CN105221142A - A kind of method identifying shale subterranean minerals mass content - Google Patents

Abstract

The invention discloses a kind of method identifying shale subterranean minerals mass content, comprise the following steps: the relative amount obtaining element in shale formation based on ECS geochemical well logging, and obtain the quality absolute content of element in shale formation; The mineral model response equation of structure shale formation, determines error and the measure error of mineral model response equation; Based on the object function being obtained the quality absolute content of element in shale formation, mineral model response equation, the error of response equation and measure error by oxygen closed model and set up well log interpretation; Being optimized process to described object function makes described object function obtain optimum mineral quality content parameter corresponding to minimum value to ask for, and the mineral model response of drawing optimum mineral quality content parameter corresponding just drills result curve; Check the response of described mineral model just drilling result curve whether to mate with the quality absolute content of actual element, just drill mineral quality content parameter corresponding to result curve as determination result using what mate.

Description

A kind of method identifying shale subterranean minerals mass content

Technical field

The present invention relates to petroleum exploration and development technical field, specifically, relate to the recognition methods of subterranean minerals mass content in a kind of shale formation exploration and development process.

Background technology

Shale formation mineral type is various, content is complicated, has multiple method to determine shale formation mineral quality content in prior art.

Harvey (1992) utilizes prosthetic graft by xrf analysis, obtains the transformational relation between the content of oxide and mineral content; Herron (1996) utilizes mineral to test the transformational relation set up between shale element and mineral, and this transformational relation is the basis that stratum element arrives Mineral Transformation; Fang (1996) genetic algorithm calculates the element that the obtains conversion to mineral of logging well; Quirein etc. (2010) directly establish the calculating of shale formation element to mineral content with optimization method; Gao Chuqiao (1999) carries out inverting with linear programming relax to geochemical well logging, draws sedimentary rock formations mineral content; Cheng Huaguo etc. (2004) utilize ECS data and oxides closure model and integrated treatment explanation results, determine stratum mineral content; Han Lin, Pan Baozhi (2009) realize the explanation of element to igneous rocks with TAS plate; Harmony generation and (nineteen ninety-five) optimizing application algorithm realization calculate subterranean minerals content with Using Conventional Logs.

These are asked for mineral quality content means of interpretation and are summed up as two kinds: a kind of is take Schlumberger as the experience means of interpretation of representative, and another kind take Halliburton Company as the optimum interpretation method of representative.Schlumberger's means of interpretation asks for shale formation element relative amount and mineral quality content by rule-of-thumb relation; Halliburton Company's means of interpretation directly utilizes optimization method inverting to obtain subterranean minerals mass content by stratum element content.

Schlumberger is that the means of interpretation of representative relies on a large amount of regional experimental datas, and more corresponding new stratum, may need to re-establish model, and the model set up is not open, and applicability needs checking further; Halliburton Company is that the means of interpretation compliance of representative is comparatively strong, but the error of inverting mineral is large.

Accurately to determine shale formation mineral quality content, with shale core experimental technique determine usually, or determined by many mineral interpretation model.Experimental technique rock core limited amount, experimental result obtain not prompt enough, and many mineral interpretation model result is not often inconsistent with actual mineral type, Minerals and rocks resultant error is larger.In prior art, all right direct geochemical well logging is in conjunction with the volume content of other Using Logging Data To Evaluate shale formation.Because elements are contained result is mass content, and the result that well-log information result normally draws under volume-based model, therefore there will be certain error in interpretation process.

Based on above-mentioned situation, need a kind of method that quick and precisely can identify shale subterranean minerals mass content.

Summary of the invention

For above-mentioned technical problem, the invention provides a kind of method identifying shale subterranean minerals mass content, comprise the following steps:

Obtain the relative amount of element in shale formation based on ECS geochemical well logging, and obtain the quality absolute content of element in shale formation according to oxygen closed model;

The mineral model response equation of structure shale formation under different minerals mass content Parameter Conditions, determines error and the measure error of mineral model response equation;

Based on the object function being obtained the quality absolute content of element in shale formation, mineral model response equation, the error of response equation and measure error by oxygen closed model and set up well log interpretation;

Being optimized process to described object function makes described object function obtain optimum mineral quality content parameter corresponding to minimum value to ask for, and the mineral model response of drawing optimum mineral quality content parameter corresponding just drills result curve;

Check the response of described mineral model just drilling result curve whether to mate with the quality absolute content of actual element, just drill mineral quality content parameter corresponding to result curve as determination result using what mate.

