A study on the spatial distribution and the influencing factors of dolomitization in carbonate rock
 
Date and time: May 21, 2014, 9:00am.
Place: Room 457, Science Building, North Campus of Jilin University
Reporter: BingYang

      
Abstract:  
       Dolomite is an important reservoir rock. Globally, dolomite accounts for 50% in the carbonate reservoir. Especially in North America, about 80% oil and gas in carbonate rock are stored in dolomite. There are a lot of dolomite reservoirs in Russia, North Africa, South Africa, Western Europe, Africa, the Middle East and the Far East. Besides, a batch of oil and gas dolomite reservoirs were gradually found in China spreading among areas as Sichuan Basin, Tarim Basin and Erdos basin. However, the formation mechanism of dolomite is the most complex problem in Carbonate petrology bearing the longest argument, and quite difficult to conclude a good solution. Dolomite is one of the most common carbonate minerals in the rocks. It distributes widely in the ancient carbonate platform but rarely in the Holocene Sediments. The study on it brings a great challenge to the plausible principle “uniformitarianism”.  
       In the last two centuries, it has been proofed that dolomite formation is a kinetically controlled process. Many genetic models (dolomitization models) have been proposed to account for the formation reason of the observed large scale dolomite reservoir in the field. Several models are widely accepted such as: evaporation model (Sabkha model), seepage reflux model, mixed model, the sea water model, burial and hydrothermal genesis model. Due to the different types of dolomite formed in varying diagenetic environment and stage, the dolomite may take on different petrological, geochemical and geophysical response characteristics. Many scholars adopted the approach of laboratory test to study the formation mechanism of dolomite. These methods include the core section scanning, isotope geochemical data analysis as their first step where after combined with logging and seismic response characteristics, palaeogeography and ancient climate, tectonic background information to complete the whole study.  
       Although the explanation based on the field observations gives the reason of the dolomite formation to a certain extent, it couldn’t point out the process of dolomite formation explicitly. On the other hand, we can’t synthesize dolomite directly using the inorganic method at normal temperature and pressure in the laboratory. As a consequence of the fact, the lack of direct evidence for dolomitization controlled conditions is inevitable and by the same token, the direct prediction for the dolomite reservoir space distribution is incapable. This study adopts numerical simulation, with the access to the "seepage reflux" model, to delve into dolomite space distribution and influence factors of dolomitization, and expects to provide a new approach for oil and gas exploration in the future. 
 

Personal Profile:

      Bing Yang is a postgraduate of Environment and Resources College of Jilin University, and majors in Groundwater Science and Engineering. He graduated from College of Resources and Environment of Lanzhou University majoring in hydrology and water resources engineering in July 2012, and obtained the bachelor's degree. In September of the same year, he was admitted to the College of Environment and Resources, Jilin University, to do his master's research. His research area focuses on the diagenesis of carbonate rocks.
 
Publications:
杨冰，李佳琦，杨磊磊等. 渗透回流模式白云石化作用对碳酸盐岩储层的影响研究 [J]. 现代地质（已收录）