CN105136643B - The implementation method of one-way flow dynamic pressure mercury system under effective overburden pressure - Google Patents

Abstract

The invention discloses a one-way flow mercury injection system under effective overlying pressure and its realization method. The system includes a high-pressure rock core chamber, the output end of which is connected to the input end of the high-pressure rock core chamber through a first pipeline, a valve and a pressure gauge. A micro metering pump, a power pump connected to the side hole of the rock core chamber that provides effective overlying pressure through the second pipeline, valve, and pressure gauge; the other end of the high-pressure rock core chamber is connected to the vacuum pump through a pipeline and a vacuum pressure gauge; A mercury breakthrough display unit connected to both ends of the ventricle; pressure gauges are provided on the first pipeline and the second pipeline. The mercury injection capillary pressure curve measured by the present invention can truly reflect the real pore structure characteristics, pore-throat size distribution, interconnection relationship and the breakthrough pressure when mercury breaks through the core, and the fluid flow in the oil and gas reservoir development process. Flow conditions, thus providing important parameters for the exploration and development of oil and gas fields.

Description

Realization method of unidirectional flow mercury injection system under effective overlying pressure

technical field

The invention relates to a method for realizing a one-way flow mercury injection system under effective overlying pressure.

Background technique

At present, the techniques for measuring the size distribution of rock throats both at home and abroad are to inject mercury into the core by four-sided mercury injection, and then calculate the throat radius r according to the theoretical formula of capillary pressure Pc=2σcosθ/r.

This mercury intrusion technique with mercury injection from four sides can only measure the throat size distribution under ground conditions. Since the oil and gas reservoirs are under the temperature and pressure conditions of hundreds of meters to several kilometers underground, the combined effect of temperature and pressure will make the pores and throats of the reservoir rocks squeezed by temperature and pressure and become smaller, especially the throats. The reduction of r will affect the throat size distribution of reservoir rocks. As a result, the use of existing techniques for determining the size distribution of rock throats will seriously affect oil and gas exploration and development.

Contents of the invention

Aiming at the above technical deficiencies, the present invention provides a unidirectional flow mercury injection system under effective overlying pressure and its realization method. The pore structure parameters obtained by it can truly reflect the pore structure characteristics and pore throat size of oil and gas reservoirs. The distribution and the characteristics of the interconnected relationship.

In order to achieve the above object, the technical scheme adopted in the present invention is as follows:

A method for realizing a mercury one-way flow mercury injection system under an effective overlying pressure. The system includes a high-pressure rock core chamber, the output end of which is connected to the input end of the high-pressure rock core chamber through a first pipeline, and a micro metering pump connected to the input end of the high-pressure rock core chamber through a second pipeline. The power pump connected to the side hole of the rock core chamber providing the overlying pressure, the vacuum pump connected to the outlet end of the high-pressure rock chamber through the third pipeline, and the mercury breakthrough display unit connected to the two ends of the high-pressure rock chamber; the first pipeline and the second The pipelines are respectively provided with valves and digital pressure gauges; the third pipeline is respectively provided with valves and vacuum pressure gauges; the implementation method includes the following steps:

(1) The porosity measurement under the effective overlying pressure is carried out to the rock core by conventional measurement methods, and the formation porosity and pore volume values under different pressures are obtained;

(2) Dry the experimental rock core and put it into the high-pressure rock core chamber;

(3) Start the power pump, so that the overlying pressure in the high-pressure rock core chamber maintains its set value;

(4) Start the vacuum pump to evacuate the rock core until the required vacuum degree and close the valve on the third pipeline;

(5) Start the micro-metering pump, inject mercury into the rock core in the high-pressure rock core chamber from low to high according to the designed pressure interval, record the pressure and the mercury injection amount at the corresponding pressure point at the same time, and use the mercury breakthrough display unit to record when the mercury breaks through the rock core When the pressure reaches the maximum designed pressure, the mercury intrusion data of one-way flow of mercury under the effective overlying pressure can be obtained;

(6) According to the pore volume value under the effective overlying pressure of the corresponding point, the mercury one-way flow mercury injection data is processed according to the conventional mercury intrusion data processing method, and the mercury one-way flow under the effective overlying pressure of the core is obtained Mercury injection curves, curve eigenvalues, normal and non-normal probability eigenvalues, pore-throat distribution frequency plots, and relevant parameters and graphs for permeability contribution plots.

Compared with the prior art, the present invention has the following beneficial effects:

(1) The present invention is equipped with a high-pressure rock core chamber, a power pump, a micro metering pump, and a mercury breakthrough display unit, which obtains an effective upper pressure through porosity measurement, rock core drying, mercury injection, recording and display of mercury breakthrough rock core pressure. Mercury one-way flow mercury injection data under the condition of overburden pressure, and then obtain the mercury one-way flow mercury injection curve, curve eigenvalue, normal and non-normal probability eigenvalue, and pore throat distribution frequency of the core under the effective overburden pressure condition These parameters can reflect the pore structure characteristics of real oil and gas reservoir rocks, the distribution of pore throat size, the interconnection relationship, and the fluid development in the process of oil and gas reservoir development. The invention provides real and effective reference data for exploration research of oil and gas fields, and promotes the exploration and development of oil and gas fields to a large extent.

(2) The structure design of the present invention is reasonable and easy to popularize. Therefore, compared with the prior art, it has outstanding substantive features and remarkable progress.

Description of drawings

Fig. 1 is a schematic diagram of the system structure of the present invention.

Figure 2 shows the mercury intrusion curves under conventional and effective overburden pressure conditions.

Fig. 3 is a histogram of pore-throat distribution under conventional and effective overburden pressure conditions.

Among them, the names of parts corresponding to the reference signs are:

1-high pressure core chamber, 2-power pump, 3-micro metering pump, 4-digital pressure gauge, 5-mercury breakthrough display unit, 6-vacuum gauge, 7-vacuum pump, 8, 9, 10-valve.

Detailed ways

The present invention will be further described below with reference to the accompanying drawings and examples, and the embodiments of the present invention include but not limited to the following examples.

Example

As shown in Figure 1, the present invention provides a mercury one-way flow mercury intrusion system under effective overlying pressure, and the pore structure parameters obtained by processing the mercury intrusion data obtained by the system can truly reflect the characteristics of oil and gas reservoirs. Real pore structure characteristics, pore throat size distribution and interconnection relationship. The mercury injection system includes a high pressure core chamber 1 , a power pump 2 , a micro metering pump 3 , a mercury breakthrough display unit 5 , a vacuum gauge 6 and a vacuum pump 7 . The output end of the micrometering pump 3 is connected to the input end of the high-pressure rock core chamber 1 through the first pipeline, while the power pump 2 is connected to the side hole of the high-pressure rock core chamber through the second pipeline, and the first pipeline and the second pipeline are respectively provided with There are valves 8, 10 and digital pressure gauge 4. The vacuum pump 7 is connected to the outlet end of the high-pressure core chamber 1 through a third pipeline, the vacuum gauge 6 is arranged on the third pipeline, and a valve 9 is also provided on the third pipeline. The mercury breakthrough display unit 5 is an existing technology, which is connected to both ends of the high-pressure rock core chamber 1, and is used for recording and displaying the situation when the mercury breaks through the rock core. In this embodiment, the power pump can provide an overlying pressure of 200 MPa, while the micro metering pump 3 can provide a mercury injection pressure of 100 MPa.

Main workflow of the present invention is as follows:

First, it is necessary to measure the porosity of the core under effective overlying pressure conditions in order to obtain formation porosity and pore volume values under different pressures.

Next, dry the core and put it into the high temperature and high pressure core chamber 1, start the power pump 2 to provide the corresponding overlying pressure, turn on the vacuum pump 7 to evacuate the system, and close the valve 9 and the vacuum pump 7 when the vacuum meets the requirements. Then start the micrometering pump 3 again, slowly inject mercury into the high-pressure rock core chamber 1 according to the designed pressure interval from low to high, and simultaneously use the pressure gauge and the micrometering pump 4 to record the pressure and mercury injection, and use the mercury breakthrough display unit 5 to record Mercury breaks through pressure.

When the pressure reaches the maximum value, the injection of mercury is stopped. At this time, the mercury intrusion data of one-way flow of mercury under the condition of effective stress can be obtained. The processing method processes the data of mercury one-way flow mercury injection, and obtains the mercury one-way flow mercury injection curve, curve eigenvalue, normal and non-normal probability eigenvalue, pore-throat distribution frequency map, permeability Parameter values for the rate contribution plot. Finally, according to the parameter values, the real pore structure characteristics of the oil and gas reservoir, as well as the distribution of pore throat size and interconnection relationship can be obtained. At the same time, according to the formation conditions designed according to the formation pressure of the actual oil and gas reservoirs, mercury unidirectional flow mercury injection, and its data will also be able to reflect the fluid production during the development of oil and gas reservoirs. Mercury injection curves and pore throat distribution histograms under conventional and effective overburden pressure conditions are shown in Figures 2 and 3, respectively. In Fig. 2, the upper curve is the mercury injection curve under effective stress, and the lower curve is the conventional mercury injection curve.

The present invention breaks through the limitations of the prior art by designing a brand-new mercury injection system, and realizes innovation well. The principle process designed by the invention can truly reflect the pore structure characteristics of the oil and gas reservoir, the distribution of the pore throat size and the interconnection relationship, thereby laying a solid foundation for the exploration and development of the oil and gas field.

The above-mentioned embodiment is only one of the preferred implementation modes of the present invention, and should not be used to limit the protection scope of the present invention. Any modification or embellishment made to the technical solution of the present invention under the main design idea and spirit of the present invention, or equivalent Substitutions whose technical problems are still substantially consistent with the present invention shall fall within the protection scope of the present invention.

Claims (1)

1. the implementation method of the one-way flow dynamic pressure mercury system under effective overburden pressure, which is characterized in that the system includes height Core chamber (1), the Micro-metering Pumps (3) that output end is connect by first pipe with high pressure core chamber (1) input terminal is pressed to pass through The kinetic pump (2) that second pipe is connect with the core chamber's side opening for providing burden pressure, passes through third pipeline and high pressure core chamber (1) The vacuum pump (7) of outlet end connection, and the mercury being connect with high pressure core chamber (1) both ends break through display unit (5)；Described It is each provided with valve and digital pressure gauge on one pipeline and second pipe；It is respectively equipped with valve and vacuum on the third pipeline Pressure gauge (6)；The implementation method then includes the following steps：

(1) porosity determination under effective overburden pressure does rock core using conventional determining method, obtains the ground under different pressures Layer porosity and pore-body product value；

(2) experiment rock core is dried, and be put into high pressure core chamber；

(3) start kinetic pump, the value for making the indoor burden pressure of high pressure rock core that it be maintained to set；

(4) start vacuum pump to evacuate rock core, until closing the valve on third pipeline after desired vacuum degree；

(5) start Micro-metering Pumps, mercury be injected into the rock core in high pressure core chamber from low to high by the pressure intervals of design, The amount of mercury injection rate for recording pressure and relevant pressure point simultaneously, when breaking through display unit record mercury breakthrough rock core using mercury Pressure, until reach design maximum pressure when stop, you can obtaining the mercury one-way flow dynamic pressure mercury under effective overburden pressure Data；

(6) according to the pore-body product value under the effective overburden pressure of respective point, according to conventional pressure mercury data processing method to water Silver-colored one-way flow mercury pressuring data is handled, obtain mercury one-way flow intrusive mercury curve of the rock core under effective overburden pressure, The relevant parameter and figure of eigenvalue of curve, normal state and abnormal probability characteristics value, throat distribution frequency diagram, permeability contribution plot Table.