According to one embodiment of present invention, the described relative amount obtaining element in shale formation based on ECS geochemical well logging, and comprise according to the quality absolute content that oxygen closed model obtains element in shale formation:

Gamma ray spectrum is obtained, to gamma ray spectrum spectrum unscrambling to obtain the relative amount of shale formation element by ECS geochemical well logging;

Based on oxygen closed model, element relative amount is converted into element quality absolute content, described oxygen closed model is

∑y _i＝F∑Y _i/S _i＝1

Wherein, y _ibe the quality absolute content of i-th kind of element, F is normalization factor, Y _ibe the relative amount of i-th kind of element, S _iit is the sensitivity factor of i-th kind of element.

According to one embodiment of present invention, described mineral model response equation is:

$y_i=\underset{j=1}{\overset{N}{\mathrm{\Σ}}}{W}_j{C}_{\mathrm{ij}}$

Wherein, W _jfor the mass content of jth kind mineral, N is mineral species, C _ijbe the factor of proportionality of i-th kind of element in jth kind mineral, y _iis the quality absolute content of i kind element.

According to one embodiment of present invention, the object function of described well log interpretation is:

$F(x,a)=\underset{i=1}{\overset{m}{\mathrm{\Σ}}}\frac{{[a_i-f_i(x,z)]}^2}{{\mathrm{\σ}}_i^2+{\mathrm{\τ}}_i^2}+\underset{j=1}{\overset{p}{\mathrm{\Σ}}}\frac{g_j^2\left(x\right)}{{\mathrm{\τ}}_j}$

Wherein, a _iit is the quality absolute content of i-th kind of element;

X=(W ₁... W _i) be the mineral quality content parameter in shale formation;

Z is current depth-logger;

σ _iit is the measure error of the quality absolute content of i-th kind of element;

τ _ifor the error of i-th kind of mineral model response equation of structure;

F _i(x, z) i-th kind of mineral model response equation for constructing when the z degree of depth;

M is the kind of element;

G _jx jth kind constraints that () is x, τ _jfor jth kind constraint error;

P is constraint number.

According to one embodiment of present invention, the error of described mineral model response equation is:

${\mathrm{\τ}}_i=A\underset{j=1}{\overset{N}{\mathrm{\Σ}}}{W}_j^2$

Wherein, τ _ifor the error of i-th kind of mineral model response equation of structure, W _jfor the mass content of jth kind mineral, N is mineral species, and A is error coefficient.

According to one embodiment of present invention, the constraints g in the object function of described well log interpretation _jx () is expressed as

$\underset{j=1}{\overset{N}{\mathrm{\Σ}}}{W}_j=1$

Wherein, W _jfor the quality absolute content of shale formation jth kind shale formation mineral, N is mineral species.

According to one embodiment of present invention, the measure error of the quality absolute content of described i-th kind of element is 5% of its quality absolute content numerical values recited.

According to one embodiment of present invention, described to described object function be optimized process comprise the following steps to ask for the optimum mineral quality content parameter making described object function obtain corresponding to minimum value:

The BFGS variable-metric method determination direction of search is utilized to be wherein for direction matrix, represent the gradient of object function, in the direction of search upper any point is expressed as (x, a) is converted to one-variable function φ (t) to objective function F;

DSPOW parabolic interpolation is utilized to ask for the minimum point t of one-variable function φ (t) ₀, according to t ₀determine the optimum mineral quality content parameter x=of shale formation (W ₁... W _i).

