地质分层（The geological stratification）

地质分层（The geological stratification） 地质分层(The geological stratification) The lithological characteristics of the lithologic features in the southern shaanxi basin gas field The ningxia basin is a sedimentary basin with a steady subsidence, depression and movement. Basin are further divided into west margin thrust nappe tectonic belt, ring day syncline, central palaeohigh, shanbei slope, around the fold area of weihe river, the jin west around the fold zone, 'fold zone around seven first-order tectonic units, such as the main body of the central ancient uplift tectonic basin, is a bigger first-order tectonic units in the basin, it is in the Paleozoic has been developing inheritance. From the analysis of regional geological structure, the west of the basin is the slope area of deep depression. The middle is the ancient uplift tidal plateau; East is shallow depression salt depression belt, now ? area is located in the northern shaanxi slope structure, master ? zone formation lithology characteristics, the field logging is necessary. Weald basin formation deposition is stable, the sedimentary period of denudation, differentiation degree is different, so a slight change in the thickness, will now place ? area formation lithology feature points above are as follows: First, the fourth department of the New Territories: Lithologic characteristics as follows: the unconsolidated khaki SongSanZhuang sandy soil, bottom glutenite, thickness: 20 ~ 110 m, this ? zone thickness is controlled in 10, the scene change when logging should be paid attention to during drilling, drilling time varying slowly, out of the ground factors, strata have awful a jump phenomenon, this is the bottom well depth, the attention characteristics. The variation of the four thickness is mainly influenced by the tectonic movement of the himalaya, and the third part of the Mesozoic is the fourth system of rock, which is not integrated with the cretaceous. 2. Cretaceous zhidan series: 1. The lithology of palm red mudstone and palm red fine sandstone, sandstone are mainly quartz and feldspar, granularity is both, half angular, argillaceous cementation, relatively thin, loose mudstone, absorbent and plasticity. 2. Stratified basis: the sandstone in the bottom of zhidan system and the color of mudstone are mainly red. The scene is divided by the mud color and the change of the drill. The strata in this area are affected by yanshan movement, which is divided and denuded to luohe group, so the thickness is below 450m. The formation of the overlying group was not integrated. Iii. Jurassic middle school: Stable groups: 1. Lithology: the top is grayish - brown mudstone, which is the symbol layer of the stability group in this area, and the bottom is light grey green mudstone and gray fine sandstone interlayer. Mudstone: high in gray matter, uneven distribution of mud, severe reaction of hydrochloric acid, shell-like fracture. Sandstone: the composition is mainly quartz, feldspar, granularities. The particles are semi - angular - round. Cementation of mud, loose. Mudstone: pure, sand, absorbent and malleable. 2. Electricity: the resistivity is in the middle and high value, the well diameter rule, the natural gamma is serrated. 3. Stratified basis: the top clay limestone in this group is a symbol, and the top speed curve of electricity is a distinct step. The bottom features are obvious. The regional stability group has a thickness of 25 to 45m, the top mudstone features are obvious, the drilling time is slow, the debris meets the dilute hydrochloric acid reaction is intense, is the site marker layer. This section is integrated with the lower volvos formation. Straight ROM group: 1. Lithology: green ash, grey and grey sandstone with grayish green and dark gray mudstone interlayer with different thickness. The sandstone composition is mainly quartz, followed by feldspar, semi-angular, mud, and loose. Mudstone contains sand, water absorption and plasticity, soft. 2. Electricity: the resistivity is high from low to high, The well diameter is irregular, multiple is serrated, the sound speed curve is basically flat. 3. Hierarchical basis: straight into the group mudstone color deepened gradually, the red strata ~ green formation ~ gray formation, characterized by from oxidizing environment to the transformation of the weak reduction environment ~ the strong reduction environment. The sandstone is slightly green with obvious electrical characteristics. The thickness of local bottom sandstone can be used