深层页岩气是页岩气勘探开发重要的战略接替领域,设计并优化井距获取最大经济效益,对其勘探开发具有十分重要的指导意义。基于经济效益优化水平井压裂关键参数,为井距优化设计提供设计基础。通过数值模拟方法,采用正交试验方法对水力压...深层页岩气是页岩气勘探开发重要的战略接替领域,设计并优化井距获取最大经济效益,对其勘探开发具有十分重要的指导意义。基于经济效益优化水平井压裂关键参数,为井距优化设计提供设计基础。通过数值模拟方法,采用正交试验方法对水力压裂缝参数研究,确定单一裂缝参数最优参数范围,获得变水力裂缝参数设计最优方案。研究结果如下:(1) 结合经济净现值,通过数值模拟的方法优化水平井距参数,得到该区块最优井距为300米;(2) 基于水平井距300米的开发方案,得到最优裂缝参数为:采取交叉式布缝,半缝长155米,缝高为55 m,裂缝导流能力为0.2 D∙cm;(3) 基于该区块裂缝参数优化模拟结果,推测层厚较薄、区块范围较广的深层页岩气区块,可以考虑适当牺牲缝高参数条件获取更长的半缝长参数,获取更高产量和经济效益。Deep shale gas is an important strategic replacement field for shale gas exploration and development. Designing and optimizing well spacing to obtain maximum economic benefits is of great guiding significance for its exploration and development. Based on the economic benefits, the key parameters of horizontal well fracturing are optimized, which provides the design basis for the optimization design of well spacing. Through the numerical simulation method, the orthogonal test method is used to study the hydraulic fracture parameters, determine the optimal parameter range of single fracture parameters, and obtain the optimal design scheme of variable hydraulic fracture parameters. The research results are as follows : (1) Combined with the economic net present value, the horizontal well spacing parameters are optimized by numerical simulation, and the optimal well spacing in this block is 300 meters;(2) Based on the development plan of 300 m horizontal well spacing, the optimal fracture parameters are obtained as follows: cross-type fracture arrangement, half-fracture length of 155 m, fracture height of 55 m, fracture conductivity of 0.2 mD·cm;(3) Based on the simulation results of fracture parameters optimization in this block, it is inferred that for deep shale gas blocks with thin layer thickness and wide block range, longer half-length parameters can be obtained by appropriately sacrificing fracture height parameters, so as to obtain higher production and economic benefits.展开更多
为了提升我国页岩气产量与开采效率,深入探讨影响页岩气富集与保存的因素尤为关键,其中天然裂缝的发育程度起着关键作用。本研究结合测井、地震解释、岩心分析、薄片及扫描电镜等多种技术手段,基于川东南地区龙马溪组龙一段的实验数据...为了提升我国页岩气产量与开采效率,深入探讨影响页岩气富集与保存的因素尤为关键,其中天然裂缝的发育程度起着关键作用。本研究结合测井、地震解释、岩心分析、薄片及扫描电镜等多种技术手段,基于川东南地区龙马溪组龙一段的实验数据和现场资料,系统分析了该区域页岩的天然裂缝特征、主控因素及其分布规律。同时,探讨了裂缝发育对页岩气富集的影响及多尺度裂缝系统对储层压裂改造效果的作用。研究结果表明,区域内的天然裂缝主要分为沉积裂缝、构造裂缝和异常压力裂缝,其中构造裂缝占主导地位。构造变形强度决定裂缝的发育密度,变形强度越大、曲率越大、断层越近,裂缝发育越密集。大尺度断裂显著影响页岩气逸散,二级断层会导致产量下降,而适度规模的大尺度断裂有助于提升产量。中小尺度裂缝的发育程度和产状对页岩气的富集与保存具有重要影响,裂缝的有效性直接关系到页岩气的自封闭性和保存能力。研究为川东南地区页岩气高效开发提供了理论依据和技术支持。Enhancing China’s shale gas production and extraction efficiency necessitates a thorough investigation of factors affecting shale gas enrichment and preservation, with the development of natural fractures playing a pivotal role. This study employs well logging, seismic interpretation, core analysis, thin sections, and scanning electron microscopy data from the Long 1 Member of the Longmaxi Formation in southeastern Sichuan. It comprehensively analyzes the characteristics, controlling factors, and distribution patterns of natural fractures in the shale. Additionally, the research examines the impact of fracture development on shale gas enrichment and the effectiveness of multi-scale fracture systems in reservoir hydraulic fracturing. The findings indicate that natural fractures in the region are categorized into depositional fractures, tectonic fractures, and overpressure fractures, with tectonic fractures being predominant. The intensity of tectonic deformation critically influences fracture density;stronger deformation, greater curvature, and proximity to faults result in higher fracture density. Large-scale faults significantly affect shale gas leakage, particularly secondary faults, which can decrease gas production. Conversely, moderately sized large-scale faults may enhance production. The influence of medium and small-scale fractures is more complex, as their development and orientations are crucial for shale gas enrichment and preservation. The effectiveness of these fractures directly impacts the self-sealing and preservation capabilities of shale gas. This study provides essential theoretical and technical insights for the efficient development and resource evaluation of shale gas in southeastern Sichuan.展开更多
