A method for evaluating oil recovery ratio during in-situ heating and upgrading of shale oil

Abstract

The application relates to a method for evaluating the oil recovery rate during in-situ heating and upgrading of shale oil, and is applied to the field of oil development. The method comprises the following steps: 1, constructing a three-dimensional grid model of a shale oil reservoir between two horizontal wells, and determining the initial temperature, initial fluid pressure, initial porosity, initial oil saturation, initial gas saturation, initial water saturation and initial dissolved gas amount of each three-dimensional grid unit of the reservoir; 2, determining the pressure of each three-dimensional grid unit of the reservoir when the fluid pressure is balanced according to the bottom hole pressure of the shale oil layer and the reservoir displacement pressure gradient; 3, obtaining the temperature and instantaneous fluid pressure parameters of each three-dimensional grid unit of the reservoir according to the temperature field and pressure field of the in-situ heating shale oil reservoir, and determining the porosity and fluid saturation at each time point; and 4, determining the oil, gas and water production and recovery rate of each reservoir grid unit according to the instantaneous fluid pressure and balanced fluid pressure of each three-dimensional grid unit of the reservoir, and combining the oil, gas and water saturations.

Description

Technical Field

[0001] This invention relates to the field of petroleum exploration and development technology, and to a method for evaluating crude oil utilization rate during in-situ heating and upgrading of shale oil. Background Technology

[0002] Due to the high viscosity and poor mobility of most shale oil resources, shale oil horizontal well volumetric fracturing suffers from high costs, low yields, and rapid decline in production per well. Many scholars both domestically and internationally have proposed in-situ heating and upgrading technologies for shale oil extraction. In-situ heating involves heating the underground shale oil reservoir in situ (without bringing the shale oil reservoir to the surface). In-situ heating at relatively low temperatures, which generally does not produce kerogen or crude oil cracking into natural gas, primarily reduces shale oil viscosity and increases mobility; in-situ heating at relatively high temperatures, primarily inducing hydrocarbon generation from kerogen in immature to low-mature source rocks, is called in-situ heating and upgrading.

[0003] In-situ heating methods for shale oil extraction mainly include three types: heat conduction (electric heating rods, steam circulation pipes, dielectric heating, etc.), convection + conduction (injection of steam, hot organic gases, and CO2), and radiation + conduction (electric fields, electromagnetic waves, and microwaves, etc.). Due to the low permeability of shale oil reservoirs, injecting hot fluids into them is difficult and costly. Numerous scholars both domestically and internationally have conducted research on heating unconventional oil and gas reservoirs such as heavy oil, oil sands, shale oil, and shale gas using low-frequency electric fields (a type of dielectric heating), microwaves, and high-frequency electromagnetic fields. Oil companies such as Shell have already conducted field trials in several blocks using heating pipes to heat shale oil reservoirs on a large scale for shale oil extraction.

[0004] In-situ heating and refining for shale oil extraction can reduce shale oil viscosity, increase reservoir fluid pressure, create fractures to increase seepage capacity, increase shale oil well production, and reduce shale oil extraction costs. In other words, it involves viscosity reduction, pressure enhancement, permeability enhancement, production increase, and cost reduction in shale oil extraction. This method eliminates the need for staged hydraulic fracturing, essentially eliminating the need for water resources; it only requires a large amount of electricity, but there are no requirements for the stability of the electricity supply. It has broad prospects for promotion in Northwest my country, where wind and solar energy resources are abundant, and is expected to break through the technological bottlenecks in shale oil extraction.

[0005] In-situ heating and upgrading for shale oil extraction involves several core issues: evaluation of the dynamic pressure field of the shale oil reservoir during temperature rise; characteristics of pore fluid pressure changes in the shale oil reservoir; and the characteristics of mobilization of shale oil and gas resources. These issues respectively determine whether the shale oil reservoir can be heated over a large area, whether the reservoir can form a large-area fluid overpressure to drive shale oil resources, the recoverable quantity and mobilization rate of shale oil resources, and whether it is economically feasible, collectively influencing the success of in-situ heating and upgrading for shale oil extraction. Domestic scholars have studied the first two core issues, but research on the characteristics of mobilization of shale oil and gas resources during in-situ heating and upgrading for shale oil extraction is still lacking.

[0006] Therefore, this invention proposes a method for evaluating crude oil utilization rate during in-situ thermal reforming of shale oil. This method can quantitatively evaluate the characteristics of shale oil utilization rate during in-situ thermal reforming of shale oil, providing important technical parameters for this process and supporting the overcoming of technological bottlenecks in shale oil extraction. Summary of the Invention

[0007] The purpose of this invention is to provide a method for evaluating the crude oil utilization rate during in-situ thermal upgrading of shale oil, enabling quantitative evaluation of the characteristics of shale oil reservoir pressure field changes with temperature field during the in-situ thermal upgrading process, providing important technical parameters for in-situ thermal upgrading of shale oil, and supporting the breakthrough of shale oil extraction technology bottlenecks.

