技术领域technical field
本发明属于二氧化碳处置利用技术领域，具体涉及一种二氧化碳封存与储层压裂改造方法。The invention belongs to the technical field of carbon dioxide disposal and utilization, and in particular relates to a carbon dioxide sequestration and reservoir fracturing transformation method.
背景技术Background technique
我国能源结构特征为多煤、少油、乏气。煤炭、天然气等在使用时都会产生大量CO2，CO2的大量排放引起的温室效应会对气候产生严重的影响。煤炭作为我国第一能源消耗品，其消费量占一次能源消费总量的比重始终超过百分之五十，大量的煤炭消耗决定了我国在能源利用时将会产生大量的煤基固废，特别是在燃煤发电区以及中西部产煤区，煤基固废的利用率极低，大部分产生的碎煤矸石、粉煤灰、炉渣等只能进行露天堆积处理，占用了大量的土地资源，对环境污染极其严重。my country's energy structure is characterized by more coal, less oil, and lack of gas. The use of coal and natural gas will produce a large amount of CO2 , and the greenhouse effect caused by the massive emission of CO2 will have a serious impact on the climate. Coal is the primary energy consumer in my country, and its consumption accounts for more than 50% of the total primary energy consumption. A large amount of coal consumption determines that my country will generate a large amount of coal-based solid waste during energy utilization, especially Especially in coal-fired power generation areas and coal-producing areas in the central and western regions, the utilization rate of coal-based solid waste is extremely low, and most of the generated crushed coal gangue, fly ash, and slag can only be piled up in the open air, occupying a large amount of land resources , extremely serious environmental pollution.
我国非常规天然气储量丰富，页岩气储量更是位居世界第一，因此天然气作为清洁能源将成为未来接替煤炭的重要能源。非常规天然气高效开发需要对储层进行压裂增透，当前的压裂增透方式多为水力压裂，这种技术虽然对非常规天然气的开发起到了重要的作用，但水力压裂存在水资源消耗巨大、储层黏土膨胀、地下水污染等缺点。my country has abundant unconventional natural gas reserves, and shale gas reserves rank first in the world. Therefore, natural gas, as a clean energy, will become an important energy source to replace coal in the future. Efficient development of unconventional natural gas requires fracturing to increase permeability of the reservoir. The current fracturing and enhancement methods are mostly hydraulic fracturing. Although this technology has played an important role in the development of unconventional natural gas, hydraulic fracturing has water Disadvantages such as huge resource consumption, expansion of reservoir clay, and groundwater pollution.
综上所述，我国煤炭资源开发过程中面临煤基固废处置利用率低，CO2排放量高等难题，而非常规天然气等清洁能源开采中又面临着水资源过度消耗及污染等难题。因此，实现大宗煤基固废有效处置利用，同时发展适用于非常规天然气的绿色开采技术，是重要举措。To sum up, the development of coal resources in China is faced with the problems of low utilization rate of coal-based solid waste disposal and highCO2 emissions, while the mining of clean energy such as unconventional natural gas is faced with problems such as excessive consumption of water resources and pollution. Therefore, it is an important measure to realize the effective disposal and utilization of bulk coal-based solid waste and to develop green mining technologies suitable for unconventional natural gas.
发明内容Contents of the invention
针对上述现有技术存在的问题，本发明提供一种二氧化碳封存与储层压裂改造方法，该方法实施步骤简单、实施成本低，其对储层的压裂增透效果理想，且压裂后不会引起储层黏土膨胀、地下水污染等问题，其可同时解决现有技术存在的煤基固废处置困难、CO2不能有效封存、非常规天然气水力压裂改造存在的环境破坏与储层破裂程度不足等一系列问题，能实现煤基固废利用、非常规天然气绿色开发与CO2封存处理的一体化作业。Aiming at the problems existing in the above-mentioned prior art, the present invention provides a carbon dioxide sequestration and reservoir fracturing reconstruction method. The method has simple implementation steps and low implementation cost. It will not cause problems such as reservoir clay expansion and groundwater pollution, and it can simultaneously solve the existing problems of coal-based solid waste disposal, CO2 cannot be effectively sequestered, environmental damage and reservoir rupture in unconventional natural gas hydraulic fracturing. Insufficient level and other problems can realize the integrated operation of coal-based solid waste utilization, green development of unconventional natural gas andCO2 storage and treatment.
