Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
At present, the deep ancient pressure recovery scheme of the basin mainly comprises a fluid inclusion test analysis thermodynamic simulation method and a basin simulation technology. The thermodynamic simulation method for fluid inclusion test and analysis is the most commonly used method at present for recovering the ancient pressure by mainly utilizing data of components, uniform temperature, freezing point temperature, salinity and the like of a fluid inclusion through an equation of state empirical formula method, a PVT thermodynamic simulation method, an inclusion laser Raman shift method and the like. The basin simulation rule is that simulation software petroMod and BasinMod are used for carrying out relevant operations.
The inventor finds that the current deep basin ancient pressure recovery method has the technical problems that:
the PVT thermodynamic simulation method is only suitable for the condition that an oil inclusion and a brine inclusion coexist, and is not suitable for a stratum with a deep carbonate gas reservoir and few hydrocarbon inclusions; the equation of state law has the problem that the equation of state of pure substances cannot be used simply to estimate the pressure of the inclusion due to the complex composition of the system. In addition, although the accuracy of the testing of the basic parameters of the fluid inclusion is already high, the requirements on the testing experience of testers are high, and the testing results of different testers often have large differences. The basin simulation law is restricted by factors such as a plurality of prior parameter selections, geological data density and the like.
In the 60 s of the twentieth century, after laser light was introduced into raman spectrometers as excitation light sources, raman spectroscopy was rapidly developed and applied to many fields. Because of its non-destructive, high sensitivity and high resolution, it has been one of the important methods for studying fluid inclusions. Each substance has its own characteristic raman spectrum, and the number of raman lines, the magnitude of the shift values and the intensity of the bands, the full width at half maximum and the integrated area, etc. are all related to the vibrational and rotational energy levels of the substance molecules. Intensity and shift (wavenumber) are two important characterizing parameters of raman spectroscopy. The intensity of the lines of the raman spectrum depends on the magnitude of the change in molecular polarizability during the corresponding normal vibration. Due to the molecular vibration or rotation frequency, inelastic collision-Raman scattering and elastic collision-Rayleigh scattering, the two will have a frequency difference called Raman shift, which is the molecular vibration or rotation frequency, independent of the incident ray frequency and dependent on the molecular structure. The Raman characteristic parameters and the good linear relation among concentration, temperature and pressure can accurately and comprehensively acquire the information of the composition, salinity, isotope, pressure and the like of a single fluid inclusion in the mineral by utilizing the characteristics.
In recent years, some scholars have proposed methods for studying trapping pressure by using raman spectroscopy of inclusion sub-minerals due to the relationship between raman characteristic parameters and pressure, however, since the sub-minerals in fluid inclusions are not widely present, their widespread application is limited. Some scholars calibrate the pressure by using the Raman spectrum of the hydrocarbon in the inclusion and obtain a pressure calibration formula, but the test is carried out in a diamond pressure cavity with high temperature and high pressure, and the test pressure far exceeds the inclusion forming pressure in the actual geology. In order to solve the problem of pressure recovery of a hydrocarbon-containing brine inclusion in a deep carbonate rock stratum, the inventor provides a scheme for determining the ancient pressure of the deep carbonate rock of a sedimentary basin, the scheme utilizes the change value of a characteristic peak value of methane in a hydrocarbon-containing brine inclusion along with the temperature rise to be tested, combines a methane gas inclusion formation reservoir pressure analysis chart to recover the ancient pressure of the deep carbonate rock of the basin, establishes an intersection chart by combining the obtained inclusion pressure value and the corresponding temperature, finally obtains a trend line of the inclusion capture pressure along with the change of the temperature of the inclusion, and further can obtain the ancient pressure value of the inclusion at the uniform temperature.
Therefore, the embodiment of the invention effectively records the change of the characteristic peak value of methane in the inclusion along with the change of the displacement value generated by the temperature rise by carrying out the laser Raman test on the hydrocarbon-containing brine inclusion, and successfully predicts the paleo-pressure of the deep basin carbonate rock stratum by combining with a methane gas inclusion accumulation pressure analysis chart, so that the method has clear thought and reliable result. In order to fill the blank of the method for recovering the pressure of the hydrocarbon-containing brine inclusion in the deep carbonate formation, the embodiment of the invention provides a method for effectively recovering the pressure of the hydrocarbon-containing brine inclusion in the deep carbonate formation. The protocol for determining the paleo-pressure of carbonate deep in sedimentary basins is described in detail below.
