CN116413093A - Preparation method of shale continuous sheet - Google Patents

Abstract

The invention relates to a preparation method of a shale continuous slice. Firstly, placing the rock core into a rock core box according to the original condition, coating a layer of glue on the surface of the rock core, and solidifying and shaping to prevent micro-crack expansion. The sample is solidified and then is put on a cutting machine frame to be cut in a longitudinal section, the sample is subjected to secondary glue seepage to mainly solidify surface colloid of the cut rock, the sample plane is subjected to rough grinding to ensure that the sample is complete, the sample is subjected to fine grinding to ensure that the process is continuous aiming at the next bonding surface, the sample and the glass slide are subjected to slicing after being solidified with the colloid of the glass slide adhesive, then the secondary rough grinding is performed, finally, a common microscope for reducing the abrasion to the edge of the sample during fine grinding is used, and the grinding is carried out until the light transmission and the thickness is 0.03mm. The preparation method can completely retain the surface continuity, the bedding integrity and the original mineral definition of the rock core, can carry out original gyratory omnibearing identification and description on the rock sheet for a long time, and provides powerful guarantee for subsequent core description and various test analysis.

Description

Preparation method of shale continuous sheet

Technical field:

the invention relates to the technical field of oil field exploration and development, in particular to a preparation method of a shale continuous sheet.

The background technology is as follows:

shale continuous sheeting is used to study shale construction and some of the macroscopic and microscopic phenomena of geology of minerals during the depositions, known as "most difficult to make" sheeting. The original geological environment in the diagenetic and mineral formation process can be researched by utilizing the macroscopic recoverable subsurface deposition structure of the continuous sheet, and the method is a technical method with high accuracy and manufacturing and process difficulty. Wherein microscopic information can be provided for studying chemical composition, physical properties, structure of basin geological historic period and evolution of organisms in shale for the development of deposit minerals in the tattoos; and the formation movement in the shale diagenetic stage causes cracks, so that direct evidence can be provided for the porosity analysis of shale, particularly, the existence of hot liquid in the cracks can effectively indicate the soft sediment structure in shale layers and provide effective geological information for researching paleogeography. However, the primary premise of properly recognizing the above-mentioned geological problems is to use a good microscope to make detailed lithology and microscopic observation of minerals, structures and sedimentary environment in shale, which requires the production of continuous thin sheets of shale samples.

At present, the shale slice is manufactured by adopting a process method for grinding sandstone, the area of the ground shale slice is smaller than the minimum value in the industry standard, so that the observation under a microscope is limited, and at the same time, micro-cracks in a page development grain layer are deformed and disintegrated due to some human factors and mechanical cutting processes, which can cause that the shale structure at a specific position cannot be accurately observed and described, and the grinding liquid and the polishing liquid mainly comprise water and alumina powder. The grinding fluid can absorb the corresponding adsorbed water on the surfaces of shale microcracks and samples in the grinding and polishing processes; the use of alumina powder as the polishing liquid and polishing liquid may result in great amount of scratches and weak fluorescence on the surface of the sample, and the destruction of organic matter in the sample may result in interference of fluorescence observed under microscope.

In summary, in the manufacturing process of the process flow, the water and alumina powder or silicon carbide are used as the grinding liquid and the polishing liquid, so that the surface of the sample is damaged to a certain extent, the original geological information is lost due to pollution and cracking, the area of the manufactured final finished product sheet is smaller, the observation range under a microscope is limited, or the sample is damaged due to indoor humidity factors, and therefore, errors exist in the analysis data of identification and subsequent tests under a polarizing microscope, and even erroneous analysis interpretation conclusion is obtained.

The invention comprises the following steps:

the invention aims to solve the problem that the existing method in the background technology cannot completely retain the surface continuity, the layer integrity and the original mineral definition of a rock core in the cutting and grinding processes of shale, and provides a preparation method of a shale continuous sheet. The preparation method of the shale continuous slice can completely retain the surface continuity, the layer integrity and the original mineral definition of the rock core, can carry out original gyratory omnibearing identification and description on the rock slice for a long time, and provides powerful guarantee for subsequent rock core description and various test analysis.

The invention solves the problems by the following technical proposal: the preparation method of the shale continuous slice comprises the following steps:

step 1: performing glue permeation treatment on the shale;

step 2: cutting the mud shale sample subjected to the glue seepage treatment;

step 3: performing sample secondary glue permeation on the cut sample;

step 4: carrying out rough grinding on the sample plane after the secondary glue permeation;

step 5: carrying out plane fine grinding on the coarsely ground sample;

step 6: adhering the sample after the fine grinding treatment to a glass slide;

step 7: slicing a sample of the slide;

step 8: cutting the sample and then carrying out secondary coarse grinding;

step 9: carrying out secondary fine grinding on the sample;

step 10: the sample was finally finely ground and observed microscopically until the quartz interference color was bright white or off-white.

