SY/T 5478-1992 Specification for the classification of carbonate diagenesis stagesSY/T5478-1992 Standard download decompression password: www.bzxz.net

Petroleum and Natural Gas Industry Standard of the People's Republic of China SY/T5478-92
Specification for the Division of Diagenetic Stages of Carbonate Rocks
Published on September 17, 1992
Ministry of Energy of the People's Republic of China
Implementation on February 1, 1993
1 Subject Content and Scope of Application
Petroleum and Natural Gas Industry Standard of the People's Republic of China, Specification for the Division of Diagenetic Stages of Carbonate Rocks
This standard specifies the division, naming, basis, signs and methods of the diagenetic stages of carbonate rocks. This standard is applicable to the division and characteristic research of the diagenetic stages of carbonate rocks. 2 Basis for the Division of Diagenetic Stages
2.1 Petrological Signs
2.1.1 Distribution, Fabric Characteristics and Generation Sequence of Carbonate Authigenic Minerals. 2.1.2 Distribution, Fabric Characteristics and Generation Sequence of Non-carbonate Authigenic Minerals. 2.2 Paleotemperature
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Calculated based on the empirical formula of homogenization temperature of inclusions in carbonate authigenic minerals, vitrinite or asphalt reflectivity (R.) and paleotemperature. 2.3 Vitrinite or asphalt reflectivity (R.). 2.4 Organic matter maturity.
3 Division of diagenetic stages and diagenetic environments and their corresponding relationship 3.1 Division of diagenetic stages
The burial diagenetic process of the gradual escape can be divided into the syngenetic stage, the early diagenetic stage and the late diagenetic stage. Due to the multi-stage nature of tectonic movement, carbonate rocks can be lifted into the epigenetic stage many times. 3.2 Division of diagenetic environment
The diagenetic environment can be divided into near-surface syngenetic environment (including lake bottom, sea bottom, supratidal, atmospheric fresh water, mixed water and other diagenetic environments), reservoir diagenetic environment (including shallow burial, medium burial and deep burial diagenetic environment), and epigenetic environment. 3.3 Correspondence between diagenetic stage and diagenetic environment 3.3.1 Syngenetic stage - lake bottom, sea bottom, supratidal, atmospheric fresh water and mixed water diagenetic environment. 3.3.2 Early diagenetic stage - shallow burial diagenetic environment. 3.3.3 Late diagenetic stage - small burial and deep reservoir diagenetic environment. Epigenetic stage - epigenetic environment. 3,3.43
4 Signs of each diagenetic stage
The signs of different diagenetic stages, such as lithology, morphology, vitrinite or diagenetic reflectivity and organic matter maturity, are shown in Table 1. 4.1 Syngenetic stage and its petrological signs The period of changes and actions that occurred after sediment deposition and before burial is called the syngenetic stage. 4.1.1 Petrological signs of syngenetic stage in shallow seabed 4.1.1.1 Signs of biological diagenesis
Algae drilling,
Approved by the Ministry of Energy of the People's Republic of China on September 17, 1992, and implemented from February to January 1993
b. Mud rat set,
Grain micrite.
4.1.1.2 Calcite cement
$Y/T 5478-92
It is mainly the product of the new deformation of aragonite or magnesium calcite cement. The chemical composition contains 1-2mol of magnesium carbonate. Its structural characteristics are as follows: a.
Grain hardening: hardened fecal pellets, pellets, grapestone, etc. b.
Thin edge cementation: composed of crystals such as microparticles, fibers or horse teeth (complex trigonal scalenohedrons) Equal thickness ring edge cementation: composed of crystals such as fibers or horse teeth, sewed columns, and blades, c.
4. Spherulitic cementation: Southern fine-grained forging structure or granular calcite composition spherulitic pseudo-image. 4.1.1.3 Metasomatic dolomite and dolomite cementation are formed by infiltration reflux dolomitization. Generally, it is powder crystal or fine crystal, semi-white, euhedral, low in order, rich in calcium and poor in iron, and the crystal structure is relatively mixed. It is sometimes produced in the form of cement. Intercrystalline pores are often developed in the metasomatic dolomite in the form of patches, lenses, laminae or thin layers. 4.1.1.4 Raw gypsum
is in the form of plates, strips, and radial fibers, and is often associated with dolomite. 4.1.1.5 Authigenic sea green
or micro-aggregate grains.
