CN106324688A - Reservoir irreducible water saturation determining method and device - Google Patents

Abstract

The present invention provides a reservoir irreducible water saturation determining method and device. The method includes the following steps that: an exponential hyperbolic sine function is constructed, and Laplace transformation is performed on the exponential hyperbolic sine function, so that a progressive step function can be obtained; an unknown parameter in the exponential hyperbolic sine function is solved according to a special value condition which the progressive step function satisfies, and the constructed exponential hyperbolic sine function is updated according to the solved unknown parameter; integral transformation is performed on acquired nuclear magnetic resonance echo data according to the updated exponential hyperbolic sine function, and reservoir irreducible water saturation can be determined. According to the method and device provided by the invention, inverse Laplace transformation for inversion is not required to be performed on the nuclear magnetic resonance echo data, uncertainties caused by the inversion can be avoided; and accurate irreducible water saturation can be obtained under a condition that the signal noise ratio of the nuclear magnetic resonance echo data is low.

Description

A kind of reservoir irreducible water saturation determines method and device

Technical field

The present invention relates to log data processing technical field in oil exploration, particularly relate to a kind of reservoir irreducible water saturation Determine method and device.

Background technology

Nuclear magnetic resonance log is the currently the only logging method that can distinguish movable fluid in stratum and constraint fluid, has it The unique advantage that its logging method does not possesses.The whether accurate of reservoir irreducible water saturation calculating directly affects reservoir hydrocarbons evaluation Accuracy, reserves calculate reasonability and the reliability of capability forecasting, simultaneously it also directly affect the later stage test completion program. Therefore, study reservoir irreducible water saturation accurately and determine that method is significant.

Nuclear magnetic resonance log at present determines that nuclear magnetic resonance, NMR echo data is mainly drawn by the method for irreducible water saturation Inverse Laplace transformation, inverting obtains T₂Spectrum, then utilizes T₂Cutoff obtains irreducible water saturation.But, nuclear magnetic resonance, NMR number of echoes Being a serious ill-conditioning problem according to inverting, inversion result all can be had a huge impact by the small sample perturbations in measurement data, Cause the T that inverting obtains₂Spectrum has the biggest uncertainty, thus according to T₂Compose calculated reservoir irreducible water saturation by mistake Difference increases.Therefore, in prior art, for the nuclear magnetic resonance, NMR echo data of low signal-to-noise ratio, reservoir irreducible water saturation calculates essence Degree can not meet the needs of Oil Field application.

Summary of the invention

The application provides a kind of reservoir irreducible water saturation to determine method and device, is used for solving in prior art by right Nuclear magnetic resonance, NMR echo data carries out inverse Laplace transformation inverting and obtains T₂Spectrum, utilizes T₂Cutoff obtains irreducible water saturation It is inaccurate to there is inversion result in method, the T that inverting obtains₂There is the biggest uncertainty in spectrum, thus causes calculated reservoir The problem that irreducible water saturation error is big.

In order to solve above-mentioned technical problem, a technical scheme of the present invention determines for providing a kind of reservoir irreducible water saturation Method, including:

Structural index hyperbolic sine function, does Laplace transform to described index hyperbolic sine function and obtains T₂Territory is gradually Enter jump function；

The particular value condition met according to described progressive jump function, asks for the unknown in described index hyperbolic sine function Parameter, according to the index hyperbolic sine function of the unknown parameter tried to achieve more neotectonics；

According to the index hyperbolic sine function updated, the nuclear magnetic resonance, NMR echo data gathered is integrated conversion, determines storage Layer irreducible water saturation.

Another technical scheme of the present invention determines device for a kind of reservoir irreducible water saturation of offer, including:

Data acquisition unit, is used for gathering nuclear magnetic resonance, NMR echo data；

Construction unit, for structural index hyperbolic sine function, is Laplce and becomes described index hyperbolic sine function Get T in return₂The progressive jump function in territory；

Unknown parameter asks for unit, for the particular value condition met according to described progressive jump function, asks for described finger Unknown parameter in number hyperbolic sine function, according to the index hyperbolic sine function of the unknown parameter tried to achieve more neotectonics；

Reservoir irreducible water saturation determines unit, returns, according to the index hyperbolic sine function updated, the nuclear magnetic resonance, NMR gathered Wave datum is integrated conversion, determines reservoir irreducible water saturation.