Preferably, the step 1 of the cementing treatment process of the shale comprises the following steps:

placing the sample in a box, placing the core sample box in a ventilation kitchen, and drying the core sample; then coating the mixed glue on the surface of the sample, repeatedly coating the sample for about 3-6 times, and placing the glued surface of the sample in a fume hood in a core box for drying and curing;

the colloid is cured according to the room temperature, the room temperature of the sample is controlled at 15-28 ℃, the humidity is controlled at 35-46%, and the curing time is 20-80 minutes;

the adhesive is mixed adhesive, and comprises the following components in parts by weight: 502T-1 type: 502K-2 is 2-3:1.

preferably, the specific method for cutting the mud shale sample subjected to the glue seepage treatment in the step 2 comprises the following steps: firstly, recording the sample in detail before cutting, and cutting according to requirements when the manufacturing direction, the number, the positions and the construction surface of the sample are marked; after the sample is cut, the sample is spliced and restored with the sample, the designated position of the sample is marked on the sample by a color pen after the sample is restored, the sample is cut strictly according to a certain direction of a cross section or a longitudinal section, the cutting mode is that the sample is cut in a dry manner, the sample is pushed to the cutting blade direction slowly aiming at the cutting line to cut the sample, and the cut surface of the cut sample is cleaned and dried; the cleaning liquid is potassium chloride saturated solution; the cooling liquid is also saturated potassium chloride solution in the cutting process, and the cut sample is placed in a fume hood for airing.

Preferably, the specific method for performing the second glue seepage flow on the sample cut in the step 3 is as follows: placing the samples into a fume hood, drying the samples in the shade after the samples are placed in sequence, carrying out glue permeation treatment on the A surface of the samples after the dried samples are subjected to glue permeation treatment on the B surface after the dried samples are treated, wherein the glue on the B surface is thicker than the A surface glue, and carrying out glue permeation treatment on the side surface of the samples C, D, E, F; the temperature in the fume hood is controlled at 28-32 ℃ and the humidity is controlled at 40-46%.

Preferably, the specific method for grinding the sample plane after the secondary glue permeation in the step 4 is as follows:

firstly, the residual glue on the surface A of the sample is shoveled by a knife, the glue on other planes is remained and can not be shoveled, namely W40 carborundum is used, the saturated solution is mixed for rough grinding, scratches or pits are formed in the process of rough grinding of the surface A, and the carborundum with the W40 meshes is also treated;

finally, rough grinding the surface A of the sample, namely, the surface A is smooth and free of concave-convex, then cleaning the sample by using saturated solution, wiping the sample by using cotton soft paper, and if degumming and threshing exist, drying the sample in a fume hood for glue invasion treatment;

after the glue dipping treatment, 1000-mesh sand paper is used for mixing saturated solution for detail surface treatment until the plane is smooth and has no concave-convex.

Preferably, in the step 5, the method for carrying out the plane fine grinding process on the coarsely ground sample comprises the following steps:

grinding with green silicon carbide with the abrasive grain size of W28 and the hardness of 3200-3400 kgf/mm 2; the fine grinding is carried out by using W28 silicon carbide;

then cleaning with saturated potassium chloride solution, changing the solution to a glass plate, further finely grinding with W3.5 micro powder, and adding a small amount of saturated potassium chloride solution to mix micro powder during fine grinding; the micropowder is alumina micropowder.

Preferably, the method for adhering the sample after the fine grinding treatment to the glass slide in the step 6 is as follows:

the shale adhesive sheet is to be adhered to a frosted glass sheet, firstly, a glass slide is wiped, the frosted surface is placed in a ventilation kitchen upwards, a sample on the adhered surface faces upwards, mixed glue is smeared on the sample on the plane upwards, the smearing area and the sample area are proper, and the glue is not needed to be excessive; the rough surface of the slide glass moves downwards and upwards by the edge of the bottom of the sample, the slide glass is pressed on the sample by forceps to be lightly pressed and bonded, and the thickness of the adhesive layer is 0.01-0.02 mm after the air bubbles are discharged; then the gel is horizontally placed in a sample box for 40 to 60 minutes, and the next working procedure can be carried out after the gel is solidified.

Preferably, step 7 is performed on a sample of the slide, and the slide is mainly kept parallel to the blade during cutting; cutting a sample to a proper thickness of 1mm, cleaning and wiping the cut rock slide, and placing the rock slide into a drying vessel for storage; the cutting speed is 8000-10000 rpm.

Preferably, the method of performing secondary coarse grinding after cutting the sample in the step 8: the grinding is carried out on a coarse grinding machine, and the grinding thickness is 1 mm-0.08 mm; holding a slide glass with a rock slice by a right hand during rough grinding, dipping a small amount of potassium chloride saturated solution and W40 silicon carbide by a small brush by a left hand, brushing on a grinding disc, pressing an index finger, a middle finger, a ring finger and a little finger on the slide glass, and applying force on two sides of the slide glass by the index finger and the middle finger; the rock slice continuously moves slowly from the right side to the left side of the millstone, and a small amount of grinding liquid is added, so that the rock slice is slowly ground, and the direction of the rock slice is rotated during grinding; coating colloid on the surface of a sample when the thickness of the rock slice is 0.2mm, wherein the colloid is thin but not thick, and carrying out grinding treatment after airing, wherein the coating times are 1-3 times; when the thickness of the rock slice is approximately 0.2mm, the grinding liquid can be stopped, the pressure on the finger and the glass slide is reduced, the rock slice is taken up to visually observe the thickness of the rock slice, the rock slice is excessively thick, the grinding is required to be carried out on a grinding disc, the direction is changed, the force is evenly applied, the grinding is 0.08mm, and the rough grinding work is completed.