[0008] The technical solution adopted in this invention is: a method for evaluating crude oil utilization rate during in-situ heating and refining shale oil extraction, characterized in that:

[0009] Step 1: Construct a 3D mesh model of the shale oil reservoir between two horizontal wells. The length, width, and height of each reservoir mesh cell are all L. Determine the initial temperature T of each reservoir mesh cell. x, y, z, 0 Initial fluid pressure P x, y, z, 0 Initial porosity Ф x, y, z, 0 Initial oil saturation S o, x, y, z, 0 Initial gas saturation S g, x, y, z, 0 Initial water saturation S w, x, y, z, 0 Initial dissolved gas volume V dis-g, x, y, z, 0 The initial rock skeleton thermal expansion coefficient β r, x, y, z, 0 Initial crude oil thermal expansion coefficient β o, x, y, z, 0 Initial thermal expansion coefficient of natural gas β g, x, y, z, 0 and the initial hydrothermal expansion coefficient β w, x, y, z, 0 ;

[0010] Step 2: Based on the reservoir displacement pressure gradient P x,y,z,d And the shale oil wellbore fluid pressure P at time t. z,tDetermine the pore fluid pressure P of each reservoir 3D grid cell at time t when the fluid pressure is in equilibrium. x, y, z, t ;

[0011]

[0012] Step 3: Based on the temperature field and fluid pressure field characteristics of the in-situ heated shale oil reservoir, obtain the temperature T of each reservoir grid unit at a heating time t. x, y, z, t Determine the porosity Ф of each reservoir grid cell at time t. x, y, z, t Oil saturation S o, x, y, z, t Gas saturation S g, x, y, z, t Water saturation S w, x, y, z, t Dissolved gas volume V dis-g, x, y, z, t ;

[0013] Ф x, y, z, t = Ф x, y, z, 0 – β r, x, y, z, t (T x, y, z, t – T x, y, z, 0 ) (1– Ф x, y, z, 0 )

[0014] S o, x, y, z, t = S' o, x, y, z, t / (S' o, x, y, z, t + S' g, x, y, z, t + S' w, x, y, z, t )

[0015] S g, x, y, z, t = S' g, x, y, z, t / (S' o, x, y, z, t + S' g, x, y, z, t + S' w, x, y, z, t )

[0016] S w, x, y, z, t = S' w, x, y, z, t / (S' o, x, y, z, t + S' g, x, y, z, t + S' w, x, y, z, t )

[0017] V dis-g, x, y, z, t = 2.4ρ rel-g (P x, y, z, t ﹒ exp (1.77 / ρ oil – 0.001638T x, y, z, t –1.67)) 1.205

[0018] in,

[0019] S' o, x, y, z, t = S o, x, y, z, 0 (1+β o, x, y, z, t (T x, y, z, t – Tx, y, z, 0 ))

[0020] S' g, x, y, z, t = S g, x, y, z, 0 (1+β g, x, y, z, t (T x, y, z, t – T x, y, z, 0 ))+ΔV dis-g, x, y, z, t / Ф x, y, z, t

[0021] S' w, x, y, z, t = S w, x, y, z, 0 (1+β w, x, y, z, t (T x, y, z, t – T x, y, z, 0 ))

[0022] ΔV dis-g, x, y, z, t = (V dis-g, x, y, z, 0 – V dis-g, x, y, z, t ) Ф x, y, z, t S o, x, y, z, t P c T x, y, z, t / P x, y, z, t / T c

[0023] Step 4: Based on the instantaneous fluid pressure and equilibrium fluid pressure of each reservoir three-dimensional grid unit, combined with the oil, gas and water saturation and reservoir temperature, determine the oil, gas and water production and utilization rate per unit volume of reservoir in each reservoir grid unit when the in-situ electric field heating and upgrading extraction time of shale oil is t.

[0024] ΔQ o,x,y,z,t = Q o,x,y,z,0 - Q o,x,y,z,t

[0025] =Ф x, y, z, 0 S o, x, y, z, 0 (1+β o, x, y, z, 0 (T x, y, z, 0 -T c ))-Ф x, y, z, t S o, x, y, z, t (1+β o, x, y, z, t (T x, y, z, t -T c ))

[0026] ΔQ g,x,y,z,t = Q g,x,y,z,0 - Q g,x,y,z,t

[0027] =(Ф x, y, z, 0 S g, x, y, z, 0 (1+β g, x, y, z, 0 (T x, y, z, 0 -T c ))+ V dis-g, x, y, z, 0 ) –(Фx, y, z, t S g, x, y, z, t (1+β g, x, y, z, t (T x, y, z, t -T c ))+ V dis-g, x, y, z, t )

[0028] ΔQ w,x,y,z,t = Q w,x,y,z,0 - Q w,x,y,z,t

[0029] =Ф x, y, z, 0 S w, x, y, z, 0 (1+β w, x, y, z, 0 (T x, y, z, 0 -T c ))-Ф x, y, z, t S w, x, y, z, t (1+β w, x, y, z, t (T x, y, z, t -T c ))

[0030] E o, x, y, z ,t =ΔQ o, x, y, z, t / (Ф x, y, z, 0 S o, x, y, z, 0 (1+β o, x, y, z, 0 (T x, y, z, 0 -T c )))

[0031] E g, x, y, z, t =ΔQ g, x, y, z, t / (Ф x, y, z, 0 S g, x, y, z, 0 (1+β g, x, y, z, 0 (T x, y, z, 0 -T c ))+ V dis-g, x, y, z, 0 )

[0032] E w, x, y, z, t =ΔQ w, x, y, z, t / (Ф x, y, z, 0 S w, x, y, z, 0 (1+β w, x, y, z, 0 (T x, y, z, 0 -T c )))