The reservoir irreducible water saturation that the present invention provides determines method and device, enters the index hyperbolic sine function of structure Row Laplace transform obtains progressive jump function, the particular value condition met according to progressive jump function, determines index hyperbolic Parent magnetic resonance echoes data are directly amassed by the unknown parameter of SIN function according to the index hyperbolic sine function determined Divide conversion, determine the irreducible water saturation of required reservoir, obtain T without first passing through inverse Laplace transformation inverting₂Spectrum, so Avoid the uncertainty that inverting is brought.Therefore, in the case of nuclear magnetic resonance, NMR echo data signal to noise ratio is the lowest, the method Still it is obtained in that reservoir irreducible water saturation accurately.

Accompanying drawing explanation

In order to be illustrated more clearly that the embodiment of the present invention or technical scheme of the prior art, below will be to embodiment or existing In having technology to describe, the required accompanying drawing used is briefly described, it should be apparent that, the accompanying drawing in describing below is only this Some embodiments of invention, for those of ordinary skill in the art, on the premise of not paying creative work, it is also possible to Other accompanying drawing is obtained according to these accompanying drawings.

Fig. 1 is the flow chart that the reservoir irreducible water saturation of the embodiment of the present invention determines method；

Fig. 2 is reservoir T₂Distributed model (solid line) and corresponding progressive jump function (dotted line)；

Fig. 3 A and the T2 T of two kinds of reservoirs of simulation that Fig. 3 B is the embodiment of the present invention₂Distributed model schematic diagram；

Fig. 4 A and Fig. 4 B is the nuclear magnetic resonance, NMR echo data of the not Noise of the embodiment of the present invention and with the addition of noise Nuclear magnetic resonance, NMR echo data schematic diagram；

Fig. 5 A and Fig. 5 B is the T of the embodiment of the present invention_CIndex hyperbolic sine function during=33ms and asymptotic jump function；

Fig. 6 is the structure chart that the reservoir irreducible water saturation of the embodiment of the present invention determines device.

Detailed description of the invention

Technical characterstic and effect in order to make the present invention become apparent from, and do technical scheme below in conjunction with the accompanying drawings Further illustrating, the present invention also can have other different instantiations be illustrated or implement, any those skilled in the art The equivalents done within the scope of the claims belongs to the protection category of the present invention.

In the description of this specification, reference term " embodiment ", " specific embodiment ", " some enforcements Example ", " such as ", " example ", the description of " concrete example " or " some examples " etc. mean to combine this embodiment or example describes Specific features, structure, material or feature are contained at least one embodiment or the example of the present invention.In this manual, The schematic representation of above-mentioned term is not necessarily referring to identical embodiment or example.And, the specific features of description, knot Structure, material or feature can combine in any one or more embodiments or example in an appropriate manner.Each embodiment In the sequence of steps that relates to for schematically illustrating the enforcement of the present invention, sequence of steps therein is not construed as limiting, can be as required Appropriately adjust.

About " comprising " used herein, " including ", " having ", " containing " etc., it is the term of opening, i.e. Mean including but not limited to.

As it is shown in figure 1, the reservoir irreducible water saturation that Fig. 1 is the embodiment of the present invention determines the flow chart of method, this enforcement Example can overcome the nuclear magnetic resonance, NMR echo data in prior art for low signal-to-noise ratio, and reservoir irreducible water saturation result of calculation is by mistake The problem that difference is big.Concrete, including:

Step 101: structural index hyperbolic sine function, does Laplace transform to described index hyperbolic sine function and obtains T₂The progressive jump function in territory.