Fig. 1 is a schematic flow chart of a method for determining paleo-pressure of carbonate rock deep in a sedimentary basin in an embodiment of the present invention, as shown in fig. 1, the method includes the following steps:
step 101: measuring a uniform temperature of a target hydrocarbon-containing brine inclusion; the target hydrocarbon-containing saline inclusion is manufactured by using a target rock core sample of the sedimentary basin deep carbonate rock;
step 102: performing a methane laser Raman spectrum test on the target hydrocarbon-containing brine inclusion to obtain a change value of a Raman peak characteristic value of methane in the target hydrocarbon-containing brine inclusion at each target temperature;
step 103: obtaining a plurality of pressure values of the target hydrocarbon-containing brine inclusion according to the change value of the Raman peak characteristic value of methane in the target hydrocarbon-containing brine inclusion at each target temperature and each target temperature;
step 104: establishing a relation between the temperature and the inclusion pressure according to a plurality of pressure values of the target hydrocarbon-containing brine inclusion and the corresponding target temperature;
step 105: and obtaining the paleo-pressure value of the inclusion at the uniform temperature according to the uniform temperature and the relation between the temperature and the inclusion pressure.
In particular, the invention is suitable for use in deep basin (>4000km) carbonate reservoirs (as shown in fig. 2) and for gas reservoirs with small hydrocarbon inclusions (e.g. less than 5% hydrocarbon inclusions) and large hydrocarbon-bearing brine inclusions (e.g. greater than 95%) in the scope of the scope.
The steps involved in the embodiments of the present invention will be described in detail below with reference to fig. 2 to 5.
The embodiment of the invention provides a method for determining ancient pressure of deep carbonate rock of a sedimentary basin, namely a recovery method for effectively recovering the pressure of a hydrocarbon-bearing saline water inclusion of a deep carbonate rock stratum, namely a new method for calculating the ancient heat flow of a sedimentary basin depression region, which comprises the following specific steps of:
first, the steps of making a hydrocarbon-containing brine inclusion are described.
1. Selecting a dolomitic rock core with rich litholytic veins or quartz particles in a deep carbonate rock reservoir as a target sample (a target core sample), and preparing a fluid inclusion sheet which is not more than 4mm and has better transparency (for example, the transparency is more than 40%).
2. And observing the lithofacies characteristics of the fluid inclusion. Primary and secondary inclusion were identified under transmitted light and fluorescence microscopy. Under a transmission light microscope and a fluorescence microscope, the primary inclusion is taken as a research target, the inclusion formation period is observed and analyzed, the type of the fluid inclusion is distinguished, and the form, the structure, the size, the structural characteristics and the gas-liquid ratio of various types of inclusions are observed and recorded. Selecting the following preset conditions: hydrocarbon-containing brine inclusions (target hydrocarbon-containing brine inclusions) with sharp edges, regular morphology, large individuals (e.g., greater than 5 μm) and large gas-to-liquid ratios (e.g., greater than 15%), are marked with a pencil to facilitate later testing.
In the specific implementation, it should be noted that: firstly, a gas-liquid two-phase inclusion with a large gas-liquid ratio CH4 is needed for an inclusion observed and tested under a mirror; secondly, the calibration standard sample must be tested accurately; thirdly, the test is to ensure that the test is an equal volume closed environment.
That is, in one embodiment, the process of making the targeted hydrocarbon-containing brine inclusion may include:
selecting a dolomite rock sample enriched with calcite veins or containing quartz particles from a sedimentary basin deep carbonate rock reservoir, and making a fluid inclusion sheet with the transparency of not more than 4mm and exceeding a preset value;
and performing phase characteristic observation on the fluid inclusion slice, and marking the hydrocarbon-containing brine inclusion meeting preset conditions as the target hydrocarbon-containing brine inclusion.
Secondly, the above step 101 is described.