为了实现上述目的，本发明提供一种二氧化碳封存与储层压裂改造方法，具体包括以下步骤；In order to achieve the above object, the present invention provides a method for carbon dioxide sequestration and reservoir fracturing reconstruction, which specifically includes the following steps;
本发明提供了一种二氧化碳封存与储层压裂改造方法，具体包括以下步骤；The invention provides a method for carbon dioxide sequestration and reservoir fracturing reconstruction, which specifically includes the following steps;
步骤一：利用煤基固废制备支撑剂原料；Step 1: using coal-based solid waste to prepare proppant raw materials;
S11：选择煤矸石、粉煤灰和高炉渣三种煤基固废制作压裂支撑剂原料；S11: Select coal gangue, fly ash and blast furnace slag as raw materials for fracturing proppant from three types of coal-based solid waste;
S12：对煤矸石进行破碎处理，然后再进行筛选处理，选出粒径为0.25～0.42mm的煤矸石备用；对粉煤灰进行筛选处理，选出粒径为0.21mm的粉煤灰备用；对高炉渣进行筛选处理，选出粒径为0.21mm的高炉渣备用；S12: crushing the coal gangue, and then screening to select the coal gangue with a particle size of 0.25-0.42 mm for use; screening the fly ash to select the fly ash with a particle size of 0.21 mm for use; The blast furnace slag is screened, and the blast furnace slag with a particle size of 0.21mm is selected for use;
S13：将煤矸石：粉煤灰：高炉渣以2:1:1的体积比例进行均匀混合，制成多源煤基固废支撑剂原料；S13: uniformly mix coal gangue: fly ash: blast furnace slag at a volume ratio of 2:1:1 to make a multi-source coal-based solid waste proppant raw material;
步骤二：液态CO2压裂造缝；Step 2: creating fractures by fracturing with liquid CO2 ;
S21：将液态CO2存储罐中的液态CO22输送至压裂车中，同时，将与高压油管连接的压裂装置通过井筒下放到目标储层段，并将高压油管与压裂车连接；S21: Transport the liquid CO2 in the liquid CO2 storage tank to the fracturing vehicle, and at the same time, lower the fracturing device connected to the high-pressure oil pipe to the target reservoir section through the wellbore, and connect the high-pressure oil pipe to the fracturing vehicle ;
S22：利用压裂车对液态CO2进行加压后经高压油管和压裂装置挤注到与井筒相连通的压裂孔道和与压裂孔道相连通的地层裂缝中，进而压裂地层形成复杂地层裂缝网络，该过程中，利用液态CO2对地层中的甲烷进行充分地置换，以对储层进行增透改造；S22: Use the fracturing vehicle to pressurize the liquid CO2 and squeeze it into the fracturing channels connected with the wellbore and the formation fractures connected with the fracturing channels through the high-pressure tubing and fracturing equipment, and then the fracturing formation forms complex Formation fracture network, in this process, liquid CO2 is used to fully replace the methane in the formation, so as to enhance the permeability of the reservoir;
步骤三：液态CO2携带支撑剂原料进入地层裂缝；Step 3: Liquid CO2 carries proppant raw materials into formation fractures;
S31：将一定量的多源煤基固废支撑剂原料和一定量的液态CO2加入至混合系统中，利用混合系统中对其进行充分的搅拌形成混合液；S31: Add a certain amount of multi-source coal-based solid waste proppant raw materials and a certain amount of liquid CO2 into the mixing system, and use the mixing system to fully stir them to form a mixed solution;
S32：将混合液输送至压裂车中，利用压裂车对混合液进行加压后经高压油管和压裂装置泵注到压裂孔道中；S32: Transport the mixed fluid to the fracturing truck, use the fracturing truck to pressurize the mixed fluid, and then pump the mixed fluid into the fracturing tunnel through the high-pressure oil pipe and the fracturing device;
S33：连续二次重复执行S31和S32；将步骤一制备出的多源煤基固废支撑剂原料分三批次地泵入到地层中，以实现复杂地层裂缝网络的充分填充，其中，三批次多源煤基固废支撑剂原料体积分数分别为5％、7％、10％；S33: Repeat S31 and S32 twice in a row; pump the multi-source coal-based solid waste proppant raw materials prepared in Step 1 into the formation in three batches to fully fill the fracture network in the complex formation. Among them, three The volume fractions of batches of multi-source coal-based solid waste proppant raw materials are 5%, 7%, and 10% respectively;
