CN113374460B - Method for extracting shale oil and high-calorific-value fuel gas from self-heating underground dry distillation oil shale - Google Patents

Abstract

Disclosure of the inventionThe method for extracting shale oil and high-calorific-value fuel gas from self-heating underground dry distillation oil shale utilizes oxygen-enriched gas and steam to cooperate with oil shale to complete dry distillation, not only promotes pyrolysis reaction and enables the oil shale to react completely, but also forms a self-cracking dry distillation process through coupled exothermic/endothermic pyrolysis reaction, after the dry distillation is started, required heat is mainly provided by heat released by low-temperature oxidation of fixed carbon generated by cracking of the oil shale, and the remaining fixed carbon is gasified into H₂ And fuel gas such as CO, and the high-temperature sensible heat generated after the dry distillation reaction is also recovered. The method for extracting shale oil and high-calorific-value fuel gas from the self-heating underground dry distillation oil shale can solve the problems of complex oil shale dry distillation oil extraction and gas production system, high management difficulty, low oil recovery rate and the like; the method has the advantages of simple operation, low mining cost, high mining efficiency and resource utilization rate, less three-waste discharge, remarkable environmental benefit and the like.

Description

Translated fromChinese

自热式地下干馏油页岩提取页岩油和高热值燃料气的方法Method for extracting shale oil and high calorific value fuel gas from autothermal underground retorting oil shale

技术领域technical field

本发明涉及油气开采技术领域，特别是一种自热式地下干馏油页岩提取页岩油和高热值燃料气的方法。The invention relates to the technical field of oil and gas exploitation, in particular to a method for extracting shale oil and high calorific value fuel gas from self-heating underground dry distillation oil shale.

背景技术Background technique

油页岩是一种含可燃有机质、高灰分(高无机质含量)的沉积岩，其含有的有机质经干馏可得到类似原油的页岩油。油页岩作为一种非常规的化石燃料资源，全球储量巨大，若折算成可获得的页岩油，相当于已探明石油储量的5.4倍。因此，油页岩被列为21世纪最重要的接替能源之一。Oil shale is a kind of sedimentary rock containing combustible organic matter and high ash content (high inorganic matter content). The organic matter contained in it can be retorted to obtain shale oil similar to crude oil. As an unconventional fossil fuel resource, oil shale has huge global reserves. If converted into available shale oil, it is equivalent to 5.4 times the proven oil reserves. Therefore, oil shale is listed as one of the most important replacement energy sources in the 21st century.

由于油页岩有机质(主要为大分子结构的干酪根)具有不溶、不熔的性质，所以很难用普通的溶剂提取。目前，热化学转化技术，即干馏或热解，是唯一推荐的油页岩制油方法。油页岩干馏通常是指在隔绝空气的条件下，将油页岩加热到500℃左右，从而使油页岩热解生成油和气的过程。油页岩干馏技术从方式上分为地上和地下工艺。地上技术是指先将油页岩矿石从地下开采运到地面后、再送到干馏炉内进行干馏的方法。地下技术又称原位干馏，即不经开采直接在地下加热矿层进行干馏。由于油页岩资源利用的主要瓶颈之一是其无机质含量非常高，提炼1吨页岩油会同时生成10-30吨固体废弃物，占用了大量的土地、环境污染严重，因此地下技术更有应用前景。并且地下技术可用于开发地表300米以下的深层油页岩资源，我国60％的油页岩矿层埋藏在地表300米以下，采矿成本高昂，地下技术被认为更适用于中国油页岩。Due to the insoluble and infusible nature of oil shale organic matter (mainly kerogen with macromolecular structure), it is difficult to extract with common solvents. Currently, thermochemical conversion techniques, i.e. retort or pyrolysis, are the only recommended methods for producing oil from oil shale. Oil shale dry distillation usually refers to the process of heating oil shale to about 500 °C under the condition of isolating air, thereby pyrolyzing oil shale to generate oil and gas. Oil shale dry distillation technology is divided into aboveground and underground processes in terms of methods. Above-ground technology refers to the method of first transporting oil shale ore from underground mining to the surface, and then sending it to a dry distillation furnace for dry distillation. Underground technology, also known as in-situ retorting, means retorting directly in the underground heating ore layers without mining. Because one of the main bottlenecks in the utilization of oil shale resources is its very high inorganic content, 10-30 tons of solid waste will be generated at the same time when 1 ton of shale oil is extracted, which occupies a lot of land and causes serious environmental pollution. Therefore, underground technology is more There are application prospects. And underground technology can be used to develop deep oil shale resources below the surface 300 meters. 60% of the oil shale layers in my country are buried below the surface 300 meters, and the mining cost is high. The underground technology is considered to be more suitable for Chinese oil shale.