According to one embodiment of present invention, check described mineral model to respond just to drill result curve whether to mate with the quality absolute content of actual element to comprise:

The confidential interval that mineral model is just drilling curve is drawn according to the quality absolute content of actual element, response equation error and measure error wherein a _ibe the quality absolute content of i-th kind of element, σ _iand τ _icorrespond to measure error and mineral model response equation error;

When described mineral model respond just drill result curve be in mineral model just drilling in the confidential interval of curve time, mineral model response is just being drilled result curve and is being mated with the quality absolute content of actual element.

Beneficial effect of the present invention is: mineral constituent occupies very important status in shale formation evaluation, and the complicated mineral constituent of accurate evaluation shale formation is conducive to follow-up geologic assessment and engineering evaluation.The present invention utilizes geochemical well logging data to identify the complicated mineral constituent of shale formation fast, not only shale class mineral are subdivided into illite, chlorite, montmorillonite and kaolinite, and segmented quartz and feldspar, dolomite and calcite, the complicated mineral constituent of shale formation can be determined exactly, for follow-up geology and engineering evaluation provide mineral parameter accurately.

Other features and advantages of the present invention will be set forth in the following description, and, partly become apparent from manual, or understand by implementing the present invention.Object of the present invention and other advantages realize by structure specifically noted in manual, claims and accompanying drawing and obtain.

Accompanying drawing explanation

In order to be illustrated more clearly in the embodiment of the present invention or technical scheme of the prior art, do simple introduction by accompanying drawing required in embodiment or description of the prior art below:

Fig. 1 is the flow chart of steps of the method for identification shale subterranean minerals mass content according to the embodiment of the present invention;

Fig. 2 is the mass percent of element in mineral type common in stratum and each mineral type;

Fig. 3 is the result of X well 2120-2150 rice ECS geochemical well logging inverting mineral quality content in certain geologic province;

Fig. 4 is the result of X well 2150-2185 rice ECS geochemical well logging inverting mineral quality content in certain geologic province.

Detailed description of the invention

Describe embodiments of the present invention in detail below with reference to drawings and Examples, to the present invention, how application technology means solve technical problem whereby, and the implementation procedure reaching technique effect can fully understand and implement according to this.It should be noted that, only otherwise form conflict, each embodiment in the present invention and each feature in each embodiment can be combined with each other, and the technical scheme formed is all within protection scope of the present invention.

In addition, can perform in the computer system of such as one group of computer executable instructions in the step shown in the flow chart of accompanying drawing, and, although show logical order in flow charts, but in some cases, can be different from the step shown or described by order execution herein.

The present invention obtains stratum element relative amount according to primitive element well logging (ECS) data spectrum unscrambling, owing to there is certain relation between subterranean minerals quality and constituent content, by the constituent content response equation under structure stratum different minerals model, optimized algorithm is utilized to calculate shale formation mineral quality content.

embodiment one

Fig. 1 is the flow chart of steps of the method for identification shale subterranean minerals mass content according to the present embodiment.Below in conjunction with Fig. 1, the method for the present embodiment is elaborated.

In step S101, obtain the relative amount of element in shale formation based on ECS geochemical well logging, and obtain the quality absolute content of element in shale formation according to oxygen closed model.

Concrete, utilize ECS to capture geochemical well logging technology, the gamma ray spectrum that neutron-gamma (n, γ) nuclear reaction that acquisition neutron and stratum element atomic nucleus occur produces.Because the Characteristic γ ray energy of different element is different, the different element relative amount in stratum can be obtained by carrying out solution analysis of spectrum to gamma ray spectrum.

Oxygen closed model is adopted to calculate stratum different element quality absolute content.In stratum, element relative amount and element quality absolute content meet following formula:

∑y _i＝F∑Y _i/S _i＝1(1.1)

Wherein, y _ibe i-th kind of element quality absolute content, F is normalization factor, changes with the degree of depth, and each degree of depth all needs to calculate, Y _ibe the quality relative amount of i-th kind of element, S _iit is the sensitivity factor of i-th kind of element.

In stratum, the mass percent sum of all elements is 1, namely meets closure condition.Obtain gamma-rays non-ballistic gamma spectra based on ECS well logging, its stratum element closed model formula is:

$F_I\underset{i}{\mathrm{\Σ}}{Y}_{\mathrm{Ii}}/S_{\mathrm{Ii}}+W_H=1---\left(1.2\right)$

Wherein, F _ifor the normalization factor of non-ballistic gamma spectra, S _iifor the non-ballistic gamma spectra sensitivity factor of element i, Y _iifor the non-ballistic gamma spectra relative amount of element i, W _hfor protium quality absolute content.

