技术领域technical field
本发明涉及煤矿瓦斯消突工艺，特别是指一种地面区域条带煤矿瓦斯消突工艺。The invention relates to a coal mine gas outburst elimination technology, in particular to a coal mine gas outburst elimination technology in strips on the ground.
背景技术Background technique
煤炭在我国国民经济建设，能源需求方面占有举足轻重的地位。随着国家经济的飞速发展，对煤炭需求不断增加，开采强度、开采深度、地应力不断增大，绝对瓦斯涌出量不断增加，导致单一依靠通风解决瓦斯超限难度增加，煤岩-瓦斯复合动力灾害现象出现的机会和煤与瓦斯突出的可能性明显增多。因此，需要通过一些措施来降低煤层中的瓦斯含量，减少煤与瓦斯突出、煤岩复合动力灾害事故的发生。降低煤层瓦斯含量的方法主要包括井下抽采和地面抽采。井下瓦斯抽采虽然可以起到快速降低瓦斯含量的目的，但是其工程量大，治理成本高。同时，由于抽采瓦斯浓度低，利用率比较低，直接排放到大气中的甲烷气体，不仅对环境造成严重污染，而且造成资源浪费。随着我国地面煤层气基础理论研究的不断完善，煤层气地面开发工艺逐渐趋于成熟。对于短期内不需要采煤的区域，通过地面煤层气井进行瓦斯抽采，可以降低煤层瓦斯含量，减少煤与瓦斯突出的危险性。但是现有常规直井控制范围相对有限，地面进行煤层气抽采时容易出现盲区，且开发周期相对比较长，煤矿开采过程中对于高瓦斯矿井，尤其是煤与瓦斯突出矿井，往往导致在未完全降到煤矿安全规程规定的瓦斯含量标准时井下已开始进行采煤作业，导致工作面接替紧张，影响煤矿安全、高效生产。因此，迫切需要一种工艺不仅可以有效降低煤层瓦斯含量，而且可以缩短开发周期，实现煤层瓦斯快速降低的目的。只有降低了煤层瓦斯，煤矿才能安全、高效生产，提高煤矿产量。Coal plays an important role in my country's national economic construction and energy demand. With the rapid development of the country's economy, the demand for coal continues to increase, the mining intensity, mining depth, and ground stress continue to increase, and the absolute gas emission volume continues to increase, making it more difficult to solve gas exceeding the limit by relying solely on ventilation. The chances of dynamic disaster phenomena and the possibility of coal and gas outbursts have increased significantly. Therefore, it is necessary to take some measures to reduce the gas content in the coal seam and reduce the occurrence of coal and gas outburst and coal-rock composite dynamic disaster accidents. The methods to reduce the gas content of coal seams mainly include underground drainage and ground drainage. Although underground gas drainage can quickly reduce the gas content, it requires a large amount of work and high treatment costs. At the same time, due to the low concentration and low utilization rate of the extracted gas, the methane gas directly discharged into the atmosphere not only causes serious pollution to the environment, but also causes a waste of resources. With the continuous improvement of basic theoretical research on surface coalbed methane in my country, the surface development technology of coalbed methane is gradually becoming mature. For areas that do not require coal mining in the short term, gas drainage through surface coalbed methane wells can reduce the gas content of coal seams and reduce the risk of coal and gas outbursts. However, the control range of existing conventional vertical wells is relatively limited. Blind spots are prone to occur when coalbed methane is extracted from the ground, and the development cycle is relatively long. When the gas content standard stipulated in the coal mine safety regulations has been reduced, coal mining operations have started underground, resulting in tension in the replacement of the working face, which affects the safety and high-efficiency production of the coal mine. Therefore, there is an urgent need for a process that can not only effectively reduce the gas content of coal seams, but also shorten the development cycle and achieve the purpose of rapid reduction of coal seam gas. Only by reducing coal seam gas can coal mines be able to produce safely and efficiently and increase coal mine output.
发明内容Contents of the invention
本发明提出一种地面区域条带煤矿瓦斯消突工艺，解决了现有技术中常规煤层气直井、水平井开发过程中抽采周期长，难以解决工作面接替紧张的问题。The present invention proposes a strip coal mine gas outburst elimination process in the ground area, which solves the problem of long drainage cycle and difficult replacement of working faces in the conventional conventional coalbed methane vertical well and horizontal well development process in the prior art.
本发明的技术方案是这样实现的：一种地面区域条带煤矿瓦斯消突工艺，包括如下步骤：The technical solution of the present invention is realized in the following way: a strip coal mine gas outburst elimination process in the ground area comprises the following steps:
a.根据储层特点以及地质特征，对分支布置方式进行优选；a. According to the characteristics of the reservoir and geological characteristics, optimize the arrangement of branches;
b.根据资源潜力评价结果，以及岩层岩性、空间展布，对直井井位进行优选；b. According to the evaluation results of resource potential, as well as the lithology and spatial distribution of rock formations, optimize the location of vertical wells;
c.根据以往勘探开发资料以及煤矿揭露等资料对造斜点进行优选；c. Optimizing kickoff points based on previous exploration and development data and coal mine disclosure data;
d.根据煤储层渗透性特征以及预测区工作面布置，对分支参数进行优选；d. According to the permeability characteristics of the coal reservoir and the layout of the working face in the prediction area, optimize the branch parameters;
e.根据储层特征，对储层改造工艺进行优选；e. Optimizing the reservoir stimulation process according to the characteristics of the reservoir;
f.将钻井设备搬运到井场后，根据前期设计，开始直井段钻进，当钻至基岩以下设计深度后完成一开完井，其中固井水泥返至地面，随后继续钻进，在钻至预造斜点时，根据取芯结果对岩性及地层特征进行判识，若符合造斜要求开始造斜，否则重新选取造斜点，并完成二开固井；f. After moving the drilling equipment to the well site, according to the previous design, start drilling in the vertical well section. After drilling to the designed depth below the bedrock, complete the first drilling and completion, in which the cementing cement returns to the ground, and then continue drilling. When drilling to the pre-build point, judge the lithology and formation characteristics according to the results of coring. If the build-up requirements are met, start the build-up; otherwise, re-select the build-up point and complete the second well cementing;
g.完成造斜后，根据设计要求，完成主支段钻进，并对煤岩心进行观测，分析沿主支煤体结构变化特征，为分支造斜点选取提供依据，其中三开不进行水泥固井；g. After the build-up is completed, according to the design requirements, complete the drilling of the main branch section, observe the coal core, analyze the change characteristics of the coal body structure along the main branch, and provide a basis for the selection of the branch build-up point, of which no cement is used for the third opening Cementing;
h.选取造斜点后，继续钻进至设计深度，依次完成分支钻进；h. After selecting the kickoff point, continue to drill to the design depth, and complete branch drilling in sequence;
i.根据压裂设计完成主支水力喷射压裂，依次完成后续工作；i. Complete the hydraulic jet fracturing of the main branch according to the fracturing design, and complete the follow-up work in sequence;
j.根据排采设计开始排采。j. Start drainage according to the drainage design.