然而目前地下技术还难以获得实际应用。主要的技术瓶颈之一是由于油页岩中的有机质为固态交联的大分子网状结构，需要升温到500℃以上将有机质裂解为油、气产物，然而在地下加热、升温油页岩矿层极为困难，操作难度很大。目前原位加热技术以电加热技术较为成熟，耗能巨大。同时在地下干馏工艺中，油页岩裂解后产生的碳留在地下而没有应用，这是一种资源的浪费，因为这些碳具有很高的热值。此外，如用热载气直接将油页岩加热到500℃以上，需要先将大量的热载气加热到650℃以上，高温热载气会造成油气的二次裂解和焦化而降低收油率，同时大量使用热载气导致干馏出口气量很大，油回收系统庞大，由于小量的油气混在大量的热载气中，摊薄了干馏出口气体中的含油比例，不仅使冷凝回收油比较困难，而且造成大量的热载气中低含量的油不能回收，降低了油回收率，冷凝收油后，不凝气中由于混有大量的N₂等不可燃气体使得气体产物的热值很低，有时不能点燃，不得不建煤气发生炉等为干馏补充热源，不仅加大了初始投入，也增加了运行成本，还有由于油气和热载气是混在一起的，所以冷凝收油时就必须同时冷凝热载气，这相当于不断重复升温和冷凝大量热载气的操作。However, the current underground technology is still difficult to obtain practical application. One of the main technical bottlenecks is that since the organic matter in the oil shale is a solid cross-linked macromolecular network structure, it needs to be heated to above 500 °C to crack the organic matter into oil and gas products. Extremely difficult, very difficult to operate. At present, the in-situ heating technology is relatively mature with electric heating technology, which consumes a lot of energy. At the same time, in the underground retorting process, the carbon generated after oil shale cracking remains underground without application, which is a waste of resources, because these carbons have a high calorific value. In addition, if the oil shale is directly heated to above 500°C with hot carrier gas, a large amount of hot carrier gas needs to be heated to above 650°C first. The high temperature hot carrier gas will cause secondary cracking and coking of oil and gas and reduce the oil recovery rate. At the same time, a large amount of hot carrier gas is used, which leads to a large amount of dry distillation outlet gas and a huge oil recovery system. Because a small amount of oil and gas is mixed with a large amount of hot carrier gas, the oil content in the dry distillation outlet gas is diluted, which not only makes it difficult to condense and recover oil, but also In addition, a large amount of low-content oil in the hot carrier gas cannot be recovered, which reduces the oil recovery rate. After the oil is condensed and recovered, the non-condensable gas is mixed with a large amount of non-flammable gases such as_N2 , which makes the calorific value of the gas product very low. Sometimes it cannot be ignited, and a gas generator has to be built to supplement the heat source for dry distillation, which not only increases the initial investment, but also increases the operating cost. In addition, because the oil and gas and the hot carrier gas are mixed together, the oil must be condensed and collected at the same time. The hot carrier gas is condensed, which is equivalent to the repeated operation of heating and condensing a large amount of hot carrier gas.

因此，急需开发一种地下干馏工艺以解决上述问题。Therefore, it is urgent to develop an underground dry distillation process to solve the above problems.

发明内容SUMMARY OF THE INVENTION

本发明的目的是要解决现有技术中存在的问题，提供一种操作简便，无高温热载体、收油率高且投资小的自热式地下干馏油页岩提取页岩油和高热值燃料气的方法。The purpose of the present invention is to solve the problems existing in the prior art, and to provide a kind of self-heating underground dry distillation oil shale extraction shale oil and high calorific value fuel that is easy to operate, has no high temperature heat carrier, has high oil recovery and low investment. gas method.

为达到上述目的，本发明是按照以下技术方案实施的：To achieve the above object, the present invention is implemented according to the following technical solutions:

一种自热式地下干馏油页岩提取页岩油和高热值燃料气的方法，包括以下步骤：A method for extracting shale oil and high calorific value fuel gas from autothermal underground dry distillation oil shale, comprising the following steps:

S1、钻数口注射井和生产井至目标油页岩层，并收集油页岩层中的水；S1. Drill several injection wells and production wells to the target oil shale formation, and collect the water in the oil shale formation;

S2、使用空气分离机分离出空气中的富O₂气体和N₂并收集；S2. Use an air separator to separate and collect the_O2 -rich gas and_N2 in the air;

S3、将空气分离机分离获得的N₂预热至250-500℃后通过注射井注入到油页岩层进行预热，待注射井附近的油页岩预热到200-400℃后停止通入N₂；S3. Preheat the N₂ obtained by the air separator to 250-500 °C and inject it into the oil shale layer through the injection well for preheating. After the oil shale near the injection well is preheated to 200-400 °C, stop feeding N₂ ;