Preferably, step 9 carries on the secondary fine grinding to the sample, the fine grinding flake requires thickness to be 0.08-0.04 mm thick; grinding on a fine grinder by using W28 carborundum, wherein the force of a hand on a sample can not be excessive, and the sample can be slightly forced to move from the center of a grinding disc to the right side edge; the rotating speed of the grinding disc is 600-800 revolutions per minute, the thickness is checked frequently, the direction of the thin sheet is changed frequently, and the phenomenon of uneven thickness is adjusted in time by matching with the size of finger stress; at this time, the interference colors of quartz under a microscope are mostly primary pale yellow, orange and a small amount of secondary orange red, and then w28 diamond is used for grinding, so that the quartz is ground to primary yellowish white to pale yellow;

and/or the number of the groups of groups,

the final finish grinding process of the sample in step 10 is as follows: the w1.5 micro powder is used for grinding the glass plate by hand, the grinding material and the saturated solution are not easy to excessively and properly used in fine grinding, and a piece of ground stone surface and the grinding material are used for grinding the glass plate, so that the grinding material on the glass plate is uniformly dispersed and coarse grinding material particles are ground, and the damage to the thin sheet due to large-particle grinding material on the thin sheet is avoided; pushing and grinding the glass plate with index finger or thumb, and changing the direction of the glass slide and the pushing and grinding position after grinding for several times so as to grind the slice to the standard thickness of 0.03mm; at this time, the interference color of quartz was observed by a microscope as bright white or off-white.

Compared with the background technology, the invention has the following beneficial effects:

1. according to the manufacturing process of the shale continuous slice, the core is subjected to preliminary treatment, so that the original form of an original sample is ensured; performing secondary photoresist infiltration treatment on the core, and ensuring the integrity of the core; core cutting ensures that the sample is not loose after cutting; the rock is subjected to glue seepage treatment after cutting, so that the rock is prevented from being damaged by water and mechanical vibration; the rock is ground and fine ground by a fine grinding machine, so that the rock is manufactured completely, original information is not lost, and the area of the rock is ensured to be accurate. The surface continuity, the layer integrity and the original mineral definition of the core are completely reserved in the cutting and grinding processes; the rock slice is manufactured by a special method without a cover plate, the surface of the slice is bright, micro pores and micro cracks are clearly visible under a microscope, and the rock slice is not influenced by environmental factors; the original gyratory omnidirectional identification and description of the rock slice can be carried out for a long time.

2. The mixed glue prepared by the method has good colloid permeability, water resistance, no fluorescence and the thickness between the colloid bonding glass slide and the rock is 0.01-0.03 mm. The colloid is transparent, has no impurity, the refractive index is 1.48-1.54N, the width of a single piece of the prepared continuous sheet is 2.3-2.5 mm, the length can be controlled to be 18-65 mm, the error of the original area and the grinding area of the prepared continuous sheet is only 1%, and the integrity of the original sample and the scientific research requirement can be effectively ensured. The method can avoid pollution to the shale sample caused by participation of the original fir glue, water or oil with faster heat conduction and other manufacturing materials, makes up the defects of small page development, tattoo and layering areas or sample fragmentation in the manufactured sheet, further achieves the purpose of maximizing the area, and can completely represent the original geological information in the sample without loss.

3. The grinding fluid disclosed by the invention uses a potassium chloride saturated solution, the expansion coefficient in the cutting process is small, and the grinding area in the grinding process is large; the destructive power to organic matter components in the sample is small, and the sample is observed comprehensively under a microscope. The abrasion rate in the grinding process of the prepared sample is low, and shale construction at specific positions can be accurately identified and described.

4. The continuous sheet manufacturing method solves the problems that the prior oil shale sheet sample manufacturing technology is insufficient and the shale core cannot be subjected to water cutting; realizing scientific research and economic value of continuous sheet samples; the working efficiency is improved, the manpower, material resources and time are saved, the timeliness of sheet processing is ensured, and high-quality service is provided for oil field exploration and development; the rock flaking quality is improved, the maximization of the ground sample is ensured, the mineral type of the sample is comprehensively reflected, and unsafe factors of the original colloid on human and environmental pollution are eradicated; the grinding level of the shale oil rock by the research institute is improved; the sample completion time and qualification rate reach 100 percent.

5. The continuous sheet can be manufactured into a millimeter-sized continuous sheet, and can be manufactured into a continuous sheet between 0.5m and 1m at the longitudinal section position of one point of a certain layer of the whole section of the rock core; such continuous webs find primary application in gyratory assembly, rock composition and content analysis.

6. The preparation method of the shale continuous sheet can completely retain the surface continuity, the layer integrity and the original mineral definition of the core, and provide powerful guarantee for subsequent core description and various test analysis. By adopting the brand-new sheet making process technology of the continuous sheet, the problems in the making process are greatly reduced, and the making efficiency of the continuous sheet process is greatly improved, so that the rock sheet with high quality is made. The method provides the most accurate geological data for identifying high-quality reservoir interpretation aiming at shale lithology.

Description of the drawings:

FIG. 1 is a schematic view of the rock of a slice according to an embodiment of the present invention in a direction above a formation location;

FIG. 2 is a schematic view of the sheet direction of an embodiment of the present invention;

FIG. 3 is a schematic view of a cutting position according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of a sample adhesive side according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of an embodiment of the invention for checking whether the surface of a rock slice is flat and smooth after grinding;

FIG. 6 is a schematic illustration of sample bonding in accordance with an embodiment of the present invention;

FIG. 7 is a schematic view of the polishing direction according to an embodiment of the present invention;

FIG. 8 is a schematic view of grinding different interference color thicknesses according to an embodiment of the present invention;

FIG. 9 is an explanatory diagram of experimental analysis of rock hand specimens and continuous sheets according to an embodiment of the present invention;

FIG. 10 is a flow chart of the process for manufacturing the shale continuous slice of the invention.

