Optimization Method for Catalyst Injection Parameters in In-Situ Hydrogen Production Process for Oil and Gas Reservoirs

Abstract

The present invention provides a method for optimizing catalyst injection parameters applicable to in-situ hydrogen production processes in oil and gas reservoirs, including: 1 obtaining parameters such as the geology, engineering, and reservoir fluid properties of the treatment well; 2 clarifying the hydrogen production reaction path and area of the treatment reservoir; 3 screening catalysts corresponding to different hydrogen production reaction paths and testing their characteristic parameters; 4 determining the amount of catalyst per unit volume in the reaction zone; 5 taking the catalyst amount as the target and conducting numerical simulations to optimize the catalyst injection process parameters. This method can meet the catalyst injection for in-situ hydrogen production in any well pattern and provide guarantee for efficient in-situ hydrogen production in oil and gas reservoirs.

Description

Technical Field

[0001] The invention belongs to the technical field of in-situ hydrogen production in oil and gas reservoirs, and in particular relates to a catalyst injection parameter optimization method for an in-situ hydrogen production process in oil and gas reservoirs. Background Art

[0002] Catalysts are the cornerstone of efficient in-situ hydrogen production in oil and gas reservoirs, and accurately injecting the catalyst into the predetermined reaction area is of utmost importance.

[0003] CN102149898A discloses a method for generating hydrogen in oil and gas reservoirs, and proposes injecting a nickel-based catalyst in a convenient manner using a metal compound, without considering the injection parameters, physical and chemical percolation, and usage of the catalyst per unit volume of the catalyst.

[0004] CN 115405283 discloses a method for injecting underground coal gasification catalyst, and explains the catalyst carrier medium and catalyst particle diameter, but does not consider the injection of in-situ hydrogen production catalyst in oil and gas reservoirs, the physical and chemical seepage effect and the amount of catalyst used per unit volume. Summary of the invention

[0005] In response to the above technical problems, the present invention proposes an implementation plan that takes into account the key paths and areas of in-situ hydrogen production reactions in oil and gas reservoirs, the amount of catalyst per unit volume, and the physical and chemical seepage effects of the catalyst system to guide catalyst injection process parameters.

[0006] The specific technical solutions are:

[0007] A catalyst injection parameter optimization method applicable to an in-situ hydrogen production process in an oil and gas reservoir comprises the following steps:

[0008] S1 Obtain the geological, engineering, reservoir fluid properties and other parameters of the measure well;

[0009] The geological parameters described in step S1 are porosity, permeability, saturation, rock pore size distribution, relative permeability curve, wettability, reservoir rock composition, reservoir pressure, and reservoir temperature.

[0010] The engineering parameters are well type, well depth and completion method.

[0011] The reservoir fluid parameters are water type, water salinity, oil phase components, gas phase components, oil viscosity-temperature curve, and combustion enthalpy corresponding to oil and gas.

[0012] S2 defines the reaction path and area of ​​hydrogen production in the reservoir;

[0013] The method for determining the key reaction path of hydrogen production in the reservoir described in step S2 is to calculate the self-heating temperature of the combustion of the reservoir per unit volume using the following formula, and determine the key reaction path that can be reached for in-situ hydrogen production in the oil and gas reservoir according to the temperature range;

[0014]

[0015] T is the reservoir temperature, °C; T0 is the initial reservoir temperature, °C, is the porosity per unit volume of the reservoir, %; S o is the oil saturation, %; ρ o is the crude oil density, kg / m 3 ; H o is the heat of combustion of the oil, KJ / mol; M o is the relative molecular mass of the crude oil; S g is the gas saturation, %; P N is the reservoir pressure, MPa; H g is the heat of combustion of the gas, KJ / mol; P is the surface pressure, MPa; is the volume of rock per unit volume, m 3 ; C R is the specific heat capacity of the rock, J / kg·°C; S w is the water saturation, %; C w is the specific heat capacity of water, J / kg·°C.

[0016] The temperature range of the key reaction path for in-situ hydrogen production in the oil and gas reservoir is; for water-gas shift, the reaction temperature is 450°C; for methane steam reforming, the temperature is 700 - 1000°C; for partial oxidation, the temperature is 1000 - 1300°C; for dry reforming, the temperature is 800 - 900°C; for coke gasification, the temperature is 800 - 1000°C; for heavy oil cracking, the temperature is 380 - 480°C.