Progressive jump function described herein is similar with unit-step function, and difference is, progressive jump function Changeover portion is an increasing function, and functional value progressive is incremented to 1 by 0, and as shown in phantom in Figure 2, and unit-step function is for jumping Transition, functional value is directly jumped to 1 by 0.

Step 102: the particular value condition met according to described progressive jump function, asks for described index hyperbolic sine function In unknown parameter.

After trying to achieve unknown parameter, according to the index hyperbolic sine function of the unknown parameter tried to achieve more neotectonics, will try to achieve Unknown parameter be substituting to structure index hyperbolic sine function in, the index hyperbolic sine function after being updated.

Particular value condition is such as 0 point function value of progressive jump function, infinite functional value, separation functional value etc..

Step 103: be integrated becoming to the nuclear magnetic resonance, NMR echo data gathered according to the index hyperbolic sine function updated Change, determine reservoir irreducible water saturation.

When being embodied as, by equation below calculating irreducible water saturation:

$S_{wi}=1-t_E\underset{i=0}{\overset{N}{\Σ}}k({\mathrm{it}}_E,T_C)G\left({\mathrm{it}}_E\right)---\left(1\right)$

Wherein, S_wiFor irreducible water saturation, t_EFor echo sounding, i is i-th echo, it_EFor time, k (it_E,T_C) it is it_ETime corresponding index hyperbolic sine function value, T_CFor nuclear magnetic resonance, NMR T₂Spectrum cutoff, can be determined by core experiment, for known Amount, G (it_E) it is it_ETime gather nuclear magnetic resonance, NMR echo data, N is echo number.

Specifically, in above-mentioned steps 101, the index hyperbolic sine function formula of structure is:

k(t,T_C)=λ e^-βtsh(at) (2)

Wherein, k (t, T_C) it is the function of time t, λ, β, a are unknown parameter, and t is the time domain time.

The T obtained after formula (2) is carried out Laplace transform₂The progressive jump function formula in territory is:

$K(T_2,T_C)=\frac{\mathrm{\λ}\mathrm{\α}}{{(s+\mathrm{\β})}^2-{\mathrm{\α}}^2},s=1/T_2---\left(3\right)$

Wherein, K (T₂,T_C) it is T₂Function, T₂For nuclear magnetic resonance, NMR T2.

Index hyperbolic sine function k (t, T described herein_C) any t > 0 is existed, progressive jump function K (T₂,T_C) right Arbitrarily T₂> 0 existence, and K (T₂,T_C) codomain be [0,1), and definition territory in monotonic increase.It is specific that progressive jump function meets Value condition (including extreme value and particular value condition) specifically includes: AndWherein, n is cutoff T_CTime progressive jump function functional value, m is cutoff T_CTime progressive step The slope of function, n and m is setting value, can rule of thumb be set.

When being embodied as, according to the character of asymptotic jump function, generally, cutoff T is set_CTime progressive jump function letter Numerical value is 0.5, i.e.Cutoff T_CTime progressive jump function slope m should not arrange excessive, m is more Greatly, progressive jump function is the steepest, and the reservoir irreducible water saturation tried to achieve is affected by noise the biggest, through overtesting, it is preferred that m takes When 0.3, effect is preferable, and now, calculated unknown parameter is respectively as follows:

Wherein,

Further, in order to understand the impact that reservoir irreducible water saturation is calculated by noise, also include passing through equation below Ask for the variance of irreducible water saturation:

${{\mathrm{\σ}}_S}^2={\mathrm{\σ}}_{\mathrm{\ϵ}}^2{t}_E\[\underset{i=0}{\overset{N}{\Σ}}{k}^2({\mathrm{it}}_E,T_c)t_E\]---\left(4\right)$

Wherein, σ_SFor irreducible water saturation standard deviation, σ_eFor the standard deviation of noise, t_EFor echo sounding, i is that i-th is returned Ripple, it_EFor time, k (it_E,T_C) it is it_ETime corresponding index hyperbolic sine function value, N is echo number.

Further, because actual acquisition to nuclear magnetic resonance, NMR echo data receive effect of noise, in order to verify meter Calculate result credibility, repeatedly calculate described irreducible water saturation, ask for repeatedly result of calculation be all worth to final Irreducible water saturation.

