CN116068664A - Method for calculating shale gas reservoir density by using element logging - Google Patents
Method for calculating shale gas reservoir density by using element logging Download PDFInfo
- Publication number
- CN116068664A CN116068664A CN202111542845.XA CN202111542845A CN116068664A CN 116068664 A CN116068664 A CN 116068664A CN 202111542845 A CN202111542845 A CN 202111542845A CN 116068664 A CN116068664 A CN 116068664A
- Authority
- CN
- China
- Prior art keywords
- reservoir
- shale gas
- density
- gas reservoir
- calculating
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000000034 method Methods 0.000 title claims abstract description 44
- 229910052500 inorganic mineral Inorganic materials 0.000 claims abstract description 119
- 239000011707 mineral Substances 0.000 claims abstract description 119
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims abstract description 74
- 238000004364 calculation method Methods 0.000 claims abstract description 74
- 239000011435 rock Substances 0.000 claims abstract description 66
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 63
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 63
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 35
- 229910052759 nickel Inorganic materials 0.000 claims abstract description 34
- 229910052900 illite Inorganic materials 0.000 claims abstract description 29
- VGIBGUSAECPPNB-UHFFFAOYSA-L nonaaluminum;magnesium;tripotassium;1,3-dioxido-2,4,5-trioxa-1,3-disilabicyclo[1.1.1]pentane;iron(2+);oxygen(2-);fluoride;hydroxide Chemical compound [OH-].[O-2].[O-2].[O-2].[O-2].[O-2].[F-].[Mg+2].[Al+3].[Al+3].[Al+3].[Al+3].[Al+3].[Al+3].[Al+3].[Al+3].[Al+3].[K+].[K+].[K+].[Fe+2].O1[Si]2([O-])O[Si]1([O-])O2.O1[Si]2([O-])O[Si]1([O-])O2.O1[Si]2([O-])O[Si]1([O-])O2.O1[Si]2([O-])O[Si]1([O-])O2.O1[Si]2([O-])O[Si]1([O-])O2.O1[Si]2([O-])O[Si]1([O-])O2.O1[Si]2([O-])O[Si]1([O-])O2 VGIBGUSAECPPNB-UHFFFAOYSA-L 0.000 claims abstract description 29
- 239000004927 clay Substances 0.000 claims description 34
- 229910052570 clay Inorganic materials 0.000 claims description 34
- 239000010453 quartz Substances 0.000 claims description 29
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 29
- 229910021532 Calcite Inorganic materials 0.000 claims description 25
- 239000010459 dolomite Substances 0.000 claims description 25
- 229910000514 dolomite Inorganic materials 0.000 claims description 25
- 229910052683 pyrite Inorganic materials 0.000 claims description 16
- 239000011028 pyrite Substances 0.000 claims description 16
- NIFIFKQPDTWWGU-UHFFFAOYSA-N pyrite Chemical compound [Fe+2].[S-][S-] NIFIFKQPDTWWGU-UHFFFAOYSA-N 0.000 claims description 16
- 229910052710 silicon Inorganic materials 0.000 claims description 14
- 238000004458 analytical method Methods 0.000 claims description 13
- GUJOJGAPFQRJSV-UHFFFAOYSA-N dialuminum;dioxosilane;oxygen(2-);hydrate Chemical compound O.[O-2].[O-2].[O-2].[Al+3].[Al+3].O=[Si]=O.O=[Si]=O.O=[Si]=O.O=[Si]=O GUJOJGAPFQRJSV-UHFFFAOYSA-N 0.000 claims description 13
- NLYAJNPCOHFWQQ-UHFFFAOYSA-N kaolin Chemical compound O.O.O=[Al]O[Si](=O)O[Si](=O)O[Al]=O NLYAJNPCOHFWQQ-UHFFFAOYSA-N 0.000 claims description 13
- 229910052622 kaolinite Inorganic materials 0.000 claims description 13
- 229910052901 montmorillonite Inorganic materials 0.000 claims description 13
- 239000010433 feldspar Substances 0.000 claims description 12
- 229910052602 gypsum Inorganic materials 0.000 claims description 12
- 239000010440 gypsum Substances 0.000 claims description 12
- 239000010445 mica Substances 0.000 claims description 12
- 229910052618 mica group Inorganic materials 0.000 claims description 12
- 230000015572 biosynthetic process Effects 0.000 claims description 10
- 229910052700 potassium Inorganic materials 0.000 claims description 8
- 229910052717 sulfur Inorganic materials 0.000 claims description 8
- DLHONNLASJQAHX-UHFFFAOYSA-N aluminum;potassium;oxygen(2-);silicon(4+) Chemical compound [O-2].[O-2].[O-2].[O-2].[O-2].[O-2].[O-2].[O-2].[Al+3].[Si+4].[Si+4].[Si+4].[K+] DLHONNLASJQAHX-UHFFFAOYSA-N 0.000 claims description 6
- 238000012937 correction Methods 0.000 claims description 6
- 238000005259 measurement Methods 0.000 claims description 6
- 239000008398 formation water Substances 0.000 claims description 5
- 239000003079 shale oil Substances 0.000 claims description 5
- 230000004807 localization Effects 0.000 claims description 4
- 239000005416 organic matter Substances 0.000 claims description 3
- 239000004215 Carbon black (E152) Substances 0.000 claims description 2
- 229930195733 hydrocarbon Natural products 0.000 claims description 2
- 150000002430 hydrocarbons Chemical class 0.000 claims description 2
- 229910052708 sodium Inorganic materials 0.000 claims description 2
- 238000001228 spectrum Methods 0.000 claims description 2
- 238000004876 x-ray fluorescence Methods 0.000 claims description 2
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 claims 1
- 239000011734 sodium Substances 0.000 claims 1
- 230000000704 physical effect Effects 0.000 abstract description 14
- 238000011156 evaluation Methods 0.000 abstract description 12
- 238000011161 development Methods 0.000 abstract description 11
- 235000010755 mineral Nutrition 0.000 description 96
- 230000000875 corresponding effect Effects 0.000 description 15
- 229910052656 albite Inorganic materials 0.000 description 12
- 239000003921 oil Substances 0.000 description 9
- 239000010703 silicon Substances 0.000 description 7
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 5
- 238000005553 drilling Methods 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- 230000002596 correlated effect Effects 0.000 description 3
- 230000008021 deposition Effects 0.000 description 3
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 235000013628 Lantana involucrata Nutrition 0.000 description 1
- 235000006677 Monarda citriodora ssp. austromontana Nutrition 0.000 description 1
- 240000007673 Origanum vulgare Species 0.000 description 1
- 239000012267 brine Substances 0.000 description 1
- 238000012512 characterization method Methods 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 230000002950 deficient Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000013210 evaluation model Methods 0.000 description 1
- 241000238565 lobster Species 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000010606 normalization Methods 0.000 description 1
- HPALAKNZSZLMCH-UHFFFAOYSA-M sodium;chloride;hydrate Chemical compound O.[Na+].[Cl-] HPALAKNZSZLMCH-UHFFFAOYSA-M 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 241000894007 species Species 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 235000013619 trace mineral Nutrition 0.000 description 1
- 239000011573 trace mineral Substances 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01V—GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS
- G01V11/00—Prospecting or detecting by methods combining techniques covered by two or more of main groups G01V1/00 - G01V9/00
Landscapes
- Physics & Mathematics (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- General Physics & Mathematics (AREA)
- Geophysics (AREA)
- Geophysics And Detection Of Objects (AREA)
Abstract
The invention provides a method for calculating shale gas reservoir density by using element logging, which comprises the following steps: according to the content of reservoir elements measured by element logging and the molecular formula of minerals in the reservoir, inverting to calculate the mass fraction of each mineral and the density of a rock skeleton; calculating the total organic carbon content in the reservoir according to the nickel element content fitting curve; calculating the porosity of the shale gas reservoir based on reservoir minerals; calculating the water saturation and the gas saturation according to the content of illite; and according to the calculation result, calculating the rock density of the shale gas reservoir. According to the method, the mineral component content and the rock skeleton density are calculated through inversion of element logging data, then the total organic carbon content, the porosity, the water content and the gas saturation are calculated sequentially, the rock density of the reservoir is obtained, the error of a calculation result is small, the evaluation of physical properties of the reservoir is accurate, and theory and data support are provided for shale gas development; the method is simple to operate, reduces the difficulty of measuring physical parameters, and has wide application range.