所述的步骤a中，分支布置方式优选，是根据煤层厚度及煤层层数，对分支的空间位置关系进行布置与优选，主支井为水平井，分支井采用与主支井同向并平行于主支井方向钻进；In the step a, the optimal arrangement of the branches is based on the thickness of the coal seam and the number of layers of the coal seam to arrange and optimize the spatial position of the branches. The main branch well is a horizontal well, and the branch wells are in the same direction and parallel to the main branch well. Drilling in the direction of the main branch well;
对于单一煤层；当只对一侧预采区工作面瓦斯进行抽采时，采用在主支井上进行若干分支井钻进；当两侧工作面相距较近，为同一个压力系统，并且储层地质条件相近时，同时对两侧工作面瓦斯进行抽采，采用在同一井筒两侧均进行一主支井钻进，在每根主支井上进行若干分支井钻进；For a single coal seam; when the gas is only extracted from the working face in the pre-mining area on one side, several branch wells are drilled on the main branch well; when the working faces on both sides are close to each other, it is the same pressure system, and the reservoir When the geological conditions are similar, the gas on both sides of the working face is extracted at the same time, and a main branch well is drilled on both sides of the same wellbore, and several branch wells are drilled on each main branch well;
对于发育两层及两层以上煤层，间距较小，并且储层条件相似的区域，采用多层煤合层排采的方式；对于两层煤距离较近，并且适合合层排采的区域，当煤体结构完整，采用在同一个主支井进行两层煤层分支井的钻进；对于同时在水平段钻出多个分支难度较大以及两层煤间距过大的区域，采用分别在同一井筒不同处进行造斜，分别在两根主支井进行两层煤层分支井的钻进。For areas with two or more coal seams with small intervals and similar reservoir conditions, the multi-layer coal seam drainage method is adopted; for areas where the distance between two coal layers is relatively close and suitable for joint seam drainage, When the coal body structure is complete, use the same main branch well to drill two-layer coal seam branch wells; for areas where it is difficult to drill multiple branches in the horizontal section at the same time and the distance between two layers of coal is too large, use the same branch well to drill separately. The wellbore is deflected at different places, and the branch wells in the two coal seams are drilled in the two main and branch wells respectively.
所述的步骤b中，井位选择时要考虑地层稳定性，远离断层、陷落柱以及地质构造复杂区域，便于造斜点的确定。In the above step b, the stability of the formation should be considered when selecting the well location, and it should be far away from faults, collapse columns and areas with complex geological structures, so as to facilitate the determination of kickoff points.
所述的步骤c中，造斜点的优选，是根据钻井轨迹所经过岩层的性质，选择层位稳定处进行造斜，包括主支井造斜点的选取和分支井造斜点的选取；对于主支井的造斜点的选取，要选择层位稳定、岩石强度较好的层位，避免在泥岩、页岩造斜；对于分支井造斜点选取，根据主支钻进过程中煤岩取芯观测，选择在硬煤发育区进行分支井的造斜与钻进。In the described step c, the optimization of the kickoff point is to select a stable layer for kickoff according to the properties of the rock strata passed by the drilling trajectory, including the selection of the kickoff point of the main branch well and the selection of the kickoff point of the branch well; For the selection of the kickoff point of the main branch well, it is necessary to choose a layer with stable formation and good rock strength, and avoid building deflection in mudstone and shale; for the selection of the kickoff point of the branch well, according to the coal Rock coring observations were carried out, and the deflection and drilling of branch wells were selected in the hard coal development area.
所述的步骤d中，分支参数优化，是根据抽采周期、储层渗透性特征，合理布置分支间距、分支数目以及分支长度；In the step d, branch parameter optimization is to rationally arrange branch spacing, branch number and branch length according to the drainage cycle and reservoir permeability characteristics;
为了确定合理的分支间距，首先应该对储层渗透性进行测试，根据储层渗透性好坏确定合理的分支间距，对于渗透性较好的区域，可以适当增加分支间距，对于渗透性比较差的区域，由于储层瓦斯运移阻力较大，应该减小分支的间距，减少瓦斯在未改造储层中的运移距离，分支间距为15~45m；In order to determine a reasonable branch spacing, the reservoir permeability should be tested first, and a reasonable branch spacing should be determined according to the reservoir permeability. For areas with better permeability, the branch spacing can be appropriately increased. For areas with poor permeability In the area, due to the high resistance to gas migration in the reservoir, the distance between branches should be reduced to reduce the migration distance of gas in the unreformed reservoir, and the distance between branches should be 15-45m;
分支数目的确定主要是根据分支间距以及回采面宽度，分支间距越小，分支数目越大，分支间距越大，分支数越小，分支数目为4~6支；The determination of the number of branches is mainly based on the distance between branches and the width of the mining face. The smaller the distance between branches, the larger the number of branches, the larger the distance between branches, the smaller the number of branches, and the number of branches is 4 to 6;
为了尽量排采储层中的煤粉，使储层应力得到释放，应该尽量增加分支长度，但是，分支长度过大，增加了钻井难度，并且长度过长导致深度瓦斯难以运移，所以，分支长度为600~800m。In order to drain the pulverized coal in the reservoir as much as possible and release the stress of the reservoir, the branch length should be increased as much as possible. However, if the branch length is too large, it will increase the difficulty of drilling, and if the branch length is too long, it will be difficult for deep gas to migrate. Therefore, the branch The length is 600~800m.