[0033] In the formula, L is the length of each reservoir grid cell, and T x, y, z, 0 and T x, y, z, t These are the initial temperatures and the temperatures of reservoir grid cells numbered x, y, and z at time t, respectively. x, y, z, 0 and P x, y, z, t These are the initial pressures and the pressures of reservoir grid cells numbered x, y, and z at time t, respectively. z, t P is the wellbore fluid pressure in the shale oil section corresponding to the depth of the vertically numbered reservoir grid cell z at time t. x, y, z, dThese are the displacement pressure gradients of reservoir grid cells numbered x, y, and z, Ф x, y, z, 0 and Ф x, y, z, t These are the porosity of reservoir grid cells numbered x, y, and z at the initial time and at time t, respectively. o, x, y, z, 0 and S o, x, y, z, t These are the oil saturation values ​​of reservoir grid cells numbered x, y, and z at the initial time and time t, respectively. g, x, y, z, 0 and S g, x, y, z, t These are the initial gas saturation values ​​of reservoir grid cells numbered x, y, and z at time t, respectively. w, x, y, z, 0 and S w, x, y, z, t These are the water saturation values ​​of reservoir grid cells numbered x, y, and z at the initial time and at time t, respectively. dis-g, x, y, z, 0 and V dis-g, x, y, z, t These represent the volumes of dissolved natural gas in crude oil under standard conditions in reservoir grid cells numbered x, y, and z at the initial time and time t, respectively, and β. r, x, y, z, 0 and β r, x, y, z, t These are the thermal expansion coefficients of the rock skeleton of reservoir grid cells numbered x, y, and z at the initial time and time t, respectively, β. o, x, y, z, 0 and β o, x, y, z, t These are the crude oil thermal expansion coefficients of reservoir grid cells numbered x, y, and z at the initial time and time t, respectively, β. g, x, y, z, 0 and β g, x, y, z, t These are the thermal expansion coefficients of natural gas in reservoir grid cells numbered x, y, and z at the initial time and time t, respectively, β. w, x, y, z, 0 and β w, x, y, z, t These are the hydrothermal expansion coefficients of reservoir grid cells numbered x, y, and z at the initial time and time t, respectively, S' o, x, y, z, t S' g, x, y, z, t and S' w, x, y, z, t These are the crude oil volume factor, natural gas volume factor, and water volume factor for reservoir grid cells numbered x, y, and z at time t, respectively, ΔV dis-g, x, y, z, t ρ is the volume of natural gas that transitions from a dissolved state to a free state in the crude oil of reservoir grid cells numbered x, y, and z from the initial state to time t under reservoir temperature and pressure conditions. rel-g and ρ oil These are the relative densities of natural gas and crude oil, respectively, P. c and T c These are the pressure and temperature under standard conditions, ΔQ o, x, y, z, t ΔQ g, x, y, z, t and ΔQ w, x, y, z, t These represent the volumes of crude oil, natural gas, and water produced per unit volume of reservoir under standard conditions in reservoir grid cells numbered x, y, and z at time t, respectively. o, x, y, z ,t E g, x, y, z ,t and E w, x, y, z ,tThese represent the utilization rates of crude oil, natural gas, and water per unit volume of reservoir in the reservoir grid cells numbered x, y, and z at time t, respectively. o, x, y, z, 0 Q g, x, y, z, 0 and Q w, x, y, z, 0 These represent the volumes of crude oil, natural gas, and water per unit volume of the reservoir in the initially numbered x, y, and z grid cells, respectively, under standard conditions. Q o, x, y, z, t Q g, x, y, z, t and Q w, x, y, z, t These represent the volumes of crude oil, natural gas, and water per unit volume of the reservoir in the reservoir grid cells numbered x, y, and z at time t, under standard conditions. x, y, and z are integers, representing the grid cell numbers on the x, y, and z axes in three-dimensional space, respectively. ox, oy, and oz are integers, representing the wellbore numbers on the x, y, and z axes in three-dimensional space, respectively. i, j, and k are integers, ranging from ox to x, oy to y, and oz to z, respectively. The unit for reservoir grid cell length is meters (m), temperature is Kelvin (K), pressure is MPa, displacement pressure gradient is MPa / m, porosity is %, oil saturation is %, gas saturation is %, and water saturation is %. The unit for the volume of dissolved natural gas in crude oil under standard conditions is cubic meters per second (m³). 3 / m 3 This represents the volume of dissolved natural gas per cubic meter of crude oil at a pressure of 101 kPa and a temperature of 0°C. The unit of the coefficient of thermal expansion is K. -1 The volume factor is expressed as a percentage (%). The volume of free natural gas under reservoir temperature and pressure conditions is expressed in cubic meters (m³). 3 / m 3 This represents the volume of free natural gas per cubic meter of reservoir under reservoir pressure and temperature conditions. The relative density of natural gas and crude oil are dimensionless parameters. The unit for the volume of crude oil, natural gas, and water extracted per unit volume of reservoir under standard conditions is m³. 3 / m 3 This represents the volume of crude oil, natural gas, and water extracted from each cubic meter of reservoir under conditions of 101 kPa and 0°C. The utilization rates of crude oil, natural gas, and water are all expressed as percentages (%). The unit for the volume of crude oil, natural gas, and water stored per unit volume of reservoir under standard conditions is m³. 3 / m 3 This represents the volume of crude oil, natural gas, and water contained in each cubic meter of reservoir under conditions of 101 kPa pressure and 0°C temperature.

