CN106154351A - A kind of evaluation method of low porosity permeability reservoir permeability - Google Patents

Abstract

The invention discloses the evaluation method of a kind of low porosity permeability reservoir permeability, belong to petroleum geology exploration field.Including: calculate according to sound wave, neutron and density log curve and regard limestone porosity；Calculate the first shale content instruction according to nutural potential logging curve；Calculate the second shale content instruction according to Natural Gamma-ray Logging Curves；Regard limestone porosity according to what sound wave, neutron and density log curve calculated, calculate the lithologic index of reservoir rock；Calculate the particle diameter of formation rock according to the first shale content instruction, the second shale content instruction and reservoir lithology index；Calculate cementation factor according to resistivity and porosity statistical fit relation.Particle diameter d according to formation rock, the cementation factor m estimation permeability of rock stratum.The present invention, by utilizing the computing permeability relation of well logs and the present invention, obtains the high precision computation result of low porosity permeability reservoir permeability, is low porosity permeability complex lithology and a kind of powerful of Complicated Pore Structures reservoir permeability evaluation offer.

Description

A kind of evaluation method of low porosity permeability reservoir permeability

Technical field

The invention belongs to petroleum geology exploration development field, relate to the method for low porosity permeability reservoir estimate, it is comprehensive Application litho-electric parameters, particle diameter and well-log information achieve the calculating of reservoir permeability, belong to having in petroleum exploration and development Not in the Slope map of pixels of the experiment measurement of traditional penetration rate or a kind of reservoir permeability of empirical relation prediction.

Background technology

Permeability is the crucial physical parameter in evaluating reservoir and capability forecasting, and it controls the oil-gas accumulation of reservoir, oil Gas generates and oil-gas mining efficiency.Up to the present, a kind of continuous in-situ method of testing directly obtaining permeability is also lacked, greatly Most permeability datas are the pressure being recorded by core experiment and flow speed data estimation obtains.In the case of Xu Duo, drilling well takes rock Core and to core experiment Analysis extremely difficult and cost intensive, in addition by coring processing and experiment measuring uncertainty Impact, the permeability of core analysis is generally only and is limited to a small amount of emphasis interval.But, comprehensive logging data connect in well depth Continue uniformly, and the multiclass physical property of reservoir rock can be reacted, study a kind of well logging can demarcated by a small amount of core-analysed data Data conversion predicts that the method for permeability has important theory and actual application and is worth.The conventional permeability of oil and gas industry circle Forecasting Methodology is the statistical relationship based on core laboratory analysis of data, is estimated permeability by log value, for example porosity-permeability Statistical relationship, the correctness of these methods changes with pore structure and the distribution of pores on stratum.Estimate permeability at present Conventional empirical relation, substantially by three class parameter combinations, i.e. utilizes the particle size of pore media, considers porosity size and combination Specific grain surface and porosity.

1) calculation model of permeability based on pore size

Utilizing porosity and NMR data to carry out the SDR model of Permeability Prediction, its predictive equation is:

$k_{SDR}=4\×{10}^{-11}{\mathrm{\φ}}^4{T}_{2lm}^2$

Wherein, k_SDRUnit is m², φ is the porosity derived by NMR, and unit is fraction, and T_2lmIt is NMRT₂Relaxation time Logarithmic mean value, unit is s.

2) calculation model of permeability based on specific surface area

Kozeny-Carmen model is to be derived in nineteen twenty-seven by Kozeny, is then utilized experimental analysis data by Carman Being modified perfect, current form is:

Wherein, K_KCUnit is m², S_grIt is the specific surface (i.e. the internal surface area of unit grain volume, unit 1/m) of rock, it Related to grain shape, particle diameter size d (m) and fraction porosity.To spheric granules S_gr=6/d.

3) calculation model of permeability based on granular size

Berg examines particle packing mode, granular size, grain sorting and porosity size, is used for deriving complicated hole The Permeability Prediction relation of medium, was reduced to later:

K_B=8.4 × 10^-2d²φ^5.1

Wherein, K_BUnit is m², d is granular size (m), and φ is fraction porosity.But, as other empirical models, Whether the quality predicting the outcome depends on applied rock similar to the rock characteristic of equation scale.