所述的分支间距为20-30m。The distance between the branches is 20-30m.
所述的步骤e中，根据储层特征，对储层改造工艺进行优选；储层改造工艺优选，是根据储层特点选择与之相适应的储层改造工艺，提高储层渗透性，包括对主支井进行水力喷射改造；其中水力喷射段间距为30~50m，喷嘴布置采用180°相位分布，每米4-5个喷嘴，喷射水压20-35MPa，时间不低于30分钟。In the step e, according to the characteristics of the reservoir, the reservoir transformation process is optimized; the optimization of the reservoir transformation process is to select a suitable reservoir transformation process according to the characteristics of the reservoir to improve the permeability of the reservoir, including Main and branch wells undergo hydrojet transformation; the interval of hydrojet sections is 30-50m, the nozzle layout adopts 180° phase distribution, 4-5 nozzles per meter, the jet water pressure is 20-35MPa, and the time is not less than 30 minutes.
本发明的优点：Advantages of the present invention:
（1）多个水平井共用一个直井段，减少了直井段钻井工程量，缩短了施工时间，同时大大降低了直井段钻井费用，减少了开发投入。(1) Multiple horizontal wells share one vertical well section, which reduces the drilling engineering volume of the vertical well section and shortens the construction time. At the same time, it greatly reduces the drilling cost of the vertical well section and reduces the development investment.
（2）多个水平井段共用一套抽采设备，减少了地面井场数和抽采设备，降低了成本，同时便于现场维护、操作及气体集输。(2) Multiple horizontal well sections share a set of extraction equipment, which reduces the number of surface well sites and extraction equipment, reduces costs, and facilitates on-site maintenance, operation, and gas gathering and transportation.
（3）钻井过程大量煤粉排出起到了泄应力作用，提高了储层导流能力。同时，缩短了气体向井筒运移距离，降低了气体向井筒运移阻力，便于煤层气快速产出，满足了煤矿工作面接替需要。(3) During the drilling process, a large amount of pulverized coal is discharged to relieve stress and improve the conductivity of the reservoir. At the same time, it shortens the gas migration distance to the wellbore, reduces the gas migration resistance to the wellbore, facilitates the rapid production of coalbed methane, and meets the replacement needs of coal mine working faces.
通过该工艺不仅可以降低地面煤层气开发成本，而且可以缩短瓦斯抽采周期，实现快速降低煤层瓦斯含量的目的，对提高煤矿产量，加快煤炭行业快速发展具有极大的促进作用。This process can not only reduce the development cost of ground coalbed methane, but also shorten the gas drainage cycle, achieve the purpose of quickly reducing the gas content of coal seams, and greatly promote the increase of coal mine output and the rapid development of the coal industry.
附图说明Description of drawings
为了更清楚地说明本发明实施例或现有技术中的技术方案，下面将对实施例或现有技术描述中所需要使用的附图作简单地介绍，显而易见地，下面描述中的附图仅仅是本发明的一些实施例，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据这些附图获得其他的附图。In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative work.
图1为单一煤层单向分支井布置示意图。Figure 1 is a schematic diagram of the layout of one-way branch wells in a single coal seam.
图2为单一煤层双向分支井布置示意图。Figure 2 is a schematic diagram of the layout of two-way branch wells in a single coal seam.
图3为两层煤层分支井布置示意图一。Figure 3 is a schematic diagram of the layout of branch wells in two coal seams.
图4为两层煤层分支井布置示意图二。Figure 4 is the second schematic diagram of the layout of branch wells in two coal seams.
具体实施方式Detailed ways
下面将结合本发明实施例中的附图，对本发明实施例中的技术方案进行清楚、完整地描述，显然，所描述的实施例仅仅是本发明一部分实施例，而不是全部的实施例。基于本发明中的实施例，本领域普通技术人员在没有付出创造性劳动前提下所获得的所有其他实施例，都属于本发明保护的范围。The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.
一种地面区域条带煤矿瓦斯消突工艺，包括如下步骤：A gas outburst elimination process in a strip coal mine on the ground, comprising the following steps:
a.根据储层特点以及地质特征，对分支布置方式进行优选；a. According to the characteristics of the reservoir and geological characteristics, optimize the arrangement of branches;
河南大部分为单一煤层，仅平顶山为多煤层开发，但煤层层间距较大，多数不具备开采保护层条件。Most of Henan has a single coal seam, and only Pingdingshan is developed with multiple coal seams, but the distance between coal seams is relatively large, and most of them do not meet the conditions for mining protective layers.
