CN105372298A - Analysis method for formation rock mineral constituents - Google Patents

Abstract

The invention discloses an analysis method for formation rock mineral constituents. The analysis method can be suitable for determination of the mineral constituents of a rock core obtained on a petroleum drilling site. The analysis method comprises the four basic steps of optical experiment determination of the rock sample mineral constituents, measurement of acoustical and electrical characteristics and the like of a rock sample, establishment of a calculating and responding model for a formation lithology and electrical method measurement result and inversion of the formation mineral constituents of the rock core sample; inversion of the formation mineral constituents of the rock core sample comprises the steps that logging information of the obtained rock core sample is matched with a sample in a database, possible rock parameters are selected to be substituted into the calculating model established in the third step, and the rock parameter which has the minimum error between a calculating result and an actual measurement result can serve as the mineral constituent and convent parameter of the rock core sample. The analysis method has the advantages that the formation lithology parameter needing to be specified can be obtained according to the logging information, and the defects that an indoor test is long in cycle and high in cost can be overcome.

Description

A kind of analytical approach of formation rock mineralogical composition

Technical field

The present invention relates to a kind of acquiring method being applicable to the formation rock mineralogical composition qualification at petroleum drilling scene, especially a kind of analytical approach of formation rock mineralogical composition.

Background technology

Rock mineral composition and content thereof, to determining stratigraphic type, judge that the abrasive property feature of rock drillability rank and rock has vital role.Rock mineral composition test is all carry out directly test by indoor Experiments of Optics to the core sample after process to obtain usually.In petroleum drilling industry, only have the preparatory reconnaissance borehole of only a few just may carry out coring operation in drilling process.Because coring operation has a strong impact on drilling efficiency, core costly, limited core sample mainly carries out the relevant test of oily, rarely has the experimental analysis about rock mineral composition.But, in the log data that project is various, have the test result of a lot of project (as rock resistivity, interval transit time, density etc.) all with rock mineral composition and content closely related.Situ of drilling well institute coring sample carries out analytical test from obtaining sample to sending laboratory back to, and experimental period is longer, and its test result is unfavorable for for situ of drilling well service.

Summary of the invention

The technical problem to be solved in the present invention is to provide a kind of analytical approach of formation rock mineralogical composition, and it can make up indoor test cycle long, weak point costly.

In order to solve the problems of the technologies described above, the analytical approach of a kind of formation rock mineralogical composition of the present invention comprises the following steps:

The Experiments of Optics of step one, rock sample mineralogical composition are determined: many groups of choosing in survey region have the core sample of Typical Representative meaning, carry out polarized microscope analysis and X-ray diffraction analysis respectively, determine mineral species and the content of rock sample;

The acoustics of step 2, rock sample and electricity characteristic measuring: to the rock sample in step one, measure the interval transit time of rock, resistivity and density in laboratory conditions, sets up the related logging document data base with the core sample of different minerals type and content;

Step 3, set up rock acoustics and electrical testing result and the mutual relationship between rock mineral composition and content, based on the result of core analysis, set up the computation model between each test result and many mineral;

Step 4, the inverting of formation core sample mineralogical composition: the well-log information of institute's coring sample is mated with sample in database, choose and may substitute in step 3 the computation model set up by rock parameter, wherein namely result of calculation and the minimum rock parameter of measured result error can be used as mineralogical composition and the content parameter of this core sample.

The invention has the beneficial effects as follows: the present invention is intended to utilize well-log information and the rock mineral composition that drawn by rock polarized microscope analysis and X-ray diffraction analysis and content, obtain the corresponding relation between rock parameter and some logging trace value, for the determination of on-the-spot drilling technology parameter provides stratum reference frame.In addition, the formation lithology parameter of specifying needed for achievement of the present invention can draw according to well-log information, can make up indoor test cycle long, weak point costly.

Accompanying drawing explanation

Fig. 1 is the process flow diagram of the analytical approach of a kind of formation rock mineralogical composition of the present invention.

Embodiment

The invention provides and a kind ofly utilize the method that core sample carries out polarized microscope analysis, XRD test is proved mutually with well-log information, obtaining the main mineral constituent of formation rock by conventional gas and oil well-log information, is drilling engineering service.

Below in conjunction with the drawings and specific embodiments, the present invention is further detailed explanation:

See Fig. 1, the analytical approach of a kind of formation rock mineralogical composition of the present invention comprises the following steps:

Step one, to choose in survey region the core sample that many groups have different rock mineral composition and content, carry out polarized microscope analysis and X-ray diffraction analysis respectively.Comprehensive Correlation is carried out to the test result of two class experiments, draws mineral type and the content thereof of each group rock.

Step 2, the resistivity measurement core sample in step one being carried out respectively to rock, density and interval transit time are tested, and set up the related logging document data base of the core sample of different minerals type and content.