In sum, although above-mentioned several method can solve the forecasting problem of reservoir permeability to a certain extent, but It is that in these relations, particle diameter size and specific surface area are still difficult to be directly obtained by log data so far.Therefore, for low hole The complex lithology district oozed, the application of existing Permeability Prediction method is restricted.

For accurate evaluation reservoir permeability and production capacity, preferably evaluate oil-gas accumulation, generative capacity and the exploitation of reservoir Efficiency, arranges for optimizing well location in petroleum exploration and development, improves that the implementation decision of production yield rate development stimulation provides help.The present invention Consider the similitude that in rock, fluid neuron network performance and electric current in reservoir flow and both and reservoir rock particle diameter Relation, litho-electric parameters and rock particles diameter are introduced reservoir permeability projected relationship.The present invention responds base from rock electricity This relation is set out, the corresponding relation of current lead-through performance in Study In Reservoir fluid neuron network ability and rock, set up litho-electric parameters, Comprehensive response equation between grain diameter and permeability, the log data prediction permeability for lithologic analysis data scaling provides reason Opinion and technical support.

Content of the invention

Drawbacks described above present in solution prior art, it is an object of the invention to provide a kind of based on rock electricity sound Should be with the relationship analysis of pore structure, rock particles diameter, low porosity permeability reservoir estimate method.

The present invention is realized by following technical proposals.

The evaluation method of a kind of low porosity permeability reservoir permeability, comprises the following steps:

Step one, calculates according to sound wave compressional wave log, neutron well logging hydrogen index curve and density log curve and regards Limestone porosity parameter；

Step 2, according to nutural potential logging curve, calculates the first shale content instruction；

Step 3, according to Natural Gamma-ray Logging Curves, calculates the second shale content instruction；

Step 4, calculates according to sound wave compressional wave log, neutron well logging hydrogen index curve and density log curve Depending on limestone porosity parameter, calculate the lithologic index of reservoir rock；

Step 5, refers to according to described first shale content instruction, described second shale content instruction and described reservoir lithology Number, calculates the particle diameter d of formation rock；

Step 6, the resistivity obtaining according to described full water core experiment measurement and the statistical fit relation of porosity, meter Calculate the cementation factor m of rock stratum；

Step 7, the particle diameter d according to formation rock, the cementation factor m estimation permeability output permeameter of rock stratum Calculate result.

Further, in described step one, according to sound wave compressional wave log, neutron porosity log curve, density log Curve calculates and regards limestone Pore genesis, is calculated by following formula:

Wherein, φ_nFor the neutron porosity calculating；φ_cnlPorosity response for neutron well logging；φ_maRing for skeleton neutron Should；φ_cfNeutron response for fluid；φ_dThe porosity tried to achieve for density log；ρ_maFor matrix density value；ρ_bFor density Log reading；ρ_fFor pore-fluid density；φ_sThe porosity calculating for sound wave；Layer acoustic travel time logging value for the purpose of Δ t；Δ t_maFor rock matrix interval transit time；Δt_fFor formation fluid interval transit time；For the total porosity calculating.

Further, in described step 2, the first shale content is calculated according to nutural potential logging curve, by following formula Calculate:

$I_{sh1}=\frac{{\mathrm{SP}}_{log}-{\mathrm{SP}}_{sand}}{{\mathrm{SP}}_{sh}-{\mathrm{SP}}_{sand}}$

Wherein, I_sh1It is the first shale content index, SP_logFor the natural potential value recording on argillaceous sandstone stratum, SP_shFor The natural potential value recording on shale layer, SP_sandFor the natural potential value recording in sand layers.

Further, in described step 3, the second shale content instruction is calculated according to Natural Gamma-ray Logging Curves, by following Formula calculates:

$I_{sh2}=\frac{{\mathrm{GR}}_{log}-{\mathrm{GR}}_{sand}}{{\mathrm{GR}}_{sh}-{\mathrm{GR}}_{sand}}$

Wherein, I_sh2It is the second shale content index, GR_logFor the GR value recording on argillaceous sandstone stratum, GR_shFor The GR value recording on shale layer, GR_sandFor the GR value recording in sand layers.

