CN-121805331-B - Testing device and method for simulating gas-liquid competitive adsorption under reservoir electric field environment

CN121805331BCN 121805331 BCN121805331 BCN 121805331BCN-121805331-B

Abstract

The invention provides a testing device and a method for simulating gas-liquid competitive adsorption under a reservoir electric field environment, and relates to the technical field of oil and gas field development experiment simulation, wherein the device comprises a QCM-D host, a special electric field flow cavity, a high-voltage power supply, a fluid injection system and a signal isolation and shielding system; the method comprises the steps of establishing a base line, monitoring crude oil adsorption dynamics, monitoring displacement gas competitive desorption dynamics under the condition of applying a high-voltage electric field, and generating an evaluation result based on frequency and dissipation double parameter changes. According to the invention, through the vertical transmission type non-contact electric field loading cavity and the high-voltage-weak signal isolation circuit, the real-time, in-situ and quantitative monitoring of the QCM-D chip surface gas-liquid competitive adsorption microscopic process under the kilovolt-level high-voltage electric field environment is realized for the first time, the different effects of the electric field on mass desorption and interface rheological change can be distinguished, and a reliable experimental tool and analysis method are provided for revealing the microscopic mechanism of electric field enhanced oil displacement.

Inventors

ZHANG WENTONG
JIA QIXIN
ZHANG JUNXI
HUANG HAI
SHI JUNTAI
LIU CHONG
CAO YI
WANG YANWEI

Assignees

西安石油大学

Dates

Publication Date: 20260508
Application Date: 20260312

Claims (9)

1. The utility model provides a testing arrangement of simulation reservoir electric field environment gas-liquid competition absorption which characterized in that includes: the QCM-D host is used for generating and receiving high-frequency electric signals; The special electric field flow cavity is made of insulating and pressure-resistant materials and is internally provided with: the upper electrode is a netlike electrode embedded at the top of the cavity flow channel; the lower electrode is a conductive coating arranged on the surface of the QCM-D chip at the bottom of the cavity; the upper electrode and the lower electrode are arranged in parallel and opposite to each other so as to form a uniform electric field in the micro-channel between the upper electrode and the lower electrode; The high-voltage power generator is electrically connected with the upper electrode and is used for providing a controllable electric field with kV/cm-level intensity; the fluid injection system is used for injecting crude oil, displacement gas and background fluid into the special electric field flow cavity; the signal isolation and shielding system is connected between the QCM-D host and the QCM-D chip; the signal isolation and shielding system includes: the blocking capacitor is connected in series in the signal transmission path and used for blocking direct-current high voltage; the radio frequency transformer is used for coupling and transmitting high-frequency alternating current signals in an electrical isolation state; the Faraday shielding cage is wrapped outside the special electric field flow cavity and is used for shielding electromagnetic interference.
2. The device of claim 1, wherein the mesh electrode is a platinum mesh or a titanium mesh, and the dielectric pressure resistant material is polyetheretherketone PEEK or polytetrafluoroethylene.
3. The apparatus of claim 1, wherein the fluid injection system comprises at least two independently controllable fluid lines and a switching valve, one for injecting crude or simulated oil and the other for injecting displacement gas.
4. The apparatus of claim 1, further comprising a temperature control system for maintaining the tailored electric field flow chamber at a set reservoir simulation temperature.
5. A method of testing gas-liquid competitive adsorption in a simulated reservoir electric field environment based on the apparatus of any one of claims 1-4, said method comprising: Acquiring a baseline frequency signal and a baseline dissipation signal of the QCM-D chip; Acquiring a real-time frequency change signal and a real-time dissipation change signal of the QCM-D chip in the process of injecting crude oil into the device; based on the real-time frequency change signal and the real-time dissipation change signal, processing to obtain saturated adsorption quantity and adsorption rate constant of crude oil on the surface of the chip; Acquiring a competitive desorption frequency signal and a competitive desorption dissipation signal of the QCM-D chip in the process of switching and injecting the displacement gas into the device and simultaneously applying an electric field with preset intensity through a high-voltage power generator of the device; Based on the competitive desorption frequency signal and the competitive desorption dissipation signal, processing to obtain a desorption rate constant of the displacement gas to crude oil and oil film viscoelasticity evolution information under the assistance of an electric field; and generating an evaluation result for evaluating the enhancement effect of the electric field on the gas-liquid competitive adsorption process based on the saturated adsorption quantity, the adsorption rate constant, the desorption rate constant and the viscoelasticity evolution information.
6. The method according to claim 5, wherein the processing to obtain the saturated adsorption amount and adsorption rate constant of the crude oil on the chip surface based on the real-time frequency variation signal and the real-time dissipation variation signal comprises: When the real-time frequency change signal enters a platform period, calculating the real-time frequency change signal and the real-time dissipation change signal based on a Sauerbey equation or a Voigt model to obtain the saturated adsorption quantity; fitting the dynamic descending process of the real-time frequency change signal to obtain the adsorption rate constant.
7. The method according to claim 5, wherein the acquiring comprises the steps of switching injection of the displacement gas to the device and simultaneously applying an electric field of a preset intensity through a high-voltage power generator of the device, and specifically comprises the steps of: After the crude oil is adsorbed to be saturated, switching the injection fluid into supercritical CO 2 by a fluid injection system of the device; And simultaneously switching the fluid or lagging a preset time, controlling the high-voltage power generator to apply a direct current or pulse electric field to the special electric field flow cavity, and synchronously collecting the competitive desorption frequency signal and the competitive desorption dissipation signal.
8. The method of claim 7, wherein the applied electric field is a pulsed electric field having a frequency in the range of 10Hz to 1000Hz and a duty cycle of 20% to 80%.
9. The method of claim 5, wherein the processing based on the competitive desorption frequency signal and the competitive desorption dissipation signal to obtain desorption rate constant and oil film viscoelastic evolution information of the displacement gas to the crude oil with the assistance of an electric field comprises: fitting the dynamic rising process of the competitive desorption frequency signal to obtain the desorption rate constant; analyzing and obtaining the oil film viscoelasticity evolution information based on the change trend and the amplitude of the competitive desorption dissipation signal; the oil film viscoelasticity evolution information is used for distinguishing a mass desorption effect caused by an electric field effect from a crude oil rheological property change effect.

Description

Testing device and method for simulating gas-liquid competitive adsorption under reservoir electric field environment Technical Field The invention relates to the technical field of oil and gas field development experiment simulation, in particular to a testing device and method for simulating gas-liquid competitive adsorption under an electric field environment of a reservoir. Background As field development goes deeper into unconventional, low permeability reservoirs, the importance of enhanced recovery techniques is increasingly prominent. The electric field enhanced oil displacement is used as a potential efficient development means, and the core mechanism is that a high-voltage electric field is utilized to change microscopic acting force between the surface of the reservoir rock and crude oil and displacement gas (such as CO 2), so that desorption and migration of the crude oil are promoted. To optimize the technology, the dynamic influence rule of the electric field on the competitive adsorption behavior of the three-phase interfaces of rock, crude oil and gas must be clarified on a microscopic scale. The dissipative quartz crystal microbalance (QCM-D) is an instrument capable of measuring the nano-scale mass change and the viscoelasticity change of the surface in real time with high sensitivity, and has been applied to basic adsorption research. However, the standard QCM-D technology and equipment currently available cannot meet the need for simulating and monitoring competitive adsorption processes in a reservoir high voltage electric field environment. The basic reason is that commercial QCM-D modules lack high-voltage electric field loading capability, traditional electrochemical QCM (E-QCM) is only suitable for weak voltage of millivolt to volt level, and cannot provide kilovolt level (kV/cm) high-voltage electric field required by simulating a real reservoir, and more importantly, if high voltage is forcibly introduced, strong electromagnetic interference generated by the high-voltage electric field can completely submerge nano-level weak piezoelectric signals on which QCM-D depends to work, so that the system cannot work normally or is damaged. Therefore, the prior art cannot realize in-situ and real-time micro-dynamics monitoring and quantitative analysis on the gas-liquid competitive displacement process while applying a high-voltage electric field of a reservoir level, and prevents deep research and technical optimization of an electric field oil displacement microscopic mechanism. Disclosure of Invention In order to solve the technical problem that the microcosmic competitive adsorption process cannot be monitored in situ in real time in the high-voltage electric field environment in the background technology, the invention provides a testing device and a testing method for simulating gas-liquid competitive adsorption in the reservoir electric field environment, and the nondestructive acquisition and analysis of millisecond-level precision frequency (delta f) and dissipation (delta D) signals in the QCM-D chip surface adsorption/desorption process are realized while the safe loading of a kilovolt-level high-voltage electric field is realized by integrating a specially-made electric field flow cavity with a parallel reticular electrode structure and a set of high-voltage-weak signal isolation and shielding system. The invention provides a testing device for simulating gas-liquid competitive adsorption in a reservoir electric field environment, which comprises a QCM-D host machine, a first test device, a second test device and a third test device, wherein the QCM-D host machine is used for generating and receiving high-frequency electric signals; The special electric field flow cavity is made of insulating and pressure-resistant materials and is internally provided with: the upper electrode is a netlike electrode embedded at the top of the cavity flow channel; the lower electrode is a conductive coating arranged on the surface of the QCM-D chip at the bottom of the cavity; the upper electrode and the lower electrode are arranged in parallel and opposite to each other so as to form a uniform electric field in the micro-channel between the upper electrode and the lower electrode; The high-voltage power generator is electrically connected with the upper electrode and is used for providing a controllable electric field with kV/cm-level intensity; the fluid injection system is used for injecting crude oil, displacement gas and background fluid into the special electric field flow cavity; And the signal isolation and shielding system is connected between the QCM-D host and the QCM-D chip. Further, the signal isolation and shielding system includes: the blocking capacitor is connected in series in the signal transmission path and used for blocking direct-current high voltage; the radio frequency transformer is used for coupling and transmitting high-frequency alternating current signals in an elect