Quantitative Simulation on Porosity-Evolution in Member 8 of Yanchang Formation of Baibao-Huachi Area, Ordos Basin
详细信息
- 责任者：Yao Jinli (Research Institute of Exploration and Development ; Changqing Oilfield Company ; PetroChina ; Xi’an 710021 ; China) ; Tang Jun
- 刊名：Natural Gas Geoscience
- 出版年：2013
- 卷期：24(1)
- 关键词：砂岩储集层 ; sandstone reservoirs ; 鄂尔多斯盆地 ; Ordos Basin
- 页码：p.38-46
- 图表：illus., 39 refs.
- 分类号：1003
- issnNo：ISSN1672-1926
- isbnNo：CN62-1177/TE
摘要
Combining with the mathematical statistics method,we describe of tight sandstone reservoir characteristics and simulate the burial history and diagenetic history of the Member 8 of Yanchang Formation in the Baibao-Huachi area,Ordos basin.According to present porosity as boundary constraint conditions,geological times and burial depths,the whole porosity evolution from initial burial until present is divided into two independent processes of porosity decrease and porosity increase and establish two mathematical models,respectively.The quantitative simulation result indicates that the whole porosity-evolution quantitative simulation is a piecewise function with four sections.That is,the porosity decrease model of mechanical compaction stage is a continuous function with burial depth as the independent variable function,the compaction-cementation comprehensive stages is a continuous function with geological time and burial depth as the variables;the secondary porosity increase is caused by organic acid dissolution within a temperature window of 80-100℃.Therefore,the dissolution phase is the porosity increase model,which is a composite function of depth and burial time.After the dissolution phase,the porosity is in the phase of compaction and maintenance.The model of porosity decrease is a superimposed composite function of depth,burial time,and the porosity increase.Finally,by a case study,it is verified that the established porosity-evolution quantitative simulation is consistent with actual geological conditions and can be applied to the porosity calculation of similar lithology,burial history and sedimentary type strata in the study area.Meanwhile,this approach provides quantitative calculation method for porosity prediction and it will be helpful for oil-gas exploration of this area.