%A Jiang Tong-wen,Zhang Hui,Wang Hai-ying,Yin Guo-qing,Xiao Xiang-jiao %T Effects of faults geomechanical activity on water invasion in Kela 2 Gasfield,Tarim Basin %0 Journal Article %D 2017 %J Natural Gas Geoscience %R 10.11764/j.issn.1672-1926.2017.09.003 %P 1735-1744 %V 28 %N 11 %U {http://www.nggs.ac.cn/CN/abstract/article_4471.shtml} %8 2017-11-10 %X
After more than ten years high-speed development,the most productive continental gasfield in China,Kela 2 Gasfield is now facing challenges associated with water breakthrough in gas well and heterogeneous water invasion in the field.To further understand the water invasion mechanism of the high pressure gasfield under complex tectonic setting,an investigation of faults geomechanical activity was conducted to investigate the relationship between variation of faults mechanical activity and water breakthrough of gas well.The faults geomechanical activity prediction model was established based on the combination of modeling of four dimensional stress field and 3D faults mechanical analysis to research its effects on water invasion in this field.The results are shown:(1)There is a good correlation between water breakthrough in gas well and faults mechanical characteristics.With the development of gas reservoir,dynamic variation of stress field led to change of stress state on faults’ planes,so that the permeability of the faults zone would be able to become stronger or weaker.(2)With the depletion of gas reservoir,the gas wells near the faults with higher geomechanical activity would produce water earlier and the gas-water interface would rise faster.(3)Because the distribution of stress field and faults in the reservoir are complex,there are great differences in the faults mechanical activity on different location of structure,which result in the uplift of gas-water interface being greatly different and inhomogeneous in the reservoir.The research further clarified the mechanism of water invasion in Kela 2 Gasfield,the gas reservoir is divided into three water breakthrough risk districts based on the prediction of faults geomechanical activity to do early warning for the areas and gas wells which has the high risk of water invasion.This research provides a basis for optimizing the development program of Kela 2 Gasfield.