步骤四：支撑剂原料原位二次成型；Step 4: In-situ secondary molding of proppant raw materials;
在步骤三中的混合液泵注完毕后，关闭井口阀门，使混合液中的CO2与多源煤基固废支撑剂原料在地层裂缝网络中的高压条件下产生原位矿化反应，在该过程中，多源煤基固废支撑剂原料中含Ca、Mg的物质与CO2反应生成CaCO3、MgCO3矿物，从而形成高强度支撑剂，同时，参与原位矿化反应的CO2以碳酸盐的形式封存于地层裂缝网络中，实现了CO2封存；After the mixed liquid pumping in step 3 is completed, the wellhead valve is closed, so that the CO in the mixed liquid and the multi-source coal-based solid waste proppant raw materials produce in-situ mineralization reaction under the high pressurecondition in the formation fracture network, and the In this process, materials containing Ca and Mg in the multi-source coal-based solid waste proppant raw materials react with CO2 to generate CaCO3 and MgCO3 minerals, thereby forming high-strength proppants. At the same time, CO2 participating in the in-situ mineralization reaction It is stored in the formation fracture network in the form of carbonate, realizingCO2 storage;
步骤五：完成整体层段作业；Step 5: Complete the overall section operation;
在完成第一段地层作业后，将压裂工具移动至下一段地层，重复步骤二至四，直至完成所有层段液态CO2压裂造缝、支撑剂原位二次成型作业。After the first section of formation operation is completed, the fracturing tool is moved to the next section of formation, and steps 2 to 4 are repeated until all sections of liquid CO2 fracturing and fracture creation and in-situ secondary molding of proppant are completed.
进一步，为了确保能够获得更好的压裂效果，在步骤二中，压裂车将液态CO2加压至70MPa。Further, in order to ensure a better fracturing effect, in step 2, the fracturing vehicle pressurizes the liquid CO2 to 70MPa.
进一步，为了确保能够输送更高压力的气体，在步骤二中的高压油管的至少可以承受80MPa的气体压力。Further, in order to ensure the delivery of higher pressure gas, the high pressure oil pipe in step 2 can withstand at least 80MPa gas pressure.
本发明中，选择粒径为0.25～0.42mm的煤矸石、粒径为0.21mm的粉煤灰和粒径为0.21mm的高炉渣作为支撑剂的原料，不仅可以确保原料的输送过程更顺利方便，而且还能保证后续支撑剂原料与CO2之间的原位矿化反应更充分，从而能生成更大量的高强度支撑剂，同时，有利于实现更大量CO2的封存作业。先对液态CO2进行蓄能加压，再利用加压后的液态CO2对地层进行压裂，相比水力压裂，这种方式可以在地层中更容易形成复杂地层裂缝网络，且压裂后不会引起储层黏土膨胀、地下水污染等问题，同时，加压后的液态CO2还能对地层中的甲烷进行更充分地置换，进而可以显著提高地层的增透增产改造效果，有利于增加非常规天然气的开采效率。在利用液态CO2携带支撑剂原料进入地层裂缝的过程中，分三批次的将多源煤基固废支撑剂原料按体积比为5％、7％、10％的比例依次泵入到压裂孔道中，可以实现复杂裂缝网络的充分填充，同时，可以利用后续更大量的加注带动先前进入的混合液向更深处的裂缝中移动，进而可以有效确保压裂产生的裂缝不会愈合，进一步提高了增透增产改造效果。利用混合液中的CO2与支撑剂原料中含Ca、Mg的物质在地层裂缝中的高压条件下发生原位矿化反应并形成高强度支撑剂，可以获得能承载较大压力的支撑剂，进而可以具有更好的支撑效果，从而可以使压裂产生的裂缝得到更好的支撑，同时，这种方式还可以使参与反应的CO2以碳酸盐的形式封存于地层裂缝网络中，有效的实现了CO2的封存作业。In the present invention, coal gangue with a particle size of 0.25 to 0.42 mm, fly ash with a particle size of 0.21 mm and blast furnace slag with a particle size of 0.21 mm are selected as raw materials for the proppant, which not only ensures smoother and more convenient transportation of raw materials , and can also ensure a more sufficient in-situ mineralization reaction between the subsequent proppant raw material and CO2 , thereby generating a larger amount of high-strength proppant, and at the same time, it is beneficial to realize the storage operation of a larger amount of CO2 . Liquid CO2 is stored and pressurized first, and then the pressurized liquid CO2 is used to fracture the formation. Compared with hydraulic fracturing, this method can more easily form a complex formation fracture network in the formation, and fracturing At the same time, the pressurized liquid CO2 can more fully replace the methane in the formation, which in turn can significantly improve the effect of permeability enhancement and