Further, in described step 4, survey according to sound wave compressional wave log, neutron well logging hydrogen index curve and density Well curve calculates the lithologic index of reservoir rock, and the corresponding calculated relationship regarding limestone porosity parameter is as follows:

${\mathrm{\φ}}_n=\frac{{\mathrm{\φ}}_{cnl}-{\mathrm{\φ}}_{ma}}{{\mathrm{\φ}}_{cf}-{\mathrm{\φ}}_{ma}},{\mathrm{\φ}}_d=\frac{{\mathrm{\ρ}}_{ma}-{\mathrm{\ρ}}_b}{{\mathrm{\ρ}}_{ma}-{\mathrm{\ρ}}_f},{\mathrm{\φ}}_s=\frac{\mathrm{\Δ}t-{\mathrm{\Δt}}_{ma}}{{\mathrm{\Δt}}_f-{\mathrm{\Δt}}_{ma}},{\mathrm{\φ}}_t=\sqrt{\frac{{\mathrm{\φ}}_d^2+{\mathrm{\φ}}_n^2}{2}}$

Wherein, φ_nFor the neutron porosity calculating；φ_cnlPorosity response for neutron well logging；φ_maRing for skeleton neutron Should；φ_cfNeutron response for fluid；φ_dThe porosity tried to achieve for density log；ρ_maFor matrix density value；ρ_bFor density Log reading；ρ_fFor pore-fluid density；φ_sThe porosity calculating for sound wave；Layer acoustic travel time logging value for the purpose of Δ t；Δ t_maFor rock matrix interval transit time；Δt_fFor formation fluid interval transit time；φ_tFor Neutron-Density geometrical mean.

Further, in described step 5, by the second mud described in the first shale content instruction in step 2 and step 3 Reservoir lithology index described in the instruction of matter content and step 4, calculates the particle diameter of formation rock, obtains according to equation below:

D=Agexp (-DVsh)+BgI_AC+CgI_Rt

Wherein, A, B and C are three weight coefficients, and D is fitting coefficient, and Vsh is the shale percentage by volume on stratum, I_ACFor sound The porosity exponent that wave slowness calculates, I_RTIt is the aqueous void index that deep resistivity calculates.

Further, in described step 6, the resistivity obtaining according to described full water core experiment measurement and the system of porosity Meter fit correlation, by the cementation factor m of the described rock stratum of following relation calculating:

$m=\frac{\log R_w-\log R_o}{\log \mathrm{\φ}}$

In above formula, m is cementation factor；R_wFor stratum resistivity of water；R₀Resistivity for the core of saturation water；φ is rock The porosity of core.

Further, in described step 7, estimation permeability is obtained by following formula:

In formula, a is the constant related to interstitial space shape；D is the particle diameter size of Related Rocks；It is total pore space Degree；M is cementation factor.

The permeability relation of the present invention, not only allows for rock porosity and rock particles, considers also by parameter m and a The change of different lithology and rock pore structure, therefore, by adding the cementation factor of particle diameter and litho-electric parameters, is led The new penetration rate model going out can preferably be applicable to the fine and close class rock stratum of low porosity and low permeability and low hole height oozes the infiltration of fractured-vuggy reservoir Rate is predicted.

Compared with prior art, one or more embodiments of the invention can have the advantage that

The present invention is by the litho-electric parameters of introduction hole porosity/particle diameter and reflection pore structure geometric properties, it is proposed that A kind of method deriving Permeability Prediction formula based on the dynamic electricity relation between fluid flowing and electric current in pore media.Permeability During estimation equation is derived, it is contemplated that current lead-through performance, the impact of pore structure connectivity pair computing permeability in rock, Combine porosity/particle diameter and reflection pore structure geometric properties litho-electric parameters, better adapted to different lithology and The computing permeability of different pore structures reservoir.Additionally, the experimental data also delivered based on forefathers of the present invention and core chemical examination point Analysis data, give the infiltration that different lithology and different aperture degree reservoir are calculated by the calculation model of permeability of present invention proposition The precision evaluation criterion of rate, gives the error that variable grain diameter index calculates permeability result and actual core measurement result Scope, it is determined that optimize calculated relationship and the application conditions of particle size parameters.

Other features and advantages of the present invention will illustrate in the following description, and, Partial Feature and advantage are in reality Execute in example and specification and become apparent, or be understood by the enforcement of the present invention.Objectives and other advantages of the present invention Can be realized by structure specifically noted in specification, claims and accompanying drawing and obtain.

