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CN-121806148-B - Ultra-deep water ultra-shallow gas reservoir instability and sand production simulation evaluation experimental device and experimental method

CN121806148BCN 121806148 BCN121806148 BCN 121806148BCN-121806148-B

Abstract

The invention belongs to the field of deep water oil gas resource development and exploitation in the oil and natural gas exploitation industry, in particular to an ultra-deep water ultra-shallow gas reservoir instability and sand production simulation evaluation experimental device and an experimental method, the invention provides a complete evaluation experimental device, an experimental condition setting method, an experimental method and a quantitative evaluation method for the evaluation of the whole process of the instability of the reservoir and the interlayer and the sand production of the reservoir in the ultra-deep ultra-shallow gas exploitation process, can realize process simulation and quantitative evaluation, and provides direct support for the optimization and design implementation of the sand prevention completion mode of the ultra-deep ultra-shallow gas reservoir gas well.

Inventors

  • DONG CHANGYIN
  • XUE DONGYU
  • WANG HAOYU
  • BAI LI
  • Shi Rengang
  • LI NA
  • LI ZHANGYU

Assignees

  • 中国石油大学(华东)

Dates

Publication Date
20260508
Application Date
20260306

Claims (10)

  1. 1. The ultra-deep water ultra-shallow gas reservoir instability and sand production simulation evaluation experimental device is characterized by comprising a reservoir instability and sand production simulation main body device (1) in a multilayer production process, a four-column type servo hydraulic press (2), a data acquisition and control system (3), a sand liquid collection device (8), a pressure sensor (9), a gas flowmeter (10), a liquid flowmeter (11), a control valve (12), a liquid pipeline (13), a gas pipeline (14), an outlet pipeline (15), a liquid supply system and a gas supply system; The reservoir instability and sand production simulation main body device (1) in the multilayer production process comprises a main body tank body (17), an open hydraulic pressurizing plate (18), a deformable visual spacer (19), a tank body visual window (20), a tank body inflow port (23), a sand liquid flow outlet (24), a shaft switching valve (25), a simulation horizontal shaft (26) and a simulation vertical shaft (27); The opening of the main body tank body (17) is upward, the open hydraulic pressurizing plate (18) is arranged in the main body tank body (17) in a vertically sliding way, and the four-column type servo hydraulic press (2) is positioned above the open hydraulic pressurizing plate (18) and is connected with the open hydraulic pressurizing plate (18); A interlayer (200) and a reservoir (100) which are alternately arranged from top to bottom are arranged in the main tank body (17); The surface of the deformable visual spacer (19) is provided with grid-shaped scales, the deformable visual spacer (19) is detachably and horizontally arranged in the main tank body (17) and is respectively positioned between the reservoir (100) and the interlayer (200), and the deformable visual spacer (19) is in sealing connection with the inner wall of the main tank body (17); The side wall of the main tank body (17) is provided with a tank body visual window (20); The side wall of the main tank body (17) corresponding to the reservoir (100) is provided with a tank body inflow port (23) and a sand liquid flow outlet (24) which are oppositely arranged, the simulation horizontal shaft (26) is horizontally arranged in the reservoir (100), and one end of the simulation horizontal shaft (26) is connected with the sand liquid flow outlet (24); A tank inflow port (23) is arranged on the side wall of the main tank body (17) corresponding to the interlayer (200); The open hydraulic pressurizing plate (18) is provided with a sand liquid flow outlet (24), the simulated vertical shaft (27) is vertically arranged in the main tank body (17), the lower end of the simulated vertical shaft (27) is positioned in the reservoir (100) at the lowest layer, and the upper end of the simulated vertical shaft (27) is connected with the sand liquid flow outlet (24); The liquid supply system is connected with the tank inflow port (23) through separate liquid pipelines (13), the gas supply system is connected with the tank inflow port (23) through separate gas pipeline (14), and the sand liquid outlet (24) is connected with the sand liquid collecting device (8) through separate outlet pipelines (15); a shaft opening and closing valve (25) is arranged at the inlet (23) and the sand liquid outlet (24) of the tank body; control valves (12) are arranged on the liquid pipeline (13), the gas pipeline (14) and the outlet pipeline (15); The liquid flowmeter (11) is arranged on the liquid pipeline (13), and the gas flowmeter (10) is arranged on the gas pipeline (14); A pressure sensor (9) is arranged at a tank inflow port (23) and a sand liquid flow outlet (24) on two sides of the reservoir (100) and in the reservoir (100); The data acquisition and control system (3) is respectively connected with the four-column type servo hydraulic press (2), the pressure sensor (9), the gas flowmeter (10), the liquid flowmeter (11), the control valve (12), the shaft switching valve (25), the liquid supply system and the gas supply system.
  2. 2. The ultra-deep water ultra-shallow gas reservoir instability and sand production simulation evaluation experiment device according to claim 1, further comprising an inner sliding groove (21) and a sliding buckle (22); The inner sliding groove (21) is vertically arranged on the side wall of the main tank body (17), and the plurality of sliding buckles (22) are arranged in the inner sliding groove (21) in a vertically sliding way; the two ends of the deformable visual spacer (19) are detachably arranged on the sliding buckle (22).
  3. 3. The ultra-deep water ultra-shallow gas reservoir instability and sand production simulation evaluation experimental device according to claim 1, wherein the liquid supply system comprises a liquid pump (4) and a liquid storage tank (5), and the liquid storage tank (5) is connected with a tank inflow port (23) through the liquid pump (4); The air supply system comprises an air tank (6) and an air compressor (7), wherein the air tank (6) is connected with the tank inflow port (23), and the air compressor (7) is used for pressurizing and supplying air to the air tank (6).
  4. 4. The ultra-deep water ultra-shallow gas reservoir instability and sand production simulation evaluation experimental device according to claim 1 is characterized in that a buffer layer is arranged above an uppermost interlayer (200), and a cushion layer is arranged at the bottom of the main tank body (17).
  5. 5. The experimental device for simulating and evaluating the destabilization and the sand production of the ultra-deep water ultra-shallow gas reservoir according to claim 1, wherein the deformable visual spacer (19) is made of polyurethane elastic composite material, the thickness is 5-20mm, and the elastic modulus is 0.5-2GPa.
  6. 6. The ultra-deep water ultra-shallow gas reservoir instability and sand production simulation evaluation experimental device according to claim 2, wherein a sealing rubber ring is arranged at the edge of the deformable visual spacer (19).
  7. 7. An ultra-deep ultra-shallow gas reservoir instability and sand production simulation evaluation experimental method, which utilizes any one of the ultra-deep ultra-shallow gas reservoir instability and sand production simulation evaluation experimental device according to claims 1-6, is characterized by comprising the following steps: S1, setting experimental conditions S1.1, preparing and filling experimental samples, namely preparing reservoir simulation samples and interlayer simulation samples, and filling a main tank body (17) in a layered manner; S1.2, synchronously pressurizing and filling water for saturation, namely simultaneously starting a four-column type servo hydraulic machine (2) and a liquid supply system to realize complete water saturation; s1.3, synchronously maintaining pressure and filling gas, namely after the water saturation pressure maintaining is finished, maintaining a linkage control mode of the four-column type servo hydraulic press (2), closing a liquid supply system, starting a gas supply system, realizing the full gas saturation of a reservoir, and ensuring that samples in the whole reservoir (100) are not damaged in advance and are not displaced; s2, experimental simulation of process S2.1, simulation of a production process: Presetting an opening mode of a shaft switching valve (25) according to an actual exploitation scheme of a target gas reservoir, and setting the flow of gas-liquid production according to the conversion from actual reservoir exploitation conditions to experimental conditions; Opening a shaft switching valve (25) according to preset parameters through a data acquisition and control system (3), setting gas-liquid flow parameters, starting a gas-liquid conveying system, accurately controlling gas-liquid production flow through a gas flowmeter (10) and a liquid flowmeter (11), and simulating a mining process; S2.2, acquiring and recording experimental process data in real time; In the experimental process, the pressure of tank inflow ports (23) and sand liquid flow outlets (24) on two sides of a reservoir (100), the gas-liquid production flow and the hydraulic press pressurization pressure are collected and stored in real time through a data collection and control system (3); Aligning a tank body visual window (20) and a deformable visual spacer (19) by using a high-speed camera, and shooting deformation, sand-out starting position, sand migration track, displacement and rupture process of a spacer layer of a reservoir sample in real time; In the experimental process, the whole state of the device is manually checked every 1-2h, whether a reservoir sample is cracked and collapsed, whether a interlayer is dislocated or not, and whether a shaft is blocked by sand or not are recorded; After the experiment is finished, carrying out solid-liquid separation, drying and weighing on a sand outlet sample in the sand-liquid collecting device (8); Reading and recording the vertical displacement amount delta H, the horizontal length displacement amount delta L, the horizontal width displacement amount delta W of each reservoir