as the contrast marker. In this block, the sandstone thickness is not very high, and it can not be used as a stratified feature. The thickness is about 270m, and it is in an integrated contact with the lower vyanan formation. The second lesson extends the stratification characteristics 1. Division of direct and yanan on-site: Straight ROM group mudstone as the sage green, dark grey, main lithology suffused with green, and yan mudstone mainly for dark gray, a film, there are coal, high black body, compared with the straight of mudstone, yanan group to deeper, darker. In sandstone, straight at the bottom of the sandstone and in the south block, the thinner, the color is green, the yenan sandstone was thicker, but in large puddle and Wu Qi areas, straight and of bottom sandstone is thicker, up to 80 meters. In the southern part of the scene, the direct and yan 'an divisions are distinguished mainly from the color of cuttings. From drill was divided between the two, in drilling straight luo group, according to block the thickness of the strata, at the same time in the prediction of well depth, drill suddenly accelerated phenomenon, if any, can be classified as straight at the bottom of the sandstone, below to yanan. When dividing the strata in the real zone, the rock cuttings should be mainly used as auxiliary. In the electric test area, the bottom sandstone of straight row is better and easy to partition. Ii. Characteristics of small layer of yan 'an formation: 1. The formation of yanan formation is the formation of a river-marsh facies sedimentary layer of a set of sand mudstone interlaminated coal seam, and according to the sedimentary cycle and lithological combination characteristics, the oil sandstone is divided into ten reservoir groups, namely y1, y2,... Y10. 2. Lithology: dark ash, grey black mudstone, sandy mudstone and light gray fine sandstone with coal seam. The sandstone composition is mainly quartz, the feldspar is the second, the semi-angular and semi-circular shape, and the mud cementation is loose. Mudstone pure, brittle, hard. Poor absorption and plasticity. 3. Electrical property: the resistivity is in the middle ~ high value, the upper part of the well diameter rule, the lower part of the rules, the sound velocity curve flattens, the bottom is sharp tooth shape, the natural potential is at the top of the flat value, the bottom is negative and obvious. 4. Stratified basis: entering the yanan group, the mudstone becomes darker, and there is a thin coal seam, and the bottom sandstone develops. The stratigraphic formation of the prolongation group was disintegrated. 5. Characteristics of main oil layer delay 9 and 10: Y9, y10 lithology is a set of quartz sandstone, the grain size is medium fine grained, the gravel is not equal to the grain sandstone, the quartz content is 70 ~ 85%, the highest can reach 95%, the feldstone < 25%, generally 15 ~ 20%, the cuttings < 8%, Cementitious objects: mainly mudstone, including kaolinite, gray matter, gypsum. Consolidation type: pore type, contact type, base type, Mosaic type. Degree of cementation: loose ~ loose, denser. 6. Physical properties: average porosity 15.8%, permeability 251.9 mu m2, middle hole, middle permeability reservoir. Iii. Extended group features: 1. The extended group is a set of lakes and rivers and marsh deposits, with a thickness of 1000 ~ 1300m. Lithology is the upper grey, dark gray mudstone grey fine sandstone; The middle is brown grey, grey black mudstone and light grey, grey white fine sandstone. The lower part is ash black, brown ash, mixed color mudstone and light meat red fine sandstone interlayer. The sandstone composition is mainly quartz and feldspar, and the grain size is more than that. Mud, kaolin and zeolite cementation, denser. The mud is pure, brittle and hard. Poor absorption and plasticity. 2. Electrical property: the resistance rate fluctuate greatly, the radius is irregular, the natural potential deviation is obvious, the upper part of the sound velocity curve is gentle, the lower part is large, and the low value of natural gamma is obvious. 3. Stratified basis: into the extension group, the color of sandstone is shallow, and the bottom is mainly composed of shallow red feldspar sandstone. The electrical properties are polygyrus. The formation of the lower - volt paper mill group is in an integrated contact. The third class was to extend the subdivision and phase analysis 1. Length 10:10 meters long and 100 meters long, the bottom large segment of shallow meat red fine sandstone. Issue 2. 