Description
Technical Field
The invention belongs to the technical field of shale gas exploration and development, and relates to a method for calculating shale gas reservoir density by using element logging.
Background
With the development of unconventional oil and gas resources, shale gas has become an important component part of the development of the current oil and gas resources, and shale reservoirs are main areas for accumulating and storing shale gas, so that the characterization of relevant characteristics and parameters of the shale reservoirs is the basis of the development of the shale gas. The logging operation is a basic technology in the exploration and development activities of the oil and gas reservoirs, is the most timely and direct technical means for finding and evaluating the oil and gas reservoirs, has the characteristics of timely and various underground information acquisition and quick analysis and explanation, and can provide reliable information service support for drilling operation; the element logging is an important one in logging technology, and is mainly used for detecting and analyzing element content in rock stratum, so that mineral composition of the rock stratum is defined, evaluation of rock stratum physical properties is facilitated, and technical support is provided for oil and gas exploration and development.
In the oil and gas exploration and development process, density is an important parameter for describing reservoir capacity of a reservoir, the acquisition mode of the method comprises two modes of density logging and shale density logging, and due to factors such as engineering safety, cost reduction and the like, a large number of horizontal wells do not develop density logging, so that evaluation parameters are deficient, and the shale density is usually calculated by adopting a logging mode at present. Because the reservoir density is related to factors such as minerals, sedimentary environment and the like, and the shale gas reservoir consists of a rock skeleton, total organic carbon, stratum water, shale gas and the like, each component part needs to be comprehensively considered in calculation of the reservoir density, the rock skeleton consists of various minerals, and the imbalance of the density can be caused due to the different physical properties of the different minerals, so that the difficulty of calculation and physical property evaluation of the shale gas reservoir is further increased.
In the article of 'shale density calculation model based on multi-element self-adaptive regression spline', european biography root et al discloses a method for fitting shale density through element logging measured unit element content and multi-element self-adaptive regression spline algorithm, but because the same single element can correspond to a plurality of minerals, each mineral has specific element composition and physical properties, even if the mineral contains the same element, the properties of the mineral can be greatly different, so the unit element is fit for shale gas reservoirs with various mineral types and multi-component parts, and the method has poor universality.
CN 111997598A discloses a logging while drilling reservoir evaluation method, a model building method, a device and an electronic apparatus, the evaluation method comprises: acquiring element logging data in the drilling process; calculating brittleness index, deposition environment and physical parameters according to the element logging data; respectively carrying out normalization treatment on the brittleness index and the deposition environment; and obtaining a reservoir evaluation result while drilling according to the physical parameters, a pre-established three-parameter reservoir evaluation model, the normalized brittleness index and the deposition environment. The method does not explicitly specify a calculation method for evaluating the reservoir, but only gives related parameters, wherein logging data required by the parameters are different from parameters and data required by reservoir density calculation, and the calculation of the reservoir density based on minerals is not involved.
In summary, for element logging calculation of shale gas reservoir density, mineral composition and constituent parts in the reservoir are also required to be used as bases, so that physical properties of the reservoir can be accurately evaluated, and data support is provided for shale gas exploitation.
Disclosure of Invention
Aiming at the problems existing in the prior art, the invention aims to provide a method for calculating the density of a shale gas reservoir by using element logging, which is characterized in that the content of each mineral component and the rock skeleton density are calculated through inversion of element content measured by element logging, the porosity of the shale gas reservoir is calculated through calculation of total organic carbon content, the rock density of the reservoir is comprehensively calculated through calculation of water content and gas saturation, the error of a calculation result is smaller, the evaluation of physical properties of the reservoir is more accurate, and theory and data support are provided for shale gas development.
To achieve the purpose, the invention adopts the following technical scheme:
the invention provides a method for calculating shale gas reservoir density by using element logging, which comprises the following steps:
(1) According to mass fractions of reservoir elements measured by element logging and molecular formulas of minerals in the reservoir, inverting and calculating mass fractions of the minerals, and further calculating the density of a rock skeleton in the shale gas reservoir;
(2) Calculating the total organic carbon content in the shale gas reservoir according to a nickel element content fitting curve measured by element logging;
(3) According to the difference of the total organic carbon content obtained in the step (2), calculating the porosity of the shale gas reservoir based on quartz, calcite, dolomite and clay in the reservoir minerals;
(4) According to the content of illite in the reservoir minerals calculated in the step (1), calculating the water saturation of the shale gas reservoir, and further calculating the gas saturation of the shale gas reservoir;
(5) And (3) calculating the rock density of the shale gas reservoir according to the components of the shale gas reservoir and the calculation results of the steps (1) - (4).
In the invention, the data measured by element logging is mainly the content of each element, but the fitting formula established by fitting only single element has poor universality because the same element can correspond to a plurality of minerals, and the physical property evaluation of the shale gas reservoir is inaccurate, so the content of each mineral in the reservoir is obtained by inversion calculation of the element content measured by element logging, and the density of a rock skeleton can be calculated according to the mineral content; then fitting to obtain the total organic carbon content in the shale gas reservoir, wherein the total organic carbon content is related to the calculation of the porosity, and based on the total organic carbon content, the calculation formula of the porosity is obtained by combining the content of mineral types in the reservoir related to the porosity; obtaining a calculation formula of the water saturation according to minerals related to the water saturation of the shale gas reservoir, and obtaining the gas saturation at the same time; the density of each component is utilized to obtain a calculation formula of the integral density of the shale gas reservoir, the error between a calculation result obtained by the calculation formula and a logging result is small, the accuracy is high, the accurate evaluation of the physical properties of the shale gas reservoir is realized, the data support is provided for the calculation of other physical property parameters of the reservoir, the exploitation efficiency of the shale gas is improved, and the exploitation difficulty is reduced.