b.根据资源潜力评价结果，以及岩层岩性、空间展布，对直井井位进行优选；b. According to the evaluation results of resource potential, as well as the lithology and spatial distribution of rock formations, optimize the location of vertical wells;
c.根据以往勘探开发资料以及煤矿揭露等资料对造斜点进行优选；c. Optimizing kickoff points based on previous exploration and development data and coal mine disclosure data;
d.根据煤储层渗透性特征以及预测区工作面布置，对分支参数进行优选；d. According to the permeability characteristics of the coal reservoir and the layout of the working face in the prediction area, optimize the branch parameters;
e.根据储层特征，对储层改造工艺进行优选；e. Optimizing the reservoir stimulation process according to the characteristics of the reservoir;
f.将钻井设备搬运到井场后，根据前期设计，开始直井段钻进，当钻至基岩以下设计深度后完成一开完井，其中水泥返至地面，随后继续钻进，在钻至预造斜点时，根据取芯结果对岩性及地层特征进行判识，若符合造斜要求开始造斜，否则重新选取造斜点，并完成二开固井；f. After moving the drilling equipment to the well site, start drilling in the vertical well section according to the previous design. After drilling to the designed depth below the bedrock, complete the first drilling and completion, in which the cement returns to the ground, and then continue drilling. When pre-creating the point, judge the lithology and stratum characteristics according to the results of coring, if it meets the requirements of the build-up, start the build-up, otherwise re-select the build-up point, and complete the second cementing;
g.完成造斜后，根据设计要求，完成主支段钻进，并对煤岩心进行观测，分析沿主支煤体结构变化特征，为分支造斜点选取提供依据，其中三开不进行水泥固井；g. After the build-up is completed, according to the design requirements, complete the drilling of the main branch section, observe the coal core, analyze the change characteristics of the coal body structure along the main branch, and provide a basis for the selection of the branch build-up point, of which no cement is used for the third opening Cementing;
h.选取造斜点后，继续钻进至设计深度，依次完成分支钻进；h. After selecting the kickoff point, continue to drill to the design depth, and complete branch drilling in sequence;
i.根据压裂设计完成主支水力喷射压裂，依次完成后续工作；i. Complete the hydraulic jet fracturing of the main branch according to the fracturing design, and complete the follow-up work in sequence;
j.根据排采设计开始排采。j. Start drainage according to the drainage design.
所述的步骤a中，分支布置方式优选，是根据煤层厚度及煤层层数，对分支的空间位置关系进行布置与优选，主支井为水平井，分支井采用与主支井同向并平行于主支井方向钻进；In the step a, the optimal arrangement of the branches is based on the thickness of the coal seam and the number of layers of the coal seam to arrange and optimize the spatial position of the branches. The main branch well is a horizontal well, and the branch wells are in the same direction and parallel to the main branch well. Drilling in the direction of the main branch well;
对于单一煤层；当只对一侧预采区工作面瓦斯进行抽采时，采用在主支井上进行若干分支井钻进；当两侧工作面相距较近，为同一个压力系统，并且储层地质条件相近时，同时对两侧工作面瓦斯进行抽采，采用在同一井筒两侧均进行一主支井钻进，在每根主支井上进行若干分支井钻进；For a single coal seam; when the gas is only extracted from the working face in the pre-mining area on one side, several branch wells are drilled on the main branch well; when the working faces on both sides are close to each other, it is the same pressure system, and the reservoir When the geological conditions are similar, the gas on both sides of the working face is extracted at the same time, and a main branch well is drilled on both sides of the same wellbore, and several branch wells are drilled on each main branch well;
对于发育两层及两层以上煤层，间距较小，并且储层条件相似的区域，采用多层煤合层排采的方式；对于两层煤距离较近，并且适合合层排采的区域，当煤体结构完整，采用在同一个主支井进行两层煤层分支井的钻进；对于同时在水平段钻出多个分支难度较大以及两层煤间距过大的区域，采用分别在同一井筒不同处进行造斜，分别在两根主支井进行两层煤层分支井的钻进。For areas with two or more coal seams with small intervals and similar reservoir conditions, the multi-layer coal seam drainage method is adopted; for areas where the distance between two coal layers is relatively close and suitable for joint seam drainage, When the coal body structure is complete, use the same main branch well to drill two-layer coal seam branch wells; for areas where it is difficult to drill multiple branches in the horizontal section at the same time and the distance between two layers of coal is too large, use the same branch well to drill separately. The wellbore is deflected at different places, and the branch wells in the two coal seams are drilled in the two main and branch wells respectively.
所述的步骤b中，井位选择时要考虑地层稳定性，远离断层、陷落柱以及地质构造复杂区域，便于造斜点的确定。In the above step b, the stability of the formation should be considered when selecting the well location, and it should be far away from faults, collapse columns and areas with complex geological structures, so as to facilitate the determination of kickoff points.
所述的步骤c中，造斜点的优选，是根据钻井轨迹所经过岩层的性质，选择层位稳定处进行造斜，包括主支井造斜点的选取和分支井造斜点的选取；对于主支井的造斜点的选取，要选择层位稳定、岩石强度较好的层位，避免在泥岩、页岩造斜；对于分支井造斜点选取，根据主支钻进过程中煤岩取芯观测，选择在硬煤发育区进行分支井的造斜与钻进。In the described step c, the optimization of the kickoff point is to select a stable layer for kickoff according to the properties of the rock strata passed by the drilling trajectory, including the selection of the kickoff point of the main branch well and the selection of the kickoff point of the branch well; For the selection of the kickoff point of the main branch well, it is necessary to choose a layer with stable formation and good rock strength, and avoid building deflection in mudstone and shale; for the selection of the kickoff point of the branch well, according to the coal Rock coring observations were carried out, and the deflection and drilling of branch wells were selected in the hard coal development area.
所述的步骤d中，分支参数优化，是根据抽采周期、储层渗透性特征，合理布置分支间距、分支数目以及分支长度；In the step d, branch parameter optimization is to rationally arrange branch spacing, branch number and branch length according to the drainage cycle and reservoir permeability characteristics;
为了确定合理的分支间距，首先应该对储层渗透性进行测试，根据储层渗透性好坏确定合理的分支间距，对于渗透性较好的区域，可以适当增加分支间距，对于渗透性比较差的区域，由于储层瓦斯运移阻力较大，应该减小分支的间距，减少瓦斯在未改造储层中的运移距离，分支间距为15~45m；In order to determine a reasonable branch spacing, the reservoir permeability should be tested first, and a reasonable branch spacing should be determined according to the reservoir permeability. For areas with better permeability, the branch spacing can be appropriately increased. For areas with poor permeability In the area, due to the high resistance to gas migration in the reservoir, the distance between branches should be reduced to reduce the migration distance of gas in the unreformed reservoir, and the distance between branches should be 15-45m;
分支数目的确定主要是根据分支间距以及回采面宽度，分支间距越小，分支数目越大，分支间距越大，分支数越小，分支数目为4~6支；The determination of the number of branches is mainly based on the distance between branches and the width of the mining face. The smaller the distance between branches, the larger the number of branches, the larger the distance between branches, the smaller the number of branches, and the number of branches is 4 to 6;
为了尽量排采储层中的煤粉，使储层应力得到释放，应该尽量增加分支长度，但是，分支长度过大，增加了钻井难度，并且长度过长导致深度瓦斯难以运移，所以，分支长度为600~800m。In order to drain the pulverized coal in the reservoir as much as possible and release the stress of the reservoir, the branch length should be increased as much as possible. However, if the branch length is too large, it will increase the difficulty of drilling, and if the branch length is too long, it will be difficult for deep gas to migrate. Therefore, the branch The length is 600~800m.
所述的分支间距为20-30m。The distance between the branches is 20-30m.
所述的步骤e中，In said step e,
根据储层特征，对储层改造工艺进行优选Optimizing the reservoir stimulation process according to the characteristics of the reservoir
储层改造工艺优选，是根据储层特点选择与之相适应的储层改造工艺，提高储层渗透性，包括对主支井进行水力喷射改造；其中水力喷射段间距为30~50m，喷嘴布置采用180°相位分布，每米4-5个喷嘴，喷射水压20-35MPa，时间不低于30分钟。Reservoir stimulation process optimization is to select a suitable reservoir stimulation process according to the characteristics of the reservoir to improve the reservoir permeability, including hydrojet stimulation of the main and branch wells; the distance between the hydrojet sections is 30~50m, and the nozzle layout Adopt 180° phase distribution, 4-5 nozzles per meter, spray water pressure 20-35MPa, and the time is not less than 30 minutes.
该发明内容主要包括：分支布置方式优化、井位优选、造斜点优选、分支参数优化以及储层改造工艺优选。其中分支布置方式优化主要是根据煤层厚度及煤层层数等对分支布置方式进行选择；井位优选主要根据资源潜力评价以及地质资料，对井位进行优化；造斜点的优选主要是根据钻井轨迹所经过岩层的性质，选择层位稳定处进行造斜；分支参数优化主要是根据抽采周期、储层渗透性特征，合理布置分支间距以及分支数目；储层改造工艺优选主要是根据储层特点选择与之相适应的储层改造工艺，提高储层渗透性。The content of the invention mainly includes: optimization of branch layout, optimization of well location, optimization of kickoff point, optimization of branch parameters and optimization of reservoir stimulation process. Among them, the optimization of branch layout is mainly to select the branch layout according to the thickness of coal seam and the number of coal seams; the optimization of well location is mainly based on the evaluation of resource potential and geological data, and the optimization of well location; the optimization of kickoff point is mainly based on the drilling trajectory. According to the properties of the rock strata that pass through, select the place where the horizon is stable to build up; the optimization of branch parameters is mainly based on the drainage period and the permeability characteristics of the reservoir, and the reasonable arrangement of the branch spacing and the number of branches; the optimization of the reservoir stimulation process is mainly based on the characteristics of the reservoir Choose the appropriate reservoir reconstruction technology to improve the reservoir permeability.
（1）分支布置方式优化(1) Optimization of branch layout
分支布置方式优化主要是对分支的空间位置关系进行布置与优化。Branch layout optimization is mainly to arrange and optimize the spatial position relationship of branches.
对于单一煤层，为了增加井筒与煤层的接触面积，减少瓦斯向井筒运移阻力，实现快速降低煤层瓦斯含量的目的。分支采用平行于主支方向钻进，当只对一侧预采区工作面瓦斯进行抽采时分支布置如图1所示。当两侧工作面相距较近，为同一个压力系统，并且储层地质条件相近时，可以同时对两侧工作面瓦斯进行抽采，其中分支布置如图2所示。这种布置方式较图1布置方式，减少了一个垂直井筒的施工。For a single coal seam, in order to increase the contact area between the wellbore and the coal seam, reduce the gas migration resistance to the wellbore, and achieve the purpose of quickly reducing the gas content of the coal seam. The branches are drilled parallel to the direction of the main branch, and the arrangement of the branches is shown in Figure 1 when the gas is only extracted from the working face in the pre-mining area on one side. When the working faces on both sides are close to each other, they belong to the same pressure system, and the geological conditions of the reservoirs are similar, the gas drainage on both working faces can be carried out at the same time, and the branch layout is shown in Figure 2. Compared with the arrangement shown in Figure 1, this arrangement reduces the construction of a vertical shaft.
对于发育两层及两层以上煤层，间距较小，并且储层条件相似的区域，可以采用多层煤合层排采的方式。多层煤层合层抽采布置方式和两层煤合层抽采布置方式相似，在此，仅以两层煤为例进行论述。For areas where two or more coal seams are developed, the spacing is small, and the reservoir conditions are similar, the multi-layer coal seam drainage method can be adopted. The drainage layout of multi-layer coal seams is similar to that of two-layer coal seams. Here, only two coal seams are used as an example for discussion.
对于两层煤距离较近，并且适合合层排采的区域，当煤体结构完整，适合进行分支钻进的区域，可以采用在同一个主支水平段进行两层煤分支的钻进，如图3所示。对于同时在水平段钻出多个分支难度较大以及两层煤间距过大的区域，可以采用分别在直井段不同处进行造斜，分别在两个主支水平段进行两层煤分支的钻进，如图4所示。For areas where the distance between the two coal layers is relatively close and suitable for combined seam drainage, when the coal body structure is complete and suitable for branch drilling, the two-layer coal branch drilling can be carried out in the same horizontal section of the main branch, such as Figure 3 shows. For areas where it is difficult to drill multiple branches in the horizontal section at the same time and the distance between the two coal layers is too large, it is possible to build up the deviation at different points in the vertical well section, and drill the two coal branches in the horizontal section of the two main branches. enter, as shown in Figure 4.
（2）井位优选(2) Well location optimization
井位优选主要根据煤层气地质条件选择，如：煤层埋深、煤层厚度、构造复杂程度、瓦斯赋存情况、煤体结构等地质因素确定，井位优选为现有技术，因地制宜选择不同的优化参数进行选择确定。Well location selection is mainly based on the geological conditions of coalbed methane, such as: coal seam depth, coal seam thickness, structural complexity, gas occurrence, coal structure and other geological factors. Parameter selection is confirmed.