The beneficial effects of the present invention is:

The Permeability Estimation Model invented combines porosity/particle diameter and the rock of reflection pore structure geometric properties Electrical quantity, has better adapted to different lithology and the computing permeability of different pore structures reservoir, is surveyed by the experiment that forefathers deliver Amount data and cementing and non-cementing core-analysed data, demonstrate the validity of calculation model of permeability of the present invention, with existing its The result obtaining higher precision compared by its model.

The rock electroanalysis data on the middle low porosity permeability stratum in China North China, different oil district, northwest and log data is utilized to estimate Permeability contrasts with core analysis permeability, and the permeability relation of the present invention is micro-to low porosity permeability muddy ore and densification Fracture reservoir has more preferable adaptability, and it has a extensive future.

According to the experiment analysis results of different directions resistivity, the formation cementation index obtaining different directions can be added up, Penetration rate model so of the present invention goes for the particle size of different directions and the permeability of seam hole type anisotropic formation Estimation, and then calculate the permeability of different directions, it will develop into low porosity permeability complex lithology and Complicated Pore Structures reservoir oozes The powerful that saturating rate is evaluated.

Permeability Estimation Model owing to being invented is insensitive to lithology factor a, invented be applicable to large range of Formation lithology, improves the precision that complex lithology reservoir permeability is evaluated.

Brief description

Accompanying drawing is used for providing a further understanding of the present invention, and constitutes a part for specification, the reality with the present invention Execute example to be provided commonly for explaining the present invention, be not intended that limitation of the present invention.In the accompanying drawings:

Fig. 1 shows a kind of implementing procedure figure of the calculation of permeability that the present invention proposes；

Fig. 2 shows three mouthfuls, certain wellblock, 78 pieces of core analysis porositys of coring well and density relationship；

Fig. 3 shows the cementing finger that study area B well interval and C well interval formation factor calculate with porosity cross plot Number；

Fig. 4 shows that study area A well interval analyzes porosity/permeability and the porosity/permeability of well logging calculating Relativity；

Fig. 5 shows that study area B well interval analyzes porosity/permeability and the porosity/permeability of well logging calculating Relativity；

Fig. 6 shows that study area C well interval analyzes porosity/permeability and the porosity/permeability of well logging calculating Relativity；

Fig. 7 shows D well 3000.0-3010.0 rice nuclear-magnetism porosity and permeability and core analysis Comparative result.

Detailed description of the invention

The invention will be described in further detail with embodiment below in conjunction with the accompanying drawings, but is not intended as doing invention any limit The foundation of system.

As it is shown in figure 1, the evaluation method of low porosity permeability reservoir permeability of the present invention, comprising:

Step one, calculates according to sound wave compressional wave log, neutron well logging hydrogen index curve and density log curve and regards Limestone porosity parameter, is specifically calculated as follows:

Wherein, φ_nFor the neutron porosity calculating；φ_cnlPorosity response for neutron well logging；φ_maRing for skeleton neutron Should；φ_cfNeutron response for fluid；φ_dThe porosity tried to achieve for density log；ρ_maFor matrix density value；ρ_bFor density Log reading；ρ_fFor pore-fluid density；φ_sThe porosity calculating for sound wave；Layer acoustic travel time logging value for the purpose of Δ t；Δ t_maFor rock matrix interval transit time；Δt_fFor formation fluid interval transit time；For the total porosity calculating.

Step 2, according to nutural potential logging curve, calculates the first shale content instruction, and the first shale content specifically calculates As follows:

$I_{sh1}=\frac{{\mathrm{SP}}_{log}-{\mathrm{SP}}_{sand}}{{\mathrm{SP}}_{sh}-{\mathrm{SP}}_{sand}}$

Wherein, I_sh1It is the first shale content index, SP_logFor the natural potential value recording on argillaceous sandstone stratum, SP_shFor The natural potential value recording on shale layer, SP_sandFor the natural potential value recording in sand layers.

Step 3, according to Natural Gamma-ray Logging Curves, calculates the second shale content instruction, and the second shale content specifically calculates As follows:

$I_{sh2}=\frac{{\mathrm{GR}}_{log}-{\mathrm{GR}}_{sand}}{{\mathrm{GR}}_{sh}-{\mathrm{GR}}_{sand}}$

Wherein, I_sh2It is the second shale content index, GR_logFor the GR value recording on argillaceous sandstone stratum, GR_shFor The GR value recording on shale layer, GR_sandFor the GR value recording in sand layers.

