CN100516837C - Measuring device and method for source rock organic maturity - Google Patents

Abstract

This invention relates to a measurement device and a method for organic mature degree of hydrocarbon source ore including a coaxial optical system of strip beams generated by a convex and a cylinder lens in a shell containing a laser, a capillary on the focal plane of the cylinder lens and a semi-transparent screen behind it and a CCD camera and a computer with software program connected by leads characterizing in also including a micro-object lens, micro-holes mounted on a fine three-way adjusting frame, a micro-hole and a lens screen in front of the capillary, the front focus of the objective is coincident with the hole, which is coincident with the back focus of the convex, the capillary is set on a fine five-dimension adjusting frame to let the strip beam irradiate on the middle segment of the capillary to form an interference pattern. The method includes: using a refractive index formula to get the mature degree Ro based on the refractive index n of an extraction solution of the hydrocarbon source ore.

Description

The measurement mechanism of organic maturity degree of hydrocarbon source rocks and method

Technical field

The present invention relates to a kind of measurement mechanism and method of organic maturity degree of hydrocarbon source rocks.

Background technology

In petroleum exploration field, hydrocarbon source rock refers to generate the rock of oil and rock gas.Organic matter type difference in the hydrocarbon source rock, its character is also inequality, contains the different hydrocarbon source rock of organism type, has different genetic potentials.And the organic matter type of hydrocarbon source rock can be distinguished from the structure and the composition of solvable organic matter (pitch) and insoluble organic matter (kerogen).According to kerogen thermal degradation mechanism, oil and natural gas is organic to produce when being reached certain evolutionary phase by temperature action.A considerable number of and well-behaved hydrocarbon source rock organic matter also need could form oil and natural gas through maturing.Terrestrial facies and marine bed all can be divided into prematurity, maturation (being further divided into basic, normal, high ripe three inferior sections) and post-mature three phases.Mezzanine level is for producing the hydrocarbon stage; The stage of ripeness has stronger oil generation ability, and this stage can generate low mature oil, mature oil, white oil and moisture; The post-mature stage has the ability of very low generation gaseous hydrocarbon.Exploration practices proves only in ripe hydrocarbon source rock distributive province higher oil-gas exploration success ratio is arranged, so the evaluation of maturation of source rocks degree also is a decision oil-gas exploration key of success.The most general optical means that is used to measure the hydrocarbon source rock degree of ripeness at present has the vitrinite reflectance method.Its shortcoming is that because hydrocarbon source rock is oxidized, although its content of organic matter difference, its vitrinite reflectance no longer changes when hydrocarbon source rock when layer depth is dark accordingly.Other measuring method also has: kerogenic physical-chemical method, kerogenic element is formed and infra-red sepectrometry, the chemical method of solvable organic matter, pyrolysismethod, form the judgement maturity of organic with the C2-C7 lighter hydrocarbons, and according to the characterized degree of ripeness of C15+ hydro carbons etc., it mainly is the cost height, method is comparatively complicated.

The patent of existing measurement source rock maturity (ZH200420052821.1), though can measure source rock maturity, but owing to the light of capillary wall reflection can by cylindrical lens again secondary reflection be superimposed upon on the interference pattern of sample, can cause fringe contrast to reduce; Algorithm by striped inverting refractive index requires all stripeds all clear in addition, but for the liquid than low transparency, having only some stripeds in the interference pattern outside is clearly, and middle striped blurs, this just causes sizable difficulty to Computer Image Processing, also can influence measuring accuracy.

Summary of the invention

Originally the measurement mechanism and the method that the purpose of this invention is to provide a kind of organic maturity degree of hydrocarbon source rocks are to remedy the deficiencies in the prior art.

The present invention is on the basis of existing patent, device is improved, and adopted the dried method of penetrating pattern inverting refractive index of new foundation, whether this method is only with dried to penetrate left Yu the rightest two of pattern also be that two stripe are relevant the most clearly, clear irrelevant with the striped of centre.

For the ease of understanding, it is necessary sketching measuring principle of the present invention.Because the hydrocarbon source rock of differing maturity contains different solvable organic matters, thereby the refractive index of corresponding extract is different.According to the interference of light principle, the inevitable corresponding different interference fringe of the different refractive index of sample, the i.e. different hydrocarbon source rock of degree of ripeness, corresponding different interference fringes.