9:9 thickness between 110 ~ 150 m long, dark gray, film of mudstone clamp in the green fine siltstone, the electrical potential value, high gamma, hole diameter, velocity of sound, to divide sandstone at the bottom, mudstone roof. 3. Length 8: long 8 thick, 120 ~ 140m, lithology is light grey green medium fine siltstone and dark gray, grey black mudstone are different thickness interlayer. The diagenesis is poor, and the electrical property is reflected in the changes of large well diameter, high velocity, gamma and natural potential curve, and the bottom is bounded by sandstone. 4. 7) : long long 7 about 30 m or so thick, dark gray, film of mudstone and calcareous cementation, siltstone, electrical self-potential curve flat value, high gamma, low velocity of sound, accidentally see peak pulse. 5. Length 6: long 6 segments are delta sedimentary systems. The profile is composed of three counterrotating components, namely dark mudstone and fine grained sandstone. From top to bottom, the three gyrus groups are named long 61, 62 long, 63 long, and three subgroups (subsections). The electrical; The natural gamma curve is often funnel-shaped. Lithology: gray sandstone in gray and light gray fine grained sandstone, subangular. Cement: mud, chlorite, gray matter, silica and a little white cloud. Consolidation type: pore type. Degree of cementation: loose ~ denser. Reservoir sand body distribution: mainly affected by the underwater distributary channel of the delta front and the large area of the sand body, and the vertical layers of oil layers are overlapping, and the multi-layer oil sand body is composite. The main oil layer features: stable distribution, primary pore development, 10 ~ 20m oil layer thickness, average porosity of 11 ~ 14%, average permeability 1 x 10-3 mu m2, low permeability lithologic reservoir with low yield and low abundance. 6. 4 + 5 period: lithology is a light grey medium, fine sandstone black mudstone and carbonaceous mudstone, with a thickness of 80 ~ 110m, which is divided into the boundary of mudstone. Long 7. 3) : 70 ~ 70 m thick, lithology is light grey, green, fine sandstone and film, in the dark grey mudstone, obvious potential curve deviation, sound velocity is stable, natural gamma box shaped, bell ups and downs, sandstone at the bottom, top with mudstone roof is bounded. 8. 2) : long, fine sandstone lithology as light gray, dark gray, film of mudstone, thin coal seam, and 2 ~ 3 block sandstone segments, the thickness of more than 200 meters, natural gamma, sp curve box, bottom sandstone as the floor, The top is bounded by a mudstone. Rock type: sandstone, siltstone and fine sandstone, with a composition of 65% quartz and 2.5% feldspar. Cement: mud, kaolin, gray matter, clay green stone, sorted well. Pore type: primary intergranular pores, small amounts of feldspar or carbonate-soluble pores. Primary pore Secondary porosity Single sand layer thickness, 20 ~ 200m. Individual oil layer thickness is small, < 10m, local to 15m. Typical bottom water cap type lithologic reservoir. 9. Length 1: lithology is a light gray sandstone with grey black, dark gray mudstone interlayer, and carbonaceous mudstone and sandy mudstone. Select the identification mark layer: 1. The main section of the marker shall be 7 middle and lower large sections of dark gray limestone, tentatively fixed as S. The zone is stable and thick with a thickness of 25 meters and the deepest depth of 5 ~ 6 meters, usually about 10 meters. Both the continental facies and the lake facies are distributed. The rock property is pure, soft, slightly slippery and drillable. Electrical characteristics: low resistance, large well diameter, high sound speed, high gamma. 2. Select K 1 marker. The layer is located in the upper part of the long 7, and the lithology is the brown grey, the dark gray tufa. The characteristics of the acoustic velocity curve are obvious, and the trapezoidal or straight triangular protrusions of low value background are stable and the thickness is 5 ~ 10m, S1 and K1 are the markers of the length 7. 