CN108051643A - Multipair dynamic monitoring displacement system of multi-functional long cores radial direction - Google Patents

Abstract

The invention discloses a multi-functional long core radial multi-point dynamic monitoring displacement system, comprising a displacement system, a resistivity measurement system and a metering device, the displacement system comprising a gas displacement device, a foam displacement device and a fluid displacement device , the displacement system is connected to the resistivity measuring device through a valve; the resistivity measuring system includes a long core holder, a patrol instrument and a resistivity measuring instrument, and the metering device is an oil-gas-water three-phase automatic metering device. The system uses the displacement system and back pressure device to control the displacement type, displacement method, change the pressure difference at the end face of the rock sample, and the fluid flow rate in the rock sample. Using the characteristics of the difference in the resistivity caused by the different oil-water ratio in the rock core, through real-time Measure the resistivity changes corresponding to multiple pairs of points during the entire water flooding process, and combine the resistivity curves to obtain the saturation changes in the core at different stages, so as to obtain the remaining oil and gas distribution in the core after water flooding.

Description

Multifunctional Long Core Radial Multipoint Dynamic Monitoring and Displacement System

technical field

The patent of the invention belongs to the technical field of core saturation and resistivity measurement, and specifically relates to a multi-functional long core radial multi-point dynamic monitoring and displacement system.

Background technique

At present, most oil and gas reservoirs in the country and even the world have entered the late stage of development. Tapping the remaining oil and gas potential has always been a hot and difficult point in the oil and gas industry. Reservoir numerical simulation technology is an important means to tap the remaining oil and gas potential. However, the current technical conditions cannot be met. On the spot, the pressure drop well testing technology during the stuffy well after water injection is used. This technology is based on the principle of material balance and combines multiple rounds of well test data to solve the oil and gas saturation of oil and gas field blocks. Since the well test interpretation method requires a series of assumptions, This method also has limitations.

The experimental method has become the most representative technical method for tapping the remaining oil and gas potential. The measurement technology in the laboratory has developed various methods such as sound, light, and electricity to measure the oil and gas saturation in the process of core water flooding, mainly including ultrasonic pulse coincidence method, Land sonar method, nuclear magnetic resonance technology, computer tomography (CT) technology, chlorine energy method and resistivity logging and other methods and technologies, among which the resistivity method is widely used because of its easy-to-understand principle and easy-to-operate equipment. A conventional resistivity meter connects probes at both ends of the core, and obtains a resistivity curve by measuring the resistivity at different moments during the water flooding process. Through interpretation, the oil-water saturation at different moments during the water flooding process can be obtained. The limitation is that it cannot The saturation change in different sections of the core is measured, so the distribution of remaining oil cannot be obtained.

Contents of the invention

The technical problem to be solved by the present invention is to provide a multifunctional long core radial multi-point dynamic monitoring and displacement system, which can realize the simulation of the target oil and gas reservoir conditions under laboratory conditions, and use the different oil-water ratios in the core to cause the occurrence of resistivity By measuring the resistivity changes corresponding to multiple pairs of points during the entire water flooding process in real time, and combining the resistivity curves to obtain the saturation changes in the cores at different stages, the remaining water in the cores after water flooding can be obtained by laboratory means. Oil and gas distribution.

In order to solve the problems of the technologies described above, the present invention is achieved in the following manner:

Multifunctional long core radial multi-point dynamic monitoring displacement system, including displacement system, resistivity measurement system and metering device, wherein the displacement system includes gas displacement device, foam displacement device and fluid displacement device;

The gas displacing device includes a gas cylinder, a booster pump, an air compressor, a pressure gauge and a valve. One end of the booster pump is connected to the gas cylinder, and the other end is connected to the air compressor. The outlet pipeline of the booster pump is provided with a pressure Meters and valves to ensure that the gas can be controlled and displaced under different pressures;

The foam displacement device includes a foam observation window, a foam generator, a confining pressure pump I and a valve, the outlet end of the foam generator is connected to the foam observation window, and then connected to the confining pressure pump I, and pressurized by the confining pressure pump I to realize foam displacement;

The fluid displacement device includes two displacement pumps, a water intermediate container and an oil intermediate container, and the water intermediate container and the oil intermediate container are respectively connected with the displacement pump, thereby realizing water flooding or oil flooding or oil-water co-displacement; the said The gas displacement unit, the foam displacement unit and the fluid displacement unit are all connected through valves and resistivity measurement devices.

The resistivity measuring device includes a long rock core holder, an inspection instrument, a resistivity measuring instrument, an axial pressure pump, a confining pressure pump II and a back pressure device, and the two ends of the long rock core holder are connected with the inspection instrument , the inspection instrument is equipped with a resistivity measuring instrument, one side of the long core holder is connected with an axial pressure pump and a confining pressure pump II, and the outlet on the other side is connected with a foam window, a back pressure device and a metering device in sequence, The back pressure device includes a back pressure container, a back pressure gauge and a back pressure pump, the back pressure container is connected to the back pressure pump, and a back pressure gauge is arranged between the two, and the back pressure device is used to realize the Back pressure control.

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

1. Use multi-point radial measurement of long core displacement, obtain the distribution of remaining oil and gas under different displacement methods through resistivity curves, and improve the method of testing the remaining oil and gas distribution;

2. The structure of the foam generator is convenient for the foaming liquid and gas to be fully stirred and foamed, and through the transparent extrusion of the sintered plate with a pore size ranging from thick to fine, the foam is transformed into a micro-foam of the same order of magnitude as the core pore size, Facilitate the entry of foam into the core hole throat;

3. The pressure, temperature and saturation measuring points of the system share one, so there is no need to install inserts on the rubber tube and design multiple different measuring points, and it can be used under high pressure and ultra-high pressure conditions such as 150°C and 70MPa. The fluid can use water as the ring cavity medium.

Description of drawings

Figure 1 is a schematic diagram of the long core radial resistivity testing system.

Each mark in the figure is: 1. Gas cylinder; 2. Booster pump; 3. Air compressor; 4. Pressure gauge; 5. Valve; 6. Foam observation window; 7. Foam generator; 8. Confining pressure Pump I; 9. Water intermediate container; 10. Displacement pump; 11. Oil intermediate container; 12. Axial pressure pump; 13. Confining pressure pump II; 14. Long core holder; 15. Inspection instrument; 16. Resistivity measuring instrument; 17. Back pressure gauge; 18. Back pressure container; 19. Back pressure pump; 20. Metering device.

Detailed ways

In order to make the purpose, technical solution and advantages of the present invention more clear, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific examples described here are only used to explain the present invention, not to limit the invention.

This system is mainly used to conduct evaluation experiments such as reservoir gas injection experiment, water-gas cross-injection experiment, foam experiment and other evaluation experiments on long cores under simulated formation conditions, and through real-time measurement of the radial resistivity curve of long cores during the experiment, so as to obtain The remaining oil distribution of the long core during and after the experiment, the main functions of the system include:

1. Reservoir gas injection (N2) experiment:

Gas flooding experiment includes injection timing optimization experiment, injection method optimization experiment and alternate injection experiment evaluation. Among them, the injection timing optimization experiment is based on the core water content; the injection mode optimization experiment includes gas flooding, water flooding, foam flooding, gas-foam slug flooding, gas-profile control slug flooding, etc.; the alternate injection experiment includes water flooding , gas drive, foam drive, slug drive, etc.

2. High-pressure foam flooding experiment:

The experimental process can be verified and further explained the temporary blockage and diversion characteristics of the foam fluid and the diversion characteristics of chemical particles through indoor simulation, mainly including the following experiments:

(1) Parallel comparison test of foam plugging performance of single water-bearing core with different permeability, pressure change trend, outlet flow rate and core gas saturation change relationship during foam displacement and subsequent foaming agent solution and water displacement of single core, The plugging performance of foam on single core;

(2) Selective plugging test of foam on water-bearing core and oil-bearing core;

(3) Selective plugging test of foam on high-permeability and low-permeability core.

3. Reservoir sensitivity evaluation: including core sensitivity such as velocity sensitivity, acid sensitivity, water sensitivity, salt sensitivity, alkali sensitivity, and stress sensitivity.

4. Core liquid permeability and resistivity test: By testing the resistivity values of long cores at different water saturations, the core saturation values and related parameters are calculated.

As shown in Figure 1, the multi-functional long core radial multi-point dynamic monitoring displacement system includes a displacement system, a resistivity measurement system and a metering device, where the displacement system includes a gas displacement device, a foam displacement device and a fluid displacement device;

The gas displacement device includes a gas cylinder 1, a booster pump 2, an air compressor 3, a pressure gauge 4 and a valve 5. One end of the booster pump is connected to the gas cylinder, and the other end is connected to the air compressor. Pressure gauges and valves are installed on the pipeline to ensure that the gas can be displaced under different pressures;

Described foam displacement device comprises foam observation window 6, foam generator 7, confining pressure pump 18 and valve 5, and foam generator is connected with cylinder and produces foam, and foam generator outlet end is connected with foam observation window to observe The stability of the foam and other characteristics, and then connected with the confining pressure pump I, pressurized by the confining pressure pump I to realize foam displacement;

The fluid displacement device includes two displacement pumps 10, a water intermediate container 9 and an oil intermediate container 11, and the water intermediate container and the oil intermediate container are connected to the displacement pumps respectively, thereby realizing water flooding or oil flooding or oil-water co-displacement ; The gas displacing device, the foam displacing device and the fluid displacing device are all connected through a valve and a resistivity measuring device.

The resistivity measuring device comprises a long rock core holder 14, a patrol instrument 15, a resistivity measuring instrument 16, an axial pressure pump 12, a confining pressure pump II 13 and a back pressure device, and the two ends of the long rock core holder It is connected with the inspection instrument, and the inspection instrument is equipped with a resistivity measuring instrument. One side of the long core holder is connected with the axial pressure pump and the confining pressure pump II, and the outlet on the other side is connected with the foam window and the back pressure pump in turn. device and metering device, the back pressure device includes a back pressure container 18, a back pressure gauge 17 and a back pressure pump 19, the back pressure container is connected to the back pressure pump, and a back pressure gauge is provided between the two, and the back pressure device It is used to realize the back pressure control in the displacement process.

The foam generator in the present invention is equipped with multiple layers of sintered plates with different pore diameters, and the pore diameters gradually become smaller from the bottom to the top, so that the foam is transparently extruded through the sintered plates from thick to fine pore diameters, and the foam is transformed into a The core pore size belongs to the same order of magnitude as the micro-foam, which is convenient for the foam to enter the core pore throat.

The specification of the long core stored in the long core holder is Its saturation measuring point, pressure measuring point and temperature measuring point share the same measuring point, and the number of measuring points is 12. The system has axial pressure, which can realize the displacement pressure range of 0-70MPa and the back pressure range of 0 ~80Mpa; Two observation windows with a size of 100×100×40mm are connected to the front and rear ends of the holder, and the observation windows are divided into 4 observation ports on average.

One end of the long core holder in the present invention is provided with three inlet and outlet joints for simulating the fluid inlet end when the long core is displaced, and the other end is provided with an outlet joint; the inlet joint is connected with the inlet end of the displacement system, and the outlet The joint is connected with the metering device and the back pressure device, and the displacement system changes the displacement pressure, flow rate, displacement type, etc. to realize the measurement of the resistivity curve under different displacement methods, different displacement pressures, and different displacement fluid conditions. And then get the corresponding oil-water distribution law.

The displacement system of the present invention will meet the following conditions:

It can simulate the confining pressure, flow pressure and fluid driving force of long core mining; it can observe and record the foam changes under foam flooding conditions in real time through a set of camera equipment during the experiment; it can simulate different displacement methods, Including gas flooding, water flooding, oil flooding, foam flooding, etc.; can record the resistivity changes at different positions of long cores in real time, and can give the resistivity change curves of each position; can automatically measure the amount of oil, gas and water in the process of displacement in real time .

During the experiment, the long core is loaded into the long core holder 14, and the confining pressure is applied to the long core holder through the confining pressure pump II 13 to simulate the formation conditions, and the axial pressure pump is used to load the long core holder with axial pressure On the one hand, it simulates the formation stress, and on the other hand, it compacts the long cores spliced by different small cores, so as to avoid the occurrence of core cracks and affect the experimental results. During the displacement process, the resistivity at different positions of the long core is tested by the resistivity tester 16, and the inspection instrument 15 collects a round of resistivity measurement information at different positions of the long core every second, and the outlet end of the long core holder is connected to Foam observation window to observe foam changes.

The metering of the volume of oil, gas and water after the experiment is completed is realized by a metering device, and the metering device in this patent is an automatic oil, gas and water three-phase metering device. The system is simple in structure, strong in practicability, and has strong promotion and application value.

The above are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention. Inside.

Claims (4)

1. multipair dynamic monitoring displacement system of multi-functional long cores radial direction, it is characterised in that：It is surveyed including displacement system, resistivity Amount system and metering device, wherein displacement system include gas driving device, foam driving device and fluid drive unit；

The gas driving device includes gas cylinder, booster pump, air compressor, pressure gauge and valve, booster pump one end connection gas Bottle, other end connection air compressor, is provided with pressure gauge and valve on the port of export pipeline of booster pump, ensures that gas can be controlled System carries out displacement at various pressures；

The foam driving device includes foam observation window, foam maker, confining pressure pump I and valve, the foam maker port of export It is connected with foam observation window, and then is connected with confining pressure pump I, carrying out pressurization by confining pressure pump I realizes that foam flooding replaces；

The fluid drive unit includes two displacement pumps, water intermediate receptacle and oily intermediate receptacle, among water intermediate receptacle and oil Container is connected respectively with displacement pump, and then realizes water drive or oil drive or the same displacement of grease；The gas driving device, foam flooding replace Device is connected with fluid drive unit by valve with resistivity test device.

2. multipair dynamic monitoring displacement system of multi-functional long cores radial direction according to claim 1, it is characterised in that：Institute Stating resistivity test device includes long rock core holder, logging, resistivity measuring instrument, axis press pump, confining pressure pump II and back pressure dress It puts, the both ends of the long rock core holder are connected with logging, and resistivity measuring instrument, long rock core holder are provided on logging One side be connected with axis press pump and confining pressure pump II, the outlet of opposite side is connected with foam form, back pressure device and metering in turn Device, the back pressure device include back pressure container, back pressure meter and backpressure pump, and back pressure container is connected with backpressure pump, and the two it Between be equipped with back pressure meter, back pressure device to realize the back pressure in displacement process control.

3. multipair dynamic monitoring displacement system of multi-functional long cores radial direction according to claim 1, it is characterised in that：Institute The sintered plate that multilayer different pore size is equipped in foam maker is stated, and aperture becomes smaller successively from bottom to top.

4. multipair dynamic monitoring displacement system of multi-functional long cores radial direction according to claim 1, it is characterised in that：Institute Metering device is stated as oil-gas-water three phase automatic metering.