production enhancement of the formation, which is beneficial to Increase the extraction efficiency of unconventional natural gas. In the process of using liquidCO2 to carry the proppant raw materials into the formation fractures, the multi-source coal-based solid waste proppant raw materials are pumped into the pressure chamber in three batches according to volume ratios of 5%, 7%, and 10%. In the fracture channel, the complex fracture network can be fully filled, and at the same time, the subsequent injection of a larger amount can be used to drive the previously entered mixed fluid to move to deeper fractures, thereby effectively ensuring that the fractures generated by fracturing will not heal, and further Improve the transformation effect of increasing penetration and increasing production. Using theCO2 in the mixed liquid and the material containing Ca and Mg in the proppant raw material to undergo an in-situ mineralization reaction under high pressure in the formation fractures to form a high-strength proppant, a proppant that can bear a large pressure can be obtained. In turn, it can have a better support effect, so that the fractures generated by fracturing can be better supported. At the same time, this method can also make the CO2 participating in the reaction be stored in the formation fracture network in the form of carbonate, effectively The realization of CO2 sequestration operation.
本发明先利用液态CO2对非常规天然气储层进行绿色压裂改造实现增产增透改造，再将作为支撑剂原料的煤基固废与CO2注入至压裂裂缝中进行原位矿化反应形成可承受较大压力的高强度支撑剂，解决了现有技术存在的煤基固废处置困难、CO2不能有效封存、非常规天然气水力压裂改造存在的环境破坏与储层破裂程度不足等一系列问题，实现了煤基固废利用、非常规天然气绿色开发与CO2封存处理的一体化作业。In the present invention, liquidCO2 is used to carry out green fracturing transformation on unconventional natural gas reservoirs to realize production increase and anti-permeability transformation, and then coal-based solid waste as proppant raw material andCO2 are injected into fracturing fractures for in-situ mineralization reaction Form a high-strength proppant that can withstand relatively high pressure, which solves the difficulties in the disposal of coal-based solid waste, the ineffective storage of CO2 , the environmental damage and the insufficient degree of reservoir fracture in unconventional natural gas hydraulic fracturing, etc. A series of problems have realized the integrated operation of coal-based solid waste utilization, green development of unconventional natural gas andCO2 storage and treatment.
附图说明Description of drawings
图1是本发明中液态CO2压裂造缝的状态示意图；Fig. 1 is the state schematic diagram of liquidCO in the present invention fracturing fracture;
图2是本发明中液态CO2携带支撑剂原料进入地层裂缝的状态示意图；Fig. 2 is a schematic diagram of the state in which liquidCO carries proppant raw materials into formation fractures in the present invention;
图3是本发明中支撑剂原位二次成型的状态示意图；Fig. 3 is the state schematic diagram of in-situ secondary molding of proppant in the present invention;
图4是本发明中完成整体层段作业的状态示意图。Fig. 4 is a schematic diagram of the state of completing the overall interval operation in the present invention.
图中：1、液态CO2储存罐，2、液态CO2，3、压裂车，4、高压油管，5、压裂装置，6、井筒，7、压裂孔道，8、地层裂缝，9、复杂地层裂缝网络，10、混合系统，11、混合液，12、高强度支撑剂。In the figure: 1. Liquid CO2 storage tank, 2. Liquid CO2 , 3. Fracturing truck, 4. High-pressure tubing, 5. Fracturing device, 6. Wellbore, 7. Fracturing tunnel, 8. Formation fracture, 9 . Fracture network in complex formation, 10. Mixing system, 11. Mixed fluid, 12. High-strength proppant.