The specific embodiment is as follows:

for the purpose of making the objects, technical solutions and advantages of the present invention more apparent, the embodiments of the present invention will be described in further detail with reference to the accompanying drawings.

The preparation method of the shale continuous sheet mainly comprises ten main steps of rock surface glue seepage, sample cutting, sample secondary glue seepage, sample plane rough grinding, sample fine grinding, sample and glass slide sticking, slicing, secondary rough grinding, secondary fine grinding and final fine grinding, and cotton soft paper is used for wiping the sample surface after each step of preparation. In the cutting and grinding process, a potassium chloride saturated solution and distilled water are adopted as the whole experiment cooling liquid and grinding liquid, and samples of each step of subsequent preparation are dried in the air. The colloid used in the whole preparation process is mixed colloid, and the components and the weight ratio are as follows: 502T-1 type: 502K-2 is 2-3:1. the 502T-1 type and 502K-2 type manufacturers are Beijing chemical plants. The performance parameters of the 502T-1 type and 502K-2 type finished products are shown in Table 1.

TABLE 1

As shown in fig. 1, the rock from which the continuous sheet is made is in place of the formation, and the continuous sheet samples are generally consistent with the following:

l: the specimen is positioned upwards;

y: the specimen position is downward;

tenth, specimen horizontal line, direction line;

a+: rock formation on the longitudinal section;

a-: rock formation under longitudinal section.

By orienting the specimen, a continuous sheet of horizontal lines can be cut. Cutting the specimen at a marked position on a slicing machine, splicing and restoring the cut rock blocks with the specimen, drawing the upper and lower strata appointed by the specimen into a rectangle or square according to the required area after restoring, and cutting the required square rock blocks along the line. The position of the specimen is marked on the back of the rock block by a pencil, the other side is ground flat and is adhered to the glass slide, but the direction and the upper side and the lower side cannot be misplaced, for example, when A+ is used, the A-side is adhered to the glass slide. After the specimen is attached to the slide, the orientation is written with a pencil on both sides of the slide along with the number (as shown in fig. 2).

The manufacturing process of the shale continuous slice mainly comprises 10 steps, and the specific process of the manufacturing process and the materials and the notes required by each process are as follows:

step 1: glue penetrating treatment for shale

And performing glue permeation treatment on the shale. The samples with good and bad diagenetic effects need to be subjected to glue permeation treatment, because micro cracks and pores exist in the tattoo layer in the samples, and the samples are cracked in a large area in the cutting or grinding process without glue permeation.

The concrete method of the mud shale glue seepage treatment process comprises the following steps:

placing the sample in a box, placing the core sample box in a ventilation kitchen, and drying the core sample; then coating the mixed glue on the surface of the sample, repeatedly coating the sample for about 3-6 times, and placing the glued surface of the sample in a fume hood in a core box for drying and curing; wherein the mixed gel is an acrolein-based resin, the colloidal solvent evaporates (hydroxide ions formed by water), and the water from the air on the sample surface causes the monomers to rapidly undergo anionic polymerization, bonding the two surfaces together.

The colloid is cured according to the room temperature, the room temperature of the sample is controlled between 15 ℃ and 28 ℃, the humidity is controlled between 35% and 46%, and the curing time is 20 to 80 minutes. The adhesive is mixed adhesive, and comprises the following components in parts by weight: 502T-1 type: 502K-2 is 2-3:1.

step 2: shale sample cutting

The specific method of the flow is as follows: firstly, the sample is recorded in detail before cutting, the making direction, the number, the positions and the construction surface are marked on the rock mass, and cutting is carried out according to the requirements. After the specimen is cut, the specimen is spliced with the original specimen for restoration, the designated position of the specimen is marked on the specimen by a color pen, the specimen is cut strictly according to a certain direction of a transverse section or a longitudinal section, the cutting mode is to cut the hand-held specimen in a dry manner, the specimen is aligned with a cutting line to slowly push the cutting blade to cut the specimen, and the cut surface of the cut specimen is cleaned and dried. The cleaning liquid is potassium chloride saturated solution. The cooling liquid is also saturated potassium chloride solution (as shown in fig. 3) for the cutting process. And (5) placing the cut sample in a fume hood for airing.

The potassium chloride solution cleaning method comprises the following steps: placing the cut sample into a beaker filled with saturated potassium chloride solution to clean the surface, brushing residual particles on the surface of the rock by using a brush, wiping the cleaned surface with a dry towel, and airing for 20 minutes, wherein the surface of the rock has no water mark or adsorbed water.

Step 3, performing sample secondary glue permeation on the cut sample

The specific method of the flow is as follows: putting the sample into a fume hood, drying in the shade after the sample is put once, carrying out glue permeation treatment on all six surfaces of the dried sample, firstly carrying out glue permeation treatment on the A surface (the bonding surface of the rock and the glass slide) of the sample, carrying out glue permeation treatment on the B surface (the B surface is the opposite direction surface of the sample) after the treatment, wherein the colloid of the B surface is thicker than the A surface adhesive, mainly preventing the sample from being cracked and distinguishing the reverse of the A, B surface, secondly, carrying out glue permeation and solidification on the other four sides (C, D, E, F), and carrying out glue permeation and solidification on the C, D, E, F surface sample, thereby preventing expansion secondary deformation caused by water evaporation in the sample pores in the solidification process (as shown in fig. 4). The temperature in the fume hood is controlled at 28-32 ℃ and the humidity is controlled at 40-46%.