For clearer explanation technical scheme, ask for storage the following detailed description of index hyperbolic sine alternative approach The derivation of layer irreducible water saturation formula (1):

Nuclear magnetic resonance log institute survey time wave datum can be represented by equation below:

$G\left(t\right)={\∫}_0^{\mathrm{\∞}}{e}^{-t/T_2}f\left(T_2\right){\mathrm{dT}}_2+\mathrm{\ϵ}\left(t\right)---\left(5\right)$

Wherein, G (t) is the nuclear magnetic resonance, NMR echo data gathered, T₂For nuclear magnetic resonance, NMR T2, unit s, f (T₂) It is T for the NMR relaxation time₂The interval porosity of hole, unit pu, e (t) is noise.

As in figure 2 it is shown, abscissa is T2 T₂, vertical coordinate is interval porosity f (T₂), T₂>T_CCorresponding hole Porosity is moveable water part, T₂<T_CCorresponding porosity is irreducible water part.The saturation of moveable water is sought by equation below:

$A={\&Integral;}_0^{\mathrm{\&infin;}}K(T_2,T_C)f\left(T_2\right){\mathrm{dT}}_2---\left(6\right)$

Wherein, A is mobile water saturation, Fig. 2 bend area；K(T₂,T_C) it is progressive jump function, dotted line institute in Fig. 2 Show.

According to (6) available reservoir irreducible water saturation it is: S_wi=1-A (7)

If the laplace inverse transform function of progressive jump function is k (t, T_C), then K (T₂,T_C) it is represented by:

$K(T_2,T_C)={\&Integral;}_0^{\mathrm{\&infin;}}k(t,T_C)e^{-t/T_2}dt---\left(8\right)$

By formula (8) generation in formula (6), available equation below:

$I\left\{G\left(t\right)\right\}=A\&equiv;{\&Integral;}_0^{\mathrm{\&infin;}}k(t,T_C)G\left(t\right)dt---\left(9\right)$

Wherein, I{G (t) } represent and G (t) is made integral transformation, discretization formula (9), public affairs can be obtained in conjunction with formula (7) Formula (1).

Further, below with an EXPERIMENTAL EXAMPLE illustrate reservoir irreducible water saturation method that the application provides compared to The reservoir irreducible water saturation that prior art determines is more accurate.

1) two kinds of reservoir nuclear magnetic resonance, NMR T2 T of simulation₂Distributed model, as shown in Fig. 3 A and Fig. 3 B, Fig. 3 A is T₂ Distribution mono-modal model, Fig. 3 B is T₂Being distributed bimodal model, total porosity is 20pu.Abscissa is T₂(unit is s), vertical coordinate For porosity (unit is pu), T₂It is distributed 128 components of preliminary election and minima and is respectively 10 with maximum^-4S and 10s.

2) two kinds of reservoir T2 T of Fig. 3 A and Fig. 3 B are just being drilled₂Distributed model, obtains shown in Fig. 4 A and Fig. 4 B Nuclear magnetic resonance, NMR echo data, Fig. 4 A is by the T of Fig. 3 A₂Distribution mono-modal forward modeling gained, Fig. 4 B is by the T of Fig. 3 B₂It is distributed bimodal model Just drilling gained, containing the nuclear magnetic resonance, NMR echo data of non-plus noise and be applied with the nuclear magnetic resonance, NMR echo data of noise, echo Being spaced apart 0.2ms, echo number is 2000.Abscissa is time (unit is s), and vertical coordinate is porosity (unit is pu).

Fig. 4 A and Fig. 4 B center concrete acquisition process of magnetic resonance echoes data be: by the nuclear-magnetism of simulation in Fig. 3 A and Fig. 3 B altogether Shake T2 T₂Distributed model is just being drilled and is being obtained nuclear magnetic resonance, NMR echo data, and now obtaining nuclear magnetic resonance, NMR echo data is not Noisy, then, applying noise criteria difference on the nuclear magnetic resonance, NMR echo data obtained is the noise of 2.0pu, obtains Fig. 4 A And Fig. 4 B is applied with the nuclear magnetic resonance, NMR echo data of noise.