The following technical scheme is a preferred technical scheme of the invention, but is not a limitation of the technical scheme provided by the invention, and the technical purpose and beneficial effects of the invention can be better achieved and realized through the following technical scheme.
As a preferred embodiment of the present invention, the reservoir element in step (1) includes Si, ca, al, mg, K, na, fe, S and Ni.
Preferably, the mineral components of the shale gas reservoir include quartz, calcite, dolomite and clay.
Preferably, the mineral component of the shale gas reservoir further comprises any one or a combination of at least two of pyrite, gypsum, or feldspar, with typical but non-limiting examples of such combinations being: a combination of pyrite and gypsum, a combination of gypsum and feldspar, a combination of pyrite, gypsum and feldspar, and the like.
Preferably, the clay comprises any one or a combination of at least two of illite, montmorillonite, kaolinite, or mica, with typical but non-limiting examples: a combination of illite and montmorillonite, a combination of kaolinite and mica, a combination of illite, montmorillonite and kaolinite, a combination of illite, montmorillonite, kaolinite and mica, and the like.
Preferably, the feldspar comprises any one or a combination of at least two of potassium feldspar, albite or analcite, typical but non-limiting examples of which are: a combination of potassium feldspar and albite, a combination of albite and analcite, a combination of potassium feldspar, albite and analcite, and the like.
In the invention, the shale gas reservoir is mainly positioned in a sedimentary rock stratum, the related mineral components comprise quartz, clay, carbonate rock, feldspar, gypsum and the like, the mineral components comprise quartz, potassium feldspar, albite, analcite, kaolinite, montmorillonite, illite, mica, calcite, dolomite, gypsum, pyrite and the like, and the chemical molecular formulas and main elements of the minerals are shown in table 1.
TABLE 1 chemical formulas and major elements of minerals in shale gas reservoirs
The minerals listed in the above table are not all of the minerals that make up the shale gas reservoir, but are only the larger mass fraction of the minerals, and of course, not all shale reservoirs include the minerals described above, and may include only some of the minerals described above, depending on the region and horizon.
According to the preferred technical scheme, inversion calculation of each mineral in the shale gas reservoir is further carried out by determining at least one coefficient representing the mass fraction proportion of two minerals according to the region and the horizon of the shale gas reservoir.
Preferably, the two minerals corresponding to the coefficients contain at least one identical element.
In the invention, the inversion calculation of the mineral content needs not only the content of each element and the molecular formula of the mineral, but also the minerals containing the same kind of elements, especially the few kinds of minerals containing the same kind of elements, so that the simultaneous equation system is convenient to calculate the content of each mineral.
Preferably, the density of the rock skeleton in the step (1) is calculated by taking the reciprocal of the sum of the ratio of the mass fraction of each mineral to the respective density, and the rock skeleton density is expressed as ρ s-el 。
In the invention, the density of the rock skeleton is calculated according to the mineral composition of the rock skeleton in the shale gas reservoir and the density of single minerals, and the calculated formula is given as an example of the enumerated minerals
ρ s-el ＝100/(ω 1-el /ρ 1 +ω 2-el /ρ 2 +ω 3-el /ρ 3 +ω 4-el /ρ 4 +ω 5-el /ρ 5 +ω 6-el /ρ 6 +ω 7-el /ρ 7 )
wherein ,ω1-el 、ω 2-el 、ω 3-el 、ω 4-el 、ω 5-el 、ω 6-el and ω7-el Mass fractions of quartz, calcite, dolomite, clay, pyrite, gypsum and feldspar, ρ, calculated for elemental logging, respectively 1 、ρ 2 、ρ 3 、ρ 4 、ρ 5 、ρ 6 and ρ7 Densities of quartz, calcite, dolomite, clay, pyrite, gypsum and feldspar, respectively, if a certain mineral is not contained in the reservoir, the mineral is not included in calculation, and if a certain mineral is included in a plurality of minerals, the mineral is split for calculation respectively; of the above-mentioned mineral species, quartz density takes on value2.5, potassium feldspar density value 2.57, albite density value 2.62, analcite density value 2.6, kaolinite density value 2.63, montmorillonite density value 2.6, illite density value 2.8, mica density value 3.05, calcite density value 2.71, dolomite density value 2.87, gypsum density value 2.4, pyrite density value 5.2, density units of g/cm 3 。
As a preferred technical scheme of the invention, the equipment used for element logging measurement comprises an X-ray fluorescence spectrum analyzer (XRF), wherein the common equipment model is Tianrui EDX4500H type and Tianrui EDX5500H type.
Preferably, the zone of elemental log measurements includes a longmaxi group shale formation and a pentamodal group shale formation.
At present, shale gas exploration and exploitation mainly comes from shale reservoirs of a Lobster group and a five-peak group, wherein the shale reservoirs belong to a volunteer system bottom layer, and the shale reservoirs belong to an Oregano system stratum; parameters acquired through element logging are element types and contents, wherein main elements are Na, mg, al, si, P, S, cl, K, ca, ti, V, cr, mn, fe and the like, and trace elements are Co, ni, cu, zn, as, rb, sr, Y, zr, nb, mo, ag, cd, in, sn, W, pb, se, ga, cr and the like.
As a preferred technical scheme of the invention, the fitting curve in the step (2) needs a plurality of groups of data of nickel element content and total organic carbon content.
Preferably, the data of total organic carbon content is obtained from a localization logging analysis or laboratory analysis.
In the invention, in order to fit a calculation formula for obtaining the total organic carbon content, besides the nickel element content, the point value of the total organic carbon content is needed, so that the point value is obtained by adopting other modes, a fitting curve is used for obtaining the formula, then the total organic carbon content in the element record is calculated, and data with smaller difference between the two calculation modes is selected.
As a preferable technical scheme of the invention, the formula obtained after the curve is fitted is
TOC el ＝(2.1228×ln(ω Ni -ω Ni-B )+14.4470)×ω 0
wherein ,TOCel Total organic carbon content, ω, calculated for elemental logging Ni Normalized nickel content, ω, for elemental log measurements Ni-B The nickel element content base value for element logging refers to the corresponding nickel element content, omega in the stratum with lower total organic carbon content 0 The TOC correction factor is a correction factor having a value ranging from 0.5 to 2, for example, 0.5, 0.8, 1, 1.2, 1.5 or 2, and is related to the degree of enrichment of nickel in the region and the measured value of TOC.