S4、将空气分离机分离获得的富O₂气体和水蒸气按O₂/H₂O摩尔比为0.03-2.5的比例混合后通过注射井通入油页岩层对油页岩进行干馏，水蒸气和O₂与油页岩反应使油页岩温度上升，油页岩热解生成油气和固定碳，油气从生产井采收，部分固定碳同时与O₂反应放出干馏所需的热量，剩下的固定碳留在油页岩中；S4. Mix the O₂ rich gas and water vapor obtained by the separation of the air separator according to the ratio of O₂ /H₂ O molar ratio of 0.03-2.5, and then pass it into the oil shale layer through the injection well to dry distillation of the oil shale, and the water vapor Reacting with O₂ and oil shale makes the temperature of oil shale rise, oil shale pyrolysis generates oil and gas and fixed carbon, oil and gas are recovered from production wells, and part of the fixed carbon reacts with O₂ to release the heat required for dry distillation, and the remaining of fixed carbon remains in oil shale;

S5、待油页岩热解生油阶段结束后，停止通入富O₂气体，继续通过生产井向油页岩层通入水蒸气，水蒸气与残留在油页岩中的固定碳发生气化反应，生成富含H₂、CO和CH₄的燃料气并从生产井采收；S5. After the oil generation stage of oil shale pyrolysis, stop feeding_O2 -rich gas, continue feeding water vapor into the oil shale layer through the production well, and the water vapor reacts with the fixed carbon remaining in the oil shale to gasify , generating fuel gas rich in H₂ , CO and CH₄ and recovered from production wells;

S6、气化反应结束后，继续通过生产井向油页岩层通入水蒸气，水蒸气带走油页岩上的热量使油页岩温度降低，进而达到回收热岩石上显热的目的；S6. After the gasification reaction is completed, continue to inject water vapor into the oil shale layer through the production well, and the water vapor takes away the heat on the oil shale to reduce the temperature of the oil shale, thereby achieving the purpose of recovering the sensible heat on the hot rock;

S7、重复步骤S4-S6，使得油页岩从注射井到生产井方向不断反应，直至所有的油页岩采收完毕；S7. Repeat steps S4-S6 to make the oil shale react continuously from the injection well to the production well until all the oil shale is recovered;

S8、在地面分离和处理采出的油气，首先将其与水换热，先冷凝出页岩油并收油；剩下的气体产物继续与水换热将气体产物中的水蒸气冷凝为液态水；再除去剩下的气体产物中的CO₂，除去CO₂后得含H₂、CO和CH₄的燃料气。S8. Separating and processing the produced oil and gas on the ground, first exchanging heat with water, first condensing the shale oil and recovering the oil; the remaining gas product continues to exchange heat with water to condense the water vapor in the gas product into a liquid state Water; then remove CO₂ in the remaining gaseous product, after removing CO₂ , a fuel gas containing H₂ , CO and CH₄ is obtained.

作为本发明的进一步优选技术方案，所述步骤S2中，使用空气分离机分离出空气中的富O₂气体和N₂的具体过程为：使用空气分离机先将从空气中分离出N₂，然后使用空气分离机从空气中分离出富O₂气体。As a further preferred technical solution of the present invention, in the step S2, the specific process of using an air separator to separate the_O2 -rich gas and_N2 in the air is as follows: using an air separator to first separate_N2 from the air, The_O2 -rich gas is then separated from the air using an air separator.

作为本发明的进一步优选技术方案，所述步骤S8中，在地面分离和处理采出的油气与水换热冷凝出页岩油时，水蒸发为水蒸气，所用水主要为收集的油页岩层中的水，所述水蒸气用于步骤S4-S6。As a further preferred technical solution of the present invention, in the step S8, when the shale oil is condensed by heat exchange between the produced oil and gas and water in the ground separation and treatment, the water evaporates into water vapor, and the water used is mainly the collected oil shale layer The water in the water vapor is used in steps S4-S6.

作为本发明的进一步优选技术方案，所述步骤S8中，剩下的气体产物继续与水换热将气体产物中的水蒸气冷凝成的液态水循环用于在地面分离和处理采出的油气与水换热冷凝出页岩油。As a further preferred technical solution of the present invention, in the step S8, the remaining gas product continues to exchange heat with water to condense the water vapor in the gas product into a liquid water cycle for separating and processing the oil, gas and water produced on the ground. The heat exchange condenses out the shale oil.