Step 4, calculates storage according to sound wave compressional wave log, neutron well logging hydrogen index curve and density log curve The lithologic index of layer rock, the corresponding calculated relationship regarding limestone porosity parameter is as follows:

${\mathrm{\φ}}_n=\frac{{\mathrm{\φ}}_{cnl}-{\mathrm{\φ}}_{ma}}{{\mathrm{\φ}}_{cf}-{\mathrm{\φ}}_{ma}},{\mathrm{\φ}}_d=\frac{{\mathrm{\ρ}}_{ma}-{\mathrm{\ρ}}_b}{{\mathrm{\ρ}}_{ma}-{\mathrm{\ρ}}_f},{\mathrm{\φ}}_s=\frac{\mathrm{\Δ}t-{\mathrm{\Δt}}_{ma}}{{\mathrm{\Δt}}_f-{\mathrm{\Δt}}_{ma}},{\mathrm{\φ}}_t=\sqrt{\frac{{\mathrm{\φ}}_d^2+{\mathrm{\φ}}_n^2}{2}}$

Wherein, φ_nFor the neutron porosity calculating；φ_cnlPorosity response for neutron well logging；φ_maRing for skeleton neutron Should；φ_cfNeutron response for fluid；φ_dThe porosity tried to achieve for density log；ρ_maFor matrix density value；ρ_bFor density Log reading；ρ_fFor pore-fluid density；φ_sThe porosity calculating for sound wave；Layer acoustic travel time logging value for the purpose of Δ t；Δ t_maFor rock matrix interval transit time；Δt_fFor formation fluid interval transit time；φ_tFor Neutron-Density geometrical mean.

Step 5, according to the first shale content instruction, the second shale content instruction and reservoir lithology index, calculates rock stratum rock The particle diameter of stone, obtains according to equation below:

D=Agexp (-DVsh)+BgI_AC+CgI_Rt

Wherein, Vsh=min{I_sh1,I_sh2, A, B and C are three weight coefficients, and D is fitting coefficient, and Vsh is the shale on stratum Percentage by volume,The porosity exponent calculating for acoustic slowness, C_pFor formation compaction coefficient, I_RtIt is deep resistivity The water-filled porosity index calculating.

Step 6, the resistivity obtaining according to described full water core experiment measurement and the statistical fit relation of porosity, meter Calculate the cementation factor m of described rock stratum:

$m=\frac{\log R_w-\log R_o}{\log \mathrm{\φ}}$

In above formula, m is cementation factor；R_wFor stratum resistivity of water；R₀Resistivity for the core of saturation water；φ is rock The porosity of core.

Step 7, the particle diameter d according to formation rock, the cementation factor m estimation permeability output permeameter of rock stratum Calculate result.

Estimation permeability is obtained by following formula:

In formula, a is the constant related to interstitial space shape, and span is 2-12, k unit 10-3 μm 2；D is related The particle diameter size of rock；It is total porosity, decimal；M is cementation factor.Ball particle a=8/3 to three-D volumes arrangement, M=3/2；Then computing permeability relation deteriorates to:

High and the well-graded clean sandstone particle to psephicity, takes a=8/3, m=1.8, and the calculated relationship of permeability is degenerated For:

It should be noted that the permeability relation invented here, not only allow for rock porosity and rock particles, also logical Cross parameter m and a considers the change of different lithology and rock pore structure, therefore, by adding particle diameter and litho-electric parameters Cementation factor, the new penetration rate model derived can preferably be applicable to the fine and close class rock stratum of low porosity and low permeability and low hole height oozes seam The Permeability Prediction of hole type reservoir.

Below by specific embodiment, low porosity permeability reservoir estimate method of the present invention is elaborated.

Embodiment 1: application in the evaluation of western part of China low porosity permeability muddy ore for the Permeability Estimation Model of the present invention

In western part of China exploratory area given here, hypotonic and ultra-permeable reservior real logging data applies this The permeability result that bright penetration rate model calculates.The low porosity permeability reservoir lithology of study area is complex, quartz, feldspar, landwaste and The content of cement is relatively big on the impact of sound wave, neutron and density porosity log response, especially the white clouds matter in reservoir and ash Matrix parameter in how many pairs of porosity calculations of matter cement content selects to have a strong impact on, for eliminating the uncertainty of porosity On the impact evaluating Permeability Estimation Model performance of the present invention, in the examples below, lithology and cement characteristic phase are all selected The well-log information of similar well is analyzed and contrasts.