Preferably according to TOC el Numerical value, if the calculation result is smaller than 0, TOC el Taking 0.
In the invention, the calculation of the total organic carbon content is carried out by selecting the content of metallic nickel as a calculation reference, and the calculation is mainly based on the fact that the correlation between TOC (total organic carbon) or element nickel content calculated by analyzing TOC or geochemical logging in a core laboratory is good, the correlation coefficient is 0.7563, and the corresponding fitting goodness is 0.572.
As a preferred embodiment of the present invention, the total organic carbon content in step (3) is divided into two ranges, TOC respectively el Less than or equal to 2.5 weight percent and TOC el >2.5wt％。
In the invention, the two ranges of total organic carbon content are divided, namely the empirical value obtained mainly according to parameter statistics, and are mainly used for distinguishing organic silicon and inorganic silicon, when TOC el >2.5wt% of silicon in the shale gas reservoir is mainly organic silicon, and the porosity is positively correlated with the organic silicon content; taking the Drama stream group and the five-peak group as examples, most of high-silicon reservoirs of the Drama stream group have the characteristics of high TOC and high porosity, and the Drama stream group covers the high-silicon reservoirs of the stratum five-peak shale of the stratum, and has the characteristics of low TOC and low porosity.
Preferably, the porosity is calculated in relation to the mass fractions of quartz, calcite, dolomite and clay in the mineral, which mass fractions are denoted ω, respectively 1-el 、ω 2-el 、ω 3-el and ω4-el 。
As a preferred embodiment of the present invention, the total organic carbon content TOC el At less than or equal to 2.5wt percent, the porosity of the shale gas reservoir is less than or equal to 2wt percentThe calculation formula is that
wherein ,
porosity, epsilon calculated for elemental logging 1 Is the first hydrocarbon reservoir coefficient.
Preferably, the first shale gas reservoir coefficient epsilon 1 The value is 2 to 5, for example, 2, 3, 4 or 5, but is not limited to the recited values, and other values not recited in the range of values are equally applicable.
As a preferred embodiment of the present invention, the total organic carbon content TOC el >At 2.5wt%, the calculation formula of the shale gas reservoir porosity is as follows
wherein ,
porosity, epsilon calculated for elemental logging 2 Is the second shale gas reservoir coefficient.
Preferably, the second shale gas reservoir coefficient ε 2 The value is 5 to 15, for example, 5, 6, 8, 10, 12 or 15, etc., but is not limited to the recited values, and other values not recited in the range of values are equally applicable.
In the invention, quartz, calcite, dolomite and clay are selected as the basis of shale gas reservoir porosity calculation, mainly because the shale gas reservoir porosity and the siliceous content are totally positively correlated and inversely correlated with the clay content and the carbonate content according to the previous study; in addition, under the same conditions, the thermal expansion coefficient of quartz is 5-10 times that of most other rock minerals, quartz is more prone to crack, and the porosity of a reservoir with high quartz content is higher.
As a preferable technical scheme of the invention, the illite in the step (4) belongs to one of clay, and the mass fraction of illite is calculated in the step (1) and is marked as omega 41-el 。
Preferably, the water saturation calculation formula in step (4) is
S w-el ＝19.2828×POWER(ω 41-el ,1/2)-3.6675
wherein ,Sw-el Water saturation calculated for elemental logging.
Preferably according to S w-el If the value is less than 0, S w-el Taking 0, if the value is greater than 100, S w-el Taking 100.
In the invention, the water saturation calculation formula is obtained, besides the point value of the mass fraction of illite calculated by element logging, the water saturation value is also needed, and the water saturation is obtained by core laboratory analysis or logging calculation; the calculation of the water saturation is based on the illite content, mainly because the water saturation has better correlation with the illite content, the correlation coefficient of the water saturation and the square root of the illite content is 0.7426, and the corresponding fitting goodness is 0.5515.
Preferably, the shale gas reservoir has a gas saturation S g-el ＝100-S w-el 。
Preferably, if the reservoir is a shale oil reservoir, the corresponding is oil saturation S o-el ＝100-S w-el 。
In the invention, when the stratum is a shale gas reservoir, the gas saturation is calculated from the water saturation, and if the stratum is a shale oil reservoir, the oil saturation is calculated from the water saturation.
As a preferable technical scheme of the invention, the shale gas reservoir in the step (5) consists of a rock skeleton, total organic carbon, formation gas and formation water.
Preferably, the rock density in step (5) is calculated by the formula
wherein ,ρb-el Rock density, ρ, calculated for elemental logging s-el Rock skeleton density, ρ, calculated for elemental logging g Is the formation gas density ρ fw Is the formation water density ρ TOC Is the density of organic matter; among the above densities, the formation gas density takes a value of 1.5, the brine density takes a value of 1.05, and the organic matter density takes a value of 1.5; if the shale oil contains an oil phase, the shale oil density takes a value of 1.0, and the units are g/cm 3 。
According to the method, the calculation of the rock density of the shale gas reservoir is determined by the relation between each component and the whole density, wherein in the formula, the shale gas reservoir consists of four parts of a rock skeleton, formation water, formation gas and organic matters, and the rock density is calculated according to a rock volume model and the conversion relation of the volume fraction, mass fraction and density of each part.
As a preferred technical solution of the present invention, the method comprises the steps of:
(1) According to mass fractions of reservoir elements measured by element logging and molecular formulas of minerals in a reservoir, wherein the reservoir elements comprise Si, ca, al, mg, K, na, fe, S and Ni, mineral components of the reservoir comprise quartz, calcite, dolomite and clay, and any one or a combination of at least two of pyrite, gypsum and feldspar, the mass fractions of the minerals are calculated in an inversion mode, and at least one coefficient representing mass fraction proportion of two minerals is determined according to the region and the layer where the shale gas reservoir is located in the inversion calculation mode, and the two minerals corresponding to the coefficient at least contain one same element; further calculating the density of a rock skeleton in the shale gas reservoir, wherein the density of the rock skeleton is calculated by taking the reciprocal after adding the ratio of the mass fraction of each mineral to the respective density;
(2) Fitting a curve according to the nickel element content measured by element logging, wherein the fitting curve requires a plurality of groups of data of the nickel element content and the total organic carbon content, the data of the total organic carbon content is obtained by a localization logging analysis or a laboratory analysis, and a formula obtained after the fitting curve is TOC el ＝(2.1228×ln(ω Ni -ω Ni-B )+14.4470)×ω 0 Calculating the total organic carbon content in the shale gas reservoir, and if the calculation result is smaller than 0, TOC el Taking 0;
(3) According to the difference of the total organic carbon content obtained in the step (2), the total organic carbon content is divided into two ranges, namely TOC el Less than or equal to 2.5 weight percent and TOC el >2.5 wt.% of total organic carbon TOC based on mass fraction of quartz, calcite, dolomite and clay in reservoir minerals el When the weight percentage is less than or equal to 2.5 percent, the calculation formula of the shale gas reservoir porosity is that
Total organic carbon content TOC el >2.5wt% of shale gas reservoir porosity is calculated as +.>
Calculating the porosity of the shale gas reservoir;
(4) Mass fraction ω of illite in reservoir minerals calculated according to step (1) 41-el Calculating the water saturation of the shale gas reservoir, wherein the calculation formula of the water saturation is S w-el ＝19.2828×POWER(ω 41-el 1/2) -3.6675, and further calculating the gas saturation S of the shale gas reservoir g-el ＝100-S w-el ；
(5) According to the components of the shale gas reservoir and the calculation results of the steps (1) - (4), calculating the rock density of the shale gas reservoir, wherein the calculation formula of the rock density is as follows
/>
Compared with the prior art, the invention has the following beneficial effects:
(1) According to the method, the content of each mineral component and the rock skeleton density are calculated through inversion of element content measured by element logging, the porosity of the shale gas reservoir is calculated through calculation of total organic carbon content, the rock density of the reservoir is comprehensively calculated through calculation of water content and gas saturation, the error of a calculation result is smaller than that of a logging result, the error of an average value of the calculation result and the logging result is only-0.44%, the overall average error is-0.35%, the evaluation of physical properties of the reservoir is accurate, and theory and data support are provided for shale gas development;
(2) The method disclosed by the invention is simple to operate, the difficulty in measuring the physical property parameters of the shale gas reservoir is reduced by obtaining the fitting formula, and the application range is wide.