The present invention includes the convex lens of laser instrument in interior housing and the centered optical system of the bar shaped light beam that produces of cylindrical lens, be in the computing machine that contains software program that kapillary on the cylindrical lens focal plane and subsequent translucent screen and high precision CCD camera and lead are electrically connected, it is characterized in that it also comprises is at least the microcobjective that is equipped with on the three-dimensional meticulous adjusting bracket, the light hurdle that micropore is preceding with placing kapillary, the front focus of this microcobjective overlaps with micropore, the back focus of micropore and convex lens overlaps, kapillary vertically is placed on the meticulous adjusting bracket of five dimensions, half is marked with liquid kapillary, second half is an air, and bar shaped light beam is radiated on the kapillary interlude and forms interference pattern clearly respectively.

The refractive index formula that obtains testing liquid from existing geometrical optics is:

$n=\frac{\sin (b-c)}{\sin (\frac{\mathrm{\θ}}{2}-c)}---\left(1\right)$

θ is the deflection angle of the corresponding light of the left or the rightest striped of interference pattern (also being the brightest two stripe the most clearly) with respect to optical axis in the formula, just can determine this angle apart from EF/2 and kapillary axis to the distance D C of translucent screen with respect to optical axis by measuring this stripe.The striped (only having one) that b produces for the capillary air in tube is a very little constant with respect to kapillary center angulation.This constant, b=AB/2DC just can be determined to the distance D C of translucent screen in width AB by measuring the air striped and kapillary center.C can determine by one group of normal fluid (ranges of indices of refraction is 1.33-1.80) of known refractive index, measure the θ of each normal fluid interference pattern correspondence, set up the n of normal fluid and the typical curve of θ, can obtain the value of c simultaneously by least square method. for the low transparency liquid of unknown refractive index, as long as measure the pairing θ ' of the left or the rightest interference fringe of its interference pattern, b, c and θ ' substitution (1) formula can be calculated refractive index, or directly read refractive index from typical curve.

The solvable organic matter of hydrocarbon source rock is low transparency liquid, get at least 9 the hydrocarbon source rock standard models of degree of ripeness scope Ro at 0.3-2.5, measure the refractive index of its solvable organic matter with above-mentioned steps, set up the typical curve of degree of ripeness Ro and refractive index n,, to unknown degree of ripeness hydrocarbon source rock, measure its solvable organic refractive index n with said method, with typical curve, i.e. Ro-n curve contrast can obtain degree of ripeness Ro.

Utilize this device can directly measure hydrocarbon source rock extract refractive index, and then obtain corresponding organic maturity degree of hydrocarbon source rocks, and simple in structure, measurement range is big, and cost is low, and light path need not fine adjustment, and is easy to operate.

Description of drawings

Fig. 1 general structure synoptic diagram of the present invention.

Fig. 2 determines the synoptic diagram of constant b.Wherein AB is the width of air striped, and C is the mid point of AB, and D is the intersection point of kapillary axis and optical axis, and CD is the distance of kapillary axis to translucent screen.

The refractive index n of Fig. 3 normal fluid and the typical curve of left or the rightest interference fringe deflection angle θ.

Wherein * is the normal fluid of known refractive index, and is the liquid of unknown refractive index.

Fig. 4 measurement schematic flow sheet of the present invention.

Fig. 5 interference pattern of the diesel oil of CCD camera.

Fig. 6 interference pattern the most left with the refinement synoptic diagram of right striped.

Wherein, 1 laser instrument, 2 microcobjectives, 3 micropores, 4 three-dimensional adjustable shelfs, 5 convex lens, 6 cylindrical lenses, 7 kapillaries, 8 smooth hurdle 9 five times regualting frames, 10 liquid, 11 translucent screens, 12 housings, 13 CCD cameras, 14 computing machines

Embodiment

As Fig. 1, the present invention includes the convex lens 5 of laser instrument 1 in interior housing 12 and the centered optical system of the bar shaped light beam that produces of cylindrical lens 6, be in the computing machine that contains software program 14 that kapillary 7 on cylindrical lens 6 focal planes and subsequent translucent screen 11 and high precision CCD camera 13 and lead are electrically connected, it is characterized in that it also comprises the microcobjective 2 that is equipped with on the three-dimensional adjustable shelf 4, micropore 3, with the light hurdle 8 that places before the kapillary 7, the front focus of this microcobjective 2 overlaps with micropore 3, the back focus of micropore 3 and convex lens 5 overlaps, kapillary 7 vertically is placed on the five times regualting frame 9, half fills liquid 10 kapillary 7, second half is an air, and bar shaped light beam is radiated on kapillary 7 interludes and forms interference pattern clearly respectively.

The enlargement factor of above-mentioned microcobjective 2 is 20 times, be used for expanded beam, the aperture of micropore 3 is the 10-15 micron, be placed on the front focus of microcobjective, be used for filtering, so that obtain the equally distributed hot spot of light intensity, to guarantee that technically interference pattern has high fringe visibility, microcobjective and micropore are placed on the meticulous three-dimensional adjustable shelf, micropore can be adjustable on three directions in space with respect to the position of microcobjective. and the back focus of convex lens overlaps with micropore, the laser beam that expands after restrainting becomes directional light via convex lens, directional light becomes bar shaped light beam via cylindrical lens focus. and kapillary is placed on the meticulous five times regualting frame vertically, and axle capillaceous is on the focal plane of cylindrical lens. select capillary inner diameter 2-3mm usually for use, external diameter 3-4mm, long 10cm.

For low transparency liquid, because kapillary is thinner, as internal diameter 2mm, the light intensity that sees through relevant two light beams capillaceous is equal substantially, even thereby light intensity a little less than, the contrast of striped also can be fine.The reflected light of considering capillary wall is by cylindrical lens secondary reflection and on the translucent screen that is added to, reduce the contrast of striped again, thereby in kapillary the place ahead one smooth hurdle 8 is set, and blocking this part reflected light, thereby improves the contrast of striped.

Organic maturity degree of hydrocarbon source rocks measuring method: (a) get the normal fluid sample of known refractive index n, inject kapillary 7, half fills liquid 10 to make kapillary 7, and second half is an air, and the interference pattern that produces air and standard model simultaneously is on translucent screen 11; Record kapillary 7 axis are to the distance D C of translucent screen 11, so that use in calculating; (b) take coordinate scale chi and interference pattern (as Fig. 5) on the translucent screen 11 respectively with the CCD camera, and be stored in the computing machine; If the no coordinate scale of translucent screen periphery can be after having taken interference pattern, a tight attached coordinate paper behind translucent screen, under the condition of position that does not change the CCD camera and focal length, shooting coordinate paper also stores the image in the computing machine; (c) read every centimetre pixel value of coordinate diagram picture, read the width AB of air interference fringe, calculate constant b=tg (AB/2DC) (as Fig. 2), two interference fringes (as Fig. 6) of the refinement normal fluid interference pattern leftmost side and the rightmost side, and read therebetween apart from EF, calculate deflection angle θ=tg (EF/2DC); (d) with the same method normal fluid sample of at least 9 ranges of indices of refraction at 1.33-1.80, the typical curve of setting up normal fluid refractive index n and deflection angle θ is a n-θ curve (as Fig. 3), obtains constant c by least square method; (e) the lower transparency liquid of unknown refractive index is injected the kapillary of identical material and specification, with the interference pattern on the CCD camera translucent screen, draw the deflection angle θ ' of the liquid of unknown refractive index with above-mentioned same step, b, c and θ ' substitution (1) formula are calculated refractive index, or contrast the refractive index that promptly can read the unknown solution body with typical curve; (f) get at least 9 the hydrocarbon source rock standard models of degree of ripeness scope Ro at 0.3-2.5, extract its solvable organic matter, measure the refractive index n of its solvable organic matter respectively with above-mentioned steps ((a)-(e)), set up the typical curve of degree of ripeness Ro and refractive index n, i.e. the Ro-n curve; (g) to unknown degree of ripeness hydrocarbon source rock, measure its solvable organic refractive index n with above-mentioned steps ((a)-(e)), with typical curve be Ro-n curve contrast, can obtain degree of ripeness Ro.

The normal fluid of described known refractive index n can be selected distilled water for use, acetone, absolute ethyl alcohol, glacial acetic acid, lactic acid, ethylene glycol, methenyl choloride, phenixin, whiteruss, glycerine, the potpourri of carbon disulphide and carbon disulphide and absolute ethyl alcohol, the scope of its refractive index n is between 1.33-1.62, the typical curve of refractive index n and deflection angle θ as shown in Figure 3, wherein unknown refractive index sample is automotive gear oil and naphtha, actual measurement deflection angle θ ' is respectively 0.2351,0.2031 can get refractive index by typical curve is respectively 1.4851 and 1.3904.

Claims (5)

1. A measuring device for the organic maturity of source rocks, the measuring device comprises a laser (1); a microscopic objective lens (2), a micropore (3), and a three-dimensional adjustment frame (4) in a housing (12) , convex lens (5), cylindrical lens (6), capillary (7), aperture (8), five-dimensional adjustment frame (9) and translucent screen (11); computer (14) containing software program, and The high-precision CCD camera (13) that computer (14) is connected by wire; It is characterized in that: microscopic objective lens (2) and micropore (3) are installed on the three-dimensional adjustment frame (4), and the image of microscopic objective lens (2) The square focus coincides with the microhole (3), the microhole (3) coincides with the object focus of the convex lens (5), and the beam generated from the laser (1) is expanded by the microscopic objective lens (2) and filtered by the microhole (3) Finally, a light spot with uniform distribution of light intensity is obtained. The light spot becomes parallel light after passing through the convex lens (5), and the parallel light becomes a strip beam after being focused by the cylindrical lens. Half of the capillary (7) is filled with a standard liquid with a known refractive index. Or extract the soluble organic matter (10) obtained from the source rock sample to be tested, the other half is air, and the strip beam is irradiated on the middle section of the capillary (7) to form clear interference on the translucent screen (11) pattern. 2. The measuring device of source rock organic maturity as claimed in claim 1, characterized in that the inner diameter of the above-mentioned capillary (7) is 2-3mm, the outer diameter is 3-4mm, and the length is 8-10cm. 3. The measuring device of source rock organic maturity as claimed in claim 1, characterized in that the periphery of the translucent screen (11) has a coordinate scale with a minimum scale of 1 mm. 4. The measuring device of source rock organic maturity as claimed in claim 1, characterized in that the above-mentioned laser (1) is a green or red laser with continuous power output, and the output power of the laser (1) is greater than 40mW. 5. Utilize the measuring device of claim 1 to carry out the measuring method of source rock organic maturity: (a) get the standard liquid sample of known refractive index n, inject in capillary (7), make capillary (7) half fill liquid (10), the other half is air, produces the interference pattern of air and standard liquid sample simultaneously on translucent screen (11); Record the distance DC of capillary axis to translucent screen (11), so that use in calculating; (b ) photograph the interference pattern and the coordinate scale on the periphery of the translucent screen with a CCD camera, and store it in the computer; (c) read the pixel value per centimeter of the coordinate image, read the width AB of the air interference fringe, and calculate Constant b=AB/2DC, thinning the leftmost and rightmost two interference fringes of the standard liquid interference pattern, and reading the distance EF between them, calculating the deflection angle θ, θ=EF/2DC; (d) with the same The method uses at least 9 standard liquid samples with a refractive index range of 1.33-1.80 to establish a standard curve of the standard liquid refractive index n and deflection angle θ, that is, the n-θ curve, using the formula $\mathrm{no}=\frac{\sin (b-c)}{\sin (\frac{\mathrm{\θ}}{2}-c)}$ Obtain the constant c by the least square method; (e) inject a low transparent liquid with unknown refractive index into a capillary of the same material and specification, use a CCD camera to capture the interference pattern on the translucent screen, and obtain the unknown refraction by the same steps as above The deflection angle θ' of liquid with high rate, substituting b, c and 9' into the formula $\mathrm{no}=\frac{\sin (b-c)}{\sin (\frac{\mathrm{\θ}}{2}-c)}$ Calculate the refractive index, or compare it with the n-θ curve to read the refractive index of the unknown liquid; (f) take at least 9 source rock standard samples with a maturity Ro in the range of 0.3-2.5, and extract their soluble organic matter, The above steps (a)-(e) were used to measure the refractive index of the soluble organic matter respectively, and establish a standard curve between the maturity Ro and the refractive index n, that is, the Ro-n curve; (g) for source rocks with unknown maturity, take The above steps (a)-(e) measure the refractive index n of the soluble organic matter, and compare it with the standard curve, ie, the Ro-n curve, to obtain the maturity Ro.

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