摘要
中国深层煤岩气资源丰富,勘探开发潜力巨大。水力压裂是开发深层煤岩气的重要工程技术,目前深层煤岩气水力压裂仍然存在技术瓶颈,在一定程度上制约了深层煤岩气的勘探开发。为进一步明确深层煤岩气水力压裂技术现状和发展趋势,基于鄂尔多斯盆地和沁水盆地深层煤岩气勘探开发案例,分析了深层煤岩气压裂地质特征的特殊性,论述了深层煤岩气压裂工程技术现状,剖析了深层煤岩气压裂存在的理论与技术挑战,最后展望了压裂改造理论与技术发展方向。研究结果表明:①与中深层页岩、低渗透致密砂岩和浅层煤层相比,深层煤岩具有更复杂的裂缝和割理裂隙网络系统,具有低孔低渗、煤体结构完整、高地应力、高弹性模量、低泊松比的特征,这些地质特征差异使得深层煤岩对应的压裂改造技术内涵应有差异;②深层煤岩主流压裂改造主体技术为水平井超大规模极限体积压裂和多轮次转向缝网弥合压裂;③下一步需持续研究不同煤阶、不同地域的深层煤岩气压裂地质特征差异性、压裂裂缝起裂及延伸规律、低成本压裂材料、高效压裂工艺技术。结论认为,深层煤岩气压裂改造开发需要结合压裂地质特征构建多尺度地质模型,建立“地质-工程”双甜点预测模型,并大力发展低成本、环境友好的压裂材料及工艺配套技术,进而实现深层煤岩气的规模效益开发。
In China,there are abundant deep coal-rock gas resources with immense exploration and development potential.Hydraulic fracturing is an important engineering technique for the development of deep coal-rock gas.At present,however,the hydraulic fracturing technology for deep coal-rock gas reservoirs still faces a technical bottleneck,which restricts the exploration and development of the resource to some extent.In order to further clarify the current situation and the development trend of hydraulic fracturing technology for deep coal-rock gas reservoirs,this paper analyzes the distinct geological characteristics of deep coal-rock fracturing based on the case studies of deep coal-rock gas exploration and development in the Ordos Basin and Qinshui Basin.Then,the current situation of deep coal-rock fracturing technology is illustrated,and the theoretical and technical challenges to deep coal-rock fracturing are analyzed.Finally,the development directions of fracturing stimulation theories and technologies are predicted.The following results are obtained.First,compared with medium-deep shale,low-permeability tight sandstone,and shallow coal seams,deep coal rocks have a more complex fracture and cleat network system,and are characterized by low porosity,low permeability,intact coal structure,high in-situ stress,high elastic modulus,and low Poisson’s ratio.Due to these differences in geological characteristics,the fracturing technology for deep coal rocks should be different in essence.Second,the mainstream fracturing technologies for deep coal rocks include the super large-scale extreme volume fracturing in horizontal well and the multi-round diverting fracturing technology to form a merged fracture network.Third,it is necessary to study the geological characteristic differences,hydraulic fracture initiation and propagation patterns,low-cost fracturing materials and efficient fracturing technologies corresponding to deep coal-rocks at various ranks and in different regions.In conclusion,as to the fracturing stimulation of deep coal-rocks for gas development,a multi-scale geological model shall be constructed depending on the fracturing geological characteristics,a"geology-engineering"sweet spot prediction model shall be established,and low-cost and environmentally-friendly fracturing materials and supporting technologies shall be developed,so as to realize the large-scale and beneficial development of deep coal-rock gas.
作者
李小刚
唐政
朱静怡
杨兆中
李扬
谢鹏
廖宇
LI Xiaogang;TANG Zheng;ZHU Jingyi;YANG Zhaozhong;LI Yang;XIE Peng;LIAO Yu(State Key Laboratory of Oil&Gas Reservoir Geology and Exploitation//Southwest Petroleum University,Chengdu,Sichuan 610500,China;Chengdu North Oil Exploration&Development Technology Co.,Ltd.,Chengdu,Sichuan 610066,China;Baikouquan Oil Production Plant,PetroChina Xinjiang Oilfield Company,Karamay,Xinjiang 834000,China)
出处
《天然气工业》
EI
CAS
CSCD
北大核心
2024年第10期126-139,共14页
Natural Gas Industry
基金
中国工程院战略研究与咨询项目“我国煤层气有效开发战略研究”(编号:2021-XY-24)
四川省自然科学基金项目“深煤层碳封存中超临界CO_(2)动态作用下微观润湿机理及流体运移规律研究”(编号:2023NSFSC0941)。
关键词
深层煤岩气
地质特征
多尺度地质模式
压裂改造技术
储层对比
展望
Deep coal-rock gas
Geological characteristics
Multi-scale geological model
Fracturing technology
Reservoir correlation
Prospect
作者简介
李小刚,1981年生,教授,博士,本刊青年编委,主要从事油气增产、非常规天然气产业发展等领域的研究工作。地址:(610500)四川省成都市新都区新都大道8号。ORCID:0000-0002-5875-883X。E-mail:swpuadam@126.com;通信作者:朱静怡,女,1991年生,副研究员,博士,主要从事非常规油气资源的增产改造技术研究工作。地址:(610500)四川省成都市新都区新都大道8号。ORCID:0000-0003-1973-5632。E-mail:zhujingyizoe@163.com。
