Predication method of organic holes of different types of clay shale

Abstract

The invention relates to a predication method of organic holes of different types of clay shale. The method comprises the steps of building a conceptual model and predication model for organic carbon recovery coefficients of organic matters of different types of clay shale; calculating original organic carbon, organic carbon discharged during producing hydrocarbon, and residual organic carbon after discharging hydrocarbon so as to predicate original organic down holes, formed organic down holes and organic down holes without being formed at present; predicating the currently formed actual organic holes and the organic holes lost in compressing of the clay shale after compressing and calibrating. According to the method, the models are built to predicate the original organic down holes, the formed organic down holes, the organic down holes without being formed at present, the currently formed actual organic holes and the organic hole lost in the compressing of the clay shale after compressing and calibrating; therefore, the precision is high; the calculation result is reliable; the basis is provided to accurately evaluate the size of the organic holes, in particular quantitatively evaluate the heterogeneity distribution evolution of the organic holes in different clay shale; the method is of important significance in study on the general oil and gas storage mechanisms of the clay shale, the quantitative expression of heterogeneity of oil-gas containing property of the clay shale, and evaluation of the oil-gas resource of abnormal clay shale.

Description

technical field [0001] The invention belongs to the technical fields of petroleum, geology and mining exploration and development, and in particular relates to a method for predicting organic pores of mud shale. Background technique [0002] Due to rising energy demand and increasing energy pressure, shale oil and gas, an unconventional energy source, has received more and more attention. As an important feature of unconventional oil and gas reservoirs, mud shale is self-generation and self-storage. However, the pores and throats in mud shale are small, and the pore structure is complex. How to study shale pores has become one of the primary problems to be solved for unconventional oil and gas. It is of great significance to the selection of shale oil and gas exploration layers, the evaluation of resource potential and the calculation of oil and gas seepage capacity. [0003] Organic matter pores refer to intragranular pores developed in organic matter, which are formed in ...

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Problems solved by technology

[0005] (1) The morphological characteristics given by the microscope observation method are only a thin section of a certain section, and this method cannot determine the porosity of the sample

[0006] (2) Fluid infiltration method (i.e. mercury intrusion method) is an important means of reservoir space characterization, this method uses mercury as a non-wetting fluid, and utilizes the relationship between the non-wetting mercury ingress and the ingress pressure, The pore throat radius corresponding to the pressure can be obtained according to the Washburn equation. According to the amount of mercury entering under different pressures, it is the porosity under the pressure versus the pore throat radius. Due to the limitation of pressure, this method generally measures large pores (greater than 50 nanometers). , the measured porosity lacks some nanoscale porosity, and at the same time, the shape and boundary effect of pores in shale will partially affect the test results of mercury porosimetry, and this method cannot be well used in shale Measurement of pores

[0007] (3)N 2 (or CO 2 ) adsorption method is through N 2 (or CO 2 ) adsorption method for measuring mesopores (2-50nm) and micropores (2 ) adsorption-carbon dioxide (CO 2 ) Adsorption fluid method, because the pore volume and pore size distribution of mesopores (2-50nm) and micropores (<2nm) determined by this method are affected by factors such as shale crushing degree, shale water content and shale heterogeneity , and this method gives more pore size distribution curves, which cannot be well used for the actual measurement of pores in shale, and there is no application of using this method to measure porosity in relevant literature.

It can be seen that there is still no effective method to predict different types of organic pores (such as original organic pores, organic pores that have been generated, and organic pores that have not yet formed).

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