4.1.1.6 There is chlorite.
4.1.2 Petrological signs of supratidal syngenetic stage 4,1.2.1 Metasomatic dolomite
is formed by evaporation or infiltration reflux autolithification. Sometimes it can be produced in the form of cement. Generally, it is muddy, powdery, semi-automorphic and other shapes or dispersed, characterized by window calcium and poor iron, low degree of sequence, and often coexisting with evaporite minerals such as calcite. Maintaining the structural characteristics of the original rock or original component and the development of self-clouding intercrystalline pores are important identification marks. 4.1.2.2 Original right paste
Plate, strip, radial fiber and tubercle. 4.1.2.3 Bird's eye pores.
4.1.2.4 Associated tidal flat sedimentary structures
Bird's eye structure,
Algae mat;
c. T crack breccia
d. Tent lotus structure.
4.1.3 Petrological signs of the syngenetic stage of deep-water seabed 4.1.3.1 Calcite cement
Original play is divided into magnesium calcite and part of aragonite. After transformation, it becomes mud or microcrystalline or fine powder crystal calcite, and can also present a replaced fibrous structure. The magnesium carbonate content can reach 3.5~5 mol. 4.1.3.2 Self-colloid
Generally, it is mud or microcrystalline, fine powder crystal and euhedral crystal. Sometimes it forms a large aggregate granular body (crystal diameter can reach 60um), with fog core, sometimes with growth zone, and often has carbonate and non-carbonate capsules inside. Occasionally, it replaces calcite and biological shell. 4.1.4 Petrological signs of the syngenetic stage of lake bottom 4.1.4.1 Biodiagenetic signs
Algae drilling,
b set;
grain micrite.
4.1.4.2 Calcite cement
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a. Grain hardening: hardened fecal pellets, epilepsy pellets, pellets, etc.; b. micrite, microcrystal, fine powder crystal granular: or form thin ring edge cementation; C. Horse tooth-shaped thin ring this cementation.
4.1.4.3 Marble cement and replaced marble micrite, microcrystal, powder crystal from to semi-automorphic grains, sometimes form thin ring edge cementation. Imperial plaques, lenses, laminae or thin layers of metasomatism often develop intercrystalline pores.
4.1.4.4 White raw
Plate, strip, fibrous, etc.
4.1.4.5 Authigenic glauconite.
4.1.4.6 Authigenic tremulite.
4.1.5 Petrological signs of the syngenetic stage of meteoric water 4.1.5.1 Calcite cement
It is generally iron-free calcite. In the reduced undercurrent zone, iron-bearing calcite can be formed. Its structural characteristics are: a. Small rhombus-shaped granular or fine horse-tooth-shaped thin ring-edge cementation! b. Interlocking mosaic structure of multi-stage cements: Calcite cement is a pore-filling structure of micro-fine crystals or horse-tooth-leaf-shaped-coarse grains,
C. Coaxial cementation: It is the most developed in this environment, with the coaxial growth of thorn debris being the most prominent; d. Crescent-shaped cementation and gravity (or hanging) cementation. 4.1.5.2 Dolomite cement and replaced dolomite generally have a crystal diameter of powder to fine crystals. Dolomite with different formation mechanisms has certain differences in its characteristics. a. Meteoric water dolomite: white, transparent, mainly cementation; b. Adjusted dolomite: semi-white to euhedral, with two structures, cementation and replacement. Metasomatic dolomite is often dispersed, and when it is produced in patches or lenses, inter-product pores are often developed. c. Mixed hydrodolomite: white, often with foggy core and bright edge or ring-band structure. It has two structures, cementation and replacement. When it is metasomatic in patches or lenses, inter-product pores are often developed.
4.1.5.3 Newly deformed magnesium calcite and aragonite components Magnesium calcite and aragonite bio-bone shell, particles and cement and matrix components are transformed into calcite. It is often accompanied by heavy product phenomenon. Its original structure can be well or partially preserved. 4.1.5.4 Braided pores
a. Fabric selective dissolution pores: solution mold (casting mold) pores, intergranular solution pores, intragranular solution pores, etc., b, non-fabric selective dissolution pores; melt pores, solution caves, solution grooves and solution cracks. 4.1.5.5 Seepage silt and seepage peas
in the seepage zone.
4.1.6 Petrological signs of the syngenetic stage of seawater-water mixing 4.1.6.1 Calcite cement
. Microcrystalline and leaf-shaped cement: formed at the freshwater end, b, fibrous rim cementation: is the product of the new deformation of magnesium calcite. Formed at the near-seawater end. 4.1.6.2 Dolomite cement and metasomatic dolomite mixture Water dolomite: eumorphic, sometimes deformed. Often with foggy center and bright edge. Fine to coarse crystal structure. With two structures of cementation and metasomatic a.