For capturing gamma spectra, stratum element closed model is:

$F_C\underset{i}{\mathrm{\Σ}}{Y}_{\mathrm{Ci}}/S_{\mathrm{Ci}}+W_C+W_O+W_K+W_{\mathrm{Al}}=1---\left(1.3\right)$

Wherein, F _cfor capturing the normalization factor of gamma spectra, Y _cigamma spectra relative amount is captured, S for element i _cigamma spectra sensitivity factor is captured, W for element i _c, W _o, W _k, W _albe respectively carbon, oxygen, potassium, aluminium element quality absolute content.

Adopt and capture the absolute mass content y that gamma spectra and non-ballistic gamma spectra simultaneous can solve stratum Its Related Elements _i.

One of ordinary skill in the art will readily recognize that the W in formula (1.2) and (1.3) _h, W _c, W _o, W _k, W _alcan determine according to technological means conventional in prior art.

In step s 102, the mineral model response equation of structure shale formation under different minerals mass content Parameter Conditions, determines error and the measure error of mineral model response equation.

Mineral model response equation is

$y_i=\underset{j=1}{\overset{N}{\mathrm{\Σ}}}{W}_j{C}_{\mathrm{ij}}---\left(1.4\right)$

Wherein, W _jfor the mass content of jth kind mineral, N is mineral species, C _ijbe the factor of proportionality of i-th kind of element in mineral, y _ifor the absolute mass content of i kind element.

Figure 2 shows that the mass percent of element in mineral type common in stratum and each mineral type, i.e. i-th kind of element factor of proportionality C in mineral _ij.Common mineral type includes but not limited to quartz, potassic feldspar, albite, orthoclase, muscovite, biotite, calcite, dolomite, kaolinite, illite, montmorillonite, chlorite, glauconite, ankerite, fosfosiderite, pyrite, bloodstone, steam curing, and the element in mineral includes but not limited to Al, C, Ca, Fe, K, Mg, Mn, Na, S and Si.

The error of mineral model response equation is:

${\mathrm{\τ}}_i=A\underset{j=1}{\overset{N}{\mathrm{\Σ}}}{W}_j^2$

Wherein, τ _ifor the error of i-th kind of mineral model response equation of structure, W _jfor the mass content of jth kind mineral, N is mineral species, and A is error coefficient.Preferably, A=0.01 can be set.

Because logger and data collecting system all exist certain measure error, in the present embodiment, the measure error of the quality absolute content of i-th kind of element is 5% of the quality absolute content numerical values recited of i-th kind of element.

In step s 103, based on the object function being obtained the quality absolute content of element in shale formation, mineral model response equation, the error of response equation and measure error by oxygen closed model and set up well log interpretation:

$F(x,a)=\underset{i=1}{\overset{m}{\mathrm{\Σ}}}\frac{{[a_i-f_i(x,z)]}^2}{{\mathrm{\σ}}_i^2+{\mathrm{\τ}}_i^2}+\underset{j=1}{\overset{p}{\mathrm{\Σ}}}\frac{g_j^2\left(x\right)}{{\mathrm{\τ}}_j}---\left(1.5\right)$

Wherein, a _iit is the quality absolute content of i-th kind of element;

X=(W ₁... W _i) be the mineral quality content parameter in shale formation;

Z is current depth-logger;

σ _iit is the measure error of the quality absolute content of i-th kind of element;

τ _ifor the error of i-th kind of mineral model response equation of structure;

F _i(x, z) i-th kind of mineral model response equation for constructing when the z degree of depth;

M is the kind of element;

G _jx jth kind constraints that () is x, τ _jfor jth kind constraint error;

P is constraint number.

Preferably, constraints g in the present embodiment _jx () is expressed as: wherein, W _jfor the quality absolute content of shale formation jth kind shale formation mineral.Corresponding qualitative restrain error τ _jvalue gets 1.