Secondly, the process mainly has a consolidation effect on the sample, and the better the glue seepage effect on the rock surface with larger page development, the more the sample with smaller grain layer and layer development needs to be glued for multiple times.

Step 4: coarsely grinding a sample plane;

the specific method of the flow is as follows: in view of the low hardness of the sample, the surface has a very thin layer of colloid, and care must be taken not to grind away the layer of colloid when grinding the surface A of the sample. Firstly, the residual glue on the surface A of the sample is shoveled by a knife, other plane glue can not be shoveled, namely W40 carborundum and potassium chloride saturated solution are used for rough grinding, scratches or pits are formed in the process of rough grinding of the surface A, and the carborundum with the W40 meshes is also used for treatment. And finally, roughly grinding the surface A of the sample to ensure that the surface is smooth and free of concave and convex, cleaning the sample by using saturated solution, wiping the sample by using cotton soft paper, and if degumming and threshing exist, drying the sample in a fume hood to perform glue dipping treatment, and changing the sample into 1000-mesh sand paper to mix with saturated potassium chloride solution for detail treatment after the glue dipping treatment until the plane is smooth and free of concave and convex.

The manufacturing flow is to note that rough grinding can be carried out according to the conditions of hardness, looseness and the like of the rock, the colloid surface of the rock is generally ground, and in order to avoid the problems of large-area scratches and degumming caused by uneven granularity of the carborundum on the surface A, the carborundum is preferably consistent in specification. In addition, in the process of rough grinding of the rock, the dust mask, goggles and rubber gloves are also required to be provided for protecting the safety of the rock.

Step 5: sample fine grinding plane grinding

The specific method of the flow is as follows: the green silicon carbide with the abrasive grain size of W28 and the hardness of 3200-3400 kgf/mm2 is used for grinding. The fine grinding is to grind the rough grinding plane which is ground by the W40 diamond on a fine grinding machine, so that the concave-convex gravel on the surface gradually reduces along with the gradual thinning in the fine grinding process. Grinding with W28 silicon carbide, cleaning with saturated potassium chloride solution, and further grinding with W3.5 micropowder (aluminum oxide micropowder); when the alumina powder and the potassium chloride saturated solution are added for fine grinding, a hard and flat rock block is required to be placed on a glass plate, and the alumina powder and the grinding liquid potassium chloride saturated solution are uniformly ground, so that the grinding homogenization effect is achieved, and grinding materials possibly mixed with larger particles in the grinding materials can be ground or separated out, so that scratches on the surface of a sample during fine grinding are prevented.

The flow is noted to be uneven when the plane is finely ground, some positions of the sample are fine, some positions are rough, and some positions are not even ground or have large-area unevenness. The method for checking the sample is to lift the finely ground rock sample to a height lower than the eyes by hand, the sample is in a horizontal state, and the phenomenon that the sample is ground unevenly can be found by reflecting the externally-emitted light into the eyes by tilting the sample up and down and then tilting the sample left and right by hand, so that the sample needs to be ground repeatedly if the grinding surface is level and uneven or the reflection point is low. (as shown in fig. 5).

Step 6: adhesive sheet for sample and glass slide

The specific method of the flow is as follows: shale patches are more cumbersome and difficult than typical conventional rock sample patches. The shale adhesive sheet is adhered to a frosted glass sheet, because the adhesive force of the frosted glass is larger than that of a smooth glass slide after solidification, the glass slide is firstly wiped dry, the frosted surface is placed in a ventilation kitchen (the frosted surface is upward to prevent other pollution on the glass slide), a sample on the adhered surface is upward, the mixed solidified glue is smeared on the sample on the plane upward, the smearing area and the sample area are proper, and the glue is not easy to be excessive. The rough surface of the slide glass is lifted downwards, the cover pressure is moved upwards from the edge of the bottom of the sample (as shown in figure 6), the slide glass is pressed on the sample by forceps to lightly squeeze and adhere, and the thickness of the adhesive layer is 0.01-0.02 mm after the air bubbles are discharged. Then the gel is horizontally placed in a sample box for 40 to 60 minutes, and the next working procedure can be carried out after the gel is solidified.

Wherein, the bonding process of the rock is successful in primary bonding and secondary bonding is at most carried out. If the sample cannot be well adhered for many times, taking one end of the glass slide by hand after the colloid is completely solidified, lightly beating the other end of the glass slide, beating and vibrating to take off the glass slide, and then re-infiltrating the colloid to grind the plane again and adhering the glass slide.

Step 7: slicing

The method can be directly used for cutting mudstone, shale, mudstone disintegrated rock, mudstone biological debris sample and the like with good cementation and solidification. If the clay content is high, potassium chloride saturated solution can be adopted for blending, cooling and cutting, and the slide is mainly kept parallel to the blade during cutting. Cutting the sample to a proper thickness of 1mm, cleaning and wiping the cut rock slide, and placing the rock slide into a drying vessel for storage.

The procedure requires attention, samples should be arranged in cassettes by number before slicing, with error proofing. Then observing the original structure and the gyratory feature of the sample, and selecting the slice orientation; checking the machine clamp and the graduated scale, and avoiding the phenomenon that one side is thick and the other side is thin; the cutting speed is high (8000-10000 rpm) so as to avoid the degumming of the glass slide and the rock sample caused by vibration in the cutting process.