Drawings
FIG. 1 is a graph of elemental log calculated density versus log density for an embodiment of the present invention.
Detailed Description
For better illustrating the present invention, the technical scheme of the present invention is convenient to understand, and the present invention is further described in detail below. The following examples are merely illustrative of the present invention and are not intended to represent or limit the scope of the invention as defined in the claims.
The invention provides a method for calculating the density of a shale gas reservoir by using element logging, which comprises the following steps:
(1) According to mass fractions of reservoir elements measured by element logging and molecular formulas of minerals in the reservoir, inverting and calculating mass fractions of the minerals, and further calculating the density of a rock skeleton in the shale gas reservoir;
(2) Calculating the total organic carbon content in the shale gas reservoir according to a nickel element content fitting curve measured by element logging;
(3) According to the difference of the total organic carbon content obtained in the step (2), calculating the porosity of the shale gas reservoir based on quartz, calcite, dolomite and clay in the reservoir minerals;
(4) According to the content of illite in the reservoir minerals calculated in the step (1), calculating the water saturation of the shale gas reservoir, and further calculating the gas saturation of the shale gas reservoir;
(5) And (3) calculating the rock density of the shale gas reservoir according to the components of the shale gas reservoir and the calculation results of the steps (1) - (4).
The following are exemplary but non-limiting examples of the invention:
example 1:
the embodiment provides a method for calculating the density of shale gas reservoirs by using element logging, taking a shale gas horizontal well in Luzhou area of Sichuan basin as an example, the method comprises the following steps:
(1) According to mass fractions of reservoir elements measured by element logging and molecular formulas of minerals in a reservoir, wherein the reservoir elements comprise Si, ca, al, mg, K, na, fe, S and Ni, mineral components of the reservoir comprise quartz, calcite, dolomite, clay, pyrite and albite, the clay comprises illite, montmorillonite, kaolinite and mica, the mass fractions of the minerals are calculated in an inversion mode, and four coefficients representing mass fraction proportions of two minerals are determined according to regions and layers where shale gas reservoirs are located in the inversion mode, and two minerals corresponding to the coefficients contain the same elements; further calculating the density of a rock skeleton in the shale gas reservoir, wherein the density of the rock skeleton is calculated by taking the reciprocal after adding the ratio of the mass fraction of each mineral to the respective density;
in the section with the well depth of 3900-5992 m, element logging is carried out to measure and analyze samples, 5000m well depth points are taken as an example, and calculated according to inversion of the content of each element, and the mass fractions of the minerals are respectively as follows: 49.03% of quartz, 23.12% of calcite, 10.31% of dolomite, 10.64% of clay, 2.80% of pyrite and 4.10% of albite, wherein the clay comprises 0.00% of illite, 0.95% of montmorillonite, 1.30% of kaolinite and 8.39% of mica;
and then the density of each mineral is combined to take value, and the density of the corresponding rock skeleton is ρ s-el ＝100/(49.03/2.5+4.1/2.62+8.39/3.05+0.95/2.6+1.30/2.63+0.00/2.8+23.12/2.71+10.31/2.87+2.8/5.2)＝2.67g/cm 3 ；
(2) Fitting a curve according to the nickel element content measured by element logging, wherein the fitting curve requires a plurality of groups of data of the nickel element content and the total organic carbon content, and the data of the total organic carbon content are localizedLogging analysis is carried out, and the formula obtained after the curve fitting is TOC el ＝(2.1228×ln(ω Ni -ω Ni-B )+14.4470)×ω 0 Calculating the total organic carbon content in the shale gas reservoir;
ni content of 196ppm measured by 5000m well depth point element logging, corresponding omega Ni 0.0196%, omega Ni-B 0.00%, omega 0 The correction coefficient is 0.8, and the TOC is calculated by substituting the formula el 4.88 wt.%;
(3) According to the total organic carbon content obtained in step (2), due to TOC el >2.5wt% of shale gas reservoir porosity calculated by the following formula based on the mass fraction of quartz, calcite, dolomite and clay in the reservoir minerals
wherein ε2 For 10, calculate the porosity of shale gas reservoir +.>
4.73%;
(4) Mass fraction ω of illite in reservoir minerals calculated according to step (1) 41-el Calculating the water saturation of the shale gas reservoir, and substituting the water saturation into a calculation formula S w-el ＝19.2828×POWER(ω 41-el 1/2) -3.6675, the water saturation S is less than 0 w-el Taking 0.00% and adopting formula S g-el ＝100-S w-el Calculating gas saturation S of shale gas reservoir g-el 100%;
(5) According to the calculation results of the steps (1) - (4), calculating the rock density of the shale gas reservoir, wherein the calculation formula is as follows
Binding ρ g 、ρ fw 、ρ TOC To obtain the value of (2)Rock density of shale gas reservoir is 2.52g/cm 3 。
In this example, the logging density was 2.59g/cm at the same depth and location in a shale gas well 3 The error between the calculated density of elemental logging and the logging density is-2.56%.