Step 3, set up rock forming mineral kind and content and rock sample resistivity, response model between density and interval transit time.Subterranean minerals type and content can be represented by volume-based model for the response equation of logging instrumentation test result.Be provided with the typical core sample of N group, the content of M kind mineral be calculated, and N >=M, add that volumetric balance equation can list N+1 equation.Material is thus formed three linear over-determined systems of log response such as resistivity, density and interval transit time:

$\left\{\begin{array}{c}{\mathrm{ATRX}}_1=a_1{V}_{11}+a_2{V}_{21}+a_3{V}_{31}+...+a_M{V}_{M1}\\ {\mathrm{ATRX}}_2=a_1{V}_{12}+a_2{V}_{22}+a_3{V}_{32}+...+a_M{V}_{M2}\\ .\\ .\\ .\\ {\mathrm{ATRX}}_N=a_1{V}_{1N}+a_2{V}_{2N}+a_3{V}_{3N}+...+a_M{V}_{\mathrm{MN}}\\ 1=V_1+V_2+...+V_3\end{array}\right.---\left(1\right)$

$\left\{\begin{array}{c}{\mathrm{DEN}}_1=b_1{V}_{11}+b_2{V}_{21}+b_3{V}_{31}+...+b_M{V}_{M1}\\ {\mathrm{DEN}}_2=b_1{V}_{12}+b_2{V}_{22}+b_3{V}_{32}+...+b_M{V}_{M2}\\ .\\ .\\ .\\ {\mathrm{DEN}}_N=b_1{V}_{1N}+b_2{V}_{2N}+b_3{V}_{3N}+...+b_M{V}_{\mathrm{MN}}\\ 1=V_1+V_2+...+V_3\end{array}\right.---\left(2\right)$

$\left\{\begin{array}{c}{\mathrm{AC}}_1=c_1{V}_{11}+c_2{V}_{21}+c_3{V}_{31}+...+c_M{V}_{M1}\\ {\mathrm{AC}}_2=c_1{V}_{12}+c_2{V}_{22}+c_3{V}_{32}+...+c_M{V}_{M2}\\ .\\ .\\ .\\ {\mathrm{AC}}_N=c_1{V}_{1N}+c_2{V}_{2N}+c_3{V}_{3N}+...+c_M{V}_{\mathrm{MN}}\\ 1=V_1+V_2+...+V_3\end{array}\right.---\left(3\right)$

In formula, ATRX _i, DEN _iand AC _ibe respectively the array induction resistivity of i-th group of rock sample, density and interval transit time; V _ijit is the jth kind mineral content of i-th group of rock sample; a _j, b _jand c _jbe respectively the linear response coefficient of jth kind mineral content to rock sample resistivity, density and interval transit time.

A can be obtained respectively by formula (1), (2) and (3) _j, b _jand c _j, namely draw rock forming mineral kind and content and rock sample resistivity, RESPONSE CALCULATION model between density and interval transit time, be respectively:

ATRX＝a ₁V ₁+a ₂V ₂+a ₃V ₃+…+a _MV _M(4)

DEN＝b ₁V ₁+b ₂V ₂+b ₃V ₃+…+b _MV _M(5)

AC＝c ₁V ₁+c ₂V ₂+c ₃V ₃+…+c _MV _M(6)

Step 4, drilling stratum section lithological inversion.Based on the Well logging Data storehouse set up in step 2, the resistivity of institute's coring, density and interval transit time are mated with the core sample in database respectively, draw three groups of possible rock core mineral types and content.The content of often kind of mineral type in three groups of parameters is averaged, as the 4th kind of possible rock core mineral type and content thereof, and four groups of parameters are updated in formula (4), (5) and (6) calculate.Result of calculation and measured result are analyzed, get resistivity, density and interval transit time calculated value and the minimum mineralogical composition of measured value total error and type as the mineralogical composition of institute's coring and content.

In sum, content of the present invention is not limited in the above-described embodiment, and those skilled in the art can propose other embodiment within technological guidance's thought of the present invention, but these embodiments all comprise within the scope of the present invention.

Claims (1)

1. an analytical approach for formation rock mineralogical composition, is characterized in that, comprises the following steps:

The Experiments of Optics of step one, rock sample mineralogical composition are determined: many groups of choosing in survey region have the core sample of Typical Representative meaning, carry out polarized microscope analysis and X-ray diffraction analysis respectively, determine mineral species and the content of rock sample;

The acoustics of step 2, rock sample and electricity characteristic measuring: to the rock sample in step one, measure the interval transit time of rock, resistivity and density in laboratory conditions, sets up the related logging document data base with the core sample of different minerals type and content;

Step 3, set up rock acoustics and electrical testing result and the mutual relationship between rock mineral composition and content, based on the result of core analysis, set up the computation model between each test result and many mineral;

Step 4, the inverting of formation core sample mineralogical composition: the well-log information of institute's coring sample is mated with sample in database, choose and may substitute in step 3 the computation model set up by rock parameter, wherein namely result of calculation and the minimum rock parameter of measured result error can be used as mineralogical composition and the content parameter of this core sample.