针对致密砂岩气藏在开发过程中,存在采收率低,气井产水现象严重的问题。本文从致密砂岩气藏气水两相渗流规律着手,采用CT扫描技术识别二维裂缝,并利用FLUENT数值模拟软件,模拟不同压差下致密砂岩气藏的气水两相渗流规律。结果表明:残余...针对致密砂岩气藏在开发过程中,存在采收率低,气井产水现象严重的问题。本文从致密砂岩气藏气水两相渗流规律着手,采用CT扫描技术识别二维裂缝,并利用FLUENT数值模拟软件,模拟不同压差下致密砂岩气藏的气水两相渗流规律。结果表明:残余气分布主要分布在不连通的裂隙之中,少部分气体分布在连通裂缝之中;增大压差,气水分布变化,采收率略微提高;缝网越发育,采出程度越小,最终采收率提高程度越小。建议在致密砂岩气藏开采的过程中,可以采取前期增大压差,后期降低废弃压力的方式,使得致密砂岩气藏可以获得较大的产能。研究结果对于致密砂岩气藏开发具有一定的指导意义。Aiming at the tight sandstone gas reservoirs in the development process, there are problems of low recovery rate and serious water production phenomena in gas wells. In this paper, we start from the gas-water two-phase seepage law of tight sandstone gas reservoirs, use CT scanning technology to identify two-dimensional fractures and use FLUENT numerical simulation software to simulate the gas-water two-phase seepage law of tight sandstone gas reservoirs under different pressure differences. The results show that: the residual gas distribution is mainly distributed in the disconnected fractures, and a small portion of the gas is distributed in the connected fractures;increasing the pressure difference, the gas-water distribution changes, and the recovery rate is slightly increased;the more the fracture network is developed, the smaller the degree of extraction is, and the smaller the degree of increase in the final recovery rate is. It is suggested that when mining tight sandstone gas reservoirs, the method of increasing the differential pressure in the early stage and decreasing the waste pressure in the later stage can be adopted so that the tight sandstone gas reservoirs can obtain a larger production capacity. The results of the study have a certain guiding significance for the development of tight sandstone gas reservoirs.展开更多
文摘深层页岩气是页岩气勘探开发重要的战略接替领域,设计并优化井距获取最大经济效益,对其勘探开发具有十分重要的指导意义。基于经济效益优化水平井压裂关键参数,为井距优化设计提供设计基础。通过数值模拟方法,采用正交试验方法对水力压裂缝参数研究,确定单一裂缝参数最优参数范围,获得变水力裂缝参数设计最优方案。研究结果如下:(1) 结合经济净现值,通过数值模拟的方法优化水平井距参数,得到该区块最优井距为300米;(2) 基于水平井距300米的开发方案,得到最优裂缝参数为:采取交叉式布缝,半缝长155米,缝高为55 m,裂缝导流能力为0.2 D∙cm;(3) 基于该区块裂缝参数优化模拟结果,推测层厚较薄、区块范围较广的深层页岩气区块,可以考虑适当牺牲缝高参数条件获取更长的半缝长参数,获取更高产量和经济效益。Deep shale gas is an important strategic replacement field for shale gas exploration and development. Designing and optimizing well spacing to obtain maximum economic benefits is of great guiding significance for its exploration and development. Based on the economic benefits, the key parameters of horizontal well fracturing are optimized, which provides the design basis for the optimization design of well spacing. Through the numerical simulation method, the orthogonal test method is used to study the hydraulic fracture parameters, determine the optimal parameter range of single fracture parameters, and obtain the optimal design scheme of variable hydraulic fracture parameters. The research results are as follows : (1) Combined with the economic net present value, the horizontal well spacing parameters are optimized by numerical simulation, and the optimal well spacing in this block is 300 meters;(2) Based on the development plan of 300 m horizontal well spacing, the optimal fracture parameters are obtained as follows: cross-type fracture arrangement, half-fracture length of 155 m, fracture height of 55 m, fracture conductivity of 0.2 mD·cm;(3) Based on the simulation results of fracture parameters optimization in this block, it is inferred that for deep shale gas blocks with thin layer thickness and wide block range, longer half-length parameters can be obtained by appropriately sacrificing fracture height parameters, so as to obtain higher production and economic benefits.
文摘为了提升我国页岩气产量与开采效率,深入探讨影响页岩气富集与保存的因素尤为关键,其中天然裂缝的发育程度起着关键作用。本研究结合测井、地震解释、岩心分析、薄片及扫描电镜等多种技术手段,基于川东南地区龙马溪组龙一段的实验数据和现场资料,系统分析了该区域页岩的天然裂缝特征、主控因素及其分布规律。同时,探讨了裂缝发育对页岩气富集的影响及多尺度裂缝系统对储层压裂改造效果的作用。研究结果表明,区域内的天然裂缝主要分为沉积裂缝、构造裂缝和异常压力裂缝,其中构造裂缝占主导地位。构造变形强度决定裂缝的发育密度,变形强度越大、曲率越大、断层越近,裂缝发育越密集。大尺度断裂显著影响页岩气逸散,二级断层会导致产量下降,而适度规模的大尺度断裂有助于提升产量。中小尺度裂缝的发育程度和产状对页岩气的富集与保存具有重要影响,裂缝的有效性直接关系到页岩气的自封闭性和保存能力。研究为川东南地区页岩气高效开发提供了理论依据和技术支持。Enhancing China’s shale gas production and extraction efficiency necessitates a thorough investigation of factors affecting shale gas enrichment and preservation, with the development of natural fractures playing a pivotal role. This study employs well logging, seismic interpretation, core analysis, thin sections, and scanning electron microscopy data from the Long 1 Member of the Longmaxi Formation in southeastern Sichuan. It comprehensively analyzes the characteristics, controlling factors, and distribution patterns of natural fractures in the shale. Additionally, the research examines the impact of fracture development on shale gas enrichment and the effectiveness of multi-scale fracture systems in reservoir hydraulic fracturing. The findings indicate that natural fractures in the region are categorized into depositional fractures, tectonic fractures, and overpressure fractures, with tectonic fractures being predominant. The intensity of tectonic deformation critically influences fracture density;stronger deformation, greater curvature, and proximity to faults result in higher fracture density. Large-scale faults significantly affect shale gas leakage, particularly secondary faults, which can decrease gas production. Conversely, moderately sized large-scale faults may enhance production. The influence of medium and small-scale fractures is more complex, as their development and orientations are crucial for shale gas enrichment and preservation. The effectiveness of these fractures directly impacts the self-sealing and preservation capabilities of shale gas. This study provides essential theoretical and technical insights for the efficient development and resource evaluation of shale gas in southeastern Sichuan.
文摘针对致密砂岩气藏在开发过程中,存在采收率低,气井产水现象严重的问题。本文从致密砂岩气藏气水两相渗流规律着手,采用CT扫描技术识别二维裂缝,并利用FLUENT数值模拟软件,模拟不同压差下致密砂岩气藏的气水两相渗流规律。结果表明:残余气分布主要分布在不连通的裂隙之中,少部分气体分布在连通裂缝之中;增大压差,气水分布变化,采收率略微提高;缝网越发育,采出程度越小,最终采收率提高程度越小。建议在致密砂岩气藏开采的过程中,可以采取前期增大压差,后期降低废弃压力的方式,使得致密砂岩气藏可以获得较大的产能。研究结果对于致密砂岩气藏开发具有一定的指导意义。Aiming at the tight sandstone gas reservoirs in the development process, there are problems of low recovery rate and serious water production phenomena in gas wells. In this paper, we start from the gas-water two-phase seepage law of tight sandstone gas reservoirs, use CT scanning technology to identify two-dimensional fractures and use FLUENT numerical simulation software to simulate the gas-water two-phase seepage law of tight sandstone gas reservoirs under different pressure differences. The results show that: the residual gas distribution is mainly distributed in the disconnected fractures, and a small portion of the gas is distributed in the connected fractures;increasing the pressure difference, the gas-water distribution changes, and the recovery rate is slightly increased;the more the fracture network is developed, the smaller the degree of extraction is, and the smaller the degree of increase in the final recovery rate is. It is suggested that when mining tight sandstone gas reservoirs, the method of increasing the differential pressure in the early stage and decreasing the waste pressure in the later stage can be adopted so that the tight sandstone gas reservoirs can obtain a larger production capacity. The results of the study have a certain guiding significance for the development of tight sandstone gas reservoirs.