[0017] The method for determining the reaction interval of hydrogen production in the reservoir is to use the popular software CMG in the petroleum industry for geological modeling and fitting, and determine the temperature field division and the enrichment regions of CO, water vapor, methane gas and coke according to geological, engineering and fluid characteristics, and divide the reaction regions according to the reaction path;

[0018] S3 Screen catalysts for different hydrogen production reaction paths and test their characteristic parameters;

[0019] The catalysts for different hydrogen production reaction paths described in step S3 include, for the water-gas shift, one or a mixture of nickel-based catalysts, copper-based catalysts, iron-based catalysts, and chromium-based catalysts; for steam methane reforming, one or a mixture of nickel-based catalysts, chromium-based catalysts, and platinum-based catalysts; for partial oxidation, noble metal catalysts such as rhodium, platinum, palladium, etc., non-noble metal catalysts such as nickel, molybdenum, chromium, etc., composite catalysts such as Ni-Cu, Ni-Mo, etc.; for dry reforming, one or a mixture of nickel-based catalysts, chromium-based catalysts, and palladium-based catalysts; for coke gasification, one or a mixture of nickel-based catalysts, chromium-based catalysts, palladium-based catalysts, and iron-based catalysts; for heavy oil cracking, one or a mixture of nickel-based catalysts, copper-based catalysts, iron-based catalysts, molybdenum-based catalysts, and platinum-based catalysts.

[0020] The described catalyst characteristic parameters include catalyst particle diameter, particle shape, maximum adsorption capacity, residual adsorption capacity, and adsorption critical velocity.

[0021] S4 determines the catalyst dosage per unit volume in the reaction zone;

[0022] The method for step S4 to determine the catalyst dosage per unit volume in the reaction zone is to use indoor experiments to simulate the mixing ratio of the catalyst and reservoir cuttings under different reaction paths, optimize the optimal catalyst dosage through hydrogen production efficiency, and convert the static catalyst dosage into the corresponding adsorption amount of physical and chemical seepage.

[0023] The indoor experiment simulation method is one of the reactor + gas chromatography test experiment and the ARC-GCMS coupling experiment.

[0024] The described adsorption amount is calculated according to the formula Calculate.

[0025] β is the adsorption amount of catalyst per unit volume, gmol; Per unit volume, m 3 ; ρ r Rock density, kg / m 3 ; ρ c Catalyst density, kg / m 3 ; φ porosity, %; k mass ratio of catalyst to cuttings; M c Catalyst molecular weight.

[0026] S5 takes the catalyst concentration as the target and conducts numerical simulation to optimize the catalyst injection process parameters.

[0027] The catalyst injection process parameters described in step S5 include the injection catalyst system concentration and the injection rate.

[0028] The advantages of the present invention are as follows: (1) It can completely guide the injection process parameters of a specified catalyst; (2) It can calculate the temperature range and scope that can be heated by in-situ combustion according to the reservoir fluid properties and thermodynamic properties, clarify different in-situ hydrogen conversion regions, and provide guarantee for the injection positions of corresponding catalysts; (3) Through physical simulation experiments, it clarifies the range of catalyst concentration required for efficient in-situ hydrogen conversion in the target oil and gas reservoir; (4) It can consider the characteristics of a specified catalyst in a given reservoir and optimize the injection process parameters of the catalyst by physical and chemical seepage. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is the flow chart of the present invention;

[0030] Figure 2 is the temperature field distribution diagram based on crude oil properties and heat transfer in the oil and gas reservoir in the embodiment;

[0031] Figure 3 is the schematic diagram of the catalyst injection position and process in the embodiment;

[0032] Figure 3 The reference numerals in the drawings are:

[0033] 1 injection well, 2 oil layer, 3 catalyst Pt / α-MoC, 4 catalyst Ni_ZrO_2, 5 water-gas reaction zone, 6 methane steam reforming reaction zone, 7 caprock or other formations;

[0034] Figure 4 is the relationship curve diagram of different injection concentrations and adsorption amount per unit volume in the embodiment (Pt / α-MoC);

[0035] Figure 5 is the relationship curve diagram of different injection rates and adsorption amount per unit volume in the embodiment (Pt / α-MoC);

[0036] Figure 6 is the relationship curve diagram of different injection concentrations and adsorption amount per unit volume in the embodiment (Ni_ZrO_2);

[0037] Figure 7 is the relationship curve diagram of different injection rates and adsorption amount per unit volume in the embodiment (Ni_ZrO_2). DETAILED DESCRIPTION OF THE INVENTION

[0038] The specific technical solutions of the present invention will be described in conjunction with the embodiments.