本发明的自热式地下干馏油页岩提取页岩油和高热值燃料气的方法的原理为：干馏起动时不用点火，干馏启动后靠自身供热，无需高温热载体或电能等其它形式能量的输入，所需热量主要由油页岩裂解产生的固定碳低温氧化放出的热量提供；其载气的主要作用之一是载O₂而不是载热，所以可使用富氧载气，这样可大大减少供气量及干馏油气中混有N₂和CO₂等不凝气体，由此克服干馏出口气体处理量大、干馏出口气体中的含油比例和收油后的气体产物发热值低等问题，简化油冷凝回收系统，降低油回收的难度；在油页岩热解生油阶段，利用O₂与水蒸气协同与油页岩反应，既促进反应，增加收油率，又降低热解温度；生油阶段后，利用水蒸气将残留的固定碳气化为富含H₂和CO等燃气；气化反应结束后，进一步利用水蒸气将高温岩石上的显热带走回收，同时降低矿层温度，避免随后经过其用于干馏下游油页岩矿层的富氧水蒸气通过其换热而产生过高的温度，控制下游矿层干馏段温度低于500-550℃(油页岩发生低温干馏)，防止热解阶段油气二次反应和结焦。The principle of the method for extracting shale oil and high calorific value fuel gas from self-heating underground dry distillation oil shale of the present invention is as follows: no ignition is required when dry distillation is started; The required heat is mainly provided by the heat released by the low-temperature oxidation of fixed carbon produced by oil shale cracking; one of the main functions of its carrier gas is to carry O₂ instead of heat, so oxygen-rich carrier gas can be used, which can Greatly reduce the gas supply and the non-condensable gases such as N₂ and CO₂ mixed in the dry distillation oil and gas, thus overcoming the problems of large processing capacity of the dry distillation outlet gas, the proportion of oil in the dry distillation outlet gas, and the low calorific value of the gas product after oil recovery. , simplifies the oil condensation recovery system and reduces the difficulty of oil recovery; in the oil generation stage of oil shale pyrolysis, the use of O₂ and water vapor synergistically react with the oil shale, which not only promotes the reaction, increases the oil recovery rate, but also reduces the pyrolysis temperature ; After the oil generation stage, the residual fixed carbon is gasified into gas rich in H₂ and CO by water vapor; after the gasification reaction is completed, the sensible heat on the high-temperature rock is further recovered by water vapor, and the temperature of the ore bed is reduced at the same time. , to avoid the excessively high temperature of the oxygen-enriched water vapor that is subsequently used for dry distillation of the downstream oil shale ore layer through its heat exchange, and control the temperature of the downstream ore layer dry distillation section to be lower than 500-550 ℃ (low temperature dry distillation of oil shale), Prevent secondary reaction and coking of oil and gas in the pyrolysis stage.

与现有技术相比，本发明具有以下有益效果：Compared with the prior art, the present invention has the following beneficial effects:

1、本发明提供的自热式地下干馏油页岩提取页岩油和高热值燃料气的方法，热量由自身原位产生；干馏所需的水蒸气可由水通过换热利用采出油气所含的显热制备，不消耗额外的热量，大大提高了热能的利用效率；水由页岩油矿层中的水收集而来，油气中的水冷凝回收使用，可用于补充干馏反应消耗的水，实现水/水蒸气循环使用；通过减少油气中不可燃气体的含量降低了干馏出口气量，易于二氧化碳捕获或再利用，同时克服其他工艺中大量热载体中低含量的油不能回收而降低油回收率的问题。1. The method for extracting shale oil and high calorific value fuel gas from self-heating underground dry distillation oil shale provided by the present invention, the heat is generated in situ by itself; the water vapor required for dry distillation can be used by water through heat exchange to utilize the content of the produced oil and gas. It does not consume extra heat, which greatly improves the utilization efficiency of heat energy; the water is collected from the water in the shale oil layer, and the water in the oil and gas is condensed and recycled, which can be used to supplement the water consumed by the dry distillation reaction. Water/steam recycling; by reducing the content of incombustible gas in oil and gas, it reduces the amount of dry distillation outlet gas, which is easy to capture or reuse carbon dioxide, and at the same time overcomes the problem that the low content of oil in a large number of heat carriers in other processes cannot be recovered and reduces the oil recovery rate. question.