[0034] The beneficial effects of this invention are as follows: This invention provides a method for evaluating the crude oil utilization rate during in-situ thermal reforming of shale oil. This method is easy to operate and implement. This method can quantitatively evaluate the reservoir oil and gas utilization characteristics during in-situ thermal reforming of shale oil, providing important technical parameters for in-situ thermal reforming of shale oil and supporting the breakthrough of shale oil extraction technology bottlenecks. Attached Figure Description

[0035] Figure 1 This is a schematic flowchart of the method for evaluating crude oil utilization rate in in-situ heated and modified shale oil extraction according to the present invention.

[0036] Figure 2 This is a diagram of a horizontal well layout scheme for extracting shale oil by in-situ heating and refining using an electric field.

[0037] Figure 3 It is the equilibrium pressure field of a two-dimensional reservoir grid profile perpendicular to the projection of the horizontal well section plane one hour after shale oil extraction by in-situ heating and regeneration using an electric field.

[0038] Figure 4 It is the porosity characteristics of a two-dimensional reservoir grid profile perpendicular to the projection of the horizontal well section plane 1 hour after shale oil extraction by in-situ heating and regeneration using an electric field.

[0039] Figure 5 It is the oil saturation characteristic of a two-dimensional reservoir grid profile perpendicular to the projection of the horizontal well section plane 1 hour after shale oil extraction by in-situ heating and regeneration using an electric field.

[0040] Figure 6 It is the gas saturation characteristic of a two-dimensional reservoir grid profile perpendicular to the projection of the horizontal well section plane 1 hour after shale oil extraction by in-situ heating and regeneration using an electric field.

[0041] Figure 7 It is the water saturation characteristic of a two-dimensional reservoir grid profile perpendicular to the projection of the horizontal well section plane 1 hour after shale oil extraction by in-situ heating and regeneration using an electric field.

[0042] Figure 8 It is the oil utilization rate characteristic of a two-dimensional reservoir grid profile perpendicular to the projection of the horizontal well section plane 1 hour after shale oil extraction by in-situ heating and regeneration using an electric field.

[0043] Figure 9 It is the pneumatic utilization characteristic of a two-dimensional reservoir grid profile perpendicular to the projection of the horizontal well section plane 1 hour after shale oil extraction by in-situ heating and regeneration using an electric field.

[0044] Figure 10 It is the water utilization rate characteristic of a two-dimensional reservoir grid profile perpendicular to the projection of the horizontal well section plane 1 hour after shale oil extraction by in-situ heating and regeneration using an electric field. Detailed Implementation

[0045] Example 1: As Figure 1 The method for evaluating crude oil utilization rate during in-situ heating and refining extraction of shale oil includes the following steps:

[0046] Step 1: In Figure 2 Under the well layout scheme, a three-dimensional mesh model of the shale oil reservoir between two horizontal wells was constructed. Each three-dimensional mesh cell has a length, width, and height of 5m. The length of the three-dimensional mesh model is equal to the length of the horizontal section of the well, and the width is not less than twice the distance between the horizontal sections of the two wells (60m). The height is equal to the thickness of the shale oil reservoir. The length, width, and height of this three-dimensional mesh model are 1000m, 200m, and 200m, respectively. The initial temperature T of each mesh cell was also determined. x, y, z, 0 The initial pressure is 363.15 K. x, y, z, 0 30MPa, initial porosity Ф x, y, z, 0 2% initial oil saturation S o, x, y, z, 0 50%, initial gas saturation S g, x, y, z, 0 0%, initial water saturation S w, x, y, z, 0 50%, initial crude oil dissolved natural gas volume V dis-g, x, y, z, 0 50m 3 / m 3 The initial rock skeleton's volumetric thermal expansion coefficient β r, x, y, z, 0 3.0×10 -7 K -1 Initial crude oil thermal expansion coefficient β o, x, y, z, 0 2.0×10 -4 K -1 Initial thermal expansion coefficient of natural gas β g, x, y, z, 0 2.0×10 -3 K -1 and the initial hydrothermal expansion coefficient β w, x, y, z, 0 3.0×10 -4 K -1 .

[0047] Step 2: Reservoir displacement pressure gradient P x,y,z,d The shale oil wellbore fluid pressure P at 0.2 MPa / m and time t. z,t Given a pressure of 20 MPa, determine the pore fluid pressure P of each reservoir 3D grid cell at time t when the fluid pressure is at equilibrium. x, y, z, t . Figure 3 It is the equilibrium pressure field of a two-dimensional reservoir grid profile perpendicular to the projection of the horizontal well section plane one hour after shale oil extraction by in-situ heating and regeneration using an electric field.

[0048]

[0049] Step 3: Based on the temperature field and fluid pressure field characteristics of the in-situ heated shale oil reservoir, obtain the temperature T of each reservoir grid unit at a heating time t. x, y, z, t Determine the porosity Ф of each reservoir grid cell at time t. x, y, z, t Oil saturation S o, x, y, z, t Gas saturation S g, x, y, z, t Water saturation S w, x, y, z, t Dissolved gas volume V dis-g, x, y, z, t . Figure 4 It is the porosity characteristics of a two-dimensional reservoir grid profile perpendicular to the projection of the horizontal well section plane 1 hour after shale oil extraction by in-situ heating and regeneration using an electric field. Figure 5 It is the oil saturation characteristic of a two-dimensional reservoir grid profile perpendicular to the projection of the horizontal well section plane 1 hour after shale oil extraction by in-situ heating and regeneration using an electric field. Figure 6 It is the gas saturation characteristic of a two-dimensional reservoir grid profile perpendicular to the projection of the horizontal well section plane 1 hour after shale oil extraction by in-situ heating and regeneration using an electric field. Figure 7 It is the water saturation characteristic of a two-dimensional reservoir grid profile perpendicular to the projection of the horizontal well section plane 1 hour after shale oil extraction by in-situ heating and regeneration using an electric field.