[0039] The flow chart of the present invention is as Figure 1 shown. In this embodiment, based on the geological, engineering and other data of a double horizontal well in a certain oilfield block, a three-dimensional geological model of the target well is constructed, and production history matching is carried out. The density of the reservoir crude oil is 0.92 g / cm 3, with a viscosity of 1500 mPa·s at 50°C and an enthalpy change of 2.86×10 3 kJ / mol for crude oil. Combining seepage and heat transfer theories, in-situ combustion numerical simulations were carried out, with the maximum temperature reaching 800°C. The temperature field distribution is as Figure 2 shown. The reaction regions defining the key path of hydrogen were identified as the methane steam reforming reaction zone and the water-gas shift reaction zone. Catalysts for the methane steam reforming reaction zone in the Ni_ZrO_2 catalyst were screened, and Pt / α-MoC was the catalyst for the water-gas shift + heavy oil cracking reaction zone. The particle size, physical and chemical adsorption, and other characteristics of the catalysts were tested.

[0040] Furthermore, an experimental study on the optimization of catalyst concentration was carried out in the laboratory. It was found that when the mixing mass ratio of the catalyst Pt / α-MoC to cuttings was above 0.02, the hydrogen production effect was good and stable, and the corresponding adsorption concentration per unit volume calculated according to the formula was 22.7 mol; when the mixing mass ratio of the catalyst Ni_ZrO_2 to sand was above 0.01, the hydrogen production effect was good and stable, and the corresponding adsorption amount per unit volume calculated according to the formula was 20.6 mol. Therefore, the target adsorption amount of the catalyst in the water-gas shift zone was 22.7 mol / m 3 , and the target adsorption amount of the catalyst in the methane steam reforming zone was 20.6 mol / m 3 . The catalyst concentration and injection rate of the injection system were optimized.

[0041] Upper and lower horizontal wells were used for separate injection, as Figure 3 shown. The upper horizontal well injected the catalyst Pt / α-MoC, with a system concentration of 0.05 wt% and a rate of 40 m 3 / d for an injection time of 30 d, as Figure 4 and Figure 5 shown; the lower horizontal well injected the catalyst Ni_ZrO_2, with a system concentration rate of 0.05 wt% and a rate of 40 m 3 / d for an injection time of 30 d, as Figure 6 and Figure 7 shown.

[0042] The injection of the catalyst is mainly affected by the injection method, catalyst type, and physical and chemical seepage characteristics. This scheme can divide the key reaction zones for hydrogen production in the oil and gas reservoir according to the key reaction path of oil and gas hydrogen production and temperature conditions, screen suitable catalysts and their usage amounts, and optimize the injection process parameters based on the injection system prepared with the catalyst, and transport the designed catalyst and its dosage to the target area.

