WO2016180215A1

WO2016180215A1 - Ct digital core-based microscopic displacement experiment system and microscopic displacement experiment method

Info

Publication number: WO2016180215A1
Application number: PCT/CN2016/080031
Authority: WO
Inventors: 杨永飞; 姚军; 张琦; 田同辉; 徐耀东; 明玉坤; 高莹; 魏微; 赵建林; 孙海; 张磊; 宋文辉; 安森友; 杜玉山; 王军; 晁静
Original assignee: 中国石油大学(华东); 中国石油化工股份有限公司胜利油田分公司勘探开发研究院
Priority date: 2015-05-11
Filing date: 2016-04-22
Publication date: 2016-11-17
Also published as: AU2016260347A1; AU2016102347A4; CN104819990A

Abstract

A CT digital core-based microscopic displacement experiment system comprises a core gripper (4) and a microscopic displacement device. The core gripper (4) comprises an inlet end (4-1), an outlet end (4-2), a core area, and a housing. The housing is made of a polyetheretherketone (PEEK) material. The microscopic displacement device comprises an oil-phase intermediate container (2) and an aqueous-phase intermediate container (3) that are parallel, and comprises an advection pump (1) used for driving the oil-phase intermediate container (2) and the aqueous-phase intermediate container (3). Liquid discharge ends of the oil-phase intermediate container (2) and the aqueous-phase intermediate container (3) are each connected to the inlet end (4-1) of the core gripper (4). The core gripper (4) pressurizes a core gripped in the core gripper (4) by means of a hand pump (5). The outlet end (4-2) of the core gripper (4) is provided with a measurement bottle (7). The system is applicable to a small-capacity and small-scale microscopic displacement experiment, and the comprised technical device has a higher operation precision and a higher measurement precision compared with a conventional displacement experiment device.

Description

Microscopic displacement experimental system based on CT digital core and microscopic displacement experimental method

Technical field

The invention relates to a microscopic displacement experimental system and a microscopic displacement experimental method based on CT digital core, and belongs to the technical field of physical experiments of oil and natural gas.

Background technique

The ultimate goal of oilfield development is how to extract as much crude oil as possible from the pores of the formation to reduce waste of resources. Crude oil exists in the pores of sedimentary rocks thousands of meters underground. Due to the sedimentary environment and the complexity of fluid distribution in the strata, there is no way to directly understand the distribution of oil and water in the ground. How to understand the enrichment area and enrichment form of underground crude oil, how to determine the distribution of remaining oil in the reservoir is the main problem of oilfield development, and it is also a major issue that the upstream oil industry has not been completely solved so far. The distribution of remaining oil is studied from microscopic and small-scale micro-nano levels. The microscopic formation mechanism and distribution law of remaining oil are understood and mastered, and the status quo of reservoir development is visually reproduced. On this basis, research on enhanced oil recovery is carried out, which is reservoir management. An important basis for decision making. Therefore, microscopic displacement experiments and the spatial distribution of fluids in the core after displacement have attracted the attention of major oil producers at home and abroad.

The commonly used methods for fluid distribution in porous media are mainly microphysical simulation and computer numerical simulation. Computer numerical simulation is to establish the mathematical model to study the physical properties of the reservoir and the flow and distribution of the fluid. Although this method has been widely used, there are still obvious uncertainties; microscopic physical simulation is to study the microscopic seepage process of reservoir fluid by means of microscope amplification, video recording and image processing technology, thus revealing the microscopic distribution characteristics of fluid in porous media. . At present, the micro-physical simulation is mainly based on the simulation model and the two-dimensional view, but the simulation model can not fully simulate all the features of the core, and the fluid is always distributed in three-dimensional form in the rock pores. It is easy to observe from a two-dimensional perspective. Brings a big error.

Summary of the invention

In view of the deficiencies of the prior art, the present invention provides a microscopic displacement experimental system based on CT digital core.

The present invention also provides a method of performing a microscopic displacement experiment using the above experimental system. The invention effectively combines the conventional displacement experiment with the CT technology, and uses the CT scanning technology to scan the cores of different displacement stages, thereby observing the core pore structure, and realizing the change of the fluid distribution in the pores in real time.