Example 2:
the embodiment provides a method for calculating the density of shale gas reservoirs by using element logging, taking a shale gas horizontal well in Luzhou area of Sichuan basin as an example, the method comprises the following steps:
(1) According to mass fractions of reservoir elements measured by element logging and molecular formulas of minerals in a reservoir, wherein the reservoir elements comprise Si, ca, al, mg, K, na, fe, S and Ni, mineral components of the reservoir comprise quartz, calcite, dolomite, clay, pyrite and albite, the clay comprises illite, montmorillonite, kaolinite and mica, the mass fractions of the minerals are calculated in an inversion mode, and four coefficients representing mass fraction proportions of two minerals are determined according to regions and layers where shale gas reservoirs are located in the inversion mode, and two minerals corresponding to the coefficients contain the same elements; further calculating the density of a rock skeleton in the shale gas reservoir, wherein the density of the rock skeleton is calculated by taking the reciprocal after adding the ratio of the mass fraction of each mineral to the respective density;
in the section with the well depth of 3900-5992 m, element logging is carried out to measure and analyze samples, 5600m well depth points are taken as an example, and calculated according to inversion of the content of each element, and the mass fractions of the minerals are respectively as follows: quartz 50.77%, calcite 18.30%, dolomite 13.90%, clay 9.84%, pyrite 2.30% and albite 4.89%, wherein the clay is divided into illite 0.00%, montmorillonite 1.28%, kaolinite 0.67% and mica 7.89%;
and then the density of each mineral is combined to take value, and the density of the corresponding rock skeleton is ρ s-el ＝100/(50.77/2.5+4.89/2.62+7.89/3.05+1.28/2.6+0.67/2.63+0.00/2.8+18.30/2.71+13.90/2.87+2.30/5.2)＝2.66g/cm 3 ；
(2) Fitting a curve according to the nickel element content measured by element logging, wherein the fitting curve is neededThe data of the nickel element content and the total organic carbon content are required to be multiple groups, the data of the total organic carbon content is obtained by laboratory analysis, and the formula obtained after fitting the curve is TOC el ＝(2.1228×ln(ω Ni -ω Ni-B )+14.4470)×ω 0 Calculating the total organic carbon content in the shale gas reservoir;
measuring nickel content to be 219ppm by 5600m well depth point element logging, corresponding omega Ni 0.0219%, omega Ni-B 0.00%, omega 0 The correction coefficient is 0.8, and the TOC is calculated by substituting the formula el 5.07 wt.%;
(3) According to the total organic carbon content obtained in step (2), due to TOC el >2.5wt% of shale gas reservoir porosity calculated by the following formula based on the mass fraction of quartz, calcite, dolomite and clay in the reservoir minerals
wherein ε2 For 10, calculate the porosity of shale gas reservoir +.>
5.00%;
(4) Mass fraction ω of illite in reservoir minerals calculated according to step (1) 41-el Calculating the water saturation of the shale gas reservoir, and substituting the water saturation into a calculation formula to be S w-el ＝19.2828×POWER(ω 41-el 1/2) -3.6675, the water saturation S is less than 0 w-el Taking 0.00% and adopting formula S g-el ＝100-S w-el Calculating gas saturation S of shale gas reservoir g-el 100%;
(5) According to the calculation results of the steps (1) - (4), calculating the rock density of the shale gas reservoir, wherein the calculation formula is as follows
Binding ρ g 、ρ fw 、ρ TOC The value of (2) is that the rock density of the shale gas reservoir is 2.51g/cm 3 。
In this example, the logging density of the shale gas well at the same depth and location was 2.59g/cm 3 The error between the calculated density of elemental logging and the logging density is-3.33%.
Example 3:
the embodiment provides a method for calculating the density of shale gas reservoirs by using element logging, taking a shale gas horizontal well in Luzhou area of Sichuan basin as an example, the method comprises the following steps:
(1) According to mass fractions of reservoir elements measured by element logging and molecular formulas of minerals in a reservoir, wherein the reservoir elements comprise Si, ca, al, mg, K, na, fe, S and Ni, mineral components of the reservoir comprise quartz, calcite, dolomite, clay, pyrite and albite, the clay comprises illite, montmorillonite, kaolinite and mica, the mass fractions of the minerals are calculated in an inversion mode, and four coefficients representing mass fraction proportions of two minerals are determined according to regions and layers where shale gas reservoirs are located in the inversion mode, and two minerals corresponding to the coefficients contain the same elements; further calculating the density of a rock skeleton in the shale gas reservoir, wherein the density of the rock skeleton is calculated by taking the reciprocal after adding the ratio of the mass fraction of each mineral to the respective density;
in the section with the well depth of 3900-5992 m, element logging is carried out to measure and analyze samples, a 5848m well depth point is taken as an example, and the mass fractions of the minerals are respectively as follows: 55.32% of quartz, 26.10% of calcite, 2.68% of dolomite, 11.95% of clay, 3.95% of pyrite and 0.00% of albite, wherein the clay comprises 2.11% of illite, 0.36% of montmorillonite, 3.17% of kaolinite and 6.31% of mica;
and then the density of each mineral is combined to take value, and the density of the corresponding rock skeleton is ρ s-el ＝100/(55.32/2.5+0.00/2.62+6.31/3.05+0.36/2.6+3.17/2.63+2.11/2.8+26.10/2.71+2.68/2.87+3.95/5.2)＝2.66g/cm 3 ；
(2) Fitting a curve according to the nickel element content measured by element logging, wherein the fitting curve requires a plurality of groups of data of the nickel element content and the total organic carbon content, the data of the total organic carbon content are obtained by laboratory analysis, and a formula obtained after the fitting curve is TOC el ＝(2.1228×ln(ω Ni -ω Ni-B )+14.4470)×ω 0 Calculating the total organic carbon content in the shale gas reservoir;
the content of nickel element measured by 5848m well depth point element logging is 225ppm, corresponding omega Ni 0.0225%, omega Ni-B 0.00%, omega 0 The correction coefficient is 0.8, and the TOC is calculated by substituting the formula el 5.12 wt.%;
(3) According to the total organic carbon content obtained in step (2), due to TOC el >2.5wt% of shale gas reservoir porosity calculated by the following formula based on the mass fraction of quartz, calcite, dolomite and clay in the reservoir minerals
wherein ε2 For 10, calculate the porosity of shale gas reservoir +.>
5.51%;
(4) Mass fraction ω of illite in reservoir minerals calculated according to step (1) 41-el Calculating the water saturation of the shale gas reservoir, and substituting the water saturation into a calculation formula to be S w-el ＝19.2828×POWER(ω 41-el 1/2) -3.6675, 24.36% of the calculated result is calculated, and the formula S is adopted g-el ＝100-S w-el Calculating gas saturation S of shale gas reservoir g-el 75.64%;
(5) According to the calculation results of the steps (1) - (4), calculating the rock density of the shale gas reservoir, wherein the calculation formula is as follows
Binding ρ g 、ρ fw 、ρ TOC The rock density of the shale gas reservoir is 2.49g/cm 3 。
In this example, the logging density of the shale gas well at the same depth and position is 2.55g/cm 3 The error between the calculated density of elemental log and the log density was-2.44%.
In a well section with the shale gas depth of 3900-5992 m, element logging is adopted to calculate the density of a shale gas reservoir, the logging density is given, a comparison graph of the element logging and the logging density is shown in figure 1, and a statistical result is shown in table 2.
Table 2 elemental logging calculation density and logging density statistics
As can be seen from FIGS. 1 and 2, in the above-mentioned well section, the minimum value of the calculated density of the element logging is 2.42g/cm 3 Maximum value of 2.66g/cm 3 Average value of 2.53g/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the While the minimum value of the logging density is 2.38g/cm 3 Maximum value of 2.74g/cm 3 Average value of 2.54g/cm 3 The error of the average value of the two is-0.44%; the positive average error is 1.53%, the negative average error is-1.92%, the total average error is-0.35%, the error between the positive average error and the negative average error is smaller, and the overall change trend is consistent.
According to the method, the content of each mineral component and the rock skeleton density are calculated through inversion of element content measured by element logging, the porosity of a shale gas reservoir is calculated through calculation of total organic carbon content, the rock density of the reservoir is comprehensively calculated through calculation of water and gas saturation, the error of the calculated result is smaller than that of a logging result, the error of the average value of the calculated result and the logging result is only-0.44%, the overall average error is-0.35%, evaluation of physical properties of the reservoir is accurate, and theory and data support are provided for development of shale gas; the method is simple to operate, the difficulty in measuring the physical property parameters of the shale gas reservoir is reduced by obtaining the fitting formula, and the application range is wide.
The present invention is described in detail by the above examples, but the present invention is not limited to the above detailed methods, i.e., it does not mean that the present invention must be practiced depending on the above detailed methods. It should be apparent to those skilled in the art that any modifications of the present invention, equivalent substitutions for the method of the present invention, addition of auxiliary steps, selection of specific modes, etc., are within the scope of the present invention and the scope of the disclosure.
Claims (10)
1. A method for calculating shale gas reservoir density using elemental logging, the method comprising the steps of:
(1) According to mass fractions of reservoir elements measured by element logging and molecular formulas of minerals in the reservoir, inverting and calculating mass fractions of the minerals, and further calculating the density of a rock skeleton in the shale gas reservoir;
(2) Calculating the total organic carbon content in the shale gas reservoir according to a nickel element content fitting curve measured by element logging;
(3) According to the difference of the total organic carbon content obtained in the step (2), calculating the porosity of the shale gas reservoir based on quartz, calcite, dolomite and clay in the reservoir minerals;
(4) According to the content of illite in the reservoir minerals calculated in the step (1), calculating the water saturation of the shale gas reservoir, and further calculating the gas saturation of the shale gas reservoir;
(5) And (3) calculating the rock density of the shale gas reservoir according to the components of the shale gas reservoir and the calculation results of the steps (1) - (4).
2. The method of claim 1, wherein the reservoir elements of step (1) comprise Si, ca, al, mg, K, na, fe, S and Ni;
preferably, the mineral components of the shale gas reservoir include quartz, calcite, dolomite and clay;
preferably, the mineral component of the shale gas reservoir further comprises any one or a combination of at least two of pyrite, gypsum or feldspar;
preferably, the clay comprises any one or a combination of at least two of illite, montmorillonite, kaolinite, or mica;
preferably, the feldspar comprises any one or a combination of at least two of potassium feldspar, sodium feldspar or analcite.
3. The method according to claim 1 or 2, wherein the inversion calculation of each mineral in the shale gas reservoir further requires determining at least one coefficient representing the ratio of the mass fractions of the two minerals according to the region and the horizon in which the shale gas reservoir is located;
preferably, the two minerals corresponding to the coefficients contain at least one same element;
preferably, the density of the rock skeleton in the step (1) is calculated by taking the reciprocal of the sum of the ratio of the mass fraction of each mineral to the respective density, and the rock skeleton density is expressed as ρ s-el 。
4. A method according to any one of claims 1-3, wherein the equipment for elemental log measurements comprises an X-ray fluorescence spectrum analyzer;
preferably, the zone of elemental log measurements includes a longmaxi group shale formation and a pentamodal group shale formation.
5. The method of any one of claims 1-4, wherein the fitted curve of step (2) requires multiple sets of data for nickel element content and total organic carbon content;
preferably, the data of total organic carbon content is obtained from a localization logging analysis or laboratory analysis;
preferably, the formula obtained after the curve fitting is
TOC el ＝(2.1228×ln(ω Ni -ω Ni-B )+14.4470)×ω 0
wherein ,TOCel Total organic carbon content, ω, calculated for elemental logging Ni Normalized nickel content, ω, for elemental log measurements Ni-B The nickel element content base value for element logging refers to the corresponding nickel element content, omega in the stratum with lower total organic carbon content 0 Is a TOC correction coefficient;
preferably according to TOC el Numerical value, if the calculation result is smaller than 0, TOC el Taking 0.
6. The method according to any one of claims 1 to 5, wherein the total organic carbon content of step (3) is divided into two ranges, respectively TOC el Less than or equal to 2.5 weight percent and TOC el >2.5wt％；
Preferably, the porosity is calculated in relation to the mass fractions of quartz, calcite, dolomite and clay in the mineral, which mass fractions are denoted ω, respectively 1-el 、ω 2-el 、ω 3-el and ω4-el 。
7. The method of claim 6, wherein the total organic carbon content TOC el When the weight percentage is less than or equal to 2.5 percent, the calculation formula of the shale gas reservoir porosity is that
wherein ,
porosity, epsilon calculated for elemental logging 1 The first hydrocarbon reservoir coefficient;
preferably, the first shale gas reservoir coefficient epsilon 1 The value is 2-5;
preferably, the total organic carbon content TOC el >At 2.5wt%, the calculation formula of the shale gas reservoir porosity is as follows
wherein ,
porosity, epsilon calculated for elemental logging 2 A second shale gas reservoir coefficient;
preferably, the second shale gas reservoir coefficient ε 2 The value is 5-15.
8. The method according to any one of claims 1 to 7, wherein the illite of step (4) is one of the clays, the mass fraction of which is calculated from step (1) and denoted ω 41-el ；
Preferably, the water saturation calculation formula in step (4) is
S w-el ＝19.2828×POWER(ω 41-el ,1/2)-3.6675
wherein ,Sw-el Water saturation calculated for elemental logging;
preferably according to S w-el If the value is less than 0, S w-el Taking 0, if the value is greater than 100, S w-el Taking 100;
preferably, the shale gas reservoir has a gas saturation S g-el ＝100-S w-el ；
Preferably, if the reservoir is a shale oil reservoir, the corresponding is oil saturation S o-el ＝100-S w-el 。
9. The method of any one of claims 1-8, wherein the shale gas reservoir of step (5) consists of a rock framework, total organic carbon, formation gas, and formation water;
preferably, the rock density in step (5) is calculated by the formula
wherein ,ρb-el Rock density, ρ, calculated for elemental logging s-el Rock skeleton density, ρ, calculated for elemental logging g Is the formation gas density ρ fw Is the formation water density ρ TOC Is the organic matter density.
10. The method according to any one of claims 1-9, characterized in that the method comprises the steps of:
(1) According to mass fractions of reservoir elements measured by element logging and molecular formulas of minerals in a reservoir, wherein the reservoir elements comprise Si, ca, al, mg, K, na, fe, S and Ni, mineral components of the reservoir comprise quartz, calcite, dolomite and clay, and any one or a combination of at least two of pyrite, gypsum and feldspar, the mass fractions of the minerals are calculated in an inversion mode, and at least one coefficient representing mass fraction proportion of two minerals is determined according to the region and the layer where the shale gas reservoir is located in the inversion calculation mode, and the two minerals corresponding to the coefficient at least contain one same element; further calculating the density of a rock skeleton in the shale gas reservoir, wherein the density of the rock skeleton is calculated by taking the reciprocal after adding the ratio of the mass fraction of each mineral to the respective density;
(2) Fitting a curve according to the content of nickel element measured by element loggingThe fitting curve requires a plurality of groups of data of nickel element content and total organic carbon content, the data of the total organic carbon content is obtained by a localization logging analysis or a laboratory analysis, and the formula obtained after the fitting curve is TOC el ＝(2.1228×ln(ω Ni -ω Ni-B )+14.4470)×ω 0 Calculating the total organic carbon content in the shale gas reservoir, and if the calculation result is smaller than 0, TOC el Taking 0;
(3) According to the difference of the total organic carbon content obtained in the step (2), the total organic carbon content is divided into two ranges, namely TOC el Less than or equal to 2.5 weight percent and TOC el >2.5 wt.% of total organic carbon TOC based on mass fraction of quartz, calcite, dolomite and clay in reservoir minerals el When the weight percentage is less than or equal to 2.5 percent, the calculation formula of the shale gas reservoir porosity is that
Total organic carbon content TOC el >2.5wt% of shale gas reservoir porosity is calculated as +.>
Calculating the porosity of the shale gas reservoir;
(4) Mass fraction ω of illite in reservoir minerals calculated according to step (1) 41-el Calculating the water saturation of the shale gas reservoir, wherein the calculation formula of the water saturation is S w-el ＝19.2828×POWER(ω 41-el 1/2) -3.6675, and further calculating the gas saturation S of the shale gas reservoir g-el ＝100-S w-el ；
(5) According to the components of the shale gas reservoir and the calculation results of the steps (1) - (4), calculating the rock density of the shale gas reservoir, wherein the calculation formula of the rock density is as follows
/>
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111542845.XA CN116068664A (en) | 2021-12-16 | 2021-12-16 | Method for calculating shale gas reservoir density by using element logging |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111542845.XA CN116068664A (en) | 2021-12-16 | 2021-12-16 | Method for calculating shale gas reservoir density by using element logging |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116068664A true CN116068664A (en) | 2023-05-05 |
Family
ID=86172171
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111542845.XA Pending CN116068664A (en) | 2021-12-16 | 2021-12-16 | Method for calculating shale gas reservoir density by using element logging |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116068664A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116626779A (en) * | 2023-07-21 | 2023-08-22 | 中国石油大学(华东) | Method and system for calculating porosity of subsurface mountain stratum |
-
2021
- 2021-12-16 CN CN202111542845.XA patent/CN116068664A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116626779A (en) * | 2023-07-21 | 2023-08-22 | 中国石油大学(华东) | Method and system for calculating porosity of subsurface mountain stratum |
| CN116626779B (en) * | 2023-07-21 | 2023-11-10 | 中海石油(中国)有限公司深圳分公司 | Method and system for calculating porosity of subsurface mountain stratum |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US9194974B2 (en) | Method to predict dense hydrocarbon saturations for high pressure high temperature | |
| Shepherd | Correlations of permeability and grain size | |
| Tavakoli | Geological core analysis: Application to reservoir characterization | |
| CN109653725A (en) | A layer water flooding degree log interpretation method is stored up based on sedimentary micro and the mixed of rock phase | |
| Carman et al. | Sediments and macrofauna in the Baltic Sea—characteristics, nutrient contents and distribution | |
| Abu-Ali et al. | Paleozoic petroleum systems of Saudi Arabia: a basin modeling approach | |
| CN111706319B (en) | Sea shale gas saturation evaluation method based on gradual stripping of conductive influence factors | |
| Hossain et al. | Characterization of organic matter and depositional environment of Tertiary mudstones from the Sylhet Basin, Bangladesh | |
| CN116068664A (en) | Method for calculating shale gas reservoir density by using element logging | |
| Paez-Reyes et al. | Assessing the contribution of the La Luna Sea to the global sink of organic carbon during the Cenomanian-Turonian Oceanic Anoxic Event 2 (OAE2) | |
| CN116066064B (en) | Method for calculating shale gas reservoir porosity by using element logging | |
| EP2606382A2 (en) | Method to predict dense hydrocarbon saturations for high pressure high temperature | |
| Kausik* et al. | Novel reservoir quality indices for tight oil | |
| Cardott et al. | Woodford Shale (Upper Devonian to Lower Mississippian): From Hydrocarbon Source Rock to Reservoir | |
| Liu et al. | Sedimentary microfacies and organic geochemical characterization of mudstones in the Keluke Formation in northeastern Qaidam, China | |
| Xiao et al. | Recovering original type and abundance of organic matter in spent source rocks: A review and advances in elemental proxies | |
| Baban | Sedimentary organic matter and source rock potential of the Paleocene Aaliji Formation in Qumar Oil Field, NE Iraq | |
| Mainali et al. | Formation evaluation of multiple pay zones within an unconventional reservoir (Permian Basin): An integrated interpretation using elemental, mineralogical, programmed pyrolysis, and mud gas data. | |
| Crouch | Petroleum potential of the Codell sandstone member Carlile shale, north central Denver Basin, Colorado and south eastern Wyoming | |
| CN111911141A (en) | Method for identifying conglomerate oil layer based on clay type resistance reduction rate | |
| Zhao et al. | Application of NMR T1-T2 Logs to Determine Gas in Place for Shale gas Reservoir: A Case Study in Sichuan Basin China | |
| CN109343121A (en) | A kind of method of magmatic hydrotherm scale in determining thermal contact metamorphic rocks reservoir | |
| Topchii et al. | Evaluation of Hydrocarbon-Generating Potential of Bazhenov High-Carbon Formation | |
| Yan et al. | Application of LithoScanner Logging Technology in CO2 Geological Storage Injection Well | |
| Stone | An Evaluation of the Cenomanian-Turonian Oceanic Anoxic Event, OAE2, through the Tuscaloosa Marine Shale |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |