An experimental device and experimental method for simulating continuous subsidence and hydrocarbon expulsion of hydrocarbon source rocks

Abstract

The present invention discloses an experimental device and an experimental method for simulating the continuous settlement and hydrocarbon expulsion of hydrocarbon source rocks. The experimental device includes a reaction kettle, which is placed in a box-type heating furnace. A hydraulic station top cylinder for applying upward pressure is provided at the top of the box-type heating furnace, and a hydraulic station bottom cylinder for applying downward pressure is provided at the lower end of the box-type heating furnace. Hydrocarbon expulsion pipelines for hydrocarbon expulsion are provided at the top and bottom of the reaction kettle. The experimental method includes the following steps: dividing the burial stage; designing the simulated heating stage and corresponding experimental conditions; conducting a pilot experiment to eliminate the temperature difference of the device; converting the simulated pressure conditions into the working parameters of the simulation experimental equipment; inputting the heating instruction and the pressure control instruction; simulating the sample loading, kettle loading, and leak detection processes of the experiment; conducting the heating operation; collecting the thermal simulation products and calculating the oil expulsion rate. The present invention can dynamically adjust the temperature and pressure conditions in the simulation experiment according to the burial history of the hydrocarbon source rock, simulate the hydrocarbon generation and expulsion process during the continuous settlement of the hydrocarbon source rock, and reproduce the hydrocarbon expulsion events of the hydrocarbon source rock under the formation burial history.

Description

Technical Field

[0001] The present invention belongs to the technical field of exploration and development of oil and gas geological resources, and particularly relates to an experimental device and an experimental method for simulating continuous settlement and hydrocarbon expulsion of hydrocarbon source rocks. Background Technique

[0002] Hydrocarbon source rocks, also known as oil-generating rocks, are fine-grained sedimentary rocks rich in organic matter. After the hydrocarbon source rocks settle to a specific burial depth due to tectonic movement, the dispersed organic matter inside will gradually be converted into oil and gas. During the continuous settlement of hydrocarbon source rocks, the generation and accumulation of oil and gas inside, the increase of paleogeothermal temperature, and the increase of overlying static rock pressure result in the accumulation of high-potential fluids inside the hydrocarbon source rocks.

[0003] According to the episodic hydrocarbon expulsion theory, when the internal pressure reaches the upper limit of the hydrocarbon source rock sealing pressure, fractures can be generated to form channels for the release of overpressure fluids. The relatively closed system inside the hydrocarbon source rock is broken, and the process of hydrocarbon fluid expulsion begins. When the fluid is released and the pressure decreases to a certain limit, the microfractures close and the first-stage hydrocarbon expulsion ends.

[0004] The hydrocarbon generation process of hydrocarbon source rocks does not stop. With the passage of time, the amount of hydrocarbon generation gradually increases, and the fluid pressure inside the hydrocarbon source rocks begins to gradually increase again. When the fracture pressure is accumulated again, secondary hydrocarbon expulsion occurs, and then a new cycle begins until the hydrocarbon generation capacity of the hydrocarbon source rock is exhausted or the physical and chemical conditions for hydrocarbon generation are changed and the hydrocarbon expulsion stops.

[0005] At the present stage, there are various experimental methods and mature evaluation systems for the study of the hydrocarbon generation capacity of hydrocarbon source rocks, but there is less research on hydrocarbon expulsion. The formation of oil and gas reservoirs is not completely controlled by the oil generation window of hydrocarbon source rocks. It is also necessary to consider the hydrocarbon expulsion events of hydrocarbon source rocks and comprehensively analyze the hydrocarbon contribution ratio. Studying the hydrocarbon expulsion efficiency and hydrocarbon expulsion events of hydrocarbon source rocks is also of great significance for the definition of shale reservoir rock properties or oil-generating rock properties and unconventional exploration. All of the above require simulation experiments for support.

[0006] The process of hydrocarbon generation and expulsion of hydrocarbon source rocks is very complex. The mineral composition, organic matter abundance, and source type, burial conditions, etc. of hydrocarbon source rocks will directly or indirectly affect the expulsion of hydrocarbons. At present, there are few experimental methods for studying the hydrocarbon expulsion process of hydrocarbon source rocks. The formation and expulsion simulation experiment of formation pore thermal pressure developed by the Exploration and Development Research Institute of Sinopec can set temperature, pressure, and hydrocarbon expulsion conditions according to the burial depth of the research target and keep them constant for more than 48 hours to analyze the production rates of expelled oil and residual oil to study the oil expulsion efficiency. Its experimental device has made great breakthroughs in simulating the hydrocarbon expulsion of hydrocarbon source rocks. It reproduces the intermittent hydrocarbon expulsion phenomenon of source rocks through a hydrocarbon expulsion valve with controllable pressure difference, and distinguishes the retained hydrocarbons inside the source rock and the expelled hydrocarbons that have left the hydrocarbon generation system.

[0007] However, the above method has the following problems in simulating hydrocarbon expulsion:

[0008] First, the method sets fixed temperature, pressure and hydrocarbon expulsion conditions based on the simulated target burial depth, which cannot reflect the continuously changing temperature and pressure environment of the source rock during the basin evolution history.

[0009] Second, the long-term constant temperature after rapid temperature rise cannot reflect the thermal evolution process under tectonic events such as subsidence and uplift in the burial history of the source rock.

[0010] Third, the fixed hydrocarbon expulsion conditions make it difficult for rapid source rock to expel hydrocarbons in the early stage, and temperature becomes the main factor promoting hydrocarbon expulsion. On the contrary, during the constant temperature period, which accounts for the longest proportion of the simulation time, the number of hydrocarbon expulsions is significantly lower due to the lack of the influence of other pressurization factors.

[0011] Therefore, at present, there is a lack of an experimental device and experimental method for simulating the continuous sedimentation and hydrocarbon expulsion of source rocks to solve the above problems. Summary of the Invention

[0012] The problem to be solved by the present invention is to provide an experimental device and an experimental method for simulating the continuous sedimentation and hydrocarbon expulsion of source rocks; this method can dynamically simulate the hydrocarbon expulsion process based on the tectonic background as much as possible, and the experimental process can reproduce the continuous sedimentation of source rocks, mature hydrocarbon generation, and intermittent hydrocarbon expulsion associated with oil and gas generation and source rock sedimentation.

[0013] In order to solve the above technical problems, the technical solution adopted by the present invention is: an experimental device for simulating the continuous sedimentation and hydrocarbon discharge of hydrocarbon source rocks, comprising a reactor, the reactor being placed in a box-type heating furnace, the top of the box-type heating furnace being provided with a hydraulic station top cylinder for upward pressurization, the bottom of the box-type heating furnace being provided with a hydraulic station bottom cylinder for downward pressurization, the top of the reactor being provided with an upper hydrocarbon discharge pipeline, the bottom of the reactor being provided with a lower hydrocarbon discharge pipeline, the upper hydrocarbon discharge pipeline being provided with an upper hydrocarbon discharge pneumatic valve, the lower hydrocarbon discharge pipeline being provided with a lower hydrocarbon discharge pneumatic valve, the upper hydrocarbon discharge pipeline and the lower hydrocarbon discharge pipeline being connected in parallel and then connected to a gas-liquid separation tank, the upper hydrocarbon discharge pipeline and the lower hydrocarbon discharge pipeline being connected in parallel and then connected to a gas-liquid separation tank The valve assembly is connected to the gas-liquid separation tank, and the valve assembly includes a first hydrocarbon exhaust pipeline control valve and a second hydrocarbon exhaust pipeline control valve. The first hydrocarbon exhaust pipeline control valve and the second hydrocarbon exhaust pipeline control valve are connected in series. A tee is provided between the first hydrocarbon exhaust pipeline control valve and the second hydrocarbon exhaust pipeline control valve. The third end of the tee is connected to the constant pressure container of the hydrocarbon exhaust system through the first control valve. The other end of the constant pressure container of the hydrocarbon exhaust system is connected to the hydrocarbon exhaust constant pressure pump through the second control valve. The top cylinder of the hydraulic station is used to apply vertical pressure to the source rock sample in the reactor to simulate the static rock pressure of the formation. The top cylinder oil pressure tracking pump is used to accurately regulate the oil pressure in the top cylinder of the hydraulic station.

[0014] Furthermore, the reactor comprises a reactor cylinder, a sample cavity is provided in the reactor cylinder, the sample cavity is coaxial with the reactor cylinder, and a source rock sample is placed in the sample cavity.

[0015] Further, a reactor upper plug is provided at the top of the sample chamber. The reactor upper plug is inserted into the sample chamber. An upper pressure cap is provided at the part where the reactor upper plug protrudes from the reactor cylinder body. An upper sealing assembly is provided at the part where the reactor upper plug is placed inside the reactor cylinder body. An upper hydrocarbon discharge port is provided on the reactor upper plug.

[0016] Further, the bottom of the reactor cylinder body is in a three-step shape, which successively includes a first step, a second step, and a third step from top to bottom. A reactor lower plug is provided on the second step. The reactor lower plug contacts the bottom end of the sample chamber. A lower sealing assembly is provided at the part where the reactor lower plug is placed inside the reactor cylinder body. A lower pressure cap is provided at the lower end of the lower sealing assembly. A lower hydrocarbon discharge port is provided on the reactor lower plug. The lower hydrocarbon discharge port communicates with the lower hydrocarbon discharge pipeline. A side through hole is formed in the lower pressure cap. The lower hydrocarbon discharge pipeline passes through the side through hole. A lock sleeve is provided in the third step. The lock sleeve locks the lower pressure cap.

[0017] Further, the present invention also provides an experimental method for simulating the continuous settlement and hydrocarbon discharge of source rocks, using the above experimental device for simulating the continuous settlement and hydrocarbon discharge of source rocks, including the following steps.

[0018] S1: Divide the burial stage.

[0019] S2: Design the simulated heating stage and corresponding experimental conditions.

[0020] S3: Conduct a pilot experiment to eliminate the temperature difference of the device.

[0021] S4: Convert the simulated pressure conditions into the working parameters of the simulated experimental equipment.

[0022] S5: Input the heating instruction and pressure control instruction.

[0023] S6: Simulate the sample loading, kettle loading, and leak detection procedures of the experiment.

[0024] S7: Conduct the heating operation.

[0025] S8: Collect the thermal simulation products and calculate the oil discharge rate.

[0026] Further, the S1 includes the following steps.

[0027] S11: Analyze the thermal history-burial history data of the target source rock, and divide multiple burial stages in combination with the key points of the thermal evolution of the source rock, the key points of tectonic changes, and the burial depth changes.

[0028] S12: Design the thermal simulation experiment stage according to the burial stage.

[0029] S13: Organize the burial depth changes, burial time, and maturity changes under the geological conditions of the source rocks corresponding to each of the simulation experiment stages.

[0030] Further, the S2 includes the following steps.

[0031] S21: Convert the burial stage into the simulated heating stage, and the experimental conditions for each of the simulated heating stages include temperature conditions and pressure conditions.

[0032] S22: Conduct key temperature design for the temperature conditions, and the key temperatures include the starting temperature, the ending temperature, the heating rate, and the stage duration.

[0033] S23: Conduct key pressure design for the pressure conditions, and the key pressures include the simulated lithostatic pressure, the upper limit pressure for hydrocarbon expulsion, and the lower limit pressure for hydrocarbon expulsion.

[0034] Further, the S3 includes the following steps.

[0035] S31: Detect the actual temperature of the reaction kettle and the heating temperature of the furnace chamber.

[0036] S32: When there is a deviation between the actual temperature of the reaction kettle and the heating temperature of the furnace chamber, conduct a differential temperature pilot experiment using the thermal pressure simulation experiment instrument for hydrocarbon generation and expulsion.

[0037] S33: Establish a temperature correction plan by comparing the real-time temperature difference between the real-time temperature feedback by the temperature sensor mounted on the sample-loading reaction kettle and the real-time heating temperature of the heating furnace chamber.

[0038] S34: Ensure that after the heating furnace chamber correction plan is heated up, the reaction kettle is actually heated according to the designed heating conditions.

[0039] Further, the S4 includes the following steps.

[0040] S41: Obtain the designed simulated lithostatic pressure, the maximum hydrocarbon expulsion pressure, and the minimum hydrocarbon expulsion pressure conditions.

[0041] S42: Convert the obtained target pressure into the working pressures of the corresponding cylinder block, tracking pump, pneumatic valve, and hydrocarbon expulsion container.

[0042] S43: Obtain the equipment working states of the simulated lithostatic pressure, the maximum hydrocarbon expulsion pressure, and the minimum hydrocarbon expulsion pressure.

[0043] The advantages and positive effects of the present invention are:

[0044] 1. The present invention combines the burial conditions of hydrocarbon source rocks in different geological ages, realizes dynamic adjustment of temperature conditions, pressure conditions and hydrocarbon expulsion conditions in simulation experiments, and effectively matches the continuous subsidence and mature hydrocarbon generation of hydrocarbon source rocks and forwardsimulates the hydrocarbon expulsion phenomenon of source rocks under geological conditions. This method fully considers the complexity of tectonic actions in oil and gas bearing basins, the differences in hydrocarbon generation capacity and hydrocarbon expulsion difficulty at different burial stages of source rocks, and the mutual influence between different burial stages.

[0045] 2. The present invention provides staged simulated change conditions, which can effectively divide the burial stages, enable the hydrocarbon expulsion events occurring in the simulation experiments to correspond one by one with the simulated temperature and simulated time, and study the hydrocarbon generation and expulsion characteristics of source rocks at different stages. In fact, compared with the simulation method of rapid heating followed by constant temperature, this method observes a smoother hydrocarbon expulsion phenomenon, can observe that hydrocarbon expulsion is relatively frequent in the early diagenesis stage of hydrocarbon source rocks, and there is still intermittent hydrocarbon expulsion after the high maturity stage, which is more in line with the episodic hydrocarbon expulsion theory. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 is a schematic structural diagram of the experimental device in an embodiment of the present invention;

[0047] Figure 2 is an assembly schematic diagram of the reaction kettle in an embodiment of the present invention;

[0048] Figure 3 is a process flow chart of the experimental method in an embodiment of the present invention;

[0049] Figure 4 is a thermal history - burial history diagram of hydrocarbon source rocks in a certain sag of the Bohai Bay Basin in an embodiment of the present invention;

[0050] Figure 5 is the temperature - pressure condition and hydrocarbon expulsion phenomenon of the Dong 3 Member source rocks in the experiment recorded by applying the formation pore thermal pressure hydrocarbon generation and expulsion simulation experimental method in an embodiment of the present invention;

[0051] Figure 6 is the temperature - pressure condition and hydrocarbon expulsion phenomenon of the Dong 3 Member source rocks in the experiment recorded by applying the present invention in an embodiment of the present invention;

[0052] In the figure:

[0053] 1. High - pressure injection pump;

[0054] 2. Gas - liquid separation tank;

[0055] 3. Bottom cylinder of the hydraulic station;

[0056] 4. Top cylinder of the hydraulic station;

[0057] 5. Reaction kettle; 5 - 1 Upper plug of the reaction kettle; 5 - 2 Upper pressure cap;

[0058] 5-3 Upper sealing assembly; 5-4 Upper core filter assembly; 5-5 Temperature measurement point on the kettle body;

[0059] 5-6 Source rock sample; 5-7 Reaction kettle cylinder; 5-8 Lower plug of the reaction kettle;

[0060] 5-9 Lower sealing assembly; 5-10 Lower core filter assembly; 5-11 Sample cavity;

[0061] 5-12 Upper hydrocarbon discharge port; 5-13 Lower hydrocarbon discharge port; 5-14 Lower pressing cap;

[0062] 5-15 Locking sleeve;

[0063] 6. Box-type heating furnace; 6-1 Temperature measurement point on the box-type heating furnace;

[0064] 7. Upper hydrocarbon discharge pipeline; 7-1 Upper hydrocarbon discharge pneumatic valve; 7-2 Pressure measurement point on the upper hydrocarbon discharge pipeline;

[0065] 8. Lower hydrocarbon discharge pipeline; 8-1 Lower hydrocarbon discharge pneumatic valve; 8-2 Pressure measurement point on the lower hydrocarbon discharge pipeline;

[0066] 9. Constant pressure vessel for the hydrocarbon discharge system;

[0067] 10. Hydrocarbon discharge constant pressure pump;

[0068] 11. Top cylinder oil pressure tracking pump;

[0069] 12. Gas metering device;

[0070] 13. Valve assembly. Detailed implementation manners

[0071] Next, the technical solutions of the present invention will be clearly and completely described in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

[0072] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0073] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0074] The following further describes the embodiments of the present invention with reference to the accompanying drawings:

[0075] As Figure 1 , Figure 2 shown, an experimental device for simulating the continuous sedimentation and hydrocarbon expulsion of hydrocarbon source rocks includes a reaction kettle 5, the reaction kettle 5 is arranged in a box-type heating furnace 6, a hydraulic station top cylinder 4 for applying upward pressure is provided at the top of the box-type heating furnace 6, a hydraulic station bottom cylinder 3 for applying downward pressure is provided at the lower end of the box-type heating furnace 6, a box-type heating furnace temperature measuring point 2 for temperature detection is provided in the box-type heating furnace 6, and a high-pressure injection pump 1 for airtightness detection is provided outside the box-type heating furnace 6.

[0076] An upper hydrocarbon expulsion pipeline 7 is provided at the top of the reaction kettle 5, and a lower hydrocarbon expulsion pipeline 8 is provided at the bottom of the reaction kettle 5. An upper hydrocarbon expulsion pneumatic valve 7-1 is provided on the upper hydrocarbon expulsion pipeline 7, a lower hydrocarbon expulsion pneumatic valve 8-1 is provided on the lower hydrocarbon expulsion pipeline 8, an upper hydrocarbon expulsion pipeline pressure measuring point 7-2 is provided at the end of the upper hydrocarbon expulsion pneumatic valve 7-1 close to the box-type heating furnace 6, a lower hydrocarbon expulsion pipeline pressure measuring point 8-2 is provided at the end of the lower hydrocarbon expulsion pneumatic valve 8-1 close to the box-type heating furnace 6, the upper hydrocarbon expulsion pipeline 7 and the lower hydrocarbon expulsion pipeline 8 are connected in parallel and then communicated with a gas-liquid separation tank 2 through a valve assembly 13, and the gas-liquid separation tank 2 is connected to a gas metering device 15.

[0077] The valve assembly 13 includes two series-connected hydrocarbon expulsion pipeline p control valves, a tee is arranged between the two hydrocarbon expulsion pipeline control valves, the third end of the tee is communicated with a hydrocarbon expulsion system constant pressure container 9 through a control valve, and the other end of the hydrocarbon expulsion system constant pressure container 9 is communicated with a hydrocarbon expulsion constant pressure pump 10 through a control valve.

[0078] Specifically, as Figure 2 shown, the reaction kettle 5 includes a reaction kettle cylinder body 5-7, the reaction kettle cylinder body 5-7 can be filled with a sample cavity 5-11 of corresponding size, the sample cavity 5-11 is coaxial with the reaction kettle cylinder body 5-7, and a hydrocarbon source rock sample 5-6 is placed in the sample cavity 5-11.

[0079] At the top of the sample chamber 5-11, there is an upper plug 5-1 of the reactor. The upper plug 5-1 of the reactor is inserted into the sample chamber 5-11. At the part where the upper plug 5-1 of the reactor protrudes from the reactor cylinder 5-7, there is an upper compression cap 5-2. Inside the reactor cylinder 5-7 where the upper plug 5-1 of the reactor is placed, there is an upper sealing assembly 5-3. At the lower end of the upper plug 5-1 of the reactor, there is an upper core filter assembly 5-4. The upper core filter assembly 5-4 is inserted into the sample chamber 5-11 and is in contact with the source rock sample 5-6. On the upper plug 5-1 of the reactor, there is an upper hydrocarbon discharge port 5-12, and the upper hydrocarbon discharge port 5-12 is connected to the upper hydrocarbon discharge pipeline 7.

[0080] The bottom of the reactor cylinder 5-7 is in a three-step shape, which successively includes a first step, a second step, and a third step from top to bottom. On the second step, there is a lower plug 5-8 of the reactor. The lower plug 5-8 of the reactor is in contact with the bottom end of the sample chamber 5-11. At the upper end of the lower plug 5-8 of the reactor, there is a lower core filter assembly 5-10. Inside the reactor cylinder 5-7 where the lower plug 5-8 of the reactor is placed, there is a lower sealing assembly 5-9. At the lower end of the lower sealing assembly 5-9, there is a lower compression cap 5-14. On the lower plug 5-8 of the reactor, there is a lower hydrocarbon discharge port 5-13, and the lower hydrocarbon discharge port 5-13 is connected to the lower hydrocarbon discharge pipeline 8. A side through hole is formed in the lower compression cap 5-14, and the lower hydrocarbon discharge pipeline 8 passes through the side through hole. In the third step, there is a lock sleeve 5-15. The lock sleeve 5-15 can facilitate the passage of the lower compression cap 5-14 and prevent the lower sealing assembly 5-9 from slipping out. The lower core filter assembly 5-10 is placed inside the first step.

[0081] At the outer wall of the reactor cylinder 5-7, there is a temperature measurement point for the reactor cylinder to measure the temperature of the reactor cylinder 5-7.

[0082] The box-type heating furnace 6 is used to simulate temperature rise. The working temperature of the box-type heating furnace 6 is from room temperature to 700 °C. Inside the box-type heating furnace 6, there are temperature probes and heating resistance wires. The temperature rise, constant temperature, or programmed temperature drop can be controlled programmatically through the Yamatake instrument, and the temperature control accuracy is ±0.1 °C.

[0083] Preferably, this embodiment further includes a hydraulic station. The hydraulic station is used to provide simulated static rock pressure and sealing pressure. The hydraulic station supplies pressure to the bottom cylinder 3 of the hydraulic station and the top cylinder 4 of the hydraulic station. The bottom cylinder 3 of the hydraulic station is used for the sealing of the upper sealing assembly 5-3 and the lower sealing assembly 5-9 to realize the sealing of the reactor 5. Both the upper sealing assembly 5-3 and the lower sealing assembly 5-9 are composed of graphite sealing rings and copper sealing rings.

[0084] The top cylinder 4 of the hydraulic station is used to apply vertical pressure to the source rock sample inside the reactor 5 to simulate the formation static rock pressure. The top cylinder oil pressure tracking pump is used to precisely control the oil pressure inside the top cylinder 4 of the hydraulic station.

[0085] Specifically, the vertical pressure is provided by the top cylinder 4 of the hydraulic station and is vertically applied to the columnar filled source rock sample compacted inside the autoclave 5. The real-time overlying static rock pressure borne by the source rock sample is P 模拟静压 , and its calculation method is shown in the following formula. In the experiment, the overlying static rock pressure cannot be accurately controlled only by the hydraulic station. It is necessary to rely on the top cylinder oil pressure tracking pump 11 to maintain the oil pressure in the top cylinder 4 of the hydraulic station, so that the real-time overlying static rock pressure can be consistent with the designed experimental conditions.

[0086] P 模拟静压 = 15.4×P 副缸油压 ×1000 / (0.785×R 2 )

[0087] wherein, R is the diameter of the columnar filled sample, which is generally divided into two types: 25 mm and 38 mm according to the specifications of the autoclave 5;

[0088] P 副缸油压 is the oil pressure in the auxiliary cylinder of the hydraulic station, which is controlled by the top cylinder oil pressure tracking pump and measured by the pressure transmitter in the oil circuit of the top cylinder 4 of the hydraulic station.

[0089] Specifically, the material of the autoclave 5 can withstand a pressure of 200 MPa axially, that is, the pressure applied vertically to the core, and can withstand a fluid pressure of 150 MPa internally. The autoclave 5 is connected with a temperature sensor on the wall, which can feedback the real-time temperature to the system. After the autoclave 5 is loaded with samples, the upper hydrocarbon discharge port 5-12 is connected to the upper hydrocarbon discharge pipeline 7, and the lower hydrocarbon discharge port 5-13 is connected to the lower hydrocarbon discharge pipeline 8. After the main cylinder is pressurized, the sealing ring group of the autoclave 5 is extruded and deformed to form a seal, and the internal fluid can only be discharged through the hydrocarbon discharge pipeline.

[0090] The hydrocarbon discharge pipeline is equipped with an upper hydrocarbon discharge pneumatic valve 7-1, a lower hydrocarbon discharge pneumatic valve 8-1 and a constant pressure vessel. The hydrocarbon discharge pipeline can be used to simulate the "upper generation and lower discharge" or "lower generation and upper discharge" of the source rock; Pressure sensors are installed in front of the upper hydrocarbon discharge pneumatic valve 7-1 and the lower hydrocarbon discharge pneumatic valve 8-1, which can feedback the internal pressure of the autoclave 5 in real time, and the hydrocarbon discharge pipeline can control the working mode of the pneumatic valve. Specifically, in this embodiment, the pressures for the automatic opening and closing of the upper hydrocarbon discharge pneumatic valve 7-1 and the lower hydrocarbon discharge pneumatic valve 8-1 are set through the program. The conditions for the automatic opening and closing of the upper hydrocarbon discharge pneumatic valve 7-1 and the lower hydrocarbon discharge pneumatic valve 8-1 are that the valve body is in the "automatic" working mode and the pressure detected at the front-end pressure measurement point reaches the set opening and closing pressure values.

[0091] The high-pressure injection pump 1 is used to load high-pressure fluid before the experiment to verify the tightness of the system.

[0092] The hydrocarbon discharge constant pressure pump 10 is used to adjust the pressure of the constant pressure vessel 9 in the hydrocarbon discharge system during the experiment and control the fluid pressure in the hydrocarbon discharge pipeline.

[0093] Specifically, during the simulation experiment, the fluid pressure inside the hydrocarbon source rock sample continuously changes with temperature variation and hydrocarbon generation and expulsion processes. The formation water inside the source rock is vaporized by heat, and water-rock-hydrocarbon reactions generate carbon dioxide. The generated natural gas, kerogen, and cracking of crude oil to generate hydrocarbons all produce fluid pressure. Therefore, during the hydrocarbon generation and expulsion experiment, the fluid pressure continuously increases and is released through hydrocarbon expulsion. To a certain extent, the above process reproduces the hydrocarbon generation and expulsion process of the hydrocarbon source rock during the subsidence and thermal evolution process.

[0094] During the experiment, the upper hydrocarbon expulsion pneumatic valve 7-1 of the upper hydrocarbon expulsion pipeline 7 can be selected to simulate the lower generation and upper expulsion of the hydrocarbon source rock, or the hydrocarbon expulsion pneumatic valve of the lower hydrocarbon expulsion pipeline 8 can be selected to simulate the upper generation and lower expulsion. The real-time pressures of the upper hydrocarbon expulsion pipeline 7 and the lower hydrocarbon expulsion pipeline 8 can reflect the real-time fluid pressure inside the sample in the reaction kettle 5.

[0095] The upper limit pressure and lower limit pressure of hydrocarbon expulsion are constraints on the hydrocarbon expulsion conditions. These conditions need to refer to the formation pressure changes of the hydrocarbon source rock during the thermal evolution process. Based on the hydrostatic pressure, a pressure coefficient is set. For the simulation of the hydrocarbon generation and expulsion process of hydrocarbon source rocks with normal formation pressure, the upper limit pressure of hydrocarbon expulsion can be set to 1.2 times the hydrostatic pressure corresponding to the simulated burial depth, and the lower limit pressure of hydrocarbon expulsion can be set to 0.8 times the hydrostatic pressure corresponding to the simulated burial depth.

[0096] Specifically, in the upper and lower limit experimental control mode of hydrocarbon expulsion, the upper limit of hydrocarbon expulsion is the opening pressure of the corresponding hydrocarbon expulsion pipeline pneumatic valve, and the lower limit of hydrocarbon expulsion is the closing pressure of the corresponding pneumatic valve. That is, when the fluid pressure in the reaction kettle 5 reaches the upper limit of hydrocarbon expulsion, the pneumatic valve opens, and the high-pressure fluid in the reaction kettle 5 flows through the pneumatic valve to the low-pressure potential area of the external hydrocarbon expulsion container. As the hydrocarbon expulsion process proceeds, the pressure in the kettle drops to the lower limit of hydrocarbon expulsion, and the pneumatic valve closes. This is a single hydrocarbon expulsion phenomenon. When the fluid pressure in the reaction kettle 5 accumulates again to reach the upper limit of hydrocarbon expulsion, the pneumatic valve opens again to form a new single hydrocarbon expulsion. During the above process, to prevent the fluid pressure in the kettle from dropping too rapidly during the hydrocarbon expulsion process, a constant pressure pump is required to keep the pressure of the external hydrocarbon expulsion container at a constant pressure slightly lower than the lower limit of hydrocarbon expulsion.

[0097] As Figure 3 shown, the present invention also provides an experimental method for simulating the continuous subsidence and hydrocarbon expulsion of hydrocarbon source rocks. Using the above experimental device for simulating the continuous subsidence and hydrocarbon expulsion of hydrocarbon source rocks, it includes the following steps.

[0098] S1: Divide the burial stage. Specifically, it includes the following steps.

[0099] S11: Analyze the thermal history-burial history data of the target source rock, and combine the key points of hydrocarbon source rock thermal evolution, key points of tectonic changes, and burial depth changes to divide multiple burial stages.

[0100] S12: Design the thermal simulation experiment stage according to the burial stage.

[0101] S13: Arrange the burial depth changes, burial time, and maturity changes under the geological conditions of the source rocks corresponding to each burial stage. Specifically, as shown in the following table,

[0102] Schematic diagram of the division of burial stages

[0103]

[0104] S2: Design the simulated heating stage and corresponding experimental conditions. Specifically, it includes the following steps.

[0105] S21: Convert the burial stage into a simulated heating stage. The experimental conditions for each simulated heating stage include temperature conditions and pressure conditions.

[0106] S22: Conduct key temperature design for the temperature conditions. The key temperatures include the starting temperature, ending temperature, heating rate, and stage duration.

[0107] S23: Conduct key pressure design for the pressure conditions. The key pressures include the simulated lithostatic pressure, upper limit pressure for hydrocarbon expulsion, and lower limit pressure for hydrocarbon expulsion.

[0108] In the simulated temperature conditions, the starting temperature of each simulated stage is the ending temperature of the previous stage. Based on the duration of the simulated experiment, referring to the EasyRo calculation method proposed by Burnham and Sweeney in 1989, design the stage experimental temperature so that the change in the EasyRo value of the sample after simulation under the corresponding temperature conditions is as consistent as possible with the change in maturity during the subsidence stage, that is, the Ro value.

[0109] Among them, the temperature condition for the "uplift" stage of tectonic evolution is to keep the current temperature constant for 6 minutes.

[0110] Specifically, the overall temperature design should flexibly balance the relationship between the stage heating rate and the experimental duration under the constraint of the EasyRo change in each stage. The duration of the simulated experiment stage representing the "subsidence" stage type is positively correlated with the stage duration T, and the cumulative duration of the simulated experiment should not exceed 100 hours.

[0111] Schematic diagram of the heating stage and simulated temperature design

[0112]

[0113] Specifically, in the simulated pressure conditions, the simulated lithostatic pressure P 静岩 , where the lithostatic pressure is the overlying lithostatic pressure borne by the rock skeleton of the source rock at the pressure design reference depth H, and the calculation formula is:

[0114] P 静岩 =ρ 岩石 ×g×H;

[0115] Among them, the density ρ of the overlying rock 岩石 is usually set to 2.35 g / cm 3 ;

[0116] For the stage pressure design reference depth H of the "subsidence" type, it is the average value of the stage burial depth, H = (D + D') / 2;

[0117] For the "uplift" type stage, it is the burial depth at the end of the formation uplift, H = D'.

[0118] The hydrostatic pressure P 静水 is the pressure borne by the fluid in the pores of the source rock at the reference depth H, and the calculation formula is:

[0119] P 静水 = ρ 水 × g × H

[0120] Among them, the density ρ of the formation water 水 is usually set to 1 g / cm 3 ;

[0121] The pressure coefficient is the ratio of the measured formation pressure to the hydrostatic pressure at the same depth. Usually, the pressure coefficient is regarded as 0.8 - 1.2 for the normal pressure range. The maximum and minimum values of the pressure coefficient can also be assigned by referring to the relevant while-drilling data in the study area.

[0122] The maximum hydrocarbon expulsion pressure at each stage is the product of the hydrostatic pressure P 静水 at this stage and the maximum value of the formation pressure coefficient, and the minimum hydrocarbon expulsion pressure is the product of the hydrostatic pressure P 静水 at this stage and the minimum value of the formation pressure coefficient.

[0123] Schematic diagram of the heating stage and the simulated pressure design

[0124]

[0125] S3: Conduct a pilot experiment to eliminate the temperature difference of the device. Specifically, it includes the following steps.

[0126] S31: Detect the measured temperature of the reactor 5 and the furnace heating temperature.

[0127] S32: When there is a deviation between the measured temperature of the reactor 5 and the furnace heating temperature, use the thermal pressure simulation experiment instrument for hydrocarbon generation to conduct a temperature difference pilot experiment.

[0128] S33: Establish a temperature correction scheme by comparing the real-time temperature feedback by the temperature sensor mounted on the sample-loading reactor 5 and the real-time heating temperature of the heating furnace.

[0129] S34: Ensure that after the heating furnace correction scheme is heated up, the reactor 5 is actually heated according to the designed heating conditions.

[0130] S4: Convert the simulated pressure conditions into the working parameters of the simulation experimental equipment. Specifically, it includes the following steps.

[0131] S41: Obtain the designed simulated static rock pressure, maximum hydrocarbon expulsion pressure, and minimum hydrocarbon expulsion pressure conditions.

[0132] S42: Convert the obtained target pressure into the corresponding working pressures of the cylinder block, tracking pump, pneumatic valve, and hydrocarbon expulsion container.

[0133] S43: Obtain the equipment working states of the simulated static rock pressure, maximum hydrocarbon expulsion pressure, and minimum hydrocarbon expulsion pressure. The calculation method of the real-time overlying static rock pressure P simulated static pressure borne by the sample is shown in the following formula:

[0134] P 模拟静压 = 15.4 × P 副缸油压 × 1000 / (0.785 × R 2 )

[0135] Where, R is the diameter of the columnar packed sample, in mm;

[0136] Where, P 副缸油压 is the oil pressure in the secondary cylinder of the hydraulic station, controlled by the secondary cylinder tracking pump, and measured in real time by the pressure transmitter.

[0137] The calculation formula for the hydraulic tonnage T of the top cylinder:

[0138] T = 0.785 × 140 2 × P 副缸油压 / 1000 = 15.4P (KN) = 1.54P 副缸油压 . Where, by default, g = 10,

[0139] The inner diameter of the top cylinder is 140 mm, and P 副缸油压 : MPa.

[0140] The calculation process of the overlying pressure of the rock sample is as follows:

[0141] The overlying pressure P1 of the 25-mm core sample loading = T × 1000 / (0.785 × 25 2 ) = 31.4P 副缸油压

[0142] The overlying pressure P2 of the 38-mm core sample loading = T × 1000 / (0.785 × 38 2 ) = 13.6P 副缸油压

[0143] Therefore, the working pressure of the secondary cylinder tracking pump = simulated static rock pressure / 31.4, for the loading condition of a 25-mm diameter rock sample; the working pressure of the secondary cylinder tracking pump = simulated static rock pressure / 13.6, for the loading condition of a 38-mm diameter rock sample.

[0144] The maximum hydrocarbon expulsion pressure corresponds to the opening pressure of the pneumatic valve in the hydrocarbon expulsion pipeline, and the minimum hydrocarbon expulsion pressure is the closing pressure of the pneumatic valve corresponding to the upper limit of hydrocarbon expulsion. That is, when the fluid pressure in the reactor 5 reaches the upper limit of hydrocarbon expulsion, the pneumatic valve opens, and the high-pressure fluid in the reactor 5 flows through the pneumatic valve to the low-pressure area of the external hydrocarbon expulsion container. As the pressure in the kettle drops to the lower limit of hydrocarbon expulsion during the hydrocarbon expulsion process, the pneumatic valve closes. The hydrocarbon expulsion constant pressure pump 10 tracks the hydrocarbon expulsion container to keep its pressure at a constant pressure slightly lower than the minimum hydrocarbon expulsion pressure by 0.5 Mpa.

[0145] Schematic diagram of the heating stage and dynamic adjustment of system pressure

[0146]

[0147] S5: Enter the heating instruction and pressure control instruction. Specifically, it includes the following steps.

[0148] Enter the designed simulation stage, the corrected heating instruction and pressure control instruction. Among them, the dynamic adjustment condition of the system pressure parameter for the simulation experiment stage representing the "settlement" stage type is that the real-time temperature monitored by the temperature measurement point on the kettle body reaches the starting temperature of this stage; the dynamic adjustment condition of the system pressure parameter for the simulation experiment stage representing the "lifting" stage type is to reach the starting temperature of this stage and automatically change to the pressure parameter of the next stage after 6 minutes of continuous operation; the pressure parameter adjustment instruction corresponding to each stage can only be executed once.

[0149] S6: Simulation experiment sample loading, kettle loading, and leak detection procedures. Specifically, it includes the following steps.

[0150] S61: The source rock is crushed and fully mixed, weighed and then loaded into the sample cavity 5-11 of the reactor 5. Before and after loading, the lower core filter assembly 5-10 and the upper core filter assembly 5-4 are placed in sequence. After loading, pre-compaction is carried out to compress the pores between the particles.

[0151] S62: Move the sample cavity 5-11 into the corresponding specification reactor 5. After assembling the upper seal assembly 5-3 at the top of the reactor 5 and the lower seal assembly 5-9 at the bottom of the reactor 5, place it upright on the bottom cylinder 3 of the hydraulic station in the furnace chamber of the heating box-type heating furnace 6. Connect the upper plug 5-1 and the lower plug 5-8 of the reactor to the upper hydrocarbon expulsion pipeline 7 and the lower hydrocarbon expulsion pipeline 8 respectively, and connect the temperature probe to the temperature measurement point on the kettle wall of the reactor 5.

[0152] S63: Control the bottom cylinder 3 of the hydraulic station to pressurize the bottom of the reactor 5 with 150 KN to squeeze the graphite sealing ring in the reactor 5 to form a seal.

[0153] S64: Evacuate the reactor 5 system and the hydrocarbon expulsion pipeline for 30 minutes, then start the high-pressure injection pump 1 and inject deionized water for leak detection at 1.2 times the maximum value of the maximum hydrocarbon expulsion pressure in the design scheme. After passing the leak detection, retreat the pump to release the water pressure and close the liquid outlet valve of the pump.

[0154] S7: Perform the heating operation, specifically, including the following steps.

[0155] S71: Establish a simulation experiment task, set the working pressure of the slave cylinder tracking pump, the opening pressure of the hydrocarbon discharge pneumatic valve, the closing pressure of the hydrocarbon discharge pneumatic valve, and the working pressure of the hydrocarbon discharge constant pressure pump 10 at the starting stage. Close the upper hydrocarbon discharge pneumatic valve 7-1 and the lower hydrocarbon discharge pneumatic valve 8-1 in the "manual" mode.

[0156] S72: If it is designed to discharge hydrocarbons from the top of the source rock, set the lower hydrocarbon discharge pneumatic valve 8-1 to the "manual" mode and the upper hydrocarbon discharge pneumatic valve 7-1 to the "automatic" mode; if it is designed to discharge hydrocarbons from the bottom of the source rock, set the upper hydrocarbon discharge pneumatic valve 7-1 to the "manual" mode and the lower hydrocarbon discharge pneumatic valve 8-1 to the "automatic" mode. Start recording working data and start the heating operation.

[0157] S8: Collect the thermal simulation products and calculate the oil discharge rate, specifically, including the following steps.

[0158] S81: After the simulation experiment is completed, cool the gas-liquid separation tank 2 to -10°C in advance with a cold trap. Open the control valve at the front end of the gas-liquid separation tank 2 to release the fluid in the hydrocarbon discharge pipeline. The discharged liquid enters the gas-liquid separation tank 2, and the gas part enters the gas metering device to complete collection and quantification.

[0159] S82: After the box-type heating furnace 6 cools down, remove the reaction kettle 5, take out the post-experiment source rock sample, and use dichloromethane to re-seal the upper plug 5-1, the lower plug 5-8, the sample chamber 5-11, the microporous filter pad, and the hydrocarbon discharge system pipeline and container of the reaction kettle. Collect the oil in the gas-liquid separation tank 2, filter the above oil-containing solvent, and obtain the discharged oil weight M after drying the solvent to constant weight. 排出 。

[0160] Extract the post-experiment source rock sample with a Soxhlet extractor for 48 hours, weigh it after drying the solvent to obtain the retained oil weight M 滞留 。

[0161] Calculate the oil discharge rate, i.e., V 排油 =M 排出 / (M 排出 +M 滞留 )。

[0162] The technical solution of the present invention will be further described below in conjunction with specific embodiments.

[0163] Example 1:

[0164] Dynamic hydrocarbon discharge simulation of the source rock of the third member of the Dongying Formation in a sag in the Bohai Bay Basin

[0165] S1: Divide the burial stage.

[0166] The maximum burial depth of the source rocks in the third member of the Dongying Formation in the study area is about 6500 m. Combining the thermal history - burial history data of the study area, it is analyzed that the source rocks in the third member of the Dongying Formation have continuous subsidence. The Ro value within 2000 m is not greater than 0.4%. As the starting stage, each evolution stage is set every 500 meters. As Figure 4 shown, the following table is obtained after division.

[0167] Staged Division of Hydrocarbon Source Rock Burial in the Third Member of the Dongying Formation in a Sag of the Bohai Bay Basin

[0168]

[0169] S2: Design the simulated heating stage and corresponding experimental conditions.

[0170] Set the temperature conditions and pressure conditions for the simulated experiment for the burial stages divided in S1. In terms of temperature, since the subsidence rate of the target source rock is stable below the oil generation threshold, a constant - rate heating simulated experiment method is adopted here. After balancing the simulated experiment duration and the change of EasyRo, a constant - rate heating method of 5℃ / h is selected as the experimental condition, with the highest simulated temperature of 480℃ and the cumulative simulated duration of 58 h. In terms of pressure conditions, there is a widespread phenomenon of abnormal high pressure in the hydrocarbon source rocks in the target area. According to the logging - while - drilling data, the minimum formation pressure coefficient is set to 1.2 and the maximum formation pressure coefficient is set to 1.6. On this basis, the upper and lower limits of the hydrocarbon expulsion pressure for each stage are designed, as shown in the following table.

[0171] Design Scheme of Heating Stage and Simulated Temperature

[0172]

[0173] Design Scheme of Heating Stage and Simulated Pressure

[0174]

[0175]

[0176] S3: Modify the heating scheme.

[0177] Perform a temperature - measuring pilot experiment using a thermal - pressure simulation experiment instrument for hydrocarbon generation and expulsion. Rapidly heat the box - type heating furnace 6 to 200℃, and then heat it at a rate of 5℃ / h. Observe the real - time data recorded by the equipment. When the temperature of the wall of the reaction kettle 5 reaches 480℃, the real - time temperature of the box - type heating furnace 6 is 489.7℃.

[0178] S4: Convert the simulated pressure conditions into the working parameters of the simulated experiment equipment.

[0179] The inner diameter of the sample cavity 5 - 11 selected for the current experiment is 25 mm. It is planned to adopt a "hydrocarbon generation from the bottom and expulsion from the top" hydrocarbon generation and expulsion simulation method, and use the upper - hydrocarbon - expulsion pneumatic valve 7 - 1 to control the hydrocarbon expulsion method.

[0180] Corresponding to the working parameters of the tracking pump, pneumatic valve and hydrocarbon-discharging constant-pressure pump in the simulation stage

[0181]

[0182] S5: Create a new experimental work task and input the heating instruction and pressure control change instruction.

[0183] Input the heating scheme: The initial room temperature is 24.1°C, rapidly heat up to 200°C at a rate of 100°C / h, then heat up at a rate of 5°C / h for 58 hours to 490°C, and then cool down to 200°C within 4 hours and maintain this temperature.

[0184] Input the pressure control change scheme: Set ten pressure change instructions based on the real-time temperature of the reactor 5 reaching 200°C, 270°C, 295°C, 315°C, 335°C, 350°C, 400°C, 415°C, 440°C, 455°C.

[0185] S6: Simulate the sample loading, reactor loading and leak detection processes of the experiment.

[0186] Take the low-maturity mudstone sample LDA from the third member of the Dongying Formation in the marginal depression. The basic geochemical characteristics are shown in the following table. Crush and fully mix it, load it into the sample chamber 5-11 of the reactor 5 with an inner diameter of 25 mm, pre-compact the pores between the particles, and weigh it after sample loading to obtain the actual sample loading amount of 101.82 g.

[0187] Pyrolysis and organic carbon analysis data of the simulated experiment sample LDA from the third member of the Dongying Formation

[0188]

[0189] After normal reactor loading, control the bottom cylinder 3 of the hydraulic station to apply a pressure of 150 KN, open the upper hydrocarbon-discharging pneumatic valve 7-1 and the lower hydrocarbon-discharging pneumatic valve 8-1, use the vacuum system to evacuate the reactor 5 system and the hydrocarbon-discharging pipeline for 30 minutes, then start the high-pressure injection pump 1 to test for leaks with a water pressure of 120 Mpa. After confirming that the reactor 5 and the hydrocarbon-discharging pipeline are properly sealed, close the pneumatic valve.

[0190] S7: Start the heating program.

[0191] Set the working pressure of the secondary cylinder tracking pump at the initial stage to 0.73 Mpa, the opening pressure of the hydrocarbon-discharging pneumatic valve to 11.8 Mpa, the closing pressure of the hydrocarbon-discharging pneumatic valve to 7.8 Mpa, and the working pressure of the hydrocarbon-discharging constant-pressure pump 10 to 7.3 Mpa. Close the upper hydrocarbon-discharging pneumatic valve 7-1 and the lower hydrocarbon-discharging pneumatic valve 8-1. If designing hydrocarbon expulsion from the top of the source rock, set the lower hydrocarbon-discharging pneumatic valve 8-1 to manual mode and the upper hydrocarbon-discharging pneumatic valve 7-1 to automatic mode; start recording the working data of the equipment and start heating.

[0192] S8: Collect the products of the thermal simulation and calculate the oil expulsion rate.

[0193] After the simulation experiment was completed and the box-type heating furnace 6 cooled, the reactor 5 was removed and the source rock sample was taken out. Using dichloromethane, the reactor's upper plug 5-1, lower plug 5-8, sample chamber 5-11, microporous filter pad, and hydrocarbon drainage system piping and container were reassembled. The oil in the gas-liquid separator 2 was collected and the oil-containing solvent was filtered. After evaporation of the solvent, the discharged oil mass was constant, yielding 369.5 mg. The source rock sample was extracted using a Soxhlet extractor for 48 hours. After evaporation of the solvent, the sample was weighed, yielding 33.6 mg of retained oil, and a calculated oil drainage rate of 91.7%.

[0194] Comparison of simulation experiment results:

[0195] Statistics of hydrocarbon expulsion times in the simulation experiment of continuous sedimentation and hydrocarbon expulsion of source rocks in the third section of the East China Sea using the method of the present invention

[0196]

[0197] During the hydrocarbon generation and expulsion simulation experiment, information feedback from equipment temperature, pressure sensors, and the opening and closing actions of pneumatic valves was used to calculate the changes in static rock pressure and internal fluid pressure that the source rock samples were subjected to during the experiment at each stage, as well as the number of hydrocarbon expulsions at each stage.

[0198] like Figure 5 As shown, a comparison was made using a formation pore thermal pressure simulation method for hydrocarbon generation and expulsion. This method uses fixed pressure conditions and rapid temperature increase followed by a long period of constant temperature. This resulted in hydrocarbon expulsion occurring primarily during the 7-hour rapid temperature increase period. Specifically, hydrocarbon expulsion occurred 33 times, while during the 70-hour constant temperature period, only once. Analysis indicates that the direct application of deep burial pressure conditions makes hydrocarbon expulsion during the early rapid temperature increase phase of the source rock more difficult, making temperature the dominant factor influencing hydrocarbon expulsion. During the constant temperature period, which accounts for the largest portion of the simulation time, hydrocarbon expulsion is significantly less frequent due to the lack of external pressure increases caused by changes in burial depth.

[0199] The simulation experiment method of the present invention shows that the source rock of the East Section 3 has expelled hydrocarbons 102 times in total, 7 times of hydrocarbon expulsion occurred during the continuous sedimentation process of 3000-4500m as the source rock generated oil, and 3 times of hydrocarbon expulsion occurred during the large-scale gas generation stage of 5000-5500m. Figure 6 As shown, the hydrocarbon expulsion process of the present invention under dynamic conditions closely matches the continuous sedimentation and mature hydrocarbon generation process of the source rock. Frequent hydrocarbon expulsion can be observed during the early diagenetic stage of the source rock. This intermittent hydrocarbon generation phenomenon accompanying oil and gas generation and sedimentation is more consistent with geological knowledge.

[0200] The above has described the embodiments of the present invention in detail, but the above content is only the preferred embodiments of the present invention and cannot be considered as limiting the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the application of the present invention should still fall within the scope covered by the patent of the present invention.

Claims

1. An experimental device for simulating continuous hydrocarbon expulsion during the subsidence of hydrocarbon source rocks, characterized in that: It includes a reactor, which is placed in a box-type heating furnace. There is a hydraulic station top cylinder for upper pressurization at the top of the box-type heating furnace, and a hydraulic station bottom cylinder for lower pressurization at the bottom of the box-type heating furnace. There is an upper hydrocarbon discharge pipeline at the top of the reactor, and a lower hydrocarbon discharge pipeline at the bottom of the reactor. There is an upper hydrocarbon discharge pneumatic valve on the upper hydrocarbon discharge pipeline, and a lower hydrocarbon discharge pneumatic valve on the lower hydrocarbon discharge pipeline. The upper hydrocarbon discharge pipeline and the lower hydrocarbon discharge pipeline are connected in parallel and then communicated with a gas-liquid separation tank. The upper hydrocarbon discharge pipeline and the lower hydrocarbon discharge pipeline are connected in parallel and then communicated with the gas-liquid separation tank through a valve assembly. The valve assembly includes a first hydrocarbon discharge pipeline control valve and a second hydrocarbon discharge pipeline control valve. The first hydrocarbon discharge pipeline control valve and the second hydrocarbon discharge pipeline control valve are connected in series. There is a three-way pipe between the first hydrocarbon discharge pipeline control valve and the second hydrocarbon discharge pipeline control valve. The third end of the three-way pipe is communicated with a constant-pressure container of the hydrocarbon discharge system through a first control valve. The other end of the constant-pressure container of the hydrocarbon discharge system is communicated with a hydrocarbon discharge constant-pressure pump through a second control valve. The hydraulic station top cylinder is used to apply a vertical pressure to the hydrocarbon source rock sample in the reactor to simulate the formation static rock pressure, and the top cylinder oil pressure tracking pump is used to accurately control the oil pressure in the hydraulic station top cylinder.

2. The experimental device for simulating continuous settlement and hydrocarbon expulsion of source rocks according to claim 1, wherein: The reactor includes a reactor cylinder body. There is a sample cavity in the reactor cylinder body. The sample cavity is coaxial with the reactor cylinder body, and a hydrocarbon source rock sample is placed in the sample cavity.

3. An experimental device for simulating continuous settlement and hydrocarbon expulsion of hydrocarbon source rocks according to claim 2, characterized in that: There is a reactor upper plug at the top of the sample cavity. The reactor upper plug is inserted into the sample cavity. There is an upper pressure cap at the part where the reactor upper plug protrudes from the reactor cylinder body. There is an upper sealing assembly at the part where the reactor upper plug is placed inside the reactor cylinder body. There is an upper hydrocarbon discharge port on the reactor upper plug.

4. An experimental device for simulating continuous settlement and hydrocarbon expulsion of hydrocarbon source rocks according to claim 3, characterized in that: The bottom of the reactor cylinder body is in a three-step shape, including a first step, a second step and a third step from top to bottom in sequence. There is a reactor lower plug on the second step. The reactor lower plug contacts the bottom end of the sample cavity. There is a lower sealing assembly at the part where the reactor lower plug is placed inside the reactor cylinder body. There is a lower pressure cap at the lower end of the lower sealing assembly. There is a lower hydrocarbon discharge port on the reactor lower plug. The lower hydrocarbon discharge port is communicated with the lower hydrocarbon discharge pipeline. A side through hole is formed in the lower pressure cap. The lower hydrocarbon discharge pipeline passes through the side through hole. There is a lock sleeve in the third step. The lock sleeve locks the lower pressure cap.

5. An experimental method for simulating the continuous subsidence and hydrocarbon expulsion of source rocks, characterized in that: Using the experimental device for simulating continuous sedimentation and hydrocarbon discharge of hydrocarbon source rocks according to any one of claims 1 to 4 above, it includes the following steps S1: Divide the burial stage. S2: Design the simulated heating stage and corresponding experimental conditions. S3: Conduct a pilot experiment to eliminate the temperature difference of the device. S4: Convert the simulated pressure conditions into the working parameters of the simulation experimental equipment. S5: Input the heating instruction and pressure control instruction. S6: Simulate the experimental sample loading, reactor loading and leak detection procedures. S7: Conduct the heating operation. S8: Collect the thermal simulation products and calculate the oil discharge rate.

6. The experimental method for simulating continuous settlement and hydrocarbon expulsion of hydrocarbon source rocks according to claim 5, wherein: The S1 includes the following steps S11: Analyze the thermal history-burial history data of the target source rock, and divide multiple burial stages in combination with the key points of hydrocarbon source rock thermal evolution, the key points of tectonic changes and the burial depth changes. S12: Design a thermal simulation experiment stage according to the burial stage; S13: Sort out the burial depth changes, burial time, and maturity changes under the geological conditions of the source rocks corresponding to each simulation experiment stage.

7. An experimental method for simulating continuous settlement and hydrocarbon expulsion of hydrocarbon source rocks according to claim 6, characterized in that: The said S2 includes the following steps S21: Convert the burial stage into the simulated heating stage, and the experimental conditions of each simulated heating stage include temperature conditions and pressure conditions; S22: Conduct key temperature design for the temperature conditions, and the key temperatures include starting temperature, ending temperature, heating rate, and stage duration; S23: Conduct key pressure design for the pressure conditions, and the key pressures include simulated lithostatic pressure, upper limit pressure of hydrocarbon expulsion, and lower limit pressure of hydrocarbon expulsion.

8. An experimental method for simulating continuous settlement and hydrocarbon expulsion of hydrocarbon source rocks according to claim 5 or 6, characterized in that: The said S3 includes the following steps S31: Detect the measured temperature of the reaction kettle and the heating temperature of the furnace chamber; S32: When there is a deviation between the measured temperature of the reaction kettle and the heating temperature of the furnace chamber, conduct a temperature difference pilot experiment using a thermal pressure simulation experiment instrument for hydrocarbon generation and expulsion; S33: Establish a temperature correction plan by comparing the real-time temperature difference between the real-time temperature feedback by the temperature sensor mounted on the sample-loading reaction kettle and the real-time heating temperature of the heating furnace chamber; S34: Ensure that after the heating furnace chamber is corrected and heated up, the reaction kettle is actually heated according to the designed heating conditions.

9. An experimental method for simulating continuous settlement and hydrocarbon expulsion of hydrocarbon source rocks according to claim 5 or 6, characterized in that: The said S4 includes the following steps S41: Obtain the designed simulated lithostatic pressure, maximum hydrocarbon expulsion pressure, and minimum hydrocarbon expulsion pressure conditions; S42: Convert the obtained target pressure into the working pressures of the corresponding cylinder block, tracking pump, pneumatic valve, and hydrocarbon expulsion container; S43: Obtain the equipment working states of the simulated lithostatic pressure, maximum hydrocarbon expulsion pressure, and minimum hydrocarbon expulsion pressure.

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