3. The K2 and K3 logo layer: the K2 in 63 at the bottom of the 2 ~ 5 meters long, K3 group is located in long 62 reservoir bottom 1 ~ 3 meters, lithology for dark grey tuffaceous shale, 10 to 30 m apart each other, and are generally four you calcareous mudstone thin layer. The bottom is K2, and the top is K3. The low resistance and high speed pulse large well diameter of the high acoustic velocity pulse can be divided into 7 and long 6 lines, which is usually K6 base with K2 base. 4. Choose K9 marker: lithology is a light brown yellow tuff or tuff, and the cuttings are flaky, long strips or plates, and the surface is skid and fluorescence, commonly known as "soxite mudstone". Electrical characteristics: high gamma, high speed, low resistance, low density. The regional distribution is stable, and it can be distinguished from the bottom boundary by combining the thick layer of composite sandstone with two large sections. The first choice of K9 marker in the site is the second stone K2 and K3 marker. The stratigraphic lithology characteristics of the fourth section of the paper, the monk ditch, liujiagou, shi qifeng and the stone box formation 1. Zhongtong paper group: 1. Lithology: mixed color mudstone and shallow-fleshy red fine sandstones are not interlayered, and the upper part of the mudstone is brown and gray, and the lower part is mainly purple and red. The sandstone composition is mainly composed of feldspar and quartz, semi - angular - subaricular clay and kaolin cementation, which is more dense, and the mudstone is absorbent and malleable and soft. 2. Electricity: the resistivity is in the middle, high value, the well diameter is irregular, the sound velocity curve fluctuating greatly, the upper part of the natural gamma curve has changed greatly, and the lower part gradually becomes smaller. 3. Stratified basis: after entering the formation of this group, the content of feldspar in sandstone is obviously increased, and the mud is made from grey, black and brown to dark brown, dark purple and local variegated. Ii. The following group: 1. Lithology: dark brown, grayish brown, blue-gray and red sandstone with different layers of thick red sandstone. The sandstone composition is mainly composed of feldspar, quartz, semi - angular - circular, clay and kaolin cementation, densification ~ loose. Mudstone pure, Absorbent and malleable, soft. 2. Electricity: the resistivity is high, the well diameter rules and the sound velocity curve are small. 3. Stratified basis: the formation of mudstone in this formation is mainly dark brown and the sandstone is mainly light meat red. The formation of liujiagou formation is integrated. 3. Liu jiogou group: 1. Lithology: the upper part is shallow red, and the lower part is light brown and fine sandstone mixed with colored mudstone. The bottom is mainly a set of sandstone, light red and red. Red mudstones and dark mudstones are visible in the scene, and a large number of dark gray mudstones are also found, which are well rounded, showing that the previous formation mudstone was not brought up. When continuous appear thicker layers in the cuttings, pure mudstone, namely into stone feng group, its also for palm red mudstone, drilling time on Liu Gugou bottom drill sand mudstone is respectively, as between 15 to 17 points. 2. Electricity: the resistivity is in the middle ~ low value, the well diameter rule, the sound velocity curve is gentle, the natural gamma curve is serrated. 3. Stratified basis: the formation of mudstone in the formation of the formation of the formation of the formation of the formation of the formation of the formation of the formation of the formation of the formation of the formation of the sandstone, the lower down feldspar content, the increase of quartz content, the development of the bottom sandstone, and the obvious electrical characteristics. The stratum of the upper volvos group was disintegrated. 4. The series of the series of series: 1. Lithology: the upper part is brown, brown mudstone, sandy mudstone and light brown, light grey sandstone; Middle is tan, brown red mudstone and light brown, light grey, gray white sand interstratum; The lower part is light grey fine siltstone and dark brown mudstone. The sandstone composition is mainly quartz, the feldspar is second, and the semi-angular and semi-circular shape, the mud and the iron bond, loose ~ dense. Mudstone is pure, absorbent and malleable. 2. Electricity: the resistivity is medium ~ high value, the well diameter is irregular, and the natural gamma curve is high and low value, which is obvious to sandy mudstone. 3. Stratified basis: the formation of mudstone in this formation is mainly red, and the resistance is significantly higher than that of the stone box group. The formation of the lower volvolith box formation is integrated. 