新场须五气藏混合水压裂适应性研究
发布时间：2018-11-12 20:14
【摘要】：新场须五致密气藏位于川西坳陷中段孝泉-丰谷北东东向的大型隆起带西段,为滨浅湖平原和三角洲前缘沉积,地层埋深2500-3500m,平均厚度500.6m,可分为上、中、下三个亚段,共含11套砂体,上、下亚段以砂泥岩互层沉积为主,中亚段以泥岩沉积为主,须五上、中、下亚段泥地比分别为0.625、0.768和0.55。该气藏储层物性差、孔渗性极低,很难依靠自然产能进行工业开采。但该储层主力层系有利区储量7.85×1010m3,具有极大的开发潜力。根据国内外非常规天然气开发经验,采用大规模的降阻水压裂,获得较大的改造体积是实现此类气藏开发的有效技术。然而,须五砂、泥岩互层,储层特征复杂,采用降阻水压裂容易形成大面积的无效裂缝,导致压裂井产量低且稳产时间短。经调研,采用降阻水、线性胶或交联液等多种液体协作进行压裂改造的混合水压裂可弥补降阻水压裂存在的不足,在获得较大的改造体积的同时,还能通过交联液提高支撑剂量,对裂缝实现有效支撑。然而,混合水压裂的增产机理至今仍不十分明确,在砂、泥岩互层的情况下是否适用也有待验证。本文在对国内外混合水压裂技术及其增产机理调研的基础上,首先对混合水压裂的增产机理进行了进一步研究,利用langmiur等温吸附方程和等效渗流原理分析了混合水压裂改造模式下气体的渗流、增产机理以及在微裂缝存在的情况下,主裂缝渗透率对砂岩、泥页岩气藏产能的影响;采用透明的人工裂缝模拟装置和FracproPT 2007软件对混合水压裂铺砂剖面、裂缝形态进行了模拟研究;并利用压裂酸化裂缝导流能力测试分析系统对混合水压裂铺砂方式下的支撑剂导流能力进行了实验。结果表明:①提高裂缝导流能力、缝网复杂程度、裂缝控制体积,能有效降低泥页岩储层的压力、加快吸附气解吸、提高产能,促进储层快速开发;②在微裂缝存在的情况下,提高主裂缝渗透率(导流能力),能加速致密砂岩气藏的开采速度,提高泥页岩气藏压裂井的产能;③混合水压裂在通过提高支撑剂量对裂缝进行有效支撑的同时,还可使缝内铺砂方式为非均匀铺置,形成低渗流阻力通道;④混合水压裂能获得较长的支撑裂缝以及较大的改造体积和有效改造体积;⑤混合水压裂铺砂方式能获得比常规均匀铺砂方式更高的导流能力。然后,从储层岩石脆性指数、裂缝发育情况、地应力特征、地层可压裂性4个方面对混合水压裂在新场须五致密气藏中的适应性进行了分析。研究表明,①新场须五致密气藏砂岩脆性矿物含量主要分布在60%~80%之间,泥页岩脆性矿物含量主要分布在30%~80%之间,全段平均力学脆性指数在50%左右,具有形成裂缝网络的条件,适合采用混合水压裂;②须五气藏储层部分层段天然裂缝较发育,天然裂缝以低角度缝为主,易于沟通,具有形成裂缝网络的可能,宜采用混合水压裂;③新场须五致密气藏储层水平应力差异较大(20MPa),不利于形成复杂裂缝网络,但混合水压裂相对其它压裂液仍具有优势,需与其它缝网压裂工艺技术结合;④新场须五储层各亚段基本都具备大规模、大排量压裂的条件;总体上地层越深可压性越差,但各亚段存在甜点分布。最后根据现场试验结果,对混合水压裂的适应性进行了评价,所有施工井的顺利施工、XC1井压裂微地震监测到的改造体积(8.55×107m3)以及XC1井的高产(7.78×104m3/d)充分说明混合水压裂在新场须五致密气藏具有较强的适应性,同时XC2H井未获得较高的产量亦说明,仍需对混合水压裂在砂泥岩互层的储层中的增产机理进行进一步分析,然后结合储层地质特征对混合水压裂工艺技术体系进行进一步优化研究,如低伤害压裂液体系以及合适的施工参数等。
[Abstract]:The new field shall be 5 dense gas, which is located in the western section of the large uplift belt in the middle section of the middle section of the western Sichuan depression. It is a shallow lake plain and delta front. The depth of the formation is 2500-3500m, and the average thickness is 500. 6m. It can be divided into upper, middle and lower three sub-sections, including 11 sets of sand bodies. The lower sub-section is mainly composed of sand-mudstone interbed, and the middle-Asia section is dominated by mudstone, and the mud-to-ground ratio of the upper and lower sub-sections is 0.625, 0.768 and 0.55, respectively. The gas reservoir has poor physical property and low porosity, and it is difficult to rely on natural productivity for industrial exploitation. however, that reserve of the main lay of the reservoir is 7.85-1010m3, which has great potential for development. According to the experience of non-conventional natural gas development at home and abroad, a large-scale water-drop-resistance hydraulic fracturing is adopted to obtain a large transformation volume, which is an effective technique for realizing such gas storage and development. However, it is necessary to have five sand and mudstone interbeds. The reservoir is characterized by complex characteristics. It is easy to form a large area of invalid crack by adopting the pressure-drop water pressure crack, which leads to the low yield of the fracturing well and the short production period. According to the research, the mixed water pressure crack of fracturing and modification by using various liquid such as drop-resistance water, linear glue or cross-linking liquid can be used for making up the deficiency of the pressure-reducing water pressure crack, and at the same time, the support dosage can be improved through the cross-linking liquid, and the fracture can be effectively supported. However, the mechanism of increasing the yield of mixed hydraulic fracturing is still not very clear, and whether it is applicable to sand and mudstone interlayers is still to be verified. In this paper, on the basis of the research of the mixed hydraulic fracturing technology at home and abroad and the research on the mechanism of increasing the yield, the mechanism of increasing the yield of the mixed water pressure is studied, and the flow of gas under the mixed hydraulic fracturing and reforming mode is analyzed by the langmiur isothermal adsorption equation and the equivalent seepage principle. The effect of main crack permeability on the gas storage capacity of sandstone and mud shale was studied in the presence of micro-cracks, and the fracture morphology was simulated by using the transparent artificial crack simulation device and the FractionPT 2007 software. and the proppant flow-guiding capability of the mixed hydraulic fracturing sand-laying mode is tested by using a fracturing and acidizing fracture flow-guiding capability test and analysis system. The results show that the system can effectively reduce the pressure of the shale reservoir, accelerate the desorption of the adsorption gas, improve the production capacity and promote the rapid development of the reservoir, improve the permeability of the main crack (flow