2、在油页岩裂解生油阶段，通过氧和水蒸气与油页岩的协同反应，促进油页岩的热解生油，增加油收率，同时降低了裂解的最低起始温度，并控制生油阶段的温度的最高温度在550℃以下(此温度为最理想的油页岩干馏终温，温度过低不能干馏完全，温度过高会造成油二次裂解和焦化，同样会降低油的回收率)，油回收率为90％以上；生油阶段后，水蒸汽与热岩石上的残碳反应，生成更多H₂、CO等燃气；由于使用富氧气体，即先将N₂气从空气中除掉，使得N₂气固有地与水蒸气及H₂、CO、CO₂和CH₄等不凝气分离，不仅提高了燃气的热值，还减少了传统工艺中分离这些气体所产生的高能消。2. In the oil generation stage of oil shale cracking, through the synergistic reaction of oxygen and water vapor with oil shale, the pyrolysis of oil shale is promoted to generate oil, the oil yield is increased, and the minimum initial temperature of cracking is reduced at the same time. The maximum temperature for controlling the temperature in the oil generation stage is below 550°C (this temperature is the ideal final temperature for dry distillation of oil shale. If the temperature is too low, the dry distillation cannot be completed. If the temperature is too high, it will cause secondary cracking and coking of oil, which will also reduce oil production. recovery rate), the oil recovery rate is more than 90%; after the oil generation stage, the water vapor reacts with the residual carbon on the hot rock to generate more gas such as H₂ and CO; due to the use of oxygen-enriched gas, the N₂ The gas is removed from the air, so that N₂ gas is inherently separated from water vapor and non-condensable gases such as H₂ , CO, CO₂ and CH₄ , which not only improves the calorific value of the gas, but also reduces the separation of these gases in the traditional process. The resulting high energy dissipation.

3、本发明提供的自热式地下干馏油页岩提取页岩油和高热值燃料气的方法可解决油页岩干馏采油、采气系统复杂，管理难度大，收油率低等问题；具有操作简单、开采成本较低、开采效率和资源利用率较高、三废排放少、环境效益显著等诸多优点。3. The method for extracting shale oil and high calorific value fuel gas from self-heating underground dry distillation oil shale provided by the present invention can solve the problems of complex oil shale dry distillation oil recovery and gas recovery system, difficult management, low oil recovery rate and the like; It has many advantages, such as simple operation, low mining cost, high mining efficiency and resource utilization rate, less discharge of three wastes, and significant environmental benefits.

附图说明Description of drawings

图1为本发明的流程图。FIG. 1 is a flow chart of the present invention.

图2为本发明的油页岩矿层热解及气化反应示意图。FIG. 2 is a schematic diagram of the pyrolysis and gasification reaction of the oil shale deposit of the present invention.

具体实施方式Detailed ways

为使本发明的目的、技术方案及优点更加清楚明白，以下结合实施例，对本发明进行进一步的详细说明。此处所描述的具体实施例仅用于解释本发明，并不用于限定发明。In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments. The specific embodiments described herein are only used to explain the present invention, but not to limit the invention.

如图1、图2所示，本实施例提供了一种自热式地下干馏油页岩提取页岩油和高热值燃料气的方法，包括以下步骤：As shown in FIG. 1 and FIG. 2 , the present embodiment provides a method for extracting shale oil and high calorific value fuel gas from autothermal underground retort oil shale, including the following steps:

S1、钻数口注射井和生产井至目标油页岩层，并收集油页岩层中的水；注射井用于将工艺所需的富氧气体、水蒸气和氮气等通入油页岩层，生产井用于收集油页岩热解生成的油气和固定碳的气化气；钻井过程中收集的水可用作油气冷凝收油的冷凝水，水与油气换热后气化的水蒸气可用于地下干馏；S1. Drill several injection wells and production wells to the target oil shale layer, and collect the water in the oil shale layer; the injection well is used to introduce the oxygen-rich gas, water vapor and nitrogen required by the process into the oil shale layer to produce The well is used to collect the oil and gas generated by the pyrolysis of oil shale and the gasification gas of fixed carbon; the water collected during the drilling process can be used as the condensed water for the oil and gas condensation and oil recovery, and the gasified water vapor after the heat exchange between the water and the oil and gas can be used for underground dry distillation;

S2、使用空气分离机分离出空气中的富O₂气体和N₂并收集；本实施例中，由于氮气对干馏化学反应的影响不大，所以富O₂气体不要求高纯，空分机要求不用很高，但降低氮气的浓度有利于后续油气产品的处理和可燃气体产品的质量，所以氮气的浓度可根据产物处理和制氧成本进行选择，即先将N₂气从空气中除掉，因为干馏生成的油气是和大量载气混在一起的，冷凝收油时就必须同时冷凝油气和大量载气，使得冷凝收油困难，一定量的油气不能冷凝，降低油收率，N₂气的除去意味着生产井出口处理气体量的大量降低，简化收油，提高收油效率；同时还可使N₂气固有地与水蒸气及H₂、CO、CO₂和CH₄等不凝气分离，不仅提高了燃气的热值，还减少了传统工艺中与这些气体分离所产生的高能消；S2. Use an air separator to separate and collect the_O2 -rich gas and_N2 in the air; in this embodiment, since nitrogen has little effect on the chemical reaction of dry distillation, the_O2 -rich gas does not require high purity, and the air separator requires It does not need to be very high, but reducing the concentration of nitrogen is beneficial to the treatment of subsequent oil and gas products and the quality of combustible gas products, so the concentration of nitrogen can be selected according to the cost of product treatment and oxygen production, that is, N₂ gas is removed from the air first, Because the oil and gas generated by dry distillation is mixed with a large amount of carrier gas, it is necessary to condense oil and gas and a large amount of carrier gas at the same time when condensing oil, which makes it difficult to condense oil, and a certain amount of oil and gas cannot be_condensed . Removal means that the amount of gas processed at the outlet of the production well is greatly reduced, simplifying oil recovery and improving oil recovery efficiency; at the same time, it can also inherently separate N₂ gas from water vapor and non-condensable gases such as H₂ , CO, CO₂ and CH₄ , which not only improves the calorific value of the gas, but also reduces the high energy consumption generated by the separation of these gases in the traditional process;