Also comprise following constraints: W _j>=0, j is mineral species.

In step S104, process is optimized to described object function and makes described object function obtain optimum mineral quality content parameter corresponding to minimum value to ask for, and the mineral model response of drawing optimum mineral quality content parameter corresponding just drills result curve.

By target component F (x, a) can build the Mathematical Modeling of optimum logging interpretation:

$\min F(x,a)=\min \underset{i=1}{\overset{m}{\mathrm{\Σ}}}\frac{{[a_i-f_i(x,z)]}^2}{{\mathrm{\σ}}_i^2+{\mathrm{\τ}}_i^2}+\underset{j=1}{\overset{p}{\mathrm{\Σ}}}\frac{g_j^2\left(x\right)}{{\mathrm{\τ}}_j}$

Calculating makes described objective function F, and (x a) obtains the optimum mineral quality content parameter x=(W of minimum value ₁... W _i), mass content parameter immediate with actual mineral quality content can be determined.

Preferably, the BFGS variable-metric method determination direction of search is utilized to be in the present embodiment in the direction of search on can find the minimum of object function.

Wherein positive definite symmetric matrices for Scale Matrixes, (x, a) in the gradient at kth time iteration point place, in the kth time direction of search to represent objective function F upper any point is expressed as (x a) is converted to one-variable function φ (t) to objective function F.

DSPOW parabolic interpolation is utilized to ask for the minimum point t of one-variable function φ (t) ₀, according to t ₀determine the optimum mineral quality content parameter x=of shale formation (W ₁... W _i).

Above BFGS variable-metric method and DSPOW parabolic interpolation well known to a person skilled in the art well log interpretation optimal method, can with reference to " Teaching Materials at College level: log data processing and integrated interpretation " (harmony generation and work, on August 1st, 2007 publishes).

In step S105, check the response of described mineral model just drilling result curve and whether mate with the quality absolute content of actual element, just drill mineral quality content parameter corresponding to result curve as determination result using what mate.

Concrete, draw according to the quality absolute content of actual element, response equation error and measure error the confidential interval that mineral model is just drilling curve wherein a _ibe the quality absolute content of i-th kind of element, σ _iand τ _icorrespond to measure error and mineral model response equation error; The error of i-th kind of mineral model response equation is 5% of the quality absolute content numerical values recited of i-th kind of element.

When described mineral model respond just drill result curve be in just drill curve confidential interval in time, mineral model response is just being drilled result curve and is being mated with the quality absolute content of actual element, and namely excellent mineral quality content parameter x=(W is described most ₁... W _i) fully react actual mineral quality content in shale formation.

In addition, can according to the response of the size of object function optimal value inspection mineral model just drill result curve whether with the quality absolute content Curve Matching of actual element.The optimum mineral quality content parameter x calculated for utilizing optimal method ^*, object function optimal value F ^*(x ^*, a) ≈ 0.F ^*(x ^*, be a) weigh just to drill the total mark whether mineral model curve approaches the quality absolute content curve of actual element.F ^*(x ^*, a) value is less, illustrates that the quality absolute content Curve Matching degree just drilling result curve and actual element that mineral model responds is better.

In sum, this method is according to based on the shale formation constituent content size after ECS geochemical well logging data and spectrum unscrambling, by the constituent content response equation under structure stratum different minerals model, inverting is carried out according to optimized algorithm, shale subterranean minerals mass content can be identified fast, decrease the process of core experiment determination mineral quality content, save expense and time.

embodiment two

The present embodiment utilizes southwest China block well ECS data to carry out inverting.This block high-quality shale lithology is mainly based on yellow-gray shale, silty shale folder thin layer lenticular limestone.Si, Al, Fe, Ca and Su element inverting kind coldest days of the year end shale formation mineral after application ECS well-log information spectrum unscrambling, be quartz, feldspar, limestone, dolomite, illite, chlorite, pyrite, mica and anhydrite respectively, inversion result as shown in Figure 3 and Figure 4.