3) T shown in Fig. 3 A and Fig. 3 B is set₂The cutoff T of distributed model_CFor 33ms, the finger obtained according to the application method The image of number hyperbolic sine function and progressive jump function is as shown in Fig. 5 A and Fig. 5 B, and Fig. 5 A is the index hyperbolic sine of time domain Function, Fig. 5 B be index hyperbolic sine function through Laplace transform gained at T₂Territory respective function.

4) irreducible water saturation is calculated according to echo data shown in index hyperbolic sine function shown in Fig. 5 A and Fig. 4 A, 4B (technical scheme).According to progressive jump function shown in Fig. 5 B and the f (T shown in Fig. 3 A, 3B₂) calculate irreducible water saturation (true value in the present embodiment).According to the gained f (T of echo data inverting shown in progressive jump function shown in Fig. 5 B and Fig. 4 A, 4B₂) meter Calculate irreducible water saturation (prior art).For the credibility of the result, experimental data is repeated 50 times, obtains following table Shown comparing result:

Wherein, σ_ePoor for noise criteria, TRUE is irreducible water saturation true value, and ESHT is index hyperbolic sine alternative approach Result of calculation (technical scheme), ILT is existing method result of calculation (prior art), and μ is 50 results The average of the irreducible water saturation obtained, σ is the standard deviation of 50 results, and rmse is that the root-mean-square of 50 results misses Difference.

From contrast table, irreducible water saturation determines the result and existing method that method obtains according to embodiments of the present invention The result obtained is compared, less closer to irreducible water saturation true value, standard deviation and root-mean-square error, illustrates the inventive method More accurate relative to the reservoir irreducible water saturation that existing method determines, go for low signal-to-noise ratio nuclear magnetic resonance, NMR echo data Determine reservoir irreducible water saturation.

As shown in Figure 6, Fig. 6 is the structure chart that the reservoir irreducible water saturation of the embodiment of the present invention determines device.This device Can realize running on intelligent terminal, such as in the equipment such as mobile phone, panel computer, or with functional module by logic circuit Mode is realized the function of each parts by software, runs on described intelligent terminal.Concrete, described device includes:

Data acquisition unit 601, is used for gathering nuclear magnetic resonance, NMR echo data.

Construction unit 602, for structural index hyperbolic sine function, is Laplce to described index hyperbolic sine function Conversion obtains T₂The progressive jump function in territory.

Unknown parameter asks for unit 603, for the particular value condition met according to described progressive jump function, asks for described Unknown parameter in index hyperbolic sine function, according to the index hyperbolic sine function of the unknown parameter tried to achieve more neotectonics.

Reservoir irreducible water saturation determines unit 604, according to the index hyperbolic sine function the updated nuclear-magnetism to gathering altogether The echo data that shakes is integrated conversion, determines reservoir irreducible water saturation.

In one specific embodiment, it is saturated that reservoir irreducible water saturation determines that unit 604 calculates irreducible water by equation below Degree:

Wherein, S_wiFor irreducible water saturation, t_EFor echo sounding, i is that i-th is returned Ripple, it_EFor time, k (it_E,T_C) it is it_ETime corresponding index hyperbolic sine function value, T_CFor nuclear magnetic resonance, NMR T₂Spectrum cutoff, G (it_E) it is it_ETime gather nuclear magnetic resonance, NMR echo data, N is echo number.

Specifically, the index hyperbolic sine function formula of described construction unit 602 structure is: k (t, T_C)=λ e^-βtsh (at), wherein, k (t, T_C) it is index hyperbolic sine function, λ, β, a are unknown parameter, and t is the time domain time, T_CFor nuclear magnetic resonance, NMR T₂ Spectrum cutoff.

Described progressive jump function formula is:S=1/T₂, T₂Laterally relax for nuclear magnetic resonance, NMR The Henan time.

