resistivity

of the full well section deduction of said calculating shale influence specifically comprises the steps:

A. with the shale index V that contains mud seam hole well section of linear conductance Model Calculation_ShDeduction shale additional guide is electrical;

B. said linear conductance model formation does

$\sqrt{C_t}=\sqrt{C_t^{*}}+\sqrt{C_{\mathrm{bw}}}\×V_{\mathrm{sh}}\×\mathrm{WCLP}$

C in the formula_tBe the measurement conductivity of original well logging,

Be the conductivity of deduction shale electric conductivity, C_BwBe irreducible water conductivity value in the shale, WCLP is the porosity value of shale;

Can deduct the resistivity value

of shale additional conductive by following formula

$R_t^{*}=1/{(\sqrt{1/R_t}-\sqrt{C_{\mathrm{bw}}}*V_{\mathrm{sh}}*\mathrm{WCLP})}^2.$

5. the method for identification seam as claimed in claim 4 hole type carbonate reservoir fluid properties is characterized in that said full well section apparant formation water resistivity R_Wai^*Calculate through following formula,

$R_{\mathrm{wa}}={\mathrm{\Φ}}_e\·R_t^{*}={\mathrm{\Φ}}_e/C_t^{*}$

Φ in the formula_eBe the net porosity on stratum,

Be the resistivity of having eliminated shale additional conductive influence in the stratum,

It is the corresponding conductivity of eliminating shale additional conductive influence in the stratum.

6. the method for identification seam as claimed in claim 1 hole type carbonate reservoir fluid properties is characterized in that said step (4) is the average and the root-mean-square deviation of adding up apparant formation water resistivity in the said reservoir section to be identified through following computing formula,

$\stackrel{\‾}{{R_{\mathrm{wa}}}^{*}}=\frac{\underset{i=1}{\overset{N}{\mathrm{\Σ}}}{R_{\mathrm{wai}}}^{*}}{N},$${\mathrm{\σ}}_{{R_{\mathrm{wa}}}^{*}}=\sqrt{\frac{\underset{i=1}{\overset{N}{\mathrm{\Σ}}}{({R_{\mathrm{wai}}}^{*}-\stackrel{\‾}{{R_{\mathrm{wa}}}^{*}})}^2}{N}},$

and is respectively the average and the root-mean-square deviation of the apparant formation water resistivity of said reservoir section to be identified in the formula, and N is a hits in the said reservoir section to be identified.

7. the method for identification seam as claimed in claim 1 hole type carbonate reservoir fluid properties; It is characterized in that; The fluid properties criterion is in the said step (5); When the apparant formation water resistivity average of reservoir section to be identified and root-mean-square deviation respectively greater than apparant formation water resistivity average boundary value and root-mean-square deviation boundary value, this well section properties of fluid in bearing stratum is a hydrocarbon zone so; When the apparant formation water resistivity average of reservoir section to be identified and root-mean-square deviation respectively less than apparant formation water resistivity average boundary value and root-mean-square deviation boundary value, this well section properties of fluid in bearing stratum is a water layer so.

8. the method for identification seam as claimed in claim 7 hole type carbonate reservoir fluid properties; It is characterized in that said apparant formation water resistivity average boundary value and root-mean-square deviation boundary value are to calculate out according to the apparant formation water resistivity average and the root-mean-square deviation of the reservoir section of the definite fluid properties of the some formation testings of survey region.

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