Fig. 3 is the result of X well 2120-2150 rice ECS geochemical well logging inverting mineral quality content in certain geologic province.Adopt method mentioned above to obtain mineral quality content optimal value in the present embodiment.

As shown in Figure 3, treating depth is 2120-2150 rice, the first five road is ECS element absolute mass content, the quality absolute content of element is just being drilled value and just drilled the confidential interval of result, 6th road is depth track, 7th road is target function value, 8th road is the mineral quality content of the present embodiment inverting, and the 9th road is the mineral quality content of Schlumberger's inverting.

In first, curve D WSIH represents that element silicon is just drilling the maximum value of curve confidential interval, curve D WSIL represents that element silicon is just drilling the minimum value of confidential interval, curve D WSI represents the absolute mass content of the element silicon reality that ECS geochemical well logging method is determined, curve D WST represents the optimal value of the element silicon absolute mass content of just drilling.

Second represents respectively that to the curve in the 5th road the quality absolute content of the absolute mass content of aluminium element, ferro element, calcium constituent and element sulphur is just being drilled value and just drilled the confidential interval of result, and implication and the first of each bar curve are similar, repeat no more.

8th road is the mineral quality content of the present embodiment inverting, represent the mass content of following mineral, iron ore (WPYR), illite (WILL), chlorite (WCHL), quartz (WQRZ), feldspar (WFLD), calcite (WCLC), dolomite (WDOL), mica (WMIC), andesite (WANH) and other mineral (WSM).

9th road is the mineral quality content of Schlumberger's inverting.Wherein, shale content (WCLA) corresponds to illite (WILL) and the chlorite (WCHL) of the inversion method of embodiment one, sandstone (WOFM) corresponds to quartz (WQRZ) and the feldspar (WFLD) of the inversion method of embodiment one, carbonate (WCRA) corresponds to calcite (WCLC) and the dolomite (WDOL) of the inversion method of embodiment one, find out from result, the inversion method result of embodiment one has good uniformity with Schlumberger's explanation results in three kinds of lithology, and inversion result of the present invention can segment lithology further.

Fig. 4 is the result of X well 2150-2185 rice ECS geochemical well logging inverting mineral quality content in certain geologic province.Tu Zhongge road curve meaning is identical with in Fig. 3, based on carbonate content below 2160 meters, the sandstone mass content of Schlumberger's explanation results is slightly larger than the quartz of the present embodiment inverting and feldspar content, carbonate mass content is slightly less than limestone and the dolomite content of the present embodiment inverting, but their form and trend are basically identical.

In sum, the present invention obtains stratum element relative amount according to primitive element well-log information spectrum unscrambling, then according to the relation existed between stratum mineral quality and constituent content, element absolute mass content response equation under structure stratum different minerals model, utilize optimized algorithm to calculate shale formation ore weight content, accurately can determine shale formation mineral quality content.

Although embodiment disclosed in this invention is as above, the embodiment that described content just adopts for the ease of understanding the present invention, and be not used to limit the present invention.Technician in any the technical field of the invention; under the prerequisite not departing from spirit and scope disclosed in this invention; any amendment and change can be done what implement in form and in details; but scope of patent protection of the present invention, the scope that still must define with appending claims is as the criterion.

Claims (9)

1. identify a method for shale subterranean minerals mass content, it is characterized in that, comprise the following steps:

Obtain the relative amount of element in shale formation based on ECS geochemical well logging, and obtain the quality absolute content of element in shale formation according to oxygen closed model;

The mineral model response equation of structure shale formation under different minerals mass content Parameter Conditions, determines error and the measure error of mineral model response equation;

Based on the object function being obtained the quality absolute content of element in shale formation, mineral model response equation, the error of response equation and measure error by oxygen closed model and set up well log interpretation;

Being optimized process to described object function makes described object function obtain optimum mineral quality content parameter corresponding to minimum value to ask for, and the mineral model response of drawing optimum mineral quality content parameter corresponding just drills result curve;

Check the response of described mineral model just drilling result curve whether to mate with the quality absolute content of actual element, just drill mineral quality content parameter corresponding to result curve as determination result using what mate.