Index hyperbolic sine function k (t, T described herein_C) any t > 0 is existed, progressive jump function K (T₂,T_C) To any T₂> 0 existence, and K (T₂,T_C) codomain be [0,1), and definition territory in monotonic increase.Progressive jump function meets Particular value condition (including extreme value and particular value condition) is: AndWherein, n, m value is setting value.

In one specific embodiment, working as n=0.5, during m=0.3, it is calculated not that described unknown parameter asks for unit 603 Know that parameter is respectively as follows:

Wherein,

The reservoir irreducible water saturation that the present invention provides determines device, and the index hyperbolic sine function of structure is carried out La Pu Lars conversion obtains progressive jump function, and the particular value condition met according to progressive jump function determines index hyperbolic sine letter Parent magnetic resonance echoes data are directly integrated becoming by the unknown parameter of number according to the index hyperbolic sine function determined Change, determine the irreducible water saturation of required reservoir, obtain T without first passing through inverse Laplace transformation inverting₂Spectrum, thus keeps away Exempt from the uncertainty that inverting is brought.Therefore, in the case of nuclear magnetic resonance, NMR echo data signal to noise ratio is the lowest, the method is still It is obtained in that good reservoir irreducible water saturation evaluation result.

Those skilled in the art are it should be appreciated that embodiments of the invention can be provided as method, system or computer program Product.Therefore, the reality in terms of the present invention can use complete hardware embodiment, complete software implementation or combine software and hardware Execute the form of example.And, the present invention can use at one or more computers wherein including computer usable program code The upper computer program product implemented of usable storage medium (including but not limited to disk memory, CD-ROM, optical memory etc.) The form of product.

The present invention is with reference to method, equipment (system) and the flow process of computer program according to embodiments of the present invention Figure and/or block diagram describe.It should be understood that can the most first-class by computer program instructions flowchart and/or block diagram Flow process in journey and/or square frame and flow chart and/or block diagram and/or the combination of square frame.These computer programs can be provided Instruction arrives the processor of general purpose computer, special-purpose computer, Embedded Processor or other programmable data processing device to produce A raw machine so that the instruction performed by the processor of computer or other programmable data processing device is produced for real The device of the function specified in one flow process of flow chart or multiple flow process and/or one square frame of block diagram or multiple square frame now.

These computer program instructions may be alternatively stored in and computer or other programmable data processing device can be guided with spy Determine in the computer-readable memory that mode works so that the instruction being stored in this computer-readable memory produces and includes referring to Make the manufacture of device, this command device realize at one flow process of flow chart or multiple flow process and/or one square frame of block diagram or The function specified in multiple square frames.

These computer program instructions also can be loaded in computer or other programmable data processing device so that at meter Perform sequence of operations step on calculation machine or other programmable devices to produce computer implemented process, thus at computer or The instruction performed on other programmable devices provides for realizing at one flow process of flow chart or multiple flow process and/or block diagram one The step of the function specified in individual square frame or multiple square frame.

The above is merely to illustrate the technical scheme of the application, any those of ordinary skill in the art all can without prejudice to Under the spirit and the scope of the present invention, above-described embodiment is modified and changes.Therefore, the scope of the present invention should regard Right is as the criterion.

Claims (10)

1. a reservoir irreducible water saturation determines method, it is characterised in that including:

Structural index hyperbolic sine function, does Laplace transform to described index hyperbolic sine function and obtains T₂The progressive rank in territory Jump function；

The particular value condition met according to described progressive jump function, asks for the unknown ginseng in described index hyperbolic sine function Number, according to the index hyperbolic sine function of the unknown parameter tried to achieve more neotectonics；

According to the index hyperbolic sine function updated, the nuclear magnetic resonance, NMR echo data gathered is integrated conversion, determines reservoir bundle Tie up water saturation.