In specific implementation, after the observation of the lithologic characteristics of the fluid inclusion is finished, the temperature of the selected fluid inclusion (the target hydrocarbon-containing brine inclusion, namely, the inclusion satisfying the preset condition) is measured. The temperature measuring process mainly comprises the following steps: firstly, soaking a rock sample from a slice by using acetone until all glue on the slice is cleaned; then, placing the soaked rock sample in a ventilated place for airing; then, slicing the part marked with the pencil; finally, the sheet (target hydrocarbon-containing brine inclusion) was placed in a cold-hot stage for thermometry, and the measured uniform temperature (Th) was recorded.
Third, next, the above step 102 is introduced.
In one embodiment, performing a methane laser raman spectroscopy test on the target hydrocarbon-containing brine inclusion to obtain a variation value of a raman peak characteristic value of methane in the target hydrocarbon-containing brine inclusion at each target temperature may include:
measuring a Raman peak standard value of methane in the target hydrocarbon-containing brine inclusion by using a laser Raman spectrometer at room temperature;
performing a methane laser Raman spectrum test, and measuring Raman peak shift values of methane in the target hydrocarbon-containing saline inclusion at different target temperatures;
and obtaining a change value at each target temperature according to the Raman peak displacement value and the Raman peak standard value.
In specific implementation, as shown in fig. 3A and 3B, raman peak values (characteristic raman peak values) of respective components inside the inclusion are measured by using a laser raman spectrometer at room temperature, and the raman peak value of methane is recorded as a standard value n0(Raman peak standard value), e.g. n0Multiple measurements reduce the error, 2917.8. Then, the tensile strength of methane is measured at a target temperature (e.g., 30 ℃, 50 ℃, 80 ℃, 100 ℃, 150 ℃, etc.)The variation in the shift value was observed by the raman peak shift (raman peak shift value). Calculating to obtain each displacement value and a standard value n at room temperature0The difference D between the displacement value at a specific temperature and the standard value n at room temperature0For example, as shown in fig. 3B, when the temperature is 150 ℃, the raman shift of methane in the test inclusion is 2913.39, and the shift difference (variation) D is 2913.39-2917.8-4.41.
Fourth, next, the above step 103 is described.
In one embodiment, obtaining a plurality of pressure values for the target hydrocarbon-containing brine inclusion based on the value of the raman peak signature of methane in the target hydrocarbon-containing brine inclusion at each target temperature and each target temperature comprises:
and (3) putting each change value and the corresponding target temperature on a methane gas inclusion formation pressure analysis chart, and reading a plurality of corresponding inclusion pressure values according to each change value and the corresponding target temperature.
In specific implementation, finally, a methane gas inclusion accumulation pressure analysis chart (shown in figure 4) is utilized, and the temperature value and the displacement difference D under the temperature value are projected onto the chart, so that the inclusion pressure value can be obtained. For example, when the temperature is 150 ℃, the raman shift of methane in the test inclusion is 2913.39, and the shift difference D is 2913.39-2917.8-4.41, the values and the temperature are put on a methane gas inclusion accumulation pressure analysis plate (fig. 4), and the inclusion pressure (the inclusion pressure corresponding to the two items of the variation value and the corresponding target temperature) at the temperature is read to be 53.1 MPa.
Fifth, next, for convenience of understanding, the above-described step 103 and step 104 are introduced at the same time.
In one embodiment, establishing a temperature versus volume pressure relationship based on a plurality of pressure values for a target hydrocarbon-containing brine volume and corresponding target temperatures may include:
establishing a temperature-inclusion pressure curve according to a plurality of pressure values of a target hydrocarbon-containing brine inclusion and corresponding target temperatures;
obtaining a paleo-pressure value of the inclusion at the uniform temperature according to the uniform temperature and the relationship between the temperature and the inclusion pressure, wherein the paleo-pressure value may include:
and obtaining the paleo-pressure value of the inclusion at the uniform temperature according to the uniform temperature and the temperature and inclusion pressure curve chart.
In specific implementation, the inclusion pressure values obtained through experimental test and calculation and the corresponding inclusion temperatures are collated in table 1, a convergence chart is established, a trend line (a curve graph of temperature and inclusion pressure, shown in fig. 5) of the change of the inclusion capture pressure along with the uniform temperature of the inclusions is obtained, and further an ancient pressure value of the inclusions at the uniform temperature can be obtained. For example, the temperature measurement of the cooling table in step 101 measures the uniform temperature of the inclusion to be 175 ℃, and the uniform pressure corresponding to the uniform temperature is calculated and read to be about 61MPa according to the trend line (FIG. 5).