sample and the horizontal/vertical displacement amount of the interlayer (200) through the scale marks of the deformable visual spacer (19); s3, quantitative evaluation S3.1, calculating quantitative evaluation indexes of sand production: Determining critical sand discharge pressure and critical sand discharge flow according to experimental process data, namely corresponding production pressure and gas production flow when the reservoir begins to appear obvious sand; Calculating an average sand output rate v and an average sand output rate v i of each layer of reservoir according to the experimental actual time t; Defining a sand-out intensity index I as the sand-out quantity under the conditions of unit reservoir volume and unit pressure drop, and calculating the reservoir sand-out intensity index I; After the experiment, a laser particle size analyzer is adopted to analyze the particle size and morphology of the dried sand sample, a sand particle size distribution curve is drawn, a relation curve of sand quantity, sand discharge rate, production pressure and flow is drawn, and the association relation between production parameters and sand discharge is quantified; s3.2, quantitative evaluation indexes and calculation of reservoir and interlayer instability: According to the image data shot by a high-speed camera, combining the scale marks of a deformable visual spacer (19), measuring the vertical deformation epsilon z , the horizontal length deformation epsilon l and the horizontal width deformation epsilon w of a reservoir sample, and calculating the volume strain epsilon V by utilizing the sum of the three; Measuring the horizontal displacement d L and the vertical displacement d W of the interlayer sample, and calculating the shearing strain gamma of the interlayer; the risk of instability of the reservoir and the compartment is divided into three stages according to the volume strain and the shear strain: low risk of epsilon v <2%, gamma <5%; Risk of (1): epsilon v % or more and gamma 10% or less; high risk that epsilon v is more than or equal to 5 percent and gamma is more than or equal to 10 percent; Measuring collapse radius r of a reservoir around the well shaft after experiments, namely, the maximum radius of a collapse area of the reservoir around the well shaft; the larger collapse radius indicates more serious wellbore-surrounding reservoir instability, and the worse reservoir stability corresponding to the completion mode.
  8. 8. The experimental method for simulating evaluation of destabilization and sand production of ultra-deep water ultra-shallow gas reservoir according to claim 7, further comprising step S4, optimization and design of completion mode: S4.1, carrying out production process simulation under different working conditions: The perforation completion working condition simulation comprises the steps of setting the diameter, density and distribution mode of perforation by using a simulated shaft assembly with perforation, installing the simulated shaft assembly to the corresponding position of a main tank body (17) according to actual perforation parameters, and sealing and fixing the simulated shaft assembly; simulating a perforation completion exploitation process, and monitoring deformation and sand production dynamics of a reservoir and a interlayer in real time; The sand control/no sand control working condition simulation comprises the steps of applying screens with different types and precision as sand control components according to actual reservoir sand control measures on the inner side of a well bore of a perforated well completion or an open hole well, namely, the sand control working condition is realized, and the sand control components are removed, namely, the sand control working condition is not realized, production simulation is respectively carried out according to preset parameters, the sand control effect is compared, and the deformation and sand production dynamics of a reservoir and a interlayer are monitored in real time; The open hole working condition simulation comprises the steps of removing a perforation section and a sand prevention section of a simulated shaft, adopting a solid non-hole shaft as an open hole simulation assembly, simulating the open hole exploitation process, and monitoring the deformation of a reservoir and a interlayer and sand production dynamics in real time; Independently opening a simulated vertical shaft (27) to serve as a production working condition of the vertical well, and independently opening a simulated horizontal shaft (26) to serve as a production working condition of the horizontal well; only opening a shaft switching valve (25) corresponding to a certain reservoir layer to be in a single-layer production working condition, and simultaneously opening a shaft switching valve (25) corresponding to a plurality of reservoir layers to be in a multi-layer production working condition; Developing production simulation according to preset parameters respectively, and recording reservoir response under different working conditions; in the experimental process, according to the experimental design, the production flow is gradually increased, and the reservoir working conditions under different exploitation intensities are simulated; After each time of parameter adjustment, recording the deformation and sand production change of the reservoir; When the conditions of obvious instability of the reservoir, rupture of the interlayer and sudden increase of the sand output occur, suspending the experiment, and recording critical working condition parameters; s4.2, effect comparison and optimization of different well completion modes: Carrying out comprehensive comparison analysis on critical sand production parameters, critical instability parameters, sand production intensity indexes and wellbore periphery collapse radius indexes of open hole wells, perforation well completion, sand prevention and sand prevention-free different well completion modes, and different production modes of vertical wells/horizontal wells and single-layer/multilayer production, and carrying out comparison optimization on different well completion modes and different working conditions; The method comprises the steps of taking the lowest sand-out intensity index, the maximum critical parameter value and the minimum collapse radius as core technical principles, and simultaneously combining the economical efficiency, construction difficulty and operability of field engineering implementation to screen out the optimal well completion mode and production mode of the adaptation target ultra-deep water ultra-shallow gas reservoir; Optimizing well completion parameters, namely optimizing key parameters of perforation density, aperture, distribution mode and sand control screen precision aiming at the screened optimal well completion mode, carrying out a plurality of groups of parameter optimization experiments, and determining optimal selection of the well completion parameters.
  9. 9. The simulation evaluation experiment method for ultra-deep water ultra-shallow gas reservoir instability and sand production according to claim 7 is characterized in that S1.2, synchronous pressurization and water injection saturation are implemented by starting a four-column type servo hydraulic press (2) and a liquid supply system simultaneously, wherein the four-column type servo hydraulic press (2) applies axial pressure to an open type hydraulic pressurizing plate (18) according to a preset speed, and the liquid supply system injects water to each reservoir (100) and each interlayer (200) cavity according to a constant speed mode, and the water injection speed is controlled to be 0.1-0.5L/min; in the water injection process, firstly, a shaft switching valve (25) is opened, the sand liquid flow outlets (24) continuously discharge air in the tank until each sand liquid flow outlet (24) has continuous bubble-free liquid flowing out, and then, the shaft switching valve (25) is closed; And continuously maintaining synchronous linkage of pressurization and liquid injection of the hydraulic press, synchronously increasing the water injection pressure in the tank along with the pressurization pressure of the hydraulic press until the pressurization pressure of the hydraulic press reaches 50% of the target water depth overlying pressure, maintaining the pressure for 2h, and in the pressure maintaining process, maintaining linkage of the four-column type servo hydraulic press (2) and the liquid supply system, and automatically adjusting the pressurization pressure by the four-column type servo hydraulic press (2) if the pressure of the reservoir has tiny fluctuation, so that the effective stress is stable, and realizing complete water saturation.
  10. 10. The simulation evaluation experiment method for ultra-deep water ultra-shallow gas reservoir instability and sand production according to claim 7 is characterized in that the specific steps of S1.3, synchronous pressure maintaining and gas injection saturation are that after water saturation pressure maintaining is completed, a linkage control mode of a four-column type servo hydraulic machine (2) is maintained, pressurizing pressure is maintained to be stable, a control valve (12) on a liquid pipeline (13) is closed, a control valve (12) on a gas pipeline (14) is opened, a gas supply system is started, gas is injected into a cavity of a reservoir (100), gas injection adopts a constant pressure mode, gas injection pressure synchronously increases along with the pressurizing pressure of the four-column type servo hydraulic machine (2) according to a preset rate, the gas injection rate is controlled to be 0.1-1m < 3 >/h, and data of a pressure sensor (9) in a tank are monitored in real time in the gas injection process; And continuously and synchronously maintaining pressure and injecting gas until the pressurizing pressure of the hydraulic press reaches the target water depth overlying pressure of 15.08-17.05MPa, and the reservoir gas injection pressure reaches the target reservoir original stratum pore pressure, maintaining the pressure for 2h, wherein in the pressure maintaining process, a data acquisition and control system (3) monitors and regulates in real time, so that the difference value between the pressurizing pressure of the hydraulic press and the reservoir pore pressure is always equal to the actual stratum effective stress, and the gas fully enters the pores of a reservoir sample to realize the full gas saturation of the reservoir.

Description

Ultra-deep water ultra-shallow gas reservoir instability and sand production simulation evaluation experimental device and experimental method Technical Field The invention belongs to the field of deep-ground deep-water oil and gas resource development and exploitation in the oil and gas exploitation industry, and particularly relates to an ultra-deep water ultra-shallow gas reservoir instability and sand production simulation evaluation experimental device and an experimental method. Background Deep (including deep and deep water) oil and gas resource development is a major near-well field of oil and gas energy development, wherein ultra-deep water ultra-shallow gas is an important resource type of deep oil and gas. The geological reserve of the natural gas in the deep water and the shallow layer of the cemetery water 36-1 is initially ascertained in a sea area to achieve trillion parties. But the depth of the ultra-deep and ultra-shallow air layer is 1500-1700m, the buried depth is about 150-300m below the seabed, and the method has the characteristics of shallow buried depth, weak cementing and even unconsolidated reservoir, thin interlayer and interlayer (called interlayer for short), easy destabilization and damage, multilayer superposition and the like. Especially, as the reservoir layer is weakly or even not diagenetic, the interlayer is thin, the problems of unstable damage and sand production of the reservoir layer structure, unstable damage of the interlayer, and serious problems of environmental safety, geological disasters and the like, such as natural gas leakage of the reservoir layer, are easy to occur in the exploitation process. In view of the characteristics of the ultra-deep water ultra-shallow gas reservoir and potential damage and safety risks thereof, the method is an important work for evaluating instability and sand production in the exploitation process of the reservoir, and has important significance for preventing damage and disaster occurrence by adopting a reasonable sand prevention completion mode. Experimental simulation is an important research means for destabilization and sand production evaluation, but at present, the destabilization sand production simulation experiment of the ultra-deep water ultra-shallow gas reservoir has the following key problems: (1) An international first large ultra-deep ultra-shallow gas reservoir is discovered for the first time in a sea area, and an experimental device capable of simulating the whole processes of instability of a reservoir and a interlayer and sand production of the reservoir in the ultra-deep ultra-shallow gas exploitation process is not yet available. (2) The conventional oil and gas reservoir sand production simulation experiment simulation system mainly comprises a core sand production simulation experiment device mainly comprising a core holder. The device can not simulate complex conditions such as an overlying deep water condition, an ultra-shallow layer condition, a thin interlayer condition, a multi-production layer and the like, and is difficult to be qualified for experimental simulation of reservoir and interlayer instability and reservoir sand production in an ultra-deep ultra-shallow gas exploitation process. (3) Lack of experimental quantitative evaluation methods for instability of reservoirs and interlayer and sand production of reservoirs in ultra-deep water ultra-shallow gas exploitation processes. Disclosure of Invention In order to solve the technical problems, the invention provides an ultra-deep water ultra-shallow gas reservoir instability and sand production simulation evaluation experimental device and an experimental method, which aim to simulate the production process in the ultra-deep water ultra-shallow gas reservoir exploitation process by experimental means conveniently, evaluate whether an interlayer and a reservoir can generate instability collapse and sand production, and consider deep water conditions, ultra-shallow interlayer conditions and weak-unconsolidated conditions of a multi-layer reservoir during simulation. Through experimental simulation and quantitative evaluation, the production safety evaluation of the ultra-deep water ultra-shallow gas reservoir is realized, and the optimization and engineering implementation of the sand prevention well completion mode are supported. The invention aims to solve the technical problems by adopting the following technical scheme that the ultra-deep water ultra-shallow layer gas reservoir instability and sand production simulation evaluation experimental device comprises a reservoir instability and sand production simulation main body device, a four-column type servo hydraulic press, a data acquisition and control system, a sand liquid collection device, a pressure sensor, a gas flowmeter, a liquid flowmeter, a control valve, a liquid pipeline, a gas pipeline, an outlet pipeline, a liquid supply system and a gas supply system in a multilayer produc