guiding ability), can accelerate the mining speed of the dense sandstone gas storage, and improve the production capacity of the mud shale gas storage fracturing well, and a low-seepage resistance channel is formed; the high-pressure mixed water pressure crack can obtain a long support crack and a larger transformation volume and an effective transformation volume; and the mixed hydraulic fracturing sand-laying mode can obtain higher flow-guiding capability than that of the conventional uniform sand-laying mode. Then, the adaptability of the mixed water pressure crack in the five-tight gas reservoir of the new field is analyzed from the rock-brittle index of the reservoir, the development of the fracture, the ground stress and the fracturing of the formation. The results show that the main distribution of the brittle mineral content of the five dense gas storage sandstone in the new field is between 60% and 80%, the main distribution of the brittle mineral content of the shale is between 30% and 80%, the average mechanical brittleness index of the whole section is about 50%, and the condition of forming the crack network is suitable for the use of mixed hydraulic fracturing; The natural fracture of the part of the reservoir part of the five-gas-gas-storage reservoir is relatively developed, and the natural fracture is dominated by low-angle joints, is easy to communicate, and has the possibility of forming a crack network, and the mixed hydraulic fracturing is suitable; and the horizontal stress difference of the five-tight gas-storage reservoir in the new field is larger (20MPa). It is not conducive to the formation of complex crack networks, but the mixed hydraulic fracturing has an advantage relative to other fracturing fluid, and it is necessary to be combined with other fracture network fracturing technology. Each sub-section of the new field is basically provided with the conditions of large-scale and large-displacement fracturing, and the higher the total formation is, the higher the pressure resistance, however, there is a sweet spot distribution in each sub-segment. and finally, the adaptability of the mixed water pressure crack is evaluated according to the on-site test result, and the smooth construction of all the construction wells is carried out, The modified volume (8.55-107m3) and the high yield (7.78-104m3/ d) of the XC1 well in the XC1 well are fully explained, and the high yield (7.78-104m3/ d) of the XC1 well shows that the mixed hydraulic fracturing has strong adaptability to the five-tight gas reservoir of the new field, and the high yield of the XC2H well is also described. It is still necessary to further analyze the increasing mechanism of the mixed hydraulic fracturing in the reservoir of the interbedded sand and mudstone, and then to further optimize the mixed hydraulic fracturing technology system with the reservoir geological characteristics, such as the low-damage fracturing fluid system and the appropriate construction parameters.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE377
本文编号：2328100
[Abstract]:The new field shall be 5 dense gas, which is located in the western section of the large uplift belt in the middle section of the middle section of the western Sichuan depression. It is a shallow lake plain and delta front. The depth of the formation is 2500-3500m, and the average thickness is 500. 6m. It can be divided into upper, middle and lower three sub-sections, including 11 sets of sand bodies. The lower sub-section is mainly composed of sand-mudstone interbed, and the middle-Asia section is dominated by mudstone, and the mud-to-ground ratio of the upper and lower sub-sections is 0.625, 0.768 and 0.55, respectively. The gas reservoir has poor physical property and low porosity, and it is difficult to rely on natural productivity for industrial exploitation. however, that reserve of the main lay of the reservoir is 7.85-1010m3, which has great potential for development. According to the experience of non-conventional natural gas development at home and abroad, a large-scale water-drop-resistance hydraulic fracturing is adopted to obtain a large transformation volume, which is an effective technique for realizing such gas storage and development. However, it is necessary to have five sand and mudstone interbeds. The reservoir is characterized by complex characteristics. It is easy to form a large area of invalid crack by adopting the pressure-drop water pressure crack, which leads to the low yield of the fracturing well and the short production period. According to the research, the mixed water pressure crack of fracturing and modification by using various liquid such as drop-resistance water, linear glue or cross-linking liquid can be used for making