S3、将空气分离机分离获得的N₂通入预热罐预热至250-500℃后通过注射井注入到油页岩层进行预热，待注射井附近的油页岩预热到200-400℃后停止通入N₂，其后N₂不再使用；S3. The_N2 obtained by the air separator is passed into the preheating tank to be preheated to 250-500 °C, and then injected into the oil shale layer through the injection well for preheating, and the oil shale near the injection well is preheated to 200-400 °C After ℃, stop feeding N₂ , after that, N₂ is no longer used;

S4、将空气分离机分离获得的富O₂气体和水蒸气按O₂/H₂O摩尔比为0.1-0.3的比例混合后通过注射井通入油页岩层对油页岩进行干馏，水蒸气主要由水和生产井产出的油气换热制备，不消耗额外的热量；水蒸气和O₂与油页岩反应使油页岩温度上升，油页岩热解生成油气和固定碳，油气从生产井采收，部分固定碳同时与O₂反应放出干馏所需的热量，剩下的固定碳留在油页岩中；S4. Mix the O₂ rich gas and water vapor obtained by the separation of the air separator according to the ratio of O₂ /H₂ O molar ratio of 0.1-0.3, and then pass it into the oil shale layer through the injection well for dry distillation of the oil shale, and the water vapor It is mainly prepared by heat exchange between water and the oil and gas produced by the production well, without consuming additional heat; the reaction of water vapor and O₂ with the oil shale increases the temperature of the oil shale, and the oil shale is pyrolyzed to generate oil and gas and fixed carbon. In production well recovery, part of the fixed carbon reacts with_O2 to release the heat required for dry distillation, and the remaining fixed carbon remains in the oil shale;

S5、待油页岩热解生油阶段结束后，停止通入富O₂气体，继续通过生产井向油页岩层通入水蒸气，水蒸气与残留在油页岩中的固定碳发生气化反应，生成富含H₂、CO和CH₄的燃料气并从生产井采收；S5. After the oil generation stage of oil shale pyrolysis, stop feeding_O2 -rich gas, continue feeding water vapor into the oil shale layer through the production well, and the water vapor reacts with the fixed carbon remaining in the oil shale to gasify , generating fuel gas rich in H₂ , CO and CH₄ and recovered from production wells;

S6、气化反应结束后，继续通过生产井向油页岩层通入水蒸气，水蒸气带走油页岩上的热量使油页岩温度降低，进而达到回收热岩石上显热的目的，而且还可防止热解阶段油气的二次反应和结焦；S6. After the gasification reaction is over, continue to inject water vapor into the oil shale layer through the production well, and the water vapor takes away the heat on the oil shale to reduce the temperature of the oil shale, thereby achieving the purpose of recovering the sensible heat on the hot rock, and also It can prevent the secondary reaction and coking of oil and gas in the pyrolysis stage;

S7、重复步骤S4-S6，使得油页岩从注射井到生产井方向不断反应，直至所有的油页岩采收完毕；S7. Repeat steps S4-S6 to make the oil shale react continuously from the injection well to the production well until all the oil shale is recovered;

S8、在地面分离和处理采出的油气，首先将油气与水换热，先冷凝出页岩油并收油，换热时水蒸发为水蒸气，所用水主要为收集的油页岩层中的水，所述水蒸气可循环用于步骤S4-S6；剩下的气体产物继续与水换热将气体产物中的水蒸气冷凝为液态水，液态水循环用于与油气换热；再用CO₂捕获与封存技术除去剩下的气体产物中的CO₂，除去CO₂后得含H₂、CO和CH₄的燃料气，捕获的CO₂可封存或再利用。S8. Separating and processing the produced oil and gas on the ground, first heat-exchange the oil and gas with water, condense the shale oil first and collect the oil, the water evaporates into water vapor during the heat exchange, and the water used is mainly collected from the oil shale layer. Water, the water vapor can be recycled for steps S4-S6; the remaining gas products continue to exchange heat with water to condense the water vapor in the gas products into liquid water, and the liquid water is recycled for heat exchange with oil and gas; and then use CO₂ The capture and storage technology removes the CO₂ in the remaining gas products, and after the CO₂ is removed, a fuel gas containing H₂ , CO and CH₄ is obtained, and the captured CO₂ can be stored or reused.