The technical solution of the present invention is as follows:

A microscopic displacement experimental system based on CT digital core, including a core holder and a microscopic displacement device;

The core holder comprises an inlet end, an outlet end, a core zone and an outer casing; the outer casing is a polyetheretherketone material (PEEK), and the PEEK is a special engineering plastic with excellent performance, high temperature resistance (260 ° C), Excellent mechanical properties, radiation resistance, self-lubricating, chemical corrosion resistance; PEEK material has radio transmission compared with metal, and the resulting holder housing does not affect the normal use of X-rays in CT equipment; The traditional holder shell is made of metal material, and the X-ray cannot penetrate, which makes it impossible to scan the core displacement state information by using CT equipment, and the traditional holder has a large body shape, which is inconsistent with the CT scan sample size, and affects the scanning effect;

The microscopic displacement device comprises a parallel oil phase intermediate container and a water phase intermediate container, an advection pump for reversing the oil phase intermediate container and the water phase intermediate container, and the oil phase intermediate container and the water phase intermediate container The liquid end is connected to the inlet end of the core holder, the core holder pressurizes the core clamped therein by a hand pump, and the measuring bottle is arranged at the outlet end of the core holder .

According to a preferred embodiment of the invention, a pivot seat is provided at the bottom of the core holder. The rotating base is used to fix the core holder on the CT sample stage during the CT scanning process, and the displacement during the displacement test is performed so that the core holder can be connected to the displacement process.

According to a preferred embodiment of the invention, the oil phase intermediate vessel and the aqueous phase intermediate vessel each have a capacity of from 50 to 150 mL.

According to a preferred embodiment of the invention, a pressure gauge is provided on the line between the hand pump and the core holder, the pressure The meter has a range of 10 MPa and an accuracy of 0.25 MPa.

According to a preferred embodiment of the invention, an inlet pressure gauge is provided at the inlet end of the core holder, the inlet pressure gauge having a range of 6 MPa and an accuracy of 0.25 MPa.

The method for performing microscopic displacement experiments using the above experimental system includes the following steps:

1) The core is dried and installed in the core holder, placed in the Zeiss MCT-400CT, scanned, and the three-dimensional digital core data body of the core analysis area is obtained;

2) Connecting the core holder to the micro-displacement device, realizing single-phase water phase displacement, single-phase oil phase displacement or aqueous phase and oil phase multi-phase mixed displacement experiment for the core;

3) designing the observation time point according to the research content of the displacement experiment, that is, the displacement time, suspending the core displacement at the observation time, and closing the core end of the core holder, the inlet end, and the hand pump;

4) scanning the core holder into the Zeiss MCT-400CT to obtain the fluid distribution in the core at the time of the displacement;

5) Repeat steps 2) through 4) until the fluid distribution in the core is obtained at all design observation time points in accordance with step 3).

According to a preferred embodiment of the invention, the core in the step 1) has a diameter of 1-2 cm and a length of 2-4 cm.

The advantages of the invention are:

1. The invention adopts the on-site core to minimize the pore structure of the reservoir, simulate the fluid flow condition of the reservoir, and ensure the reliability of the experiment. At the same time, the size of the rock with a diameter of 1-2 cm is easier to obtain accurate CT scan results than the standard rock sample with a diameter of 2.5 cm.

2. The experimental method of the present invention can not only measure the data through experiments, but also visually analyze the fluid distribution in the core under different displacement stages.

3. The system and method of the present invention not only can obtain the three-dimensional distribution of the fluid in the porous medium, but also ensure the accuracy of the measured fluid distribution result, which is more in line with the actual situation than the two-dimensional.

4. The invention ensures the implementation of various types of displacement indoor experiments in the petroleum industry, and can simulate various displacement methods and displacement conditions.

5. The system of the present invention is suitable for small-capacity, small-scale microscopic displacement experiments, and the technical equipment contained therein has higher operational precision and higher measurement accuracy than conventional displacement experimental equipment.

DRAWINGS

Figure 1 is a structural connection diagram of the displacement system of the present invention;

In Figure 1, 1, advection pump; 2, oil phase intermediate container; 3, water phase intermediate container; 4, core holder; 4-1, inlet end; 4-2, outlet end; 5, hand pump ; 6, pressure gauge between the core holder and the hand pump; 7, measuring bottle.

2 is a fluid distribution diagram of a digital core at a certain moment scanned by the displacement test method of the present invention.

detailed description

The present invention will be described in detail below with reference to the embodiments and the drawings, but is not limited thereto.

As shown in Figure 1, Figure 2.

Embodiment 1.

The core holder 4 includes an inlet end 4-1, an outlet end 4-2, a core region, and an outer casing; the outer casing is a polyetheretherketone material (PEEK);

The microscopic displacement device comprises a parallel oil phase intermediate container 2 and a water phase intermediate container 3, an advection pump 1 for repelling the oil phase intermediate container 2 and the aqueous phase intermediate container 3, the oil phase intermediate container 2 and The liquid outlet end of the aqueous phase intermediate container 3 is connected to the inlet end 4-1 of the core holder 4, and the core holder 4 is used to pressurize the core held therein by the hand pump 5 The metering bottle 7 is provided at the outlet end 4-2 of the core holder 4.

Example 2

A CT digital core-based micro-displacement experimental system as described in Embodiment 1 is different in that a rotating seat is disposed at the bottom of the core holder 4. The rotating base is used to fix the core holder on the CT sample stage during the CT scanning process, and the displacement is removed during the experiment so that the core holder can be connected to the displacement process.

Embodiment 3

A CT digital core-based microdisplacement experimental system as described in Example 1 differs in that the oil phase intermediate vessel 2 and the aqueous phase intermediate vessel 3 have a capacity of 50-150 mL.

A pressure gauge 6 is provided on the line between the hand pump 5 and the core holder 4, and the gauge 6 has a range of 10 MPa and an accuracy of 0.25 MPa.

An inlet pressure gauge is provided at the inlet end 4-1 of the core holder 4, and the inlet pressure gauge has a measuring range of 6 MPa and an accuracy of 0.25 MPa.

Example 4

A method of performing a microscopic displacement experiment using the experimental system according to any one of embodiments 1-3, comprising the steps of:

1) The core is dried and installed in the core holder 4, placed in a Zeiss MCT-400CT, scanned, and the three-dimensional digital core data body of the core analysis area is obtained;

2) Connecting the core holder 4 to the micro-displacement device, realizing single-phase water phase displacement, single-phase oil phase displacement or aqueous phase and oil phase multi-phase mixed displacement experiments on the core;

3) Design the observation time point according to the research content of the displacement experiment, that is, the displacement time, suspending the core displacement at the observation time, closing the core end of the core holder 4-2, the inlet end 4-1, Hand pump 5;

4) scanning the core holder 4 into the Zeiss MCT-400CT to obtain the fluid distribution in the core at the time of the displacement;

The core in the step 1) has a diameter of 1-2 cm and a length of 2-4 cm.

As can be seen from Figure 2, the fluid distribution in the core can be monitored in real time using CT scanning.

Claims

A microscopic displacement experimental system based on CT digital core, characterized in that the system comprises a core holder and a microscopic displacement device;

The core holder includes an inlet end, an outlet end, a core zone, and an outer casing; the outer casing is a polyetheretherketone material, and the microscopic displacement device includes a parallel phase oil phase intermediate container and a water phase intermediate container, And an advection pump for dispersing the oil phase intermediate container and the water phase intermediate container, wherein the oil phase intermediate container and the liquid phase intermediate container outlet end are connected to the inlet end of the core holder, the core holder The core held therein is pressurized by a hand pump, and a metering bottle is provided at the outlet end of the core holder.
The CT digital core-based micro-displacement experiment system according to claim 1, wherein a rotating seat is disposed at a bottom of the core holder.
The CT digital core-based micro-displacement experiment system according to claim 1, wherein the oil phase intermediate container and the aqueous phase intermediate container have a capacity of 50-150 mL.
A CT digital core-based micro-displacement experiment system according to claim 1, wherein a pressure gauge is provided on a pipeline between the hand pump and the core holder, and the pressure gauge is The measuring range is 10 MPa and the accuracy is 0.25 MPa.
The CT digital core-based micro-displacement experiment system according to claim 1, wherein an inlet pressure gauge is provided at an inlet end of the core holder, and the inlet pressure gauge has a range of 6 MPa. The accuracy is 0.25 MPa.
A method for performing a microscopic displacement experiment using the experimental system according to any one of claims 1 to 5, characterized in that the method comprises the following steps:

1) The core is dried and installed in the core holder, placed in the Zeiss MCT-400 CT, and the core is scanned to obtain a three-dimensional digital core data body in the core analysis area;

2) Connecting the core holder to the micro-displacement device, realizing single-phase water phase displacement, single-phase oil phase displacement or aqueous phase and oil phase multi-phase mixed displacement experiment for the core;

3) designing the observation time point according to the research content of the displacement experiment, that is, the displacement time, suspending the core displacement at the observation time, and closing the core end of the core holder, the inlet end, and the hand pump;

4) placing the core holder in a Zeiss MCT-400 CT to obtain the fluid distribution in the core at the time of the displacement;

5) Repeat steps 2) through 4) until the fluid distribution in the core is obtained at all design observation time points in accordance with step 3).
The experimental method according to claim 6, wherein the core in the step 1) has a diameter of 1-2 cm and a length of 2-4 cm.