Fig. 2 gives 78 pieces of rock samples of three mouthfuls, certain wellblock coring well and analyzes porosity and density relationship, sees, owing to grinding in figure Studying carefully district's scope less, well spacing is little, and variation of lithological is little with the relationship affect of porosity to density, utilizes density log to pass through The porosity obtaining after wellbore effect correction is more reliable.Calculating in permeability below, all using density log by following Fit correlation carrys out Estimation of porosity.

DEN=-0.0279 φ+2.6765, R²=0.9778

Fig. 3 gives the storage that the rock electroanalysis data least square fitting of study area two mouthfuls of coring wells of existing B and C obtains Layer porosimeter index, fit correlation is shown below.Therefore, in computing permeability below, all use this fixing cementing Index.

F=1.5733 φ^-1.6073, R²=0.9229

In Permeability Estimation Model of the present invention, the calculating of another important parameter particle size diameter d is also the one of logging evaluation An individual difficult problem.The present embodiment uses shale content Vsh, interval transit time AC and tri-log responses of deep resistivity Rt of natural gamma Calculate relative parameter,WithAgain with assay The fit correlation of particle diameter is predicted:

D=A exp (-DVsh)+B I_AC+C·I_Rt

Wherein, A, B and C are three weight coefficients, and D is fitting coefficient, and Vsh is the shale percentage by volume on stratum, I_ACFor sound The porosity exponent that wave slowness calculates, I_RTIt is the aqueous void index that deep resistivity calculates.

Fig. 4 gives study area A well interval and analyzes porosity/permeability and the porosity/permeability of well logging calculating Relativity, sees in figure, and generally, porosity coincide preferably with core-analysed data with computing permeability, but containing shale Heavier interval, owing to there is error in normalization in shale, causes calculating porosity higher, the particle correspondingly calculating Diameter is less than normal, ultimately results in dirty formation, k_NEWThe permeability calculating is higher, and other intervals calculate permeability and core Analyze permeability to coincide preferably.

Fig. 5 gives study area B well interval and analyzes porosity/permeability and the porosity/permeability of well logging calculating Relativity, sees in figure, and this wellhole porosity is coincide more than the A well of top with core-analysed data with computing permeability result Good, but at the interval heavier containing shale, there is also and calculate the higher phenomenon of porosity.

Embodiment 2: application in western part of China low porosity permeability Assessment of Fractured Reservoirs for the Permeability Estimation Model of the present invention

Fig. 6 gives study area C well interval and analyzes porosity/permeability and the porosity/permeability of well logging calculating Relativity, sees in figure, compared with the B well of top, and the porosity substantially ratio core analysis porosity of C well interval calculating Height, in fact, this interval generally grows microcrack, and coring results interval and core analysis porosity are insensitive to microcrack, And in the rock electroanalysis data of top, the core data accounting of microcrack interval is less, the glue being obtained by core-analysed data Knot index does not reflect the impact of microcrack substantially, and therefore, on this interval, the permeability with penetration rate model calculating of the present invention is general All over less than core analysis permeability.

Embodiment 3: Permeability Estimation Model of the present invention application in the evaluation of high porosity permeability reservoir in the microcrack of North China

Fig. 7 is shown that D well 3000.0-3010.0 rice nuclear-magnetism porosity and permeability and core analysis Comparative result, figure In have the core analysis result of 5 sampling points, result in figure is it will be seen that this interval core analysis permeability is in 10- Between 120mD, porosity is substantially between 15%-22%, belongs to middle high hole and oozes stratum.Use estimate side of the present invention The permeability (blue thick line) that method calculates is carried out with nuclear-magnetism permeability (blue dotted line), core analysis permeability (green round dot) Contrast, in figure, result sees that three coincide preferably, and the penetration rate model of the present invention is demonstrated by more preferable estimated performance.Especially It is that 3006.3～3007.17 meters of core pores degree are 15%～21%, average out to 18%, CMR-PLUS porosity is 15%～ 18%, average out to 17%, it is contemplated that core is surface condition measurement, microcrack Stress Release posttension is enlightened aobvious, causes core hole Porosity 1～2 porosity higher than the nuclear-magnetism porosity of underground survey, accordingly, it is considered to arrive the error of porosity, nuclear-magnetism permeability, Model prediction permeability of the present invention and lithologic analysis permeability three coincide very well；Drill core permeability rate is 8～122 millidarcies, CMR-PLUS permeability is 10～90 millidarcies, and the particularly change shape of the two permeability is consistent, it is shown that CMR-PLUS is high Precision and high-resolution feature.CMR-PLUS and core analysis result have indivedual point to there are differences the non-homogeneous of mainly reservoir Property causes, and well-log information can more completely reflect reservoir properties.