本发明的主要创新之处在于：利用富氧气体与水蒸气协同与油页岩反应完成干馏，不但促进了热解反应，使油页岩反应彻底，还通过耦合放热/吸热的热解反应形成自裂解的干馏过程，干馏启动后，无需高温热载体或输入其它形式的能量用于加热油页岩矿层而产生能量消耗，所需热量主要由油页岩裂解产生的固定碳低温氧化放出的热量提供，剩下的固定碳被气化为H₂和CO等燃料气，干馏反应后产生的高温显热也被回收，进而实现了资源和能量的高效利用。同时，富氧气体的使用还大大减少供气量及干馏气体产物中混有N₂等不凝气体，由此克服干馏出口气体处理量大、干馏出口气体中的含油比例和收油后的气体产物发热值低等问题，简化油冷凝回收系统，降低油回收的难度。The main innovation of the present invention is that: the dry distillation is completed by using the oxygen-rich gas and water vapor to react with the oil shale, which not only promotes the pyrolysis reaction, and makes the oil shale reaction completely, but also through the coupled exothermic/endothermic pyrolysis The reaction forms a self-cracking dry distillation process. After the dry distillation is started, there is no need for high-temperature heat carrier or input of other forms of energy to heat the oil shale layer to generate energy consumption. The required heat is mainly released from the low-temperature oxidation of fixed carbon generated by oil shale cracking. The remaining fixed carbon is gasified into fuel gas such as H and_CO , and the high-temperature sensible heat generated after the dry distillation reaction is also recovered, thereby realizing the efficient utilization of resources and energy. At the same time, the use of oxygen-enriched gas also greatly reduces the gas supply and the non-condensable gases such as N₂ mixed in the dry distillation gas product, thereby overcoming the large processing capacity of the dry distillation outlet gas, the oil content in the dry distillation outlet gas, and the recovered gas. Problems such as low calorific value of products, simplify the oil condensation recovery system and reduce the difficulty of oil recovery.

本实施例通过耦合放热/吸热裂解反应进而实现自热式的干馏方法，降低了油页岩热解生油阶段的最低起始温度和反应的最高温度，提高了产油率和可燃气体的产气量，通过水/水蒸气及高温矿层上显热的回收并循环利用，大大提高了油页岩原位开采的热能利用效率，同时减少了污染物的排放，解决了生产效率低、浪费严重等诸多问题，降低了初始投入和运行成本，实现了经济、高效的油页岩提取油和高热值燃料气的原位开采。In this embodiment, an autothermal dry distillation method is realized by coupling the exothermic/endothermic cracking reaction, which reduces the minimum initial temperature and the maximum reaction temperature in the oil generation stage of oil shale pyrolysis, and improves the oil production rate and combustible gas. Through the recovery and recycling of water/steam and sensible heat on high-temperature ore layers, the thermal energy utilization efficiency of in-situ mining of oil shale is greatly improved, and the discharge of pollutants is reduced at the same time, which solves the problem of low production efficiency and waste. Serious and many other problems, reduce the initial investment and operating costs, and realize the economical and efficient in-situ extraction of oil shale extraction oil and high calorific value fuel gas.

本发明的技术方案不限于上述具体实施例的限制，凡是根据本发明的技术方案做出的技术变形，均落入本发明的保护范围之内。The technical solutions of the present invention are not limited to the limitations of the above-mentioned specific embodiments, and all technical modifications made according to the technical solutions of the present invention fall within the protection scope of the present invention.

Claims (4)