2. reservoir irreducible water saturation as claimed in claim 1 determines method, it is characterised in that described index hyperbolic sine letter Number formula is: k (t, T_C)=λ e^-βtSh (α t), wherein, k (t, T_C) it is index hyperbolic sine function, λ, β, α are unknown parameter, t For time domain time, T_CFor nuclear magnetic resonance, NMR T₂Spectrum cutoff；

Described progressive jump function formula is:S=1/T₂, T₂During for nuclear magnetic resonance, NMR transverse relaxation Between.

3. reservoir irreducible water saturation as claimed in claim 2 determines method, it is characterised in that described particular value condition is:AndWherein, n, m are for setting Value.

4. the reservoir irreducible water saturation as described in any one of claims 1 to 3 determines method, it is characterised in that according to renewal Index hyperbolic sine function to gather nuclear magnetic resonance, NMR echo data be integrated conversion, determine reservoir irreducible water saturation bag Include: ask for reservoir irreducible water saturation according to equation below,

$S_{wi}=1-t_E\underset{i=0}{\overset{N}{\&Sigma;}}k({\mathrm{it}}_E,T_C)G\left({\mathrm{it}}_E\right);$

Wherein, S_wiFor reservoir irreducible water saturation, t_EFor echo sounding, i is i-th echo, it_EFor time, k (it_E,T_C) it is it_ETime corresponding index hyperbolic sine function value, T_CFor nuclear magnetic resonance, NMR T₂Spectrum cutoff, G (it_E) it is it_ETime the nuclear-magnetism that gathers altogether Shake echo data, and N is echo number.

5. reservoir irreducible water saturation as claimed in claim 3 determines method, it is characterised in that described n=0.5, m=0.3, Calculated unknown parameter is respectively as follows:

Wherein,

6. a reservoir irreducible water saturation determines device, it is characterised in that including:

Data acquisition unit, is used for gathering nuclear magnetic resonance, NMR echo data；

Construction unit, for structural index hyperbolic sine function, does Laplace transform to described index hyperbolic sine function and obtains To T₂The progressive jump function in territory；

Unknown parameter asks for unit, for the particular value condition met according to described progressive jump function, asks for described index double Unknown parameter in bent SIN function, according to the index hyperbolic sine function of the unknown parameter tried to achieve more neotectonics；

Reservoir irreducible water saturation determines unit, according to the index hyperbolic sine function the updated nuclear magnetic resonance, NMR number of echoes to gathering According to being integrated conversion, determine reservoir irreducible water saturation.

7. reservoir irreducible water saturation as claimed in claim 6 determines device, it is characterised in that described construction unit structure Index hyperbolic sine function formula is: k (t, T_C)=λ e^-βtSh (α t), wherein, k (t, T_C) be index hyperbolic sine function, λ, β, α is unknown parameter, and t is the time domain time, T_CFor nuclear magnetic resonance, NMR T₂Spectrum cutoff；

Described progressive jump function formula is:S=1/T₂, T₂During for nuclear magnetic resonance, NMR transverse relaxation Between.

8. reservoir irreducible water saturation as claimed in claim 7 determines device, it is characterised in that described particular value condition is:AndWherein, n, m value is for setting Definite value.

9. the reservoir irreducible water saturation as described in any one of claim 6 to 8 determines device, it is characterised in that described reservoir Irreducible water saturation determine unit specifically for asking for reservoir irreducible water saturation according to equation below,

$S_{wi}=1-t_E\underset{i=0}{\overset{N}{\&Sigma;}}k({\mathrm{it}}_E,T_C)G\left({\mathrm{it}}_E\right);$

Wherein, S_wiFor reservoir irreducible water saturation, t_EFor echo sounding, i is i-th echo, it_EFor time, k (it_E,T_C) it is it_ETime corresponding index hyperbolic sine function value, T_CFor nuclear magnetic resonance, NMR T₂Spectrum cutoff, G (it_E) it is it_ETime the nuclear-magnetism that gathers altogether Shake echo data, and N is echo number.

10. reservoir irreducible water saturation as claimed in claim 9 determines device, it is characterised in that described n=0.5, m= 0.3, described unknown parameter is asked for the calculated unknown parameter of unit and is respectively as follows:

Wherein,