井位优选主要是根据煤层气开发潜力、分支布置方式以及煤矿采掘活动等，在满足经济、高产、高效的基础上，对开发井位进行确定。Well location optimization is mainly based on the development potential of coalbed methane, branch layout and coal mining activities, etc., and on the basis of meeting the requirements of economy, high yield and high efficiency, to determine the development well location.
煤层气进行抽采的最终目的，是对预采区瓦斯进行快速抽采，满足工作面接替需要，所以在进行井位确定时首先要确定分支布置方向。工作面通常呈条带状布置，所以分支的走向通常平行与工作面走向方向。在分支走向确定以后，要根据预采区煤层气资源潜力评价结果，资源潜力主要为煤层中煤层气的赋存量大小，同煤层厚度、吨煤瓦斯含量有关，赋存量大，抽采时间就长，有限时间内降低到规定以下就需考虑布孔间距。对分支进行布置，使其尽可以能多的经过高产富集区，在效益最大化的基础上确定分支的大致布置方位。The ultimate goal of coalbed methane extraction is to quickly extract the gas in the pre-mining area to meet the replacement needs of the working face. Therefore, when determining the well location, the branch layout direction must first be determined. The working surface is usually arranged in strips, so the direction of the branches is usually parallel to the direction of the working surface. After the direction of the branches is determined, it is necessary to evaluate the resource potential of coalbed methane in the pre-mining area. The resource potential is mainly the amount of coalbed methane in the coal seam. It is long, and the hole spacing needs to be considered if it falls below the specified time within a limited time. Arrange the branches so that they pass through the high-yield enrichment area as much as possible, and determine the approximate arrangement of the branches on the basis of maximizing the benefits.
由于采用水平井进行抽采，所以造斜点位于直井井位下方，因此在井位选择时一定要考虑到地层稳定性，远离断层、陷落柱以及地质构造复杂区域，便于造斜点的确定。Because horizontal wells are used for drainage, the kickoff point is located below the vertical well. Therefore, the stability of the formation must be considered when selecting the well location, and it should be far away from faults, collapsed columns, and areas with complex geological structures, so as to facilitate the determination of the kickoff point.
（3）造斜点优选(3) Optimization of kickoff point
造斜点的选取主要是包括主支井造斜点的选取和分支井造斜点的选取。The selection of kickoff points mainly includes the selection of kickoff points for main and branch wells and the selection of kickoff points for branch wells.
对于主支井的造斜点要选择层位稳定，岩石强度较好的砂岩等强度较高的层位。尽量避免在泥岩、页岩等岩层造斜。主要是由于该类岩层强度较低，井斜方向难以确定，容易导致造斜失败。For the kickoff point of the main branch well, it is necessary to choose a layer with a stable layer and a layer with high strength such as sandstone with good rock strength. Try to avoid creating slopes in mudstone, shale and other rock formations. The main reason is that the strength of this type of rock formation is low, and it is difficult to determine the direction of well deviation, which may easily lead to the failure of building deviation.
对于分支井造斜点选取，主要是根据主支钻进过程中煤岩取芯观测。通过对煤岩取芯分析观测，进行煤体结构的划分。在分支钻进时尽量选择在硬煤发育区进行分支井的造斜与钻进。The selection of the kickoff point of the branch well is mainly based on the observation of coal and rock cores during the drilling of the main branch. Through the analysis and observation of coal rock coring, the division of coal body structure is carried out. When branch drilling, try to choose the hard coal development area for branch well deflection and drilling.
（4）分支参数优化(4) Branch parameter optimization
分支参数的优化主要是根据储层原始渗透性的好坏对分支参数进行优化。The optimization of branch parameters is mainly to optimize the branch parameters according to the original permeability of the reservoir.
分支优化根据每个矿区地质条件进行优化，每个矿区（或同一矿区不同井田）其渗透性差别很大，煤层渗透性具有较大的非均质性。总体原则根据每个矿区渗透性特点，根据渗透率大小0.001-0.1mD，确定分支间距一般选择20-30m范围。The branch optimization is optimized according to the geological conditions of each mining area. The permeability of each mining area (or different mine fields in the same mining area) is very different, and the permeability of coal seams has a large heterogeneity. The general principle is based on the permeability characteristics of each mining area, and according to the permeability of 0.001-0.1mD, the branch spacing is generally selected in the range of 20-30m.
分支优化主要是分支间距的优化。要实现快速消突的目的，则分支井控制范围内的瓦斯应该可以快速的向井筒中运移。合理的分支间距可以使瓦斯在规定的时间内刚好运移产出。为了确定合理的分支间距，首先应该对储层渗透性进行测试，根据储层渗透性好坏确定合理的分支间距。对于渗透性较好的区域，可以适当增加分支间距，对于渗透性比较差的区域，由于储层瓦斯运移阻力较大，应该减小分支的间距，减少瓦斯在未改造储层中的运移距离，建议分支间距为15~45m，可以根据各区域实际情况的差异，进行优化。Branch optimization is mainly the optimization of branch spacing. To achieve the purpose of rapid outburst elimination, the gas within the control range of the branch well should be able to quickly migrate into the wellbore. Reasonable branch spacing can make the gas transport and output within the specified time. In order to determine a reasonable branch spacing, the reservoir permeability should be tested first, and a reasonable branch spacing should be determined according to the reservoir permeability. For areas with better permeability, the distance between branches can be appropriately increased; for areas with relatively poor permeability, due to the high resistance to gas migration in the reservoir, the distance between branches should be reduced to reduce the migration of gas in unreformed reservoirs The distance between branches is recommended to be 15~45m, which can be optimized according to the actual situation of each area.