Translated fromChinese

1.一种自热式地下干馏油页岩提取页岩油和高热值燃料气的方法，其特征在于，包括以下步骤：1. a method for self-heating underground dry distillation oil shale extracting shale oil and high calorific value fuel gas, is characterized in that, comprises the following steps:S1、钻数口注射井和生产井至目标油页岩层，并收集油页岩层中的水；S1. Drill several injection wells and production wells to the target oil shale formation, and collect the water in the oil shale formation;S2、使用空气分离机分离出空气中的富O₂气体和N₂并收集；S2. Use an air separator to separate and collect the_O2 -rich gas and_N2 in the air;S3、将空气分离机分离获得的N₂预热至250-500℃后通过注射井注入到油页岩层进行预热，待注射井附近的油页岩预热到200-400℃后停止通入N₂；S3. Preheat the N₂ obtained by the air separator to 250-500 °C and inject it into the oil shale layer through the injection well for preheating. After the oil shale near the injection well is preheated to 200-400 °C, stop feeding N₂ ;S4、将空气分离机分离获得的富O₂气体和水蒸气按O₂/H₂O摩尔比为0.03-2.5的比例混合后通过注射井通入油页岩层对油页岩进行干馏，水蒸气和O₂与油页岩反应使油页岩温度上升，油页岩热解生成油气和固定碳，油气从生产井采收，部分固定碳同时与O₂反应放出干馏所需的热量，剩下的固定碳留在油页岩中；S4. Mix the O₂ rich gas and water vapor obtained by the separation of the air separator according to the ratio of O₂ /H₂ O molar ratio of 0.03-2.5, and then pass it into the oil shale layer through the injection well to dry distillation of the oil shale, and the water vapor Reacting with O₂ and oil shale makes the temperature of oil shale rise, oil shale pyrolysis generates oil and gas and fixed carbon, oil and gas are recovered from production wells, and part of the fixed carbon reacts with O₂ to release the heat required for dry distillation, and the remaining of fixed carbon remains in oil shale;S5、待油页岩热解生油阶段结束后，停止通入富O₂气体，继续通过生产井向油页岩层通入水蒸气，水蒸气与残留在油页岩中的固定碳发生气化反应，生成富含H₂、CO和CH₄的燃料气并从生产井采收；S5. After the oil generation stage of oil shale pyrolysis, stop feeding_O2 -rich gas, continue feeding water vapor into the oil shale layer through the production well, and the water vapor reacts with the fixed carbon remaining in the oil shale to gasify , generating fuel gas rich in H₂ , CO and CH₄ and recovered from production wells;S6、气化反应结束后，继续通过生产井向油页岩层通入水蒸气，水蒸气带走油页岩上的热量使油页岩温度降低，进而达到回收热岩石上显热的目的；S6. After the gasification reaction is completed, continue to inject water vapor into the oil shale layer through the production well, and the water vapor takes away the heat on the oil shale to reduce the temperature of the oil shale, thereby achieving the purpose of recovering the sensible heat on the hot rock;S7、重复步骤S4-S6，使得油页岩从注射井到生产井方向不断反应，直至所有的油页岩采收完毕；S7. Repeat steps S4-S6 to make the oil shale react continuously from the injection well to the production well until all the oil shale is recovered;S8、在地面分离和处理采出的油气，首先将其与水换热，先冷凝出页岩油并收油；剩下的气体产物继续与水换热将气体产物中的水蒸气冷凝为液态水；再除去剩下的气体产物中的CO₂，除去CO₂后得含H₂、CO和CH₄的燃料气。S8. Separating and processing the produced oil and gas on the ground, first exchanging heat with water, first condensing the shale oil and recovering the oil; the remaining gas product continues to exchange heat with water to condense the water vapor in the gas product into a liquid state Water; then remove CO₂ in the remaining gaseous product, after removing CO₂ , a fuel gas containing H₂ , CO and CH₄ is obtained.2.根据权利要求1所述的自热式地下干馏油页岩提取页岩油和高热值燃料气的方法，其特征在于，所述步骤S2中，使用空气分离机分离出空气中的富O₂气体和N₂的具体过程为：使用空气分离机先将从空气中分离出N₂，然后使用空气分离机从空气中分离出富O₂气体。2. the method for extracting shale oil and high calorific value fuel gas from self-heating underground dry distillation oil shale according to claim 1, is characterized in that, in described step S2, use air separator to separate out the rich O in the air₂ The specific process of gas and N₂ is: firstly separate N₂ from the air using an air separator, and then use an air separator to separate the O₂ rich gas from the air.3.根据权利要求1所述的自热式地下干馏油页岩提取页岩油和高热值燃料气的方法，其特征在于，所述步骤S8中，在地面分离和处理采出的油气与水换热冷凝出页岩油时，水蒸发为水蒸气，所用水主要为收集的油页岩层中的水，所述水蒸气用于步骤S4-S6。3. the method for extracting shale oil and high calorific value fuel gas from self-heating underground retort oil shale according to claim 1, is characterized in that, in described step S8, the oil and gas and water produced by ground separation and processing When the shale oil is condensed by heat exchange, the water evaporates into water vapor, and the water used is mainly the water in the collected oil shale layer, and the water vapor is used in steps S4-S6.4.根据权利要求1所述的自热式地下干馏油页岩提取页岩油和高热值燃料气的方法，其特征在于，所述步骤S8中，剩下的气体产物继续与水换热将气体产物中的水蒸气冷凝成的液态水循环用于在地面分离和处理采出的油气与水换热冷凝出页岩油。4. The method for extracting shale oil and high calorific value fuel gas from self-heating underground retort oil shale according to claim 1, characterized in that, in the step S8, the remaining gas products continue to exchange heat with water to The water vapor in the gas product is condensed into a liquid water cycle, which is used to separate and process the produced oil and gas on the ground and exchange heat with water to condense the shale oil.

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