up the deficiency of the pressure-reducing water pressure crack, and at the same time, the support dosage can be improved through the cross-linking liquid, and the fracture can be effectively supported. However, the mechanism of increasing the yield of mixed hydraulic fracturing is still not very clear, and whether it is applicable to sand and mudstone interlayers is still to be verified. In this paper, on the basis of the research of the mixed hydraulic fracturing technology at home and abroad and the research on the mechanism of increasing the yield, the mechanism of increasing the yield of the mixed water pressure is studied, and the flow of gas under the mixed hydraulic fracturing and reforming mode is analyzed by the langmiur isothermal adsorption equation and the equivalent seepage principle. The effect of main crack permeability on the gas storage capacity of sandstone and mud shale was studied in the presence of micro-cracks, and the fracture morphology was simulated by using the transparent artificial crack simulation device and the FractionPT 2007 software. and the proppant flow-guiding capability of the mixed hydraulic fracturing sand-laying mode is tested by using a fracturing and acidizing fracture flow-guiding capability test and analysis system. The results show that the system can effectively reduce the pressure of the shale reservoir, accelerate the desorption of the adsorption gas, improve the production capacity and promote the rapid development of the reservoir, improve the permeability of the main crack (flow guiding ability), can accelerate the mining speed of the dense sandstone gas storage, and improve the production capacity of the mud shale gas storage fracturing well, and a low-seepage resistance channel is formed; the high-pressure mixed water pressure crack can obtain a long support crack and a larger transformation volume and an effective transformation volume; and the mixed hydraulic fracturing sand-laying mode can obtain higher flow-guiding capability than that of the conventional uniform sand-laying mode. Then, the adaptability of the mixed water pressure crack in the five-tight gas reservoir of the new field is analyzed from the rock-brittle index of the reservoir, the development of the fracture, the ground stress and the fracturing of the formation. The results show that the main distribution of the brittle mineral content of the five dense gas storage sandstone in the new field is between 60% and 80%, the main distribution of the brittle mineral content of the shale is between 30% and 80%, the average mechanical brittleness index of the whole section is about 50%, and the condition of forming the crack network is suitable for the use of mixed hydraulic fracturing; The natural fracture of the part of the reservoir part of the five-gas-gas-storage reservoir is relatively developed, and the natural fracture is dominated by low-angle joints, is easy to communicate, and has the possibility of forming a crack network, and the mixed hydraulic fracturing is suitable; and the horizontal stress difference of the five-tight gas-storage reservoir in the new field is larger (20MPa). It is not conducive to the formation of complex crack networks, but the mixed hydraulic fracturing has an advantage relative to other fracturing fluid, and it is necessary to be combined with other fracture network fracturing technology. Each sub-section of the new field is basically provided with the conditions of large-scale and large-displacement fracturing, and the higher the total formation is, the higher the pressure resistance, however, there is a sweet spot distribution in each sub-segment. and finally, the adaptability of the mixed water pressure crack is evaluated according to the on-site test result, and the smooth construction of all the construction wells is carried out, The modified volume (8.55-107m3) and the high yield (7.78-104m3/ d) of the XC1 well in the XC1 well are fully explained, and the high yield (7.78-104m3/ d) of the XC1 well shows that the mixed hydraulic fracturing has strong adaptability to the five-tight gas reservoir of the new field, and the high yield of the XC2H well is also described. It is still necessary to further analyze the increasing mechanism of the mixed hydraulic fracturing in the reservoir of the interbedded sand and mudstone, and then to further optimize the mixed hydraulic fracturing technology system with the reservoir geological characteristics, such as the low-damage fracturing fluid system and the appropriate construction parameters.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE377
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2 苟波;郭建春;;页岩水平井体积压裂设计的一种新方法[J];现代地质;2013年01期
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