In embodiments of the present invention, porosity parameter is calculated according to sound wave, neutron and density log curve；According to natural electricity Position log, calculates the first shale content instruction, according to Natural Gamma-ray Logging Curves, calculates the second shale content instruction, root Regard limestone porosity difference according to neutron well logging curve, density log curve and interval transit time log, calculate the rock of reservoir Sex index.Then, according to first shale content instruction, second shale content instruction and lithologic index, calculate reservoir lithology Grain diameter parameters；The resistivity obtaining according to described full water core experiment measurement and the statistical fit relation of porosity, calculate institute State the litho-electric parameters m of rock stratum.Finally, low porosity permeability storage is calculated by porosity, particle diameter and litho-electric parameters three class comprehensive parameters The permeability of layer.It is characteristic of the invention that by a plurality of log, utilize current lead-through and the similitude of fluid diafiltration, it is considered to The impact on fluid filtration properties for the pore structure, has expanded the range of application of penetration rate model of the present invention.Due in the present invention Embodiment is not only indicate that log carries out the calculating of permeability according to porosity logging curve and shale, also includes rock Property parameter related with litho-electric parameters other well logging integrated informations, not only increase single reservoir permeability evaluation precision, for oil Gas exploration exploitation in exact evaluation permeability spatial variations and predict favourable oil-gas exploration and development prospective area provide support.

The invention described above embodiment sequence number, just to describing, does not represent the quality of embodiment.

The foregoing is only presently preferred embodiments of the present invention, not in order to limit the present invention, all spirit in the present invention and Within principle, any modification, equivalent substitution and improvement etc. made, should be included within the scope of the present invention.

Claims (8)

1. the evaluation method of a low porosity permeability reservoir permeability, it is characterised in that comprise the following steps:

Step one, calculates according to sound wave compressional wave log, neutron well logging hydrogen index curve and density log curve and regards limestone Porosity parameter；

Step 2, according to nutural potential logging curve, calculates the first shale content instruction；

Step 3, according to Natural Gamma-ray Logging Curves, calculates the second shale content instruction；

Step 4, regards ash according to what sound wave compressional wave log, neutron well logging hydrogen index curve and density log curve calculated Petrosal foramen porosity parameter, calculates the lithologic index of reservoir rock；

Step 5, according to described first shale content instruction, described second shale content instruction and described reservoir lithology index, meter Calculate the particle diameter d of formation rock；

Step 6, the resistivity obtaining according to described full water core experiment measurement and the statistical fit relation of porosity, calculate rock The cementation factor m of layer；

Step 7, the particle diameter d according to formation rock, the cementation factor m estimation permeability output computing permeability knot of rock stratum Really.

2. the evaluation method of low porosity permeability reservoir permeability according to claim 1, it is characterised in that in described step one, Calculate regard limestone porosity parameter according to sound wave compressional wave log, neutron porosity log curve, density log curve, pass through Following formula calculates:

Wherein, φ_nFor the neutron porosity calculating；φ_cnlPorosity response for neutron well logging；φ_maFor skeleton neutron response； φ_cfNeutron response for fluid；φ_dThe porosity tried to achieve for density log；ρ_maFor matrix density value；ρ_bFor density log Reading；ρ_fFor pore-fluid density；φ_sThe porosity calculating for sound wave；Layer acoustic travel time logging value for the purpose of Δ t；Δt_maFor Rock matrix interval transit time；Δt_fFor formation fluid interval transit time；For the total porosity calculating.