5. Upper and lower stone box group: 1. Lithology: the upper part is dark brown mudstone with light grey and grey sandstone; The central part is dark brown, light gray mudstone and gray green, gray sandstone interlayer, and the lower part of the semi-oxidized environment of inland fluvial deposits. According to the lithology combination from top to bottom is divided into four sedimentary cycle is 5 ~ 8 ~ box, each cycle is commonly by the total thickness of 5 ~ 35 m, one to three sand layer on the sealing of argillaceous rock about 20 ~ 60 m. Box 7 box 8 sandstone development, large thickness, thin mudstone and sandstone in light gray, celadon feldspar and lithic quartz sandstone in the majority, in the coarse ~ ~ seriate, top-down change from fine to coarse, from north to south and 140 ~ 140 m thick. 2. Electrical property: low value of resistivity, small serrated, irregular well diameter, and high low value of natural gamma curve. 3. Stratified basis: the formation of shale in the formation of the formation of the formation of mudstone, the color of sandstone is shallow, and the resistivity is significantly lower than that of shanxi group. The formation of the underlying shanxi formation was integrated. The stratigraphic lithologic features of shanxi, taiyuan and benxi 1. Shanxi group: 1. Lithology: the upper part is gray, brown gray mudstone, sandy mudstone with light grey, gray and fine sandstone; The lower part is grey, dark gray mudstone, sandy mudstone with grey fine sandstone, carbonaceous mudstone and coal seam, The mud is 5 ~ 8 %. 2. Electrical power: low speed of sound and low ~ ~ low characteristic of natural gamma. 3. Stratified basis: stratified by the second low gamma of natural gamma. Three horses. 1. Lithology: brown and gray cloud rock, dark grey mud, clay cloud and grey black cloud mudstone interlayer, and the bottom corner gravel development. Dolomite: about 90% of white marble in composition, about 10% in mud and calcite. 2. Electricity: the sound velocity is slightly different from the fluctuation, and the natural gamma value is generally high. 3. Stratified basis: the base Angle of the horse may be developed at the base Angle, and the rock color is deep, with a high gamma bottom layer. Four. Horse five four: 1. Lithology: the upper part is gray fine powder and cloud rock, the brown gray Angle and gravel shape of the cave cloud rock and gray Angle gravel, with mudstone and cloud rock interlayer; The middle and lower parts are grey mudstone, grey black cloud containing grey mudstone, grey - green tuff and gray paste cloud rock. Dolomite: the content of dolomite in the composition is 87 ~ 93 %, the mud content is 5 ~ 6 %, and calcite is 2 ~ 7 %. Tuff: delicate, slippery, easy to flake off. Paste cloud rock: about 75% of dolomite in composition and 25% of paste and mud. 2. Electrical properties: the top of the natural gamma is low and the lower part is serrated. 3. Layered basis: the top is the karst cloud, the bottom paste cloud rock, with the jagged gamma bottom boundary. Five. 1. Lithology: gray-black limestone and mudstone. Limestone: the composition of calcite is about 90%, the mud is about 10%, the acid reaction is strong, the mud crystal structure. 2. Electrical power: the sound speed and natural gamma are obviously reduced and flat. 3. Stratified basis: lithology is limestone, electrical flatness. Five. M5 6: 1. Lithology: deep gray mudstone and gray paste cloud interlayer. 2. Electrical power: the sound speed and natural gamma curve are serrated. 3. Stratified basis: the formation of the strata in this group is very developed and the natural gamma curve is elevated. Lesson 7 on-site oil logging technology 1. Classification and description of oil content: Saturated oil: the oil content occupies the total area of the rock > 95%, the oil is full and uniform, the surface of the particle is filled with crude oil, the local rare and non-oily patches, clumps and strips. Color is brown, brown, dark brown, dark brown, black brown, can not see the color of the rock, the oil is strong, can dye the hand, the crude oil aromatic flavor strong pungent nose, the drop test is a round strain not infiltration. Rich oil: oil bearing area of rock with a total area of 70 ~ 95%, the oil is full, is relatively uniform, article contains more oily patches, ribbon, color brown, light, yellow brown, tan, not oily part see rock character, grease sense is stronger, less dye hand after hand twist, crude oil, aromatic flavour is thicker, drop test strains not seep into a circle. Oil: oil area of rock with a total area of 40 ~ 70%, oil is not full, immersion in a ribbon, patches of uneven distribution of light color, yellow, grey, brown, gray, oily part of rock character, grease feeling