Table 1: statistics of Raman displacement difference value and pressure value at each temperature of a certain inclusion
Based on the same inventive concept, the embodiment of the invention also provides a device for determining the ancient pressure of the carbonate rock deep in the sedimentary basin, which is described in the following embodiment. Because the principle of determining the problem solved by the sedimentary basin deep carbonate rock paleo-pressure device is similar to the method for determining the sedimentary basin deep carbonate rock paleo-pressure, the implementation of determining the sedimentary basin deep carbonate rock paleo-pressure device can be referred to the implementation of the method for determining the sedimentary basin deep carbonate rock paleo-pressure, and repeated parts are not described again. As used hereinafter, the term "unit" or "module" may be a combination of software and/or hardware that implements a predetermined function. Although the means described in the embodiments below are preferably implemented in software, an implementation in hardware, or a combination of software and hardware is also possible and contemplated.
Fig. 6 is a schematic structural diagram of an apparatus for determining paleo-pressure of carbonate rock deep in a sedimentary basin according to an embodiment of the present invention, as shown in fig. 6, the apparatus includes:
a uniform temperature measuring unit 01 for measuring a uniform temperature of the object hydrocarbon-containing brine inclusion; the target hydrocarbon-containing saline inclusion is manufactured by using a target rock core sample of the sedimentary basin deep carbonate rock;
a variation value determination unit 02, configured to perform a methane laser raman spectrum test on the target hydrocarbon-containing brine inclusion to obtain a variation value of a raman peak characteristic value of methane in the target hydrocarbon-containing brine inclusion at each target temperature;
a pressure value determining unit 03, configured to obtain a plurality of pressure values of the target hydrocarbon-containing brine inclusion according to a variation value of a raman peak characteristic value of methane in the target hydrocarbon-containing brine inclusion at each target temperature and each target temperature;
the relation establishing unit 04 is used for establishing a relation between the temperature and the inclusion pressure according to a plurality of pressure values of the target hydrocarbon-containing brine inclusion and the corresponding target temperature;
and the paleo-pressure determining unit 05 is used for obtaining a paleo-pressure value of the inclusion at the uniform temperature according to the uniform temperature and the relation between the temperature and the inclusion pressure.
In an embodiment, the change value determining unit is specifically configured to:
measuring a Raman peak standard value of methane in the target hydrocarbon-containing brine inclusion by using a laser Raman spectrometer at room temperature;
performing a methane laser Raman spectrum test, and measuring Raman peak shift values of methane in the target hydrocarbon-containing saline inclusion at different target temperatures;
and obtaining a change value at each target temperature according to the Raman peak displacement value and the Raman peak standard value.
In one embodiment, the pressure value determination unit is specifically configured to:
and (3) putting each change value and the corresponding target temperature on a methane gas inclusion formation pressure analysis chart, and reading a plurality of corresponding inclusion pressure values according to each change value and the corresponding target temperature.
In an embodiment, the relationship establishing unit may be specifically configured to:
establishing a temperature-inclusion pressure curve according to a plurality of pressure values of a target hydrocarbon-containing brine inclusion and corresponding target temperatures;
the paleo pressure determination unit may specifically be configured to:
and obtaining the paleo-pressure value of the inclusion at the uniform temperature according to the uniform temperature and the temperature and inclusion pressure curve chart.
The embodiment of the invention also provides computer equipment which comprises a memory, a processor and a computer program which is stored on the memory and can run on the processor, wherein the processor executes the computer program to realize the method for determining the ancient pressure of the deep carbonatite in the sedimentary basin.
Embodiments of the present invention also provide a computer-readable storage medium storing a computer program for executing the method for determining paleo-pressure of deep carbonate rock in sedimentary basin.
The technical scheme provided by the embodiment of the invention has the beneficial technical effects that: the method realizes the rapid and accurate determination of the ancient pressure of the deep basin of the sedimentary basin, and has important significance for the research of the formation process of deep oil and gas reservoirs and the guidance of the exploration and the prospect prediction of other deep oil and gas reservoirs.
As will be appreciated by one skilled in the art, embodiments of the present invention may be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.
The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes may be made to the embodiment of the present invention by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.