[0050] Ф x, y, z, t = Ф x, y, z, 0 – β r, x, y, z, t (T x, y, z, t – T x, y, z, 0 ) (1– Ф x, y, z, 0 )

[0051] S o, x, y, z, t = S' o, x, y, z, t / (S' o, x, y, z, t + S' g, x, y, z, t + S' w, x, y, z, t )

[0052] S g, x, y, z, t = S' g, x, y, z, t / (S' o, x, y, z, t + S' g, x, y, z, t + S' w, x, y, z, t )

[0053] S w, x, y, z, t = S' w, x, y, z, t / (S' o, x, y, z, t + S' g, x, y, z, t + S' w, x, y, z, t )

[0054] V dis-g, x, y, z, t = 2.4ρ rel-g (P x, y, z, 0 ﹒ exp (1.77 / ρ oil – 0.001638T x, y, z, t –1.67))1.205

[0055] in,

[0056] S' o, x, y, z, t = S o, x, y, z, 0 (1+β o, x, y, z, t (T x, y, z, t – T x, y, z, 0 ))

[0057] S' g, x, y, z, t = S g, x, y, z, 0 (1+β g, x, y, z, t (T x, y, z, t – T x, y, z, 0 ))+ΔV dis-g, x, y, z, t / Ф x, y, z, t

[0058] S' w, x, y, z, t = S w, x, y, z, 0 (1+β w, x, y, z, t (T x, y, z, t – T x, y, z, 0 ))

[0059] ΔV dis-g, x, y, z, t = (V dis-g, x, y, z, 0 – V dis-g, x, y, z, t ) Ф x, y, z, t S o, x, y, z, t P c T x, y, z, t / P x, y, z, t / T c

[0060] Step 4: Based on the instantaneous fluid pressure and equilibrium fluid pressure of each reservoir three-dimensional grid unit, combined with the oil, gas, and water saturation and reservoir temperature, determine the oil, gas, and water production and utilization rate per unit volume of reservoir in each reservoir grid unit after 1 hour of in-situ electric field heating and upgrading for shale oil extraction. Figure 8 It is the oil utilization rate characteristic of a two-dimensional reservoir grid profile perpendicular to the projection of the horizontal well section plane 1 hour after shale oil extraction by in-situ heating and regeneration using an electric field. Figure 9 It is the pneumatic utilization characteristic of a two-dimensional reservoir grid profile perpendicular to the projection of the horizontal well section plane 1 hour after shale oil extraction by in-situ heating and regeneration using an electric field. Figure 10 It is the water utilization rate characteristic of a two-dimensional reservoir grid profile perpendicular to the projection of the horizontal well section plane 1 hour after shale oil extraction by in-situ heating and regeneration using an electric field.

[0061] ΔQ o,x,y,z,t = Q o,x,y,z,0 - Q o,x,y,z,t

[0062] =Ф x, y, z, 0 S o, x, y, z, 0 (1+β o, x, y, z, 0(T x, y, z, 0 -T c ))-Ф x, y, z, t S o, x, y, z, t (1+β o, x, y, z, t (T x, y, z, t -T c ))

[0063] ΔQ g,x,y,z,t = Q g,x,y,z,0 - Q g,x,y,z,t

[0064] =(Ф x, y, z, 0 S g, x, y, z, 0 (1+β g, x, y, z, 0 (T x, y, z, 0 -T c ))+ V dis-g, x, y, z, 0 ) –(Ф x, y, z, t S g, x, y, z, t (1+β g, x, y, z, t (T x, y, z, t -T c ))+ V dis-g, x, y, z, t )

[0065] ΔQ w,x,y,z,t = Q w,x,y,z,0 - Q w,x,y,z,t

[0066] =Ф x, y, z, 0 S w, x, y, z, 0 (1+β w, x, y, z, 0 (T x, y, z, 0 -T c ))-Ф x, y, z, t S w, x, y, z, t (1+β w, x, y, z, t (T x, y, z, t -T c ))

[0067] E o,x,y,z,t =ΔQ o,x,y,z,t / (Ф x, y, z, 0 S o, x, y, z, 0 (1+β o, x, y, z, 0 (T x, y, z, 0 -T c )))

[0068] E g,x,y,z,t =ΔQ g,x,y,z,t / (Ф x, y, z, 0 S g, x, y, z, 0 (1+β g, x, y, z, 0 (T x, y, z, 0 -T c ))+V dis-g, x, y, z, 0 )

[0069] E w,x,y,z,t =ΔQ w,x,y,z,t / (Ф x, y, z, 0 S w, x, y, z, 0 (1+β w, x, y, z, 0 (T x, y, z, 0 -T c )))

[0070] In the formula, L is the length of each reservoir grid cell, and T x, y, z, 0 and T x, y, z, t These are the initial temperatures and the temperatures of reservoir grid cells numbered x, y, and z at time t, respectively. x, y, z, 0 and P x, y, z, t These are the initial pressures and the pressures of reservoir grid cells numbered x, y, and z at time t, respectively. z, t P is the wellbore fluid pressure in the shale oil section corresponding to the depth of the vertically numbered reservoir grid cell z at time t. x, y, z, d These are the displacement pressure gradients of reservoir grid cells numbered x, y, and z, Ф x, y, z, 0 and Ф x, y, z, t These are the porosity of reservoir grid cells numbered x, y, and z at the initial time and at time t, respectively. o, x, y, z, 0 and S o, x, y, z, t These are the oil saturation values ​​of reservoir grid cells numbered x, y, and z at the initial time and time t, respectively. g, x, y, z, 0 and S g, x, y, z, t These are the initial gas saturation values ​​of reservoir grid cells numbered x, y, and z at time t, respectively. w, x, y, z, 0 and S w, x, y, z, t These are the water saturation values ​​of reservoir grid cells numbered x, y, and z at the initial time and at time t, respectively. dis-g, x, y, z, 0 and V dis-g, x, y, z, t These represent the volumes of dissolved natural gas in crude oil under standard conditions in reservoir grid cells numbered x, y, and z at the initial time and time t, respectively, and β. r, x, y, z, 0 and β r, x, y, z, t These are the thermal expansion coefficients of the rock skeleton of reservoir grid cells numbered x, y, and z at the initial time and time t, respectively, β. o, x, y, z, 0 and β o, x, y, z, t These are the crude oil thermal expansion coefficients of reservoir grid cells numbered x, y, and z at the initial time and time t, respectively, β. g, x, y, z, 0 and β g, x, y, z, t These are the thermal expansion coefficients of natural gas in reservoir grid cells numbered x, y, and z at the initial time and time t, respectively, β. w, x, y, z, 0 and β w, x, y, z, t These are the hydrothermal expansion coefficients of reservoir grid cells numbered x, y, and z at the initial time and time t, respectively, S' o, x, y, z, t S' g, x, y, z, t and S' w, x, y, z, t These are the crude oil volume factor, natural gas volume factor, and water volume factor for reservoir grid cells numbered x, y, and z at time t, respectively, ΔV dis-g, x, y, z, tρ is the volume of natural gas that transitions from a dissolved state to a free state in the crude oil of reservoir grid cells numbered x, y, and z from the initial state to time t under reservoir temperature and pressure conditions. rel-g and ρ oil These are the relative densities of natural gas and crude oil, respectively, P. c and T c These are the pressure and temperature under standard conditions, ΔQ o, x, y, z, t ΔQ g, x, y, z, t and ΔQ w, x, y, z, t These represent the volumes of crude oil, natural gas, and water produced per unit volume of reservoir under standard conditions in reservoir grid cells numbered x, y, and z at time t, respectively. o, x, y, z ,t E g, x, y, z ,t and E w, x, y, z ,t These represent the utilization rates of crude oil, natural gas, and water per unit volume of reservoir in the reservoir grid cells numbered x, y, and z at time t, respectively. o, x, y, z, 0 Q g, x, y, z, 0 and Q w, x, y, z, 0 These represent the volumes of crude oil, natural gas, and water per unit volume of the reservoir in the initially numbered x, y, and z grid cells, respectively, under standard conditions. Q o, x, y, z, t Q g, x, y, z, t and Q w, x, y, z, t These represent the volumes of crude oil, natural gas, and water per unit volume of the reservoir in the reservoir grid cells numbered x, y, and z at time t, under standard conditions. x, y, and z are integers, representing the grid cell numbers on the x, y, and z axes in three-dimensional space, respectively. ox, oy, and oz are integers, representing the wellbore numbers on the x, y, and z axes in three-dimensional space, respectively. i, j, and k are integers, ranging from ox to x, oy to y, and oz to z, respectively. The unit for reservoir grid cell length is meters (m), temperature is Kelvin (K), pressure is MPa, displacement pressure gradient is MPa / m, porosity is %, oil saturation is %, gas saturation is %, and water saturation is %. The unit for the volume of dissolved natural gas in crude oil under standard conditions is cubic meters per second (m³). 3 / m 3 This represents the volume of dissolved natural gas per cubic meter of crude oil at a pressure of 101 kPa and a temperature of 0°C. The unit of the coefficient of thermal expansion is K. -1 The volume factor is expressed as a percentage (%). The volume of free natural gas under reservoir temperature and pressure conditions is expressed in cubic meters (m³). 3 / m 3 This represents the volume of free natural gas per cubic meter of reservoir under reservoir pressure and temperature conditions. The relative density of natural gas and crude oil are dimensionless parameters. The unit for the volume of crude oil, natural gas, and water extracted per unit volume of reservoir under standard conditions is m³. 3 / m 3This represents the volume of crude oil, natural gas, and water extracted from each cubic meter of reservoir under conditions of 101 kPa and 0°C. The utilization rates of crude oil, natural gas, and water are all expressed as percentages (%). The unit for the volume of crude oil, natural gas, and water stored per unit volume of reservoir under standard conditions is m³. 3 / m 3 This represents the volume of crude oil, natural gas, and water contained in each cubic meter of reservoir under conditions of 101 kPa pressure and 0°C temperature.

Claims

1. A method for evaluating crude oil utilization rate during in-situ heating and refining extraction of shale oil, characterized in that: Step 1: Construct a 3D mesh model of the shale oil reservoir between two horizontal wells. The length, width, and height of each reservoir mesh cell are all L. Determine the initial temperature T of each reservoir mesh cell. x, y, z, 0 Initial fluid pressure P x, y, z, 0 Initial porosity Ф x, y, z, 0 Initial oil saturation S o, x, y, z, 0 Initial gas saturation S g, x, y, z, 0 Initial water saturation S w, x, y, z, 0 Initial dissolved gas volume V dis-g, x, y, z, 0 The initial rock skeleton thermal expansion coefficient β r, x, y, z, 0 Initial crude oil thermal expansion coefficient β o, x, y, z, 0 Initial thermal expansion coefficient of natural gas β g, x, y, z, 0 and the initial hydrothermal expansion coefficient β w, x, y, z, 0 ; Step 2: Based on the reservoir displacement pressure gradient P x,y,z,d And the shale oil wellbore fluid pressure P at time t. z,t Determine the pore fluid pressure P of each reservoir 3D grid cell at time t when the fluid pressure is in equilibrium. x, y, z, t ; Step 3: Based on the temperature field and fluid pressure field characteristics of the in-situ heated shale oil reservoir, obtain the temperature T of each reservoir grid unit at a heating time t. x, y, z, t Determine the porosity Ф of each reservoir grid cell at time t. x, y, z, t Oil saturation S o, x, y, z, t Gas saturation S g, x, y, z, t Water saturation S w, x, y, z, t Dissolved gas volume V dis-g, x, y, z, t ; F x, y, z, t = F x, y, z, 0 – β r, x, y, z, t (T x, y, z, t – T x, y, z, 0 ) (1– F x, y, z, 0 ) S o, x, y, z, t = S’ o, x, y, z, t / (S’ o, x, y, z, t + S’ g, x, y, z, t + S’ w, x, y, z, t ) S g, x, y, z, t = S’ g, x, y, z, t / (S’ o, x, y, z, t + S’ g, x, y, z, t + S’ w, x, y, z, t ) S w, x, y, z, t = S’ w, x, y, z, t / (S’ o, x, y, z, t + S’ g, x, y, z, t + S’ w, x, y, z, t ) V dis-g, x, y, z, t = 2.4p rel-g (P x, y, z, t ﹒exp (1.77 / ρ oil – 0.001638T x, y, z, t – 1.67)) 1.205 in, S’ o, x, y, z, t = S o, x, y, z, 0 (1+β o, x, y, z, t (T x, y, z, t – T x, y, z, 0 )) S' g, x, y, z, t = S g, x, y, z, 0 (1+b g, x, y, z, t (T x, y, z, t – T x, y, z, 0 ))+ΔV dis-g, x, y, z, t / F x, y, z, t S’ w, x, y, z, t = S w, x, y, z, 0 (1+β w, x, y, z, t (T x, y, z, t – T x, y, z, 0 )) ΔV dis-g, x, y, z, t = (V dis-g, x, y, z, 0 – V dis-g, x, y, z, t ) Ф x, y, z, t S o, x, y, z, t P c T x, y, z, t / P x, y, z, t / T c Step 4: Based on the instantaneous fluid pressure and equilibrium fluid pressure of each reservoir three-dimensional grid unit, combined with the oil, gas and water saturation and reservoir temperature, determine the oil, gas and water production and utilization rate per unit volume of reservoir in each reservoir grid unit when the in-situ electric field heating and upgrading extraction time of shale oil is t. ΔQ o,x,y,z,t = Q o,x,y,z,0 - Q o,x,y,z,t =Ф x, y, z, 0 S o, x, y, z, 0 (1+β o, x, y, z, 0 (T x, y, z, 0 -T c ))-Ф x, y, z, t S o, x, y, z, t (1+β o, x, y, z, t (T x, y, z, t -T c )) ΔQ g,x,y,z,t = Q g,x,y,z,0 - Q g,x,y,z,t =(Ф x, y, z, 0 S g, x, y, z, 0 (1+β g, x, y, z, 0 (T x, y, z, 0 -T c ))+ V dis-g, x, y, z, 0 ) –(Ф x, y, z, t S g, x, y, z, t (1+β g, x, y, z, t (T x, y, z, t -T c ))+ V dis-g, x, y, z, t ) ΔQ w,x,y,z,t = Q w,x,y,z,0 - Q w,x,y,z,t =Ф x, y, z, 0 S w, x, y, z, 0 (1+β w, x, y, z, 0 (T x, y, z, 0 -T c ))-Ф x, y, z, t S w, x, y, z, t (1+β w, x, y, z, t (T x, y, z, t -T c )) E o, x, y, z ,t =ΔQ o, x, y, z, t / (Ф x, y, z, 0 S o, x, y, z, 0 (1+β o, x, y, z, 0 (T x, y, z, 0 -T c ))) E g, x, y, z, t =ΔQ g, x, y, z, t / (Ф x, y, z, 0 S g, x, y, z, 0 (1+β g, x, y, z, 0 (T x, y, z, 0 -T c ))+V dis-g, x, y, z, 0 ) E w, x, y, z, t =ΔQ w, x, y, z, t / (Ф x, y, z, 0 S w, x, y, z, 0 (1+β w, x, y, z, 0 (T x, y, z, 0 -T c ))) In the formula, L is the length of each reservoir grid cell, and T x, y, z, 0 and T x, y, z, t These are the initial temperatures and the temperatures of reservoir grid cells numbered x, y, and z at time t, respectively. x, y, z, 0 and P x, y, z, t These are the initial pressures and the pressures of reservoir grid cells numbered x, y, and z at time t, respectively. z, t P is the wellbore fluid pressure in the shale oil section corresponding to the depth of the vertically numbered reservoir grid cell z at time t. x, y, z, d These are the displacement pressure gradients of reservoir grid cells numbered x, y, and z, Ф x, y, z, 0 and Ф x, y, z, t These are the porosity of reservoir grid cells numbered x, y, and z at the initial time and at time t, respectively. o, x, y, z, 0 and S o, x, y, z, t These are the oil saturation values ​​of reservoir grid cells numbered x, y, and z at the initial time and time t, respectively. g, x, y, z, 0 and S g, x, y, z, t These are the initial gas saturation values ​​of reservoir grid cells numbered x, y, and z at time t, respectively. w, x, y, z, 0 and S w, x, y, z, t These are the water saturation values ​​of reservoir grid cells numbered x, y, and z at the initial time and at time t, respectively. dis-g, x, y, z, 0 and V dis-g, x, y, z, t These represent the volumes of dissolved natural gas in crude oil under standard conditions in reservoir grid cells numbered x, y, and z at the initial time and time t, respectively, and β. r, x, y, z, 0 and β r, x, y, z, t These are the thermal expansion coefficients of the rock skeleton of reservoir grid cells numbered x, y, and z at the initial time and time t, respectively, β. o, x, y, z, 0 and β o, x, y, z, t These are the crude oil thermal expansion coefficients of reservoir grid cells numbered x, y, and z at the initial time and time t, respectively, β. g, x, y, z, 0 and β g, x, y, z, t These are the thermal expansion coefficients of natural gas in reservoir grid cells numbered x, y, and z at the initial time and time t, respectively, β. w, x, y, z, 0 and β w, x, y, z, t These are the hydrothermal expansion coefficients of reservoir grid cells numbered x, y, and z at the initial time and time t, respectively, S' o, x, y, z, t S' g, x, y, z, t and S' w, x, y, z, t These are the crude oil volume factor, natural gas volume factor, and water volume factor for reservoir grid cells numbered x, y, and z at time t, respectively, ΔV dis-g, x, y, z, t ρ is the volume of natural gas that transitions from a dissolved state to a free state in the crude oil of reservoir grid cells numbered x, y, and z from the initial state to time t under reservoir temperature and pressure conditions. rel-g and ρ oil These are the relative densities of natural gas and crude oil, respectively, P. c and T c These are the pressure and temperature under standard conditions, ΔQ o, x, y, z, t ΔQ g, x, y, z, t and ΔQ w, x, y, z, t These represent the volumes of crude oil, natural gas, and water produced per unit volume of reservoir under standard conditions in reservoir grid cells numbered x, y, and z at time t, respectively. o, x, y, z ,t E g, x, y, z ,t and E w, x, y, z ,t These represent the utilization rates of crude oil, natural gas, and water per unit volume of reservoir in the reservoir grid cells numbered x, y, and z at time t, respectively. o, x, y, z, 0 Q g, x, y, z, 0 and Q w, x, y, z, 0 These represent the volumes of crude oil, natural gas, and water per unit volume of the reservoir in the initially numbered x, y, and z grid cells, respectively, under standard conditions. Q o, x, y, z, t Q g, x, y, z, t and Q w, x, y, z, t These represent the volumes of crude oil, natural gas, and water per unit volume of the reservoir in the reservoir grid cells numbered x, y, and z at time t, under standard conditions. x, y, and z are integers, representing the grid cell numbers on the x, y, and z axes in three-dimensional space, respectively. ox, oy, and oz are integers, representing the wellbore numbers on the x, y, and z axes in three-dimensional space, respectively. i, j, and k are integers, ranging from ox to x, oy to y, and oz to z, respectively. The unit for reservoir grid cell length is meters (m), temperature is Kelvin (K), pressure is MPa, displacement pressure gradient is MPa / m, porosity is %, oil saturation is %, gas saturation is %, and water saturation is %. The unit for the volume of dissolved natural gas in crude oil under standard conditions is cubic meters per second (m³). 3 / m 3 This represents the volume of dissolved natural gas per cubic meter of crude oil at a pressure of 101 kPa and a temperature of 0°C. The unit of the coefficient of thermal expansion is K. -1 The volume factor is expressed as a percentage (%). The volume of free natural gas under reservoir temperature and pressure conditions is expressed in cubic meters (m³). 3 / m 3 This represents the volume of free natural gas per cubic meter of reservoir under reservoir pressure and temperature conditions. The relative density of natural gas and crude oil are dimensionless parameters. The unit for the volume of crude oil, natural gas, and water extracted per unit volume of reservoir under standard conditions is m³. 3 / m 3 This represents the volume of crude oil, natural gas, and water extracted from each cubic meter of reservoir under conditions of 101 kPa and 0°C. The utilization rates of crude oil, natural gas, and water are all expressed as percentages (%). The unit for the volume of crude oil, natural gas, and water stored per unit volume of reservoir under standard conditions is m³. 3 / m 3 This represents the volume of crude oil, natural gas, and water contained in each cubic meter of reservoir under conditions of 101 kPa pressure and 0°C temperature.

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