weak, generally don't dye hand, crude oil, aromatic taste light, oil steamed bread shaped part drop test. Oil spot: oily area occupies 5 ~ 40% of the total area of the rock, oil is not full, not even, it is the patch, the ribbon is oily, it is more the color of the rock, the oil part of the water is steamed bun or slow infiltration. Oil trace: oil content occupies less than 5% of the total rock area, and the oil is very uneven. Oil display is difficult to detect with the naked eye. When dissolved with organic solvents, it can be seen that brownish yellow and yellow color are the color of the rock. It has no grease, no color, and can smell the smell of crude oil, and water slowly infiltrates or infiltrates. Fluorescence, oil-bearing area can't estimate total rock area, and fluorescent contrast above magnitude 7 series, for ecru or microstrip yellow rock, and don't dye hand, generally can't smell, individual drop test infiltration or steamed bread shaped. Fluorescent drop test operation procedure The drip test classification table The fluorescence color of the class ? sallowness, yellow, light yellow, yellow and even ~ is relatively uniform Uneven ? yellow grey, yellow, brown yellow ~ radial ? yellow ring or spots Fluorescent series operation flow Lesson 8 1. Overview: Geophysical well logging is the method of measuring geophysical properties along the borehole with specialized instruments. Logging is one of the important means to discover and evaluate the oil and gas layers during the exploration and development of oil and gas fields, and also an important means to solve a series of geological problems. 1. The rock has a variety of geophysical characteristics, such as electrical conductivity, acoustic properties, radioactive, etc., use of these properties, the development of all kinds of logging instruments, measuring the change of the geophysical properties of the rock, can indirect understanding of the geological characteristics of rock. 2. The tasks of oil exploration and development well logging. Ii. Electrical logging: 1. Natural potential logging (SP) : Basic principle of natural potential logging: The natural potential well logging is the simplest of all logging methods. Put a measuring electrode M in borehole, and the other a measuring electrode N on the ground, in case there are no artificial electric field, making M electrode from bottom up along the wellbore with measuring instruments measure the potential difference between a relative to the N M electrode electrode borehole curves of natural potential, for oil and gas drilling, is mainly due to the formation water and the mud filtrate salt ion concentration difference, formation and drilling fluid column pressure imbalance, lead to positive and negative charge on the wall inside and outside two measuring enrichment and diffusion, adsorption electromotive force or filtering electromotive force, causing natural currents, and generate sp. Characteristics of natural potential (SP) curve: The natural potential is the relative size of the natural potential in the well, and no absolute zero value is used in the log graph. If the SP of a stratum is offset to a mudstone baseline, it is called SP anomaly. The SP curve is biased to the left side of the mudstone and the left side is negative, and the right side is the positive anomaly. The morphological features of the natural potential: in stratigraphic lithological stability, and the properties of upper and lower surrounding rocks, the formation center has symmetry. According to the characteristics of natural potential changes in the rock strata interface, the interface of the rock strata can be divided by the inflection point or half-amplitude of the SP curve. Application of natural potential logging curve: In this paper, the porosity and permeability stratification of the natural potential curve are marked by the porosity and permeability of the reservoir. To determine the lithology of the strata, such as: the simple sand mudstone section of the reservoir, the sandstone, the non-reservoir shale. (3) to determine oil and gas layer: SP anomaly can help to distinguish the oil and gas layer, but not in general, in this paper according to the SP anomaly slightly smaller than water of oil and gas layer, water completely, lithology is pure, the pure water layer thickness is larger SP anomaly is the largest, bottom water saturation obviously rise in oil and water, tree by getting down on the SP anomaly by big trend. The stratigraphic comparison and sedimentary facies study were conducted.