Characteristics and Timing of Fractures in the Callovian-Oxfordian Boundary of the Right Bank of the Amu Darya River, Turkmenistan

详细信息   

• 责任者：Xu Wenli (State Key Laboratory of Oil & Gas Reservoir Geology and Exploitation ; Chengdu University of Technology ; Chengdu 610059 ; China) ; Zheng Rongcai
• 刊名：Natural Gas Industry
• 出版年：2012
• 卷期：32(4)
• 关键词：裂隙 ; cracks ; 碳酸盐岩储集层 ; carbonate reservoirs ; 土库曼斯坦 ; Turkmenistan
• 页码：p.33-38
• 图表：2 illus., 2 tables, 22 refs.
• 分类号：1003
• issnNo：ISSN1000-0976
• isbnNo：CN51-1179/TE

摘要

 The Jurassic carbonate gas reservoirs in the Amu Darya Right Bank Block are locally poor in physical properties and strong in heterogeneity.The development of fractures is the key factor controlling gas well productivity.Detailed observation and description of cores from the Callovian-Oxfordian boundary in 18 wells show that horizontal fractures and low-angle oblique crossing fractures are well developed in the study area.According to the cross-cutting and combination relationship and occurrence of the fractures,we recognized two genetic types of fractures,i.e.diagenetic and tectonic fractures,the latter contribute more to the development of reservoirs.Based on the understanding of the genesis of core fractures,various techniques,including quartz spin resonance dating,non-directional acoustic emission testing,experimental measurement of stable isotopes,and the analysis of inclusions from fracture fillings,were used to determine the timing of the fractures.The structural fractures were formed in three stages,probably corresponding to the Late Yanshanian,the Early and Middle Himalayan episodes respectively.The fractures(or faults) formed in the Early and Middle Himalayan episodes are connected with the source rocks.Hydrocarbon charging started in the Early Himalayan and finalized in the Middle Himalayan.