Step 8: and (5) carrying out secondary rough grinding after cutting the sample.

The process is carried out on a coarse grinding machine, and the grinding thickness is 1 mm-0.08 mm. The right hand holds the slide with the rock slice and the left hand uses the small brush to dip a small amount of potassium chloride saturated solution and W40 silicon carbide, brushes on the grinding disc, presses the index finger, the middle finger, the ring finger and the little finger on the slide, and mainly uses the index finger and the middle finger to apply force on the two sides of the slide. The rock slice continuously moves slowly from the right side to the left side of the grinding disc (as shown in fig. 7), and a small amount of grinding liquid is added, so that the grinding slice is slowly ground, and the direction of the rock slice is rotated during grinding. When the thickness of each rock slice is 0.2mm, colloid is coated on the surface of the sample, the colloid is thin but not thick, and the grinding treatment is carried out after the rock slice is dried in the air, wherein the coating times are 1-3 times. When the thickness of the rock slice is approximately 0.2mm, the pressure on the finger and the glass slide is reduced, the rock slice is taken up to visually observe the thickness of the rock slice, the rock slice is excessively thick, the grinding disc is required to be used for grinding, the direction is changed, the force is evenly applied, the phenomenon of uneven thickness is overcome, the thickness is 0.08mm, and the rough grinding work is completed.

Note that in operation, the force point of the hand should be at the center of the sheet, and the force should be appropriate, and the sheet is continuously moved back and forth along the radius direction of the grinding disc. It should be frequently checked whether the thickness is uniform and the degummed phenomenon.

Step 9, carrying out secondary fine grinding on the sample

The thickness of the fine grinding thin sheet is 0.08-0.04 thickness. The W28 silicon carbide is used for grinding on a fine grinder, the force applied by a hand on a sample can not be excessive, and the force is lightly applied, so that the sample moves from the center of a grinding disc to the right side edge at 600-800 revolutions per minute, the thickness is checked, the direction of a thin sheet is frequently changed, and the uneven thickness is timely adjusted according to the force applied by fingers. At this time, the interference colors of the quartz under the microscope are mostly primary pale yellow, orange and a small amount of secondary orange red, and then the quartz is ground to primary yellowish white to pale yellow by grinding with No. w28 silicon carbide. (as shown in FIG. 8)

Step 10: final finish grinding of the sample

In the process of the finish grinding flow, w1.5 micro powder is mainly used for grinding a glass plate by hand, grinding materials and potassium chloride saturated solution are used for evenly mixing during fine grinding, the potassium chloride saturated solution is not easy to excessively and properly mix, the grinding materials are poured on the glass plate, a piece of non-sample stone is used for grinding the glass plate, and the grinding materials on the glass plate are mainly used for evenly dispersing and grinding coarse grinding particles in the grinding process, so that the thin sheet is prevented from being damaged by large-particle grinding materials. The glass plate was uniformly ground with an index finger or thumb, and the slide direction and the position of grinding were exchanged after grinding several times to uniformly grind the sheet to a standard thickness of 0.03mm. At this time, the microscope observes that the quartz interference color is bright white or first order off-white (as shown in fig. 8).

Experimental analysis of the prepared continuous sheet

The length of the experimental rock hand specimen is 27.5cm, the length of the slice is made to be 27.8cm, and the more 0.3cm is the measured length of the rock specimen after the colloid is solidified. The area ratio of the continuous sheet is 98% when 1.8cm is manufactured, 97% when 2cm is manufactured, 96% when 2.3cm is manufactured, wherein the area ratio of a lost sample when cutting is 1%, the lost area ratio in the grinding process is 1%, and the lost area ratio of a special reason is 2%; the continuous sheet has a width of 2.3 mm-2.5 mm, the integrity of the continuous hand specimen is 96%, and the explanation of the experimental analysis rock hand specimen and the continuous sheet is shown in fig. 9.

The method for preparing the shale continuous slice is compared with the prior slice preparation technology:

at present, the conventional manufacturing process is still adopted for manufacturing the shale slices, wherein fir glue is used for mucilage glue, only rock slices with the size diameter of 22mm multiplied by 22mm to 25mm multiplied by 25mm can be manufactured, and the manufactured slices are short in length and small in area. In the early treatment, the sample is complicated to manufacture, the abrasion rate of the sample is high in the grinding process, the ground sheet cannot ensure the accuracy of the original sample area, the information which completely represents the original geology in the sample is easy to lose, the mineral analysis can only be carried out, and the original gyratory omnibearing identification and description of the rock sheet cannot be carried out. The scratch and the falling off phenomenon can occur in the grinding process, and the reworking rate is high and reaches more than 40 percent. And have limited observation under a microscope; at the same time, some human factors and mechanical cutting processes can lead to micro-crack deformation and fragmentation in the page development grain layer; and moreover, the grinding fluid is water, the expansion coefficient in the cutting process is large, the corresponding adsorbed water possibly adsorbs on shale microcracks and the surface of the sample in the grinding and polishing processes, the damage to organic matters in the sample is large, the observation under a microscope is limited, and the observation of the sample is incomplete. These may result in inaccurate identification and description of the shale formation for a particular location.

The invention relates to a shale continuous slice, which is characterized in that firstly, the geological phenomena of original structure, minerals and the like of a sample are treated by the mixed glue provided by the invention, the mixed glue has the advantages of good glue permeability, water resistance, no fluorescence, and the thickness between a glue bonding glass slide and rock is 0.01-0.03 mm. The colloid is transparent, the refractive index of the impurity-free colloid is 1.48-1.54N, the width of a single piece of the prepared continuous sheet is 2.3-2.5 mm, the length can be controlled to be 18mm multiplied by 65mm, the error of the original area and the grinding area of the prepared continuous sheet is only 1%, and the integrity of the original sample and the scientific research requirement can be effectively ensured. The reworking rate is extremely low and is only 5-10%. The process for making the shale continuous sheeting of the present invention is shown in fig. 10. The grinding fluid disclosed by the invention uses a potassium chloride saturated solution, the expansion coefficient in the cutting process is small, and the grinding area in the grinding process is large; the destructive power to organic matter components in the sample is small, and the sample is observed comprehensively under a microscope. The abrasion rate in the grinding process of the prepared sample is low, and shale construction at specific positions can be accurately identified and described.

The manufacturing method of the continuous sheet is applied to shale in a Songlao basin gully shale oil well, and mainly solves the problem that the shale core can not be cut by water; the surface continuity, the layer integrity and the original mineral definition of the core are completely reserved in the cutting and grinding processes; the rock slice is manufactured by a special method without a cover plate, the surface of the slice is bright, micro pores and micro cracks are clearly visible under a microscope, and the rock slice is not influenced by environmental factors and human factors; the original gyratory omnidirectional identification and description of the rock slice can be carried out for a long time. The continuous sheet manufactured according to the experiment can distinguish lithology, structural sedimentation and gyratory of relevant mudstones, and plays a key role in microscopic interpretation of the shale.

The continuous sheet can be manufactured into a millimeter-sized continuous sheet, and can be manufactured into a continuous sheet between 0.5m and 1m at the longitudinal section position of one point of a certain layer of the whole section of the rock core; such continuous webs find primary application in gyratory assembly, rock composition and content analysis. Wherein deposition cycle refers to a sequence of layers consisting of deposition and deposition conditions that are repeatedly deposited in the same order. Deposition loops are mainly caused by the periodic oscillatory motion of the crust, while deposition loops are formed in many ways by local regional factors.

By adopting the brand-new sheet making process technology of the continuous sheet, the problems in the making process are greatly reduced, and the making efficiency of the continuous sheet process is greatly improved, so that the rock sheet with high quality is made. The method provides the most accurate geological data for rock type and paleogeographic formation and reservoir interpretation determined by the method of 'mineral composition + microstructure + sedimentary gyratory' of shale.

Claims (10)

1. A preparation method of a shale continuous slice is characterized in that: the method comprises the following steps:

step 1: performing glue permeation treatment on the shale;

step 2: cutting the mud shale sample subjected to the glue seepage treatment;

step 3: performing sample secondary glue permeation on the cut sample;

step 4: carrying out rough grinding on the sample plane after the secondary glue permeation;

step 5: carrying out plane fine grinding on the coarsely ground sample;

step 6: adhering the sample after the fine grinding treatment to a glass slide;

step 7: slicing a sample on a slide;

step 8: cutting the sample and then carrying out secondary coarse grinding;

step 9: carrying out secondary fine grinding on the sample;

step 10: the sample was finally finely ground and observed under a microscope until the quartz interference color was bright white or off-white.

2. The method for preparing the shale continuous slice according to claim 1, wherein: the method for performing the glue permeation treatment on the shale in the step 1 comprises the following steps:

placing the sample in a box, placing the core sample box in a ventilation kitchen, and drying the core sample; then coating the mixed glue on the surface of the sample, repeatedly coating the sample for about 3-6 times, and placing the glued surface of the sample in a fume hood in a core box for drying and curing;

the colloid is cured according to the room temperature, the room temperature of the sample is controlled at 15-28 ℃, the humidity is controlled at 35-46%, and the curing time is 20-80 minutes;

the adhesive is mixed adhesive, and comprises the following components in parts by weight: 502T-1 type: 502K-2 is 2-3:1.

3. the method for preparing the shale continuous slice according to claim 1, wherein: the method for cutting the mud shale sample subjected to the glue permeation treatment in the step 2 comprises the following steps:

firstly, recording the sample in detail before cutting, and cutting according to requirements when the manufacturing direction, the number, the positions and the construction surface of the sample are marked; after the sample is cut, the sample is spliced and restored with the sample, the designated position of the sample is marked on the sample by a color pen after the sample is restored, the sample is cut strictly according to a certain direction of a cross section or a longitudinal section, the cutting mode is that the sample is cut in a dry manner, the sample is pushed to the cutting blade direction slowly aiming at the cutting line to cut the sample, and the cut surface of the cut sample is cleaned and dried; the cleaning liquid is potassium chloride saturated solution; the cooling liquid is also saturated potassium chloride solution in the cutting process, and the cut sample is placed in a fume hood for airing.

4. The method for preparing the shale continuous slice according to claim 1, wherein: the method for carrying out the second glue permeation on the sample cut in the step 3 comprises the following steps: placing the sample in a fume hood, drying in the shade after the sample is placed, carrying out glue permeation treatment on the A surface of the sample on the dried sample, carrying out glue permeation treatment on the B surface after the treatment is finished, wherein the glue on the B surface is thicker than the A surface glue, and carrying out glue permeation treatment on the side surface of the sample C, D, E, F; the temperature in the fume hood is controlled to be 28-32 ℃ and the humidity is controlled to be 40-46%.

5. The method for preparing the shale continuous slice according to claim 1, wherein: the method for grinding the sample plane after the secondary glue permeation in the step 4 comprises the following steps:

firstly, removing residual glue on the surface A of a sample, wherein the glue on other planes can not be shoveled, namely W40 diamond is used for coarse grinding, a saturated solution is mixed, scratches or pits are formed in the process of coarse grinding the surface A, and the surface A is also treated in W40 mesh diamond;

finally, rough grinding the surface A of the sample to be smooth and smooth without concave-convex, cleaning the sample by using saturated solution, wiping the sample by using cotton soft paper, and if degumming and threshing exist, drying the sample in a fume hood for glue invasion treatment;

after the glue dipping treatment, 1000-mesh sand paper is used for mixing saturated solution for detail surface treatment until the plane is smooth and has no concave-convex.

6. The method for preparing the shale continuous slice according to claim 1, wherein: the method for carrying out plane fine grinding on the coarsely ground sample in the step 5 comprises the following steps:

grinding by using green silicon carbide with the abrasive grain size of W28 and the hardness of 3200-3400 kgf/mm < 2 >; the fine grinding is carried out by using W28 silicon carbide;

then cleaning with saturated potassium chloride solution, changing the solution to a glass plate, further finely grinding with W3.5 micro powder, and adding a small amount of saturated potassium chloride solution to mix micro powder during fine grinding; the micropowder is alumina micropowder.

7. The method for preparing the shale continuous slice according to claim 1, wherein: the method for sticking the sample after the fine grinding treatment and the glass slide in the step 6 is as follows: the shale adhesive sheet is to be adhered to a frosted glass sheet, firstly, a glass slide is wiped, the frosted surface is placed in a ventilation kitchen upwards, a sample on the adhered surface faces upwards, mixed glue is smeared on the sample on the plane upwards, the smearing area and the sample area are proper, and the glue is not needed to be excessive; the rough surface of the slide glass moves downwards and upwards by the edge of the bottom of the sample, the slide glass is pressed on the sample by forceps to be lightly pressed and bonded, and the thickness of the adhesive layer is 0.01-0.02 mm after the air bubbles are discharged; then the sample box is horizontally placed in the sample box for 40-60 minutes, and the next working procedure can be carried out after the colloid is solidified.

8. The method for preparing the shale continuous slice according to claim 1, wherein: step 7, when slicing the sample of the glass slide, mainly keeping the glass slide parallel to the blade during cutting; cutting a sample to a proper thickness of 1mm, cleaning and wiping the cut rock slide, and placing the rock slide into a drying vessel for storage; the cutting speed is 8000-10000 rpm.

9. The method for preparing the shale continuous slice according to claim 1, wherein: and 8, performing secondary coarse grinding after cutting the sample: grinding on a coarse grinding machine, wherein the grinding thickness is 1 mm-0.08 mm; holding a slide glass with a rock slice by a right hand during rough grinding, dipping a small amount of potassium chloride saturated solution and W40 silicon carbide by a small brush by a left hand, brushing on a grinding disc, pressing an index finger, a middle finger, a ring finger and a little finger on the slide glass, and applying force on two sides of the slide glass by the index finger and the middle finger; the rock slice continuously moves slowly from the right side to the left side of the millstone, and a small amount of grinding liquid is added, so that the rock slice is slowly ground, and the direction of the rock slice is rotated during grinding; coating colloid on the surface of a sample when the thickness of the rock slice is 0.2mm, wherein the colloid is thin but not thick, and carrying out grinding treatment after airing, wherein the coating times are 1-3 times; when the thickness of the rock slice is approximately 0.2mm, the grinding liquid can be stopped, the pressure on the finger and the glass slide is reduced, the rock slice is taken up to visually observe the thickness of the rock slice, the rock slice is excessively thick, grinding is carried out on a grinding disc, the direction is changed, the force is evenly applied, the grinding is 0.08mm, and the rough grinding work is completed; the colloid is mixed colloid.

10. The method for preparing the shale continuous slice according to claim 1, wherein: step 9, carrying out secondary fine grinding on the sample, wherein the thickness of a fine grinding sheet is required to be 0.08-0.04 mm; grinding on a fine grinder by using W28 carborundum, wherein the force of a hand on a sample can not be excessive, and the sample can be slightly forced to move from the center of a grinding disc to the right side edge; the rotating speed of the grinding disc is 600-800 revolutions per minute, the thickness is checked, the direction of the thin sheet is changed, and the phenomenon of uneven thickness is timely adjusted by matching with the size of finger stress; at this time, the interference colors of quartz under a microscope are mostly primary pale yellow, orange and a small amount of secondary orange red, and then w28 diamond is used for grinding, so that the quartz is ground to primary yellowish white to pale yellow;

and/or the number of the groups of groups,

the final finish grinding process of the sample in step 10 is as follows: grinding the glass plate by using w1.5 micro powder by hand, grinding by using an abrasive material and adding a proper amount of saturated solution during fine grinding, and grinding the glass plate by using a block of ground stone surface and the abrasive material, wherein the abrasive material on the glass plate is mainly uniformly dispersed and coarse particles of the abrasive material are ground, so that the thin sheet is prevented from being damaged by the large-particle abrasive material; pushing and grinding the glass plate with index finger or thumb, and changing the direction of the glass slide and the pushing and grinding position after grinding for several times so as to grind the slice to the standard thickness of 0.03mm; at this time, the interference color of quartz was observed by a microscope as bright white or off-white.

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