分支数目的确定主要是根据分支间距以及回采面宽度，分支间距越小，分支数目越大，分支间距越大，分支数越小，通常分支数以4~6支为宜。为了尽量排采储层中的煤粉，使储层应力得到释放，应该尽量增加分支长度。但是，分支长度过大，增加了钻井难度，并且长度过长导致深度瓦斯难以运移。所以，建议分支长度以600~800m为宜，在实际施工中要根据各区域的实际情况，进行调整。The determination of the number of branches is mainly based on the distance between branches and the width of the mining face. The smaller the distance between branches, the larger the number of branches, and the larger the distance between branches, the smaller the number of branches. Usually, the number of branches is 4-6. In order to drain the pulverized coal in the reservoir as much as possible and release the reservoir stress, the branch length should be increased as much as possible. However, the branch length is too large, which increases the difficulty of drilling, and the too long length makes it difficult for deep gas to migrate. Therefore, it is recommended that the branch length be 600~800m, and it should be adjusted according to the actual situation of each area in actual construction.
（5）储层改造工艺优选(5) Reservoir stimulation process optimization
储层改造工艺主要是对主支进行水力喷射/水力压裂改造，提高储层渗透性。The reservoir stimulation process is mainly to carry out hydraulic injection/hydraulic fracturing on the main branch to improve the permeability of the reservoir.
为了进一步提高储层渗透性，在主支实施储层改造技术，通过采用水力喷射进行储层改造，一方面可以减少常规分段压裂中的机械封隔，实现水力自动封隔，便于多次连续施工的进行。另一方面水力喷射增大了射孔孔眼深度以及造缝空间。可以通过煤粉排出，实现应力释放、卸压，达到提高储层渗透性的目的。其中建议水力喷射段间距为30~50m，喷嘴布置采用180°相位分布，以6个/米喷嘴为宜。在实际施工可以进行调整。采用泵、管柱、喷射工具、喷嘴等设备，喷射的具体方法及喷射的条件，如水压20-35MPa，时间不低于30分钟，使主支与分支有效联通。In order to further improve the reservoir permeability, the reservoir stimulation technology is implemented in the main branch. By using hydraulic injection for reservoir stimulation, on the one hand, it can reduce the mechanical isolation in conventional staged fracturing, and realize hydraulic automatic isolation, which is convenient for multiple times. Continuous construction is carried out. On the other hand, water jetting increases the perforation depth and fracture creation space. The discharge of coal powder can be used to realize stress release and pressure relief, so as to achieve the purpose of improving reservoir permeability. Among them, it is recommended that the distance between the hydraulic injection sections be 30~50m, and the nozzle layout adopts 180°phase distribution, preferably 6 nozzles/m. Adjustments can be made in actual construction. Use pumps, pipe strings, spraying tools, nozzles and other equipment, the specific method of spraying and the conditions of spraying, such as water pressure 20-35MPa, and the time is not less than 30 minutes, so that the main branch and the branch can be effectively connected.
以上所述仅为本发明的较佳实施例而已，并不用以限制本发明，凡在本发明的精神和原则之内，所作的任何修改、等同替换、改进等，均应包含在本发明的保护范围之内。The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of the present invention. within the scope of protection.
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810486202.XACN108643960A (en) | 2018-05-21 | 2018-05-21 | A kind of ground region band coal mine gas extinction technique |
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810486202.XACN108643960A (en) | 2018-05-21 | 2018-05-21 | A kind of ground region band coal mine gas extinction technique |
| Publication Number | Publication Date |
|---|---|
| CN108643960Atrue CN108643960A (en) | 2018-10-12 |
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810486202.XAPendingCN108643960A (en) | 2018-05-21 | 2018-05-21 | A kind of ground region band coal mine gas extinction technique |
| Country | Link |
|---|---|
| CN (1) | CN108643960A (en) |
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110185418A (en)* | 2019-06-20 | 2019-08-30 | 中联煤层气有限责任公司 | A kind of coal bed methane exploring method of coal seam group |
| CN110306934A (en)* | 2019-07-02 | 2019-10-08 | 中煤科工集团西安研究院有限公司 | Construction method and supporting drilling tools for large-diameter high-position directional long drilling of double-branch roof |
| CN111005722A (en)* | 2018-12-12 | 2020-04-14 | 天地科技股份有限公司 | Well arrangement method for governing rock burst at pressure relief source of ground fracturing area |
| CN111927399A (en)* | 2020-07-29 | 2020-11-13 | 山西晋城无烟煤矿业集团有限责任公司 | Coal mine mining area gas extraction method |
| CN112065355A (en)* | 2019-12-06 | 2020-12-11 | 中国石油天然气股份有限公司 | Exploitation well pattern and heavy oil reservoir exploitation method of single horizontal well and comb-shaped horizontal well |
| CN112963124A (en)* | 2021-02-23 | 2021-06-15 | 重庆万普隆能源技术有限公司 | Coal bed gas extraction method |
| CN114233369A (en)* | 2021-12-28 | 2022-03-25 | 山西晋煤集团技术研究院有限责任公司 | Method for accurately eliminating coal and gas outburst by combining up and down of well |
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102080518A (en)* | 2011-01-17 | 2011-06-01 | 河南理工大学 | Method for extracting gas from coal seam roof complex branched well |
| CN102086774A (en)* | 2011-01-17 | 2011-06-08 | 中联煤层气国家工程研究中心有限责任公司 | Drainage method of gas in coal bed |
| CN102392677A (en)* | 2011-10-21 | 2012-03-28 | 河南煤业化工集团研究院有限责任公司 | Permeability improvement technology for coal bed gas reservoir cap by using three-dimensional fracture network modification |
| CN102852546A (en)* | 2011-06-30 | 2013-01-02 | 河南煤业化工集团研究院有限责任公司 | Method for pre-pumping coal roadway stripe gas of single soft protruded coal seam of unexploited area |
| CN103485773A (en)* | 2013-09-28 | 2014-01-01 | 山西潞安环保能源开发股份有限公司 | Method for determining multi-branch horizontal well branch parameters |
| CN105134162A (en)* | 2015-08-28 | 2015-12-09 | 中国神华能源股份有限公司 | U-shaped well system and drilling method thereof |
| CN106050208A (en)* | 2016-05-25 | 2016-10-26 | 新疆工程学院 | Dual horizontal well for improving reservoir space physical property and enhancing gas production efficiency and construction method |