2. the method for claim 1, is characterized in that, the described relative amount obtaining element in shale formation based on ECS geochemical well logging, and comprises according to the quality absolute content that oxygen closed model obtains element in shale formation:

Gamma ray spectrum is obtained, to gamma ray spectrum spectrum unscrambling to obtain the relative amount of shale formation element by ECS geochemical well logging;

Based on oxygen closed model, element relative amount is converted into element quality absolute content, described oxygen closed model is

∑y _i＝F∑Y _i/S _i＝1

Wherein, y _ibe the quality absolute content of i-th kind of element, F is normalization factor, Y _ibe the relative amount of i-th kind of element, S _iit is the sensitivity factor of i-th kind of element.

3. method as claimed in claim 2, it is characterized in that, described mineral model response equation is:

$y_i=\underset{j=1}{\overset{N}{\mathrm{\Σ}}}{W}_j{C}_{\mathrm{ij}}$

Wherein, W _jfor the mass content of jth kind mineral, N is mineral species, C _ijbe the factor of proportionality of i-th kind of element in jth kind mineral, y _iis the quality absolute content of i kind element.

4. method as claimed in claim 3, it is characterized in that, the object function of described well log interpretation is:

$F(x,a)=\underset{i=1}{\overset{m}{\mathrm{\Σ}}}\frac{{[a_i-f_i(x,z)]}^2}{{\mathrm{\σ}}_i^2+{\mathrm{\τ}}_i^2}+\underset{j=1}{\overset{p}{\mathrm{\Σ}}}\frac{g_j^2\left(x\right)}{{\mathrm{\τ}}_j}$

Wherein, a _iit is the quality absolute content of i-th kind of element;

X=(W ₁... W _i) be the mineral quality content parameter in shale formation;

Z is current depth-logger;

σ _iit is the measure error of the quality absolute content of i-th kind of element;

τ _ifor the error of i-th kind of mineral model response equation of structure;

F _i(x, z) i-th kind of mineral model response equation for constructing when the z degree of depth;

M is the kind of element;

G _jx jth kind constraints that () is x, τ _jfor jth kind constraint error;

P is constraint number.

5. method as claimed in claim 4, it is characterized in that, the error of described mineral model response equation is:

${\mathrm{\τ}}_i=A\underset{j=1}{\overset{N}{\mathrm{\Σ}}}{W}_j^2$

Wherein, τ _ifor the error of i-th kind of mineral model response equation of structure, W _jfor the mass content of jth kind mineral, N is mineral species, and A is error coefficient.

6. method as claimed in claim 5, is characterized in that, the constraints g in the object function of described well log interpretation _jx () is expressed as

$\underset{j=1}{\overset{N}{\mathrm{\Σ}}}{W}_j=1$

Wherein, W _jfor the quality absolute content of shale formation jth kind shale formation mineral, N is mineral species.

7. method as claimed in claim 5, it is characterized in that, the measure error of the quality absolute content of described i-th kind of element is 5% of its quality absolute content numerical values recited.

8. the method according to any one of claim 1-7, is characterized in that, described to described object function be optimized process comprise the following steps to ask for the optimum mineral quality content parameter making described object function obtain corresponding to minimum value:

The BFGS variable-metric method determination direction of search is utilized to be wherein for direction matrix, represent the gradient of object function, in the direction of search upper any point is expressed as (x, a) is converted to one-variable function φ (t) to objective function F;

DSPOW parabolic interpolation is utilized to ask for the minimum point t of one-variable function φ (t) ₀, according to t ₀determine the optimum mineral quality content parameter x=of shale formation (W ₁... W _i).

9. whether the method according to any one of claim 1-7, is characterized in that, check described mineral model to respond just to drill result curve to mate with the quality absolute content of actual element and comprise:

The confidential interval that mineral model is just drilling curve is drawn according to the quality absolute content of actual element, response equation error and measure error wherein a _ibe the quality absolute content of i-th kind of element, σ _iand τ _icorrespond to measure error and mineral model response equation error;

When described mineral model respond just drill result curve be in mineral model just drilling in the confidential interval of curve time, mineral model response is just being drilled result curve and is being mated with the quality absolute content of actual element.