Claims

1. A method for optimizing catalyst injection parameters applicable to in-situ hydrogen production process in oil and gas reservoirs, characterized in that, It includes the following steps: Sl. Obtain the geological parameters, engineering parameters, and reservoir fluid property parameters of the treatment well; S2. Identify the hydrogen production reaction path and area in the treatment reservoir; In step S2, for the method of identifying the key hydrogen production reaction path in the reservoir, calculate the self-heating temperature of the combustion of the reservoir per unit volume using the following formula, and determine the key reaction path that can be reached for in-situ hydrogen production in this oil and gas reservoir according to the temperature range: T is the reservoir temperature, in °C; T0 is the initial reservoir temperature, in °C. is the porosity per unit volume of the reservoir, in %; S o is the oil saturation, in %; ρ o is the density of crude oil, in kg / m 3 ; H o is the heat of combustion of oil, in KJ / mol; M o is the relative molecular mass of crude oil; S g is the gas saturation, in %; P N is the reservoir pressure, in MPa; H g is the heat of combustion of gas, in KJ / mol: P is the surface pressure, in MPa: is the volume of rock per unit volume, in m 3 ; C R is the specific heat capacity of rock, in J / kg·°C; S w is the water saturation, in %; C w is the specific heat capacity of water, in J / kg·°C; S3. Screen catalysts for different hydrogen production reaction paths and test their characteristic parameters; S4. Determine the catalyst dosage per unit volume in the reaction zone; Use indoor experiments to simulate the mixing ratio of the catalyst and reservoir cuttings under different reaction paths, optimize the optimal catalyst dosage through hydrogen production efficiency, and convert the static catalyst dosage into the corresponding adsorption amount of physical and chemical seepage; The indoor experiment simulation method described above is one of the reaction kettle + gas chromatography test experiment and the ARC-GCMS combined experiment; The adsorption capacity is calculated according to the formula for calculation; β is the adsorption amount of the catalyst per unit volume, gmol; Per unit volume, m 3 ; ρ r Rock density, kg / m 3 ; ρ c Catalyst density, kg / m 3 ; φ Porosity, %; k Mass ratio of catalyst to cuttings; M c Molecular weight of catalyst; S5. With the catalyst concentration as the target, conduct numerical simulation to optimize the catalyst injection process parameters.

2. The method for optimizing catalyst injection parameters applicable to in-situ hydrogen production process in oil and gas reservoirs according to claim 1, characterized in that, The geological parameters described in step Sl include porosity, permeability, saturation, rock pore size distribution, relative permeability curve, wettability, reservoir rock composition, reservoir pressure, and reservoir temperature; The engineering parameters include well type, well depth, and completion method; The reservoir fluid parameters include water type, salinity of water, oil phase components, gas phase components, oil viscosity-temperature curve, and combustion heat enthalpy corresponding to oil and gas.

3. The method for optimizing catalyst injection parameters applicable to in-situ hydrogen production process in oil and gas reservoirs according to claim 1, characterized in that, The temperature range is as follows: for water-gas shift, the reaction temperature is 450°C; for methane steam reforming, the temperature is 700 - 1000°C; for partial oxidation, the temperature is 1000 - 1300°C; for dry reforming, the temperature is 800 - 900°C; for coke gasification, the temperature is 800 - 1000°C; for heavy oil cracking, the temperature is 380 - 480°C.

4. The method for optimizing catalyst injection parameters applicable to in-situ hydrogen production process in oil and gas reservoirs according to claim 1, characterized in that, In step S2, for the method of identifying the reaction area of hydrogen production in the reservoir, use the popular software CMG in the petroleum industry for geological modeling and fitting. According to geological, engineering, and fluid characteristics, determine the temperature field division and the enrichment areas of CO, water vapor, methane gas, and coke, and divide the reaction area according to the reaction path.

5. The method for optimizing catalyst injection parameters applicable to in-situ hydrogen production process in oil and gas reservoirs according to claim 1, characterized in that, The catalysts for different hydrogen production reaction paths described in step S3 are as follows: the catalyst for water-gas shift is one or a mixture of nickel-based catalysts, copper-based catalysts, iron-based catalysts, and chromium-based catalysts; The catalyst for methane steam reforming is one or a mixture of nickel-based catalysts, chromium-based catalysts, and platinum-based catalysts; The catalyst for partial oxidation is noble metal catalysts, non-noble metal catalysts, and composite catalysts; The catalyst for dry reforming is one or a mixture of nickel-based catalysts, chromium-based catalysts, and palladium-based catalysts; The catalyst for coke gasification is one or a mixture of nickel-based catalysts, chromium-based catalysts, palladium-based catalysts, and iron-based catalysts; The catalyst for heavy oil cracking is one or a mixture of nickel-based catalysts, copper-based catalysts, iron-based catalysts, molybdenum-based catalysts, and platinum-based catalysts.

6. The method for optimizing catalyst injection parameters applicable to in-situ hydrogen production process in oil and gas reservoirs according to claim 1, characterized in that, The catalyst characteristic parameters in step S3 include catalyst particle diameter, particle shape, maximum adsorption amount, residual adsorption amount, and adsorption critical velocity.

7. The method for optimizing catalyst injection parameters applicable to in-situ hydrogen production process in oil and gas reservoirs according to claim 1, characterized in that, The catalyst injection process parameters described in step S5 include the injection catalyst system concentration and injection rate.

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