具体实施方式Detailed ways
本发明提供了一种二氧化碳封存与储层压裂改造方法，其先利用液态CO2对非常规天然气储层进行绿色压裂改造实现增产增透改造，再将煤基固废与CO2注入至压裂裂缝中进行原位矿化反应形成高强度支撑剂，在封存CO2的同时实现了煤基固废的处理利用，解决了现有技术存在的煤基固废处置困难、CO2不能有效封存、非常规天然气水力压裂对环境破坏的一系列问题，实现了煤基固废利用、非常规天然气绿色开发与CO2封存的一体化作业，具体包括以下步骤；The invention provides a carbon dioxide sequestration and reservoir fracturing transformation method, which first uses liquid CO2 to carry out green fracturing transformation on unconventional natural gas reservoirs to realize production increase and anti-permeability transformation, and then injects coal-based solid waste and CO2 into the The in-situ mineralization reaction in the fracturing fracture forms a high-strength proppant, which realizes the treatment and utilization of coal-based solid waste while sequestering CO2 , and solves the difficulties in the disposal of coal-based solid waste and the ineffectiveness of CO2 in the prior art. A series of problems of environmental damage caused by storage and unconventional natural gas hydraulic fracturing have realized the integrated operation of coal-based solid waste utilization, green development of unconventional natural gas andCO2 storage, specifically including the following steps;
步骤一：利用煤基固废制备支撑剂原料；Step 1: using coal-based solid waste to prepare proppant raw materials;
S11：选择煤矸石、粉煤灰和高炉渣三种煤基固废制作压裂支撑剂原料；S11: Select coal gangue, fly ash and blast furnace slag as raw materials for fracturing proppant from three types of coal-based solid waste;
S12：对煤矸石进行破碎处理，然后再进行筛选处理，选出粒径为0.25～0.42mm的煤矸石备用；对粉煤灰进行筛选处理，选出粒径为0.21mm的粉煤灰备用；对高炉渣进行筛选处理，选出粒径为0.21mm的高炉渣备用；S12: crushing the coal gangue, and then screening to select the coal gangue with a particle size of 0.25-0.42 mm for use; screening the fly ash to select the fly ash with a particle size of 0.21 mm for use; The blast furnace slag is screened, and the blast furnace slag with a particle size of 0.21mm is selected for use;
由于支撑剂原料与CO2的原位矿化反应受原料粒径大小的影响，且太大的原料粒径不利于输送作业，而煤矸石初始粒径较大，因而需要先对煤矸石进行破碎处理，而粉煤灰和高炉渣初始粒径较小，则不需要额外进行处理；Because the in-situ mineralization reaction of proppant raw materials andCO2 is affected by the particle size of raw materials, and too large particle size of raw materials is not conducive to transportation operations, and the initial particle size of coal gangue is relatively large, so the coal gangue needs to be crushed first treatment, while the initial particle size of fly ash and blast furnace slag is small, no additional treatment is required;
S13：将煤矸石：粉煤灰：高炉渣以2:1:1的体积比例进行均匀混合，制成多源煤基固废支撑剂原料；S13: uniformly mix coal gangue: fly ash: blast furnace slag at a volume ratio of 2:1:1 to make a multi-source coal-based solid waste proppant raw material;
步骤二：液态CO2压裂造缝；Step 2: creating fractures by fracturing with liquid CO2 ;
S21：如图1所示，将液态CO2存储罐1中的液态CO22输送至压裂车3中，同时，将与高压油管4连接的压裂装置5通过井筒6下放到目标储层段，并将高压油管4与压裂车3连接；S21: As shown in Figure 1, transport the liquid CO2 in the liquid CO2 storage tank 1 to the fracturing vehicle 3, and at the same time, lower the fracturing device 5 connected to the high-pressure tubing 4 to the target reservoir through the wellbore 6 section, and connect the high-pressure oil pipe 4 with the fracturing vehicle 3;
S22：利用压裂车3对液态CO22进行加压后经高压油管4和压裂装置5挤注到与井筒6相连通的压裂孔道7和与压裂孔道7相连通的地层裂缝8中，进而压裂地层形成复杂地层裂缝网络9，该过程中，利用液态CO22对地层中的甲烷进行充分地置换，以对储层进行增透改造；S22: Use the fracturing vehicle 3 to pressurize the liquid CO2 2 and squeeze it through the high-pressure tubing 4 and the fracturing device 5 into the fracturing tunnel 7 connected to the wellbore 6 and the formation fracture 8 connected to the fracturing tunnel 7 In the process, the formation is further fractured to form a complex formation fracture network9. During this process, liquid CO2 2 is used to fully replace the methane in the formation to perform anti-permeability stimulation on the reservoir;