3. the evaluation method of low porosity permeability reservoir permeability according to claim 1, it is characterised in that in described step 2, Calculate the first shale content according to nutural potential logging curve, calculated by following formula:

$I_{sh1}=\frac{{\mathrm{SP}}_{log}-{\mathrm{SP}}_{sand}}{{\mathrm{SP}}_{sh}-{\mathrm{SP}}_{sand}}$

Wherein, I_sh1It is the first shale content index, SP_logFor the natural potential value recording on argillaceous sandstone stratum, SP_shFor mud stone The natural potential value recording on layer, SP_sandFor the natural potential value recording in sand layers.

4. the evaluation method of low porosity permeability reservoir permeability according to claim 1, it is characterised in that in described step 3, Calculate the second shale content instruction according to Natural Gamma-ray Logging Curves, calculated by following formula:

$I_{sh2}=\frac{{\mathrm{GR}}_{log}-{\mathrm{GR}}_{sand}}{{\mathrm{GR}}_{sh}-{\mathrm{GR}}_{sand}}$

Wherein, I_sh2It is the second shale content index, GR_logFor the GR value recording on argillaceous sandstone stratum, GR_shFor mud stone The GR value recording on layer, GR_sandFor the GR value recording in sand layers.

5. the evaluation method of low porosity permeability reservoir permeability according to claim 1, it is characterised in that in described step 4, The lithology calculating reservoir rock according to sound wave compressional wave log, neutron well logging hydrogen index curve and density log curve refers to Number, the corresponding calculated relationship regarding limestone porosity parameter is as follows:

${\mathrm{\φ}}_n=\frac{{\mathrm{\φ}}_{cnl}-{\mathrm{\φ}}_{ma}}{{\mathrm{\φ}}_{cf}-{\mathrm{\φ}}_{ma}},{\mathrm{\φ}}_d=\frac{{\mathrm{\ρ}}_{ma}-{\mathrm{\ρ}}_b}{{\mathrm{\ρ}}_{ma}-{\mathrm{\ρ}}_f},{\mathrm{\φ}}_s=\frac{\mathrm{\Δ}t-{\mathrm{\Δt}}_{ma}}{{\mathrm{\Δt}}_f-{\mathrm{\Δt}}_{ma}},{\mathrm{\φ}}_t=\sqrt{\frac{{\mathrm{\φ}}_d^2+{\mathrm{\φ}}_n^2}{2}}$

Wherein, φ_nFor the neutron porosity calculating；φ_cnlPorosity response for neutron well logging；φ_maFor skeleton neutron response； φ_cfNeutron response for fluid；φ_dThe porosity tried to achieve for density log；ρ_maFor matrix density value；ρ_bFor density log Reading；ρ_fFor pore-fluid density；φ_sThe porosity calculating for sound wave；Layer acoustic travel time logging value for the purpose of Δ t；Δt_maFor Rock matrix interval transit time；Δt_fFor formation fluid interval transit time；φ_tFor Neutron-Density geometrical mean.

6. the evaluation method of low porosity permeability reservoir permeability according to claim 1, it is characterised in that in described step 5, By reservoir described in the second shale content instruction described in the first shale content instruction in step 2 and step 3 and step 4 Lithologic index, calculates the particle diameter of formation rock, obtains according to equation below:

D=Agexp (-DVsh)+BgI_AC+CgI_Rt

Wherein, A, B and C are three weight coefficients, and D is fitting coefficient, and Vsh is the shale percentage by volume on stratum, I_ACSlow for sound wave The porosity exponent that degree calculates, I_RTIt is the aqueous void index that deep resistivity calculates.

7. the evaluation method of low porosity permeability reservoir permeability according to claim 1, it is characterised in that in described step 6, The resistivity obtaining according to described full water core experiment measurement and the statistical fit relation of porosity, calculated described by following relation The cementation factor m of rock stratum:

$m=\frac{\log R_w-\log R_o}{\log \mathrm{\φ}}$

In above formula, m is cementation factor；R_wFor stratum resistivity of water；R₀Resistivity for the core of saturation water；φ is core Porosity.

8. the evaluation method of low porosity permeability reservoir permeability according to claim 1, it is characterised in that in described step 7, Estimation permeability is obtained by following formula:

In formula, a is the constant related to interstitial space shape；D is the particle diameter size of Related Rocks；It is total porosity；m It is cementation factor.