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102080518A (en)* | 2011-01-17 | 2011-06-01 | 河南理工大学 | Method for extracting gas from coal seam roof complex branched well |
| CN102086774A (en)* | 2011-01-17 | 2011-06-08 | 中联煤层气国家工程研究中心有限责任公司 | Drainage method of gas in coal bed |
| CN102852546A (en)* | 2011-06-30 | 2013-01-02 | 河南煤业化工集团研究院有限责任公司 | Method for pre-pumping coal roadway stripe gas of single soft protruded coal seam of unexploited area |
| CN102392677A (en)* | 2011-10-21 | 2012-03-28 | 河南煤业化工集团研究院有限责任公司 | Permeability improvement technology for coal bed gas reservoir cap by using three-dimensional fracture network modification |
| CN103485773A (en)* | 2013-09-28 | 2014-01-01 | 山西潞安环保能源开发股份有限公司 | Method for determining multi-branch horizontal well branch parameters |
| CN105134162A (en)* | 2015-08-28 | 2015-12-09 | 中国神华能源股份有限公司 | U-shaped well system and drilling method thereof |
| CN106050208A (en)* | 2016-05-25 | 2016-10-26 | 新疆工程学院 | Dual horizontal well for improving reservoir space physical property and enhancing gas production efficiency and construction method |
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111005722A (en)* | 2018-12-12 | 2020-04-14 | 天地科技股份有限公司 | Well arrangement method for governing rock burst at pressure relief source of ground fracturing area |
| CN111005722B (en)* | 2018-12-12 | 2021-11-02 | 天地科技股份有限公司 | Well arrangement method for governing rock burst at pressure relief source of ground fracturing area |
| CN110185418A (en)* | 2019-06-20 | 2019-08-30 | 中联煤层气有限责任公司 | A kind of coal bed methane exploring method of coal seam group |
| CN110306934A (en)* | 2019-07-02 | 2019-10-08 | 中煤科工集团西安研究院有限公司 | Construction method and supporting drilling tools for large-diameter high-position directional long drilling of double-branch roof |
| CN110306934B (en)* | 2019-07-02 | 2021-03-19 | 中煤科工集团西安研究院有限公司 | Construction method for large-diameter high-position directional long drill hole of double-branch top plate |
| CN112065355A (en)* | 2019-12-06 | 2020-12-11 | 中国石油天然气股份有限公司 | Exploitation well pattern and heavy oil reservoir exploitation method of single horizontal well and comb-shaped horizontal well |
| CN111927399A (en)* | 2020-07-29 | 2020-11-13 | 山西晋城无烟煤矿业集团有限责任公司 | Coal mine mining area gas extraction method |
| CN112963124A (en)* | 2021-02-23 | 2021-06-15 | 重庆万普隆能源技术有限公司 | Coal bed gas extraction method |
| CN114233369A (en)* | 2021-12-28 | 2022-03-25 | 山西晋煤集团技术研究院有限责任公司 | Method for accurately eliminating coal and gas outburst by combining up and down of well |
| CN114233369B (en)* | 2021-12-28 | 2023-10-31 | 山西晋煤集团技术研究院有限责任公司 | Method for precisely eliminating coal and gas outburst by up-and-down combination |
| Publication | Publication Date | Title |
|---|---|---|
| CN108643960A (en) | A kind of ground region band coal mine gas extinction technique | |
| CN110242301B (en) | A two-step grouting modified water-retaining coal mining method for roof aquifer | |
| CN113175325B (en) | Coal and intergrown sandstone type uranium ore coordinated mining method based on key layer protection | |
| CN102080526B (en) | Method for extracting gas from bedding level fractured well of ground coal seam roof | |
| CN112879011B (en) | Method for controlling height of water guide crack zone by hard overburden rock pre-cracking weakening under aquifer | |
| CN104806217B (en) | Combined separated layer fracturing, grouping and layer-combining mining method for coal bed well group | |
| CN111594258A (en) | A technical method for rapid gas extraction in broken soft and low permeability outburst coal seams with holes instead of roadways | |
| CN106948843A (en) | A kind of double-deck multiple-limb concordant bored grouting transformation dual limestone aquifer method of roof and floor | |
| CN105545307A (en) | Method for over-pit and under-pit cooperative control of roofs of far and near fields of extra-large stoping space | |
| CN104847379B (en) | A method for strengthening the bottom plate of working face by grouting at the top of Austrian ash | |
| CN104633996B (en) | Water source heat pump recharging technical method | |
| CN106437823B (en) | Method for eliminating outburst and standard exceeding of coal mine gas explosion | |
| CN103628914B (en) | The separate zone production of a kind of low-angle dip coal seam is visited to lower and is oozed the method for low-permeability thick-layer bedrock aquifer | |
| CN104879159A (en) | Gas permeability-increase extraction device and method for soft coal seam stoping face | |
| CN114294046B (en) | Coal mine area full-coverage underground three-dimensional extraction method | |
| CN103256025A (en) | Composite well net type coal bed gas mining method | |
| CN109162731A (en) | Iron producing area deep mining gushing water grouting treatment method | |
| CN111119978B (en) | A method of drilling coal seam gas extraction by hydraulic slitting | |
| CN110306965A (en) | A kind of stimulation method for coalbed methane low-yield well area | |
| CN113090264B (en) | Horizontal deep borehole CO for hard coal seam and hard rock stratum 2 Fracturing safety roof control method | |
| CN117365624A (en) | Coal mine disaster cooperative treatment method | |
| CN117108258A (en) | Accurate advanced gas treatment method for large area of underground thick coal seam of coal mine | |
| CN107313743B (en) | A method for repairing weak zones of water-repellent layer of coal seam floor by using coalbed methane well | |
| CN115949451A (en) | Multi-disaster collaborative management method in the triangle area of coal mining face based on directional drilling | |
| CN114135265B (en) | Low-cost and high-efficiency transformation process method for low-permeability reservoir of offshore oil field |
| 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 | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication | Application publication date:20181012 |