CN109444983B - A Quantitative Evaluation Method for Classification of Oil and Gas Transport System Types - Google Patents

Abstract

The invention discloses a quantitative evaluation method for type division of an oil and gas transmission and conduction system, which comprises the following steps of firstly, carrying out fine comparison on oil and gas sources; determining the oil-gas migration distance; and finally, dividing the type of the oil and gas transmission and conduction system. The method has the advantages that the source of the oil-gas reservoir is determined through fine comparison of the oil-gas source, the oil-gas migration distance is further determined according to earthquake, oil reservoir and other data, and a quantitative evaluation model for type division of an oil-gas transmission and conduction system is established. The method can meet the requirement of quantitative evaluation of the type of the oil and gas transportation and conduction system, has good application effect in a research area, is easy to operate, can be popularized and applied to other oil and gas exploration areas, and particularly can provide a basis for oil and gas reservoir formation simulation, favorable exploration direction, zone prediction and the like.

Description

A Quantitative Evaluation Method for Classification of Oil and Gas Transport System Types

technical field

The invention belongs to the technical field of geological exploration and development evaluation of oil and gas resources, and relates to a quantitative evaluation method for classification of oil and gas transport system types.

Background technique

The oil and gas transport system refers to the various transport conductors that once carried oil and gas migration in the oil and gas system and their combinations. As a "bridge" connecting source rocks and traps, the transport system is the core of oil and gas migration, and has become an important part of oil and gas accumulation research. For the classification of oil and gas transportation system types, there are various classification schemes: for example, according to the main channel of oil and gas migration, the transportation system is divided into four types: sand body, fault, unconformity and composite type; The role of migration channels in migration can be divided into four types: fault zones, related to paleo-tectonic ridges, related to active thermal fluid diapirs, and related to unconformity. , divided into 4 types: mesh type, "T" type, stepped type, and crack type. At present, there are many ways to study the oil and gas transport system, such as the study of the transport system itself, to discuss its composition, space-time configuration, transport capacity, validity period and configuration of oil and gas migration periods, etc.; Chemical characterization, such as saturated hydrocarbon chromatography-mass spectrometry, relative content of high molecular weight n-alkanes, aromatic hydrocarbons, C ₂₉ sterane 20S/(20S+20R) and C ₂₉ sterane ββ/(ββ+αα), nitrogen-containing compounds , carbon isotopes, chromatographic effects, etc. However, regardless of the type of transport system, the above research methods mostly emphasize the analysis of the transport system from the perspective of geochemical characteristics for the process of oil and gas migration. Because the acquisition of geochemical parameters on the oil and gas migration path requires a lot of analysis and testing data, In the case of few sample test points, it is difficult to guarantee the research accuracy, which leads to the reliability and accuracy of oil and gas resource evaluation and prediction of favorable exploration zones.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a quantitative evaluation method for the classification of oil and gas transport system types. A quantitative evaluation model for the classification of oil and gas transport system types. The method can meet the requirements of quantitative evaluation of oil and gas transport system types, has good application effect in the research area, and is easy to operate, and can be applied to other oil and gas exploration areas, especially for oil and gas accumulation simulation, favorable exploration direction and zone prediction, etc. Provide evidence.

The technical scheme adopted in the present invention is to carry out according to the following steps:

(1) Fine comparison of oil and gas sources;

(2) Determination of oil and gas migration distance;

(3) Classification of oil and gas transport system types.

Further, in step (1), the method of fine comparison of oil and gas sources is to collect samples from source rocks and discovered oil and gas reservoirs in the study area, analyze the biomarker compounds, carbon isotopes and other geochemical characteristics of source rocks and crude oil. Fine comparison, determine the source of oil and gas, and divide the oil and gas system.

Further, the determination of the oil and gas migration distance in step (2) refers to the distance from the hydrocarbon generation center to the oil and gas reservoir trap in the same oil and gas system, including the horizontal distance and the vertical distance. The horizontal distance is obtained according to the oil and gas exploration result map, and the vertical distance is obtained according to the seismic Profiles and reservoir profiles were obtained.

Further, in step (3), the classification of oil and gas transport system types is to count the distances between source rocks and all oil and gas reservoirs in the same oil-gas-bearing system, to determine the distance between the source rocks and the farthest oil and gas reservoirs, and to determine the distance between the source rocks and the farthest oil and gas reservoirs. The horizontal and vertical distance ratio is used to establish the following quantitative evaluation mathematical model for the classification of oil and gas transport system types:

T=H ₁ /H ₂ (1)

In the formula, T is the division coefficient of the type of oil and gas transport system, H ₁ is the horizontal distance between the source rock in the same oil and gas system and the farthest oil and gas reservoir, in m, and H ₂ is the source rock in the same oil and gas system The vertical distance from the farthest oil and gas reservoir, in m.

Description of drawings

Fig. 1 is the block diagram of the method steps of the present invention;

Fig. 2 is a comparison chart of the geochemical characteristics of source rocks and crude oil;

Figure 3 is a model diagram of oil and gas migration distance.

Detailed ways

The present invention will be described in detail below with reference to specific embodiments.

Taking the Jiyang Depression in the Bohai Bay Basin as an example, as shown in Figure 1, the specific method is as follows:

(1) Fine comparison of oil and gas sources

Collect samples from source rocks and discovered oil and gas reservoirs in the study area (samples at the starting point and end point of oil and gas migration are easier to obtain), and analyze the biomarker compounds, carbon isotopes and other geochemical characteristics of source rocks and crude oil. Fine rock comparison (Fig. 2), determine the source of oil and gas, and divide the oil and gas system.

(2) Determination of oil and gas migration distance

The oil and gas migration distance refers to the distance from the hydrocarbon generation center to the reservoir trap in the same oil and gas system, including the horizontal distance and the vertical distance (Fig. 3). The horizontal distance can be obtained from oil and gas exploration results, and the vertical distance can be obtained from seismic profiles, reservoir profiles, etc.

(3) Classification of oil and gas transport system types

Calculate the distance between the source rock and all the oil and gas reservoirs in the same oil and gas system, determine the distance between the source rock and the farthest oil and gas reservoir, and establish the following oil and gas transport system types according to the ratio of the horizontal and vertical distances of oil and gas migration. Quantitative evaluation mathematical model:

T=H ₁ /H ₂ (1)

In the formula, T is the division coefficient of the type of oil and gas transport system, H ₁ is the horizontal distance between the source rock in the same oil and gas system and the farthest oil and gas reservoir, in m, and H ₂ is the source rock in the same oil and gas system The vertical distance from the farthest oil and gas reservoir, in m. In this example, when T < 30, the type of oil and gas transport system is vertical, and the vertical transport of faults is dominant; when T > 30, the type of oil and gas transport system is lateral, with sand bodies ( Non-integration) is dominated by lateral transport.

Using the above method, the types of oil and gas transport systems in the study area were divided (Table 1, the statistical table of classification coefficients of oil and gas transport system types). The evaluation results show that the oil and gas migration in Linfanjia, Shanjiasi and other areas is dominated by the lateral transport of sand bodies, while the oil and gas migration in Sanhe Village, Feiyantan and other areas is dominated by vertical fault transport. The evaluation results are consistent with the results of the oil and gas transport system determined by the geochemical index, indicating that the method can be used for quantitative evaluation and prediction of the type of oil and gas transport system.

Table 1

The above is only a preferred embodiment of the present invention, and does not limit the present invention in any form. Any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention belong to the present invention. within the scope of the technical solution of the invention.

Claims (2)

1. A quantitative evaluation method for type division of an oil and gas transmission and conduction system is characterized by comprising the following steps:

(1) fine comparison of oil and gas sources;

(2) determining the oil-gas migration distance;

(3) dividing the type of an oil and gas transmission and conduction system;

the determination of the oil-gas migration distance in the step (2) refers to the distance from an oil-gas hydrocarbon generation center to an oil-gas reservoir trap in the same oil-gas system, and comprises a horizontal distance and a vertical distance, wherein the horizontal distance is obtained according to an oil-gas exploration result diagram, and the vertical distance is obtained according to a seismic profile diagram and an oil reservoir profile diagram;

the type division of the oil and gas transmission and conduction system in the step (3) is to count the distances between the hydrocarbon source rocks and all oil and gas reservoirs in the same oil and gas system, determine the distance between the hydrocarbon source rocks and the oil and gas reservoir with the farthest distance, and establish a quantitative evaluation mathematical model of the type division of the oil and gas transmission and conduction system according to the oil and gas migration transverse-longitudinal distance ratio as follows:

T＝H₁/H₂(1)

in the formula, T is the type division coefficient of an oil and gas transmission and conduction system, H₁The horizontal distance between a hydrocarbon source rock and a hydrocarbon reservoir farthest away in the same oil-gas-containing system is m, H₂Is the vertical distance between the source rock and the farthest hydrocarbon reservoir in the same hydrocarbon-bearing system, and is expressed in m.

2. The quantitative evaluation method for type division of an oil and gas transmission and conduction system according to claim 1, characterized in that: the method for finely comparing the oil gas sources in the step (1) comprises the steps of collecting samples of hydrocarbon source rocks in a research area and found oil gas reservoirs, analyzing geochemical characteristics of biomarker compounds and carbon isotopes of the hydrocarbon source rocks and crude oil, determining the oil gas sources through oil-rock fine comparison, and dividing an oil-gas-containing system.

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