. Dolomite that is replaced in patches, lenses or layers often has inter-product pores. Adjustment dolomite: The product is semi-white, euhedral, and relatively mixed. b.
4.1.6.3 Replaced silicon oxide minerals
form nodular pyrophyllites. Sometimes authigenic quartz can be formed. 4.2 Formation stage and its main signs
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After the original carbonate sediments are covered by new sediments, the period of action and change from the depth that cannot be affected by seawater, atmospheric water and mixed water to before metamorphism is called the diagenesis stage. According to the burial and diagenesis sequence, it is divided into two stages: early diagenesis and late diagenesis.
4.2.1 Main signs of the early diagenesis stage
4,2.1.1 Paleotemperature
Normal temperature to 80°C.
4.2.1.2 Reflectance of vitrinite or asphalt (R.) R. 0.4%~0.5%
4.2.1.3 Maturity of organic matter
Immature and half mature, forming biogas. 4.2.1.4 Petrological signs
4.2.1.4.1 Compaction structure
Thin laminae, cracks, fractures and dislocations of encapsulated crusts and fossil shells: crushing, deformation and directional arrangement of grains, contact between the plane and the curve (concave and convex) of grains; overlapping structure
Mud cracks, bird's eyes and their primary pores are deformed, closed or disappeared#,
f, organic laminae are destroyed or deformed into irregular veins. 4.2.1.4.2 Pressure solution structure
a. Grain suture touch,
b, suture line.
4.2.1.4.3 Calcite cement
Generally iron-free calcite. Under the reducing conditions of deep or divalent iron ions, the iron-bearing calcite is formed. The fabric features are: granular mosaic structure: the grains are mainly fine-grained; I,
replaced fibrous, spherulitic, horse-tooth and blade-shaped fabrics, b.
microcrystalline, micro-bright crystals and slightly coarse grains are found in the fine pores of the original deep-sea sediments, c.
d. Coaxial ring edge cement
may appear intercrystalline cementation.
4.2.1.4.4 The formation mechanism of dolomite cement and metasomatic dolomite is burial, compaction, and possibly adjustment, hot water dolomitization, and the characteristics of the group are: a: neon crystal mosaic structure,
translucent fine crystals, eumorphic eumorphic eumorphic eumorphic cementation C. Sometimes there are deformed stem-shaped products.
Glass pores are often developed in the metasomatic dolomite in the form of patches, transparent, thin suspensions and layers. 4.2.1.4.5 Gypsum and hard stone cement and the replaced gypsum and hard stone a. Fine and coarse grain mosaic structure s
b. Intergranular cementation;
C. Dispersed granular, plate-like, strip-like, radial red-dimensional and patchy, banded, laminar and laminar metasomatic. 4.2.1.4.6 Silica mineral (chalcedony-quartz) fillings, replaced silica minerals and authigenic quartz a calcareous biological bone shell and grain and other granular components; 4
b. Nodules and masses,
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Thin lenses, bands, laminar and thin layers; c.
d. Granular or fibrous filling pores;
Automorphic authigenic quartz.
4.2.1.4.7 Non-selective dissolution pores
a. Dissolution pores,
b. Dissolution caves,bzxZ.net
C. Dissolution grooves and dissolution cracks.
4.2.1.4.8 Fissures.
4.2.2 Main signs of the late diagenetic stage
4.2.2.1 Paleotemperature
>80'0--200°0.
4.2.2.2 Vitrinite or sapphire reflectivity
R: ≥0.5%~4%.
4.2.2.3 Organic matter maturity
Organic matter is in the mature (equivalent to the medium burial diagenetic environment) to high mature, over mature stage (equivalent to the deep burial diagenetic environment). In the mature stage, organic matter can evolve into liquid hydrocarbons, and in the latter two stages, cracking gas and asphalt are formed. 4.2.2.4 Petrological characteristics
4.2.2.4.1 Compaction structure
The compaction structure in the early diagenetic stage can continue to develop, 4.2, 2.4.2 Pressure solution structure
a. Suture containing line,
b. Pressure solution of the suture.
4.2.2.4.3 Calcite cement
Rich in iron and manganese, poor in strontium, containing liquid and gas compounds or organic inclusions. a. The structural characteristics of calcite cement in deep-sea chalk: micro- to ultra-micro-crystalline grains of 1-10 μm, b. The structural characteristics of shallow-sea calcite cement, blade-shaped, several micrometers to several white micrometers and other grain mosaic structure, straight crystal boundaries, divalent iron has changes, and intercrystalline cementation.
4.2.2.4.4 Marble cement and metasomatic dolomite a. Granular dolomite: anisotropic, particle size 0.1~1mm, often wavy extinction, crystal edges curved or irregular, b. Translucent dolomite, transparent, white, coarse grains, c. Deformed dead dolomite: saddle-shaped, coarse grains, often iron-containing, with curved cleavage planes, wavy extinction, usually showing concentration zoning of divalent iron and manganese ions.
Glass-like, lenticular or layered metasomatic dolomite often develops crystalline pores. 4.2.2.4.5 Anhydrite cement and metasomatic anhydrite a: coarse granular mosaic structure,
b. Intergranular cementation,
C. Dispersed, fibrous radial and patchy metasomatic. 4.2.2.4.6 Other sulfate cementing and metasomatizing minerals barite mostly
b celestite.
.4.2.2.4.7 Authigenic quartz.
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4.2.2.4.8 Replaced quartz, pore-filling quartz and authigenic quartz a.
The false appearance of granular components such as calcareous biological shells and granules; h.
Nodules and masses;
Stripe and thin lenses,
d, pore-filling quartz: euhedral cone-shaped ring edge or crystal cluster filling, or base granular filling, e.
Authigenic quartz.
4.2.2.4,9 Coaxial metasomatic rim
The mortar matrix around the scleractinian or calcite crystal fragments partially dissolves under pressure, and the dissolved material recrystallizes around the edge of the grains to form a coaxial metasomatic rim.
4.2.2.4.10 Strong recrystallization.
4.2.2.4.111
Occurs during pressure twinning.
4.2.2.4.12 Non-fabricated selective dissolution pores a. solution pores,
b. solution caves,
c.: solution grooves and solution cracks.
4.2.2.4.13 Fractures.
4.3 Epigenetic stage and its main signs
The weakly consolidated or consolidated carbonate rock in a certain diagenetic stage is lifted to the surface or near the surface by wind tectonic action, and the changes and periods of action caused by the dissolution and filtration of atmospheric water are called epigenetic stage. 4.3.1 Paleotemperature
Normal temperature.
4.3.2 Petrological signs
4.3.2.1 Calcite cement
a. Microcrystalline,
b. Fine-coarse crystals:
c. Blade-shaped;
d. Crescent-shaped and heavy (or hanging) cement. 4.3.2. 2. Self-cloudy cement and replacement of concave and non-white shape, transparent, highly ordered.
4.3.2.3 Chalcedony or quartz cement and filling, silica deposits. 4.3.2.4 Other metasomatism
a. Degypsumization
b. Dedolomitization.
4.3.2.5 Recrystallization
Microcrystalline calcite recrystallizes into microcrystalline calcite.
4.3.2.6 Seepage particles, formed above the water table. 4.3.2.7 Seepage fillings, formed above the water table. 4.3.2.8 Supergene kaolin
Supergene kaolin is filled in the pores, caves, cracks and fissures of soil dissolution. 4.3.2.9 Soil and iron foil.
4.3.2.10 Non-selective dissolution pores
Dissolution pores: large dissolution pores are often developed
Sea filling
Chuxi bean grain
Wanzi silt sand
Marble intercrystalline pore
Rong hole·braid seam pain steel
Zhua mold hole·Yuhua
Go to enrichment
Tai's marbleization
Tianqing rightization
Huijing petrification
Hard rock uniformization
Hetie Baiyunshe||tt ||Dispersed chemical transformation
Containing calcite
New type·Tongli
Hangzhou or horsewood
Pet crystal·Microcrystalline
Wind grain chemical transformation
Membrane viscopore micrite
Vitreous group or asphalt reverse time rate
Organic matter thermal deficiency
" overflow
Main signs
Diagenetic environment
Diagenetic stage
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Mixed
Yanfalou Touchuanliu
Syngenesis
Semi-mature
Transgenesis
Medium-deep burial
Death Qiyan
Cut-generation
b. Karst fracture 3
c. Karst cave, with large karst caves developed.
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4.3.2.11 Pyrite, hematite and other low-iron minerals are transformed into limonite. 4.3.2.12 Hydration of anhydrite into gypsum and associated deformation bedding. 4.3.2.13 Collapsed angular gravels and pores and holes between gravels. 4,3.2.14 Cracks.
Additional notes:
This standard is proposed by the Petroleum Industry Standardization Technical Committee. This standard is technically coordinated by the Petroleum Geological Exploration Professional Standardization Committee. This standard is drafted by Southwest Petroleum University, and the Petroleum Exploration and Development Research Institute of Sichuan Petroleum Administration Bureau participated in the drafting. The main drafters of this standard are Fang Shaoxian, Kong Jinxiang, and Hou Fanghao. 8
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