步骤三：液态CO2携带支撑剂原料进入地层裂缝；Step 3: Liquid CO2 carries proppant raw materials into formation fractures;
S31：如图2所示，将一定量的多源煤基固废支撑剂原料和一定量的液态CO22加入至混合系统10中，利用混合系统中10对其进行充分的搅拌形成混合液11；S31: As shown in Figure 2, add a certain amount of multi-source coal-based solid waste proppant raw materials and a certain amount of liquid CO2 into the mixing system 10, and use the mixing system 10 to fully stir them to form a mixed liquid 11;
S32：将混合液11输送至压裂车3中，利用压裂车3对混合液11进行加压后经高压油管4和压裂装置5泵注到压裂孔道7中；S32: Transport the mixed liquid 11 to the fracturing truck 3, use the fracturing truck 3 to pressurize the mixed liquid 11, and pump the mixed liquid 11 into the fracturing tunnel 7 through the high-pressure oil pipe 4 and the fracturing device 5;
S33：连续二次重复执行S31和S32；将步骤一制备出的多源煤基固废支撑剂原料分三批次地泵入到地层中，以实现复杂地层裂缝网络9的充分填充，其中，三批次多源煤基固废支撑剂原料体积分数分别为5％、7％、10％，通过大量实验表明，采用这种梯度性增加的泵注方式，可以显著提高裂缝的支撑效果；S33: Repeat S31 and S32 twice in a row; pump the multi-source coal-based solid waste proppant raw material prepared in Step 1 into the formation in three batches, so as to fully fill the fracture network 9 in the complex formation, wherein, The raw material volume fractions of the three batches of multi-source coal-based solid waste proppants are 5%, 7%, and 10%, respectively. A large number of experiments have shown that the propping effect of fractures can be significantly improved by using this gradient-increased pumping method;
步骤四：支撑剂原料原位二次成型；Step 4: In-situ secondary molding of proppant raw materials;
如图3所示，在步骤三中的混合液11泵注完毕后，关闭井口阀门，使混合液11中的CO2与多源煤基固废支撑剂原料在地层裂缝网络中的高压条件下产生原位矿化反应，在该过程中，多源煤基固废支撑剂原料中含Ca、Mg的物质与CO2反应生成CaCO3、MgCO3等矿物(碳酸盐)，从而形成高强度支撑剂12，同时，参与原位矿化反应的CO2以碳酸盐的形式封存于地层裂缝网络中，实现了CO2封存；As shown in Figure 3, after the mixed solution 11 in step 3 is pumped, the wellhead valve is closed, so that the CO2 in the mixed solution 11 and the multi-source coal-based solid waste proppant raw materials are under high-pressure conditions in the formation fracture network. Produce in-situ mineralization reaction, in this process, materials containing Ca and Mg in multi-source coal-based solid waste proppant raw materials react with CO2 to generate CaCO3 , MgCO3 and other minerals (carbonates), thus forming high-strength Propant 12, at the same time, CO2 involved in the in-situ mineralization reaction is stored in the formation fracture network in the form of carbonate, realizing CO2 storage;
步骤五：完成整体层段作业；Step 5: Complete the overall section operation;
在完成第一段地层作业后，将压裂工具移动至下一段地层，重复步骤二至四，直至完成如图4所示的所有层段液态CO2压裂造缝、支撑剂原位二次成型作业。After completing the first section of formation operation, move the fracturing tool to the next section of formation, and repeat steps 2 to 4, until all sections of liquid CO2 fracturing and fracturing with proppant in situ are completed as shown in Figure 4. Forming work.
为了确保能够获得更好的压裂效果，在步骤二中，压裂车3将液态CO22加压至70MPa。In order to ensure a better fracturing effect, in step 2, the fracturing vehicle 3 pressurizes the liquid CO2 2 to 70MPa.
为了确保能够输送更高压力的气体，在步骤二中的高压油管4的至少可以承受80MPa的气体压力。In order to ensure that higher pressure gas can be delivered, the high pressure oil pipe 4 in step 2 can withstand at least 80MPa gas pressure.
本发明中，选择粒径为0.25～0.42mm的煤矸石、粒径为0.21mm的粉煤灰和粒径为0.21mm的高炉渣作为支撑剂的原料，不仅可以确保原料的输送过程更顺利方便，而且还能保证后续支撑剂原料与CO2之间的原位矿化反应更充分，从而能生成更大量的高强度支撑剂，同时，有利于实现更大量CO2的封存作业。先对液态CO2进行蓄能加压，再利用加压后的液态CO2对地层进行压裂，相比水力压裂，这种方式可以在地层中更容易形成复杂地层裂缝网络，且压裂后不会引起储层黏土膨胀、地下水污染等问题，同时，加压后的液态CO2还能对地层中的甲烷进行更充分地置换，进而可以显著提高地层的增透增产改造效果，有利于增加非常规天然气的开采效率。在利用液态CO2携带支撑剂原料进入地层裂缝的过程中，分三批次的将多源煤基固废支撑剂原料按体积比为5％、7％、10％的比例依次泵入到压裂孔道中，可以实现复杂裂缝网络的充分填充，同时，可以利用后续更大量的加注带动先前进入的混合液向更深处的裂缝中移动，进而可以有效确保压裂产生的裂缝不会愈合，进一步提高了增透增产改造效果。利用混合液中的CO2与支撑剂原料中含Ca、Mg的物质在地层裂缝中的高压条件下发生原位矿化反应并形成高强度支撑剂，可以获得能承载较大压力的支撑剂，进而可以具有更好的支撑效果，从而可以使压裂产生的裂缝得到更好的支撑，同时，这种方式还可以使参与反应的CO2以碳酸盐的形式封存于地层裂缝网络中，有效的实现了CO2的封存作业。In the present invention, coal gangue with a particle size of 0.25 to 0.42 mm, fly ash with a particle size of 0.21 mm and blast furnace slag with a particle size of 0.21 mm are selected as raw materials for the proppant, which not only ensures smoother and more convenient transportation of raw materials , and can also ensure a more sufficient in-situ mineralization reaction between the subsequent proppant raw material and CO2 , thereby generating a larger amount of high-strength proppant, and at the same time, it is beneficial to realize the storage operation of a larger amount of CO2 . Liquid CO2 is stored and pressurized first, and then the pressurized liquid CO2 is used to fracture the formation. Compared with hydraulic fracturing, this method can more easily form a complex formation fracture network in the formation, and fracturing At the same time, the pressurized liquid CO2 can more fully replace the methane in the formation, which in turn can significantly improve the effect of permeability enhancement and production enhancement of the formation, which is beneficial to Increase the extraction efficiency of unconventional natural gas. In the process of using liquidCO2 to carry the proppant raw materials into the formation fractures, the multi-source coal-based solid waste proppant raw materials are pumped into the pressure chamber in three batches according to volume ratios of 5%, 7%, and 10%. In the fracture channel, the complex fracture network can be fully filled, and at the same time, the subsequent injection of a larger amount can be used to drive the previously entered mixed fluid to move to deeper fractures, thereby effectively ensuring that the fractures generated by fracturing will not heal, and further Improve the transformation effect of increasing penetration and increasing production. Using theCO2 in the mixed liquid and the material containing Ca and Mg in the proppant raw material to undergo an in-situ mineralization reaction under high pressure in the formation fractures to form a high-strength proppant, a proppant that can bear a large pressure can be obtained. In turn, it can have a better support effect, so that the fractures generated by fracturing can be better supported. At the same time, this method can also make the CO2 participating in the reaction be stored in the formation fracture network in the form of carbonate, effectively The realization of CO2 sequestration operation.
本发明先利用液态CO2对非常规天然气储层进行绿色压裂改造实现增产增透改造，再将作为支撑剂原料的煤基固废与CO2注入至压裂裂缝中进行原位矿化反应形成可承受较大压力的高强度支撑剂，解决了现有技术存在的煤基固废处置困难、CO2不能有效封存、非常规天然气水力压裂改造存在的环境破坏与储层破裂程度不足等一系列问题，实现了煤基固废利用、非常规天然气绿色开发与CO2封存处理的一体化作业。In the present invention, liquidCO2 is used to carry out green fracturing transformation on unconventional natural gas reservoirs to realize production increase and anti-permeability transformation, and then coal-based solid waste as proppant raw material andCO2 are injected into fracturing fractures for in-situ mineralization reaction Form a high-strength proppant that can withstand relatively high pressure, which solves the difficulties in the disposal of coal-based solid waste, the ineffective storage of CO2 , the environmental damage and the insufficient degree of reservoir fracture in unconventional natural gas hydraulic fracturing, etc. A series of problems have realized the integrated operation of coal-based solid waste utilization, green development of unconventional natural gas andCO2 storage and treatment.
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310755477.XACN116658145B (en) | 2023-06-26 | 2023-06-26 | A method for carbon dioxide storage and reservoir fracturing transformation |
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310755477.XACN116658145B (en) | 2023-06-26 | 2023-06-26 | A method for carbon dioxide storage and reservoir fracturing transformation |
| Publication Number | Publication Date |
|---|---|
| CN116658145Atrue CN116658145A (en) | 2023-08-29 |
| CN116658145B CN116658145B (en) | 2024-12-13 |
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310755477.XAActiveCN116658145B (en) | 2023-06-26 | 2023-06-26 | A method for carbon dioxide storage and reservoir fracturing transformation |
| Country | Link |
|---|---|
| CN (1) | CN116658145B (en) |
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117662229A (en)* | 2023-12-21 | 2024-03-08 | 辽阳正阳机械设备制造有限公司 | New method for three-phase fracturing and permeability enhancement of coal seams |
| CN118879292A (en)* | 2024-10-08 | 2024-11-01 | 中国石油大学(华东) | Aerogel-surfactant nanofluid system and preparation method and application thereof, and method for increasing formation gas storage capacity |
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102168545B (en)* | 2011-03-30 | 2013-11-06 | 中国石油大学(北京) | Coiled tubing supercritical CO2 injection fracturing method |
| CN103288426B (en)* | 2013-05-28 | 2015-08-19 | 陕西科技大学 | A kind of method utilizing industrial waste to prepare the special fracturing propping agents of shale gas |
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117662229A (en)* | 2023-12-21 | 2024-03-08 | 辽阳正阳机械设备制造有限公司 | New method for three-phase fracturing and permeability enhancement of coal seams |
| CN118879292A (en)* | 2024-10-08 | 2024-11-01 | 中国石油大学(华东) | Aerogel-surfactant nanofluid system and preparation method and application thereof, and method for increasing formation gas storage capacity |
| Publication number | Publication date |
|---|---|
| CN116658145B (en) | 2024-12-13 |
| Publication | Publication Date | Title |
|---|---|---|
| CN115306479B (en) | A block-based CO2 sequestration method based on abandoned mine goaf | |
| CN116658145A (en) | Carbon dioxide sealing and reservoir fracturing transformation method | |
| CN109296350B (en) | Fracture network volume fracturing method for carbonate reservoir | |
| CN109505565B (en) | Method for extracting coal seam gas by water injection and gas injection alternating displacement | |
| CN113700527B (en) | Green mining method of high-strength mining face coal gangue overlying rock isolation grouting filling | |
| CN114622953B (en) | Coal mine gangue and CO 2 Mining overburden rock isolation grouting filling emission reduction method | |
| CN106089166A (en) | A CO2 foam huff and puff method for enhanced recovery in tight oil reservoirs | |
| CN112412424B (en) | Supercritical CO 2 Method for applying micro-nano proppant to exploitation of shale gas reservoir | |
| Reid et al. | Lick creek meakin sand unit immiscible CO2 waterflood project | |
| CN101333922A (en) | Fracturing process for removing breakdown fluid contamination | |
| CN103061730A (en) | Method for coal bed methane mining by multi-element thermal fluid foam displacement | |
| CN102913221A (en) | Volume transformation process of low permeability reservoir | |
| CN109025940B (en) | CO for tight oil reservoir2Fracturing oil displacement integrated oil extraction method | |
| CN114412433B (en) | Deep coal in-situ fluidization mining method based on heat extraction power generation | |
| CN111810109B (en) | Tide type sand-laying fracturing method | |
| CN103397900A (en) | Multi-hole cooperative pressure pumping integrated gas extraction method | |
| CN110924900A (en) | A method for hydraulic-liquid nitrogen composite uniform fracturing of coal | |
| CN115045643A (en) | Carbon dioxide fracturing-huff and puff combined production method applying surfactant | |
| CN117108258A (en) | Accurate advanced gas treatment method for large area of underground thick coal seam of coal mine | |
| CN118423071A (en) | A filling mining method based on multi-purpose roof horizontal well | |
| CN119531824A (en) | A natural gas hydrate reservoir reconstruction method based on recycled concrete aggregate | |
| CN104612649A (en) | Method and device for fracturing and permeability and yield increasing of coal-bed gas well of low-pressure and low permeability reservoir by means of chemical permeability increasing | |
| CN117662229B (en) | Three-phase fracturing permeability-increasing method for coal seam | |
| CN117819119B (en) | Continuous integrated device and method for trapping, sealing and separating underground rock stratum of flue gas | |
| CN107178388A